The present invention relates to cyclobutenedione derivatives, pharmaceutical compositions comprising such derivatives and their use as medicaments. More particularly, the present invention provides 4-heteroarylaminocyclobut-3-ene-1 ,2-dione derivatives which are antagonists of the CXCR-2 receptor and useful for the treatment of inflammatory conditions, including inflammatory conditions of the airways, such as asthma, chronic obstructive pulmonary disease and cystic fibrosis. The compounds are also useful in the treatment of other inflammatory conditions such as rheumatoid arthritis and psoriasis and in the treatment of non-inflammatory conditions such as cancer.

Cytokines are signaling molecules that play an important role in intercellular communication. In particular, cytokines play an important role in the functioning of the immune system, being secreted by a wide variety of cells in response to a pathogen challenge in order to recruit further immune cells to the site of infection or in response to tumour growth. Chemokines (chemotactic cytokines) are a class of cytokines that mediate such attraction between cells. They are small peptidic molecules (generally 8-10 kilodaltons in size) with a characteristic three-dimensional shape determined by cysteine residues which form disulphide bridges. Chemokines are involved in the inflammatory response and act as chemical attractants, encouraging the migration of cells including monocytes, macrophages, T-lymphocytes, eosinophils, basophils and neutrophils from the blood to sites of infection or tissue damage to protect tissues and promote healing.

Chemokines can be divided into certain classes based on sequence homology, particularly according to the distribution of cysteine residues. The members of one class, known as the CXC chemokines, have two N-terminal cysteine residues (C) separated by one amino acid (X).

Examples include interleukin-8 (IL-8), neutrophil activating protein 1 (NAP-1 ), neutrophil activating protein 2 (NAP-2), GROα, GROβ, GROγ, ENA-78, GCP-2, IP-10, MIG and PF-4.

Such CXC chemokines can further be divided on the basis of whether or not they contain a glutamic acid-leucine-arginine (E-L-R) motif immediately before the first cysteine of the CXC sequence. Those that share this E-L-R motif are responsible for inducing the migration of neutrophils by activating two cell-surface chemokine receptors CXCR1 and CXCR2. An important CXC chemokine of this kind is interleukin-8 (IL-8) which binds to both CXCR1 and

CXCR2 receptors on the surface of neutrophils and induces them to migrate from the blood stream into surrounding tissues. Tissues release these chemokines in response to bacterial, fungal or viral infection and in response to other factors as well. For example, exposure of lung tissue to cigarette smoke, dust, pollutants and noxious gas (e.g. ozone) is known to cause the release of chemokines and to result in an inflammatory response.

The CXCR2 receptor, sometimes referred to as the interleukin 8 receptor beta (IL8RB), is a G- protein coupled receptor which binds all ELR+ chemokines (CXCL1-8) with high affinity and is activiated by several of them including interleukin-8. Convincing evidence exists that the activation of the CXCR2 receptor by interleukin-8 plays an important role in the development of several inflammatory diseases such as rheumatoid arthritis, septic shock, asthma, cystic fibrosis and psoriasis (see, for example, FEBS Lett, 1992, 307, 97; Crit. Rev. Immunol., 1992, 12, 17; Annual Rev. Immunol., 1991 , 9, 617; J. Clin. Invest, 1991 , 87, 463; Am. Rev. Respir. Dis., 1992, 146, 427; and Lancet, 1993, 341 , 643). Monoclonal antibodies to interleukin-8, which block its ability to bind to CXCR-2 receptors and mediate neutrophil recruitment, are able to prevent tissue damage in the rabbit lung which normally results from lung ischemia/reperfusion (Nature, 1993, 365, 654). Another study demonstrated that antibodies to interleukin-8 have a beneficial effect in an endotoxin-induced model of pleurisy in rabbits (J. Immunol., 1994, 152, 2960). The physiological role of this receptor in mediating neutrophil recruitment has been defined in man and a range of other species (including non-human primates, rodents and rabbits) using a range of pharmacological tools (see, for example, Eur. Respir. J., 2007, 30 (supplement 1 ), 209s; J. Pharmacol. Exp. Ther., 2007, 322, 486; J. Immunol., 1999, 163, 2829; Immunobiology, 2004, 209, 225; J. Exp. Med., 2004, 200, 935; J. Leukocyte Biol., 2005, 78, 1265; Am. J. Physiol. Lung Cell MoI. Physiol., 2005, 289, L322; J. Immunol., 2002, 169, 6435; Lab. Invest., 2002, 82, 1297). Mice deficient in the CXCR-2 receptor have been generated and show a pronounced peripheral neutrophilia, altered leukocyte rolling capabilities and impaired PMN recruitment into the inflamed lung (see, for example, Science, 1994, 265, 682; Microvasc. Res., 1997, 54, 199; J. Clin. Invest, 2006, 116, 695; Am. J. Physiol. Lung Cell MoI. Physiol., 2005, 288, L61 ). Further, because of an involvement in tumour growth and angiogenesis, CXCR-2 antagonists are potentially useful for the treatment of cancer.

All the available evidence therefore suggests that interleukin-8 is an important inflammatory mediator and that an antagonist of the CXCR-2 receptor should have a beneficial effect in the treatment of inflammatory conditions by diminishing the recruitment of neutrophils and other leukocytes to the sites of inflammatory mediator release. There is therefore a need to provide new CXCR-2 receptor antagonists that are suitable as drug candidates. Such compounds should be potent, selective for CXCR-2 with respect to other physiologically important receptors (or selective for CXCR-1 and CXCR-2) and have appropriate oral bioavailability, tissue penetration, metabolic stability and pharmacokinetic properties. The invention therefore provides, as embodiment E1 , a compound of formula (I):

(I)

or a pharmaceutically acceptable salt thereof, or a pharmaceutically acceptable solvate of said compound or salt, wherein:

R ¹ is C ₁ -C ₆ alkyl, C ₃ -C ₈ cycloalkyl, C ₆ -C ₁₂ bicycloalkyl, Aryl ¹ , Aryl ² , Het ¹ , Het ² , Het ³ or Het ⁴ , said C ₁ -C ₆ alkyl, C ₃ -C ₈ cycloalkyl and C ₆ -C ₁₂ bicycloalkyl being optionally substituted by 1 to 3 substituents independently selected from -CN, halo, -NH ₂ , -SH, -SO ₂ NH ₂ , -OCONH ₂ and -X-R ^a , with the proviso that the R ¹ moiety may not be attached through a methylene (-CH ₂ -) group;

R ² is

X is a bond, C ₁ -C ₆ alkylene, -CO-, -O-, -0-(C ₁ -C ₆ alkylene)-, -NR ⁶ -, -S-, -SO-, -SO ₂ -, -COO-, - OCO-, -NR ⁶ SO ₂ -, -SO ₂ NR ⁶ -, -NR ⁶ CONR ⁶ -, -NR ⁶ COO- or -OCONR ⁶ -;

R ^a is C ₁ -C ₆ alkyl, C ₃ -C ₈ cycloalkyl, Aryl ¹ , Aryl ² , Het ¹ , Het ² , Het ³ or Het ⁴ , said C ₃ -C ₈ cycloalkyl and C ₆ -C ₁₂ bicycloalkyl being optionally substituted by one or more C ₁ -C ₆ alkyl, -OH or C ₁ -C ₆ alkoxy groups;

R ³ and R ⁴ are each independently H, -CN, halo, -OH, -NH ₂ , -SH, -COOH, -CONH ₂ , -SO ₂ NH ₂ , -NR ⁶ CONH ₂ , -OCONH ₂ or -Y-R ^b ;

or, alternatively, where R ³ and R ⁴ are attached to adjacent carbon atoms, R ³ and R ⁴ , taken together with the carbon atoms to which they are attached, form a 5 or 6-membered ring which may be aromatic or partially saturated and which may be carbocyclic or contain up to two heteroatoms selected from N, S and O, said ring being optionally substituted by 1-3 substituents selected from C ₁ -C ₆ alkyl, C ₃ -C ₈ cycloalkyl, halo, -CN, -OR ⁶ , -NR ⁷ R ⁸ , -SR ⁶ , -SOR ⁹ , -SO ₂ R ⁹ , -COR ⁶ , -OCOR ⁶ , -COOR ⁶ , -NR ⁶ COR ⁶ , -CONR ⁷ R ⁸ , -NR ⁶ SO ₂ R ⁹ , -SO ₂ NR ⁷ R ⁸ , -NR ⁶ CONR ⁷ R ⁸ , -NR ⁶ COOR ⁹ and -NR ⁶ SO ₂ NR ⁷ R ⁸ ;

R ⁵ is H, -CN, halo, -OH, -NH ₂ , -SH, -CONH ₂ , -SO ₂ NH ₂ , -NR ⁶ CONH ₂ , -OCONH ₂ or -Y-R ^b ;

Y is a bond, C ₁ -C ₆ alkylene, -CO-, -0-, -NR ⁶ -, -S-, -SO-, -SO ₂ -, -CONR ⁶ -, -COO-, -OCO-, -NR ⁶ CO-, -NR ⁶ SO ₂ -, -SO ₂ NR ⁶ -, -NR ⁶ CONR ⁶ -, -NR ⁶ COO- or -OCONR ⁶ -;

R ^b is C ₁ -C ₆ alkyl, C ₃ -C ₈ cycloalkyl, C ₆ -C ₁₂ bicycloalkyl, Aryl ¹ , Aryl ² , Het ¹ , Het ² , Het ³ or Het ⁴ , said C ₁ -C ₆ alkyl, C ₃ -C ₈ cycloalkyl and C ₆ -C ₁₂ bicycloalkyl being optionally substituted by 1-5 substituents selected from R ⁹ , -CN, -OR ⁶ , -NR ⁷ R ⁸ , -SR ⁶ , -SOR ⁹ , -SO ₂ R ⁹ , -COR ⁶ , -OCOR ⁶ , -COOR ⁶ , -NR ⁶ COR ⁶ , -CONR ⁷ R ⁸ , -NR ⁶ SO ₂ R ⁹ , -SO ₂ NR ⁷ R ⁸ , -NR ⁶ CONR ⁷ R ⁸ , -NR ⁶ COOR ⁹ and -NR ⁶ SO ₂ NR ⁷ R ⁸ and optionally substituted by 1 substituent R ^d ;

Aryl ¹ is phenyl or naphthyl, said phenyl and naphthyl being optionally substituted by 1 substituent -Z-R ^d and 1-4 substituents each independently selected from -Z-R ^e ;

Aryl ² is a 3 to 8-membered monocyclic or 6 to 12-membered bicyclic carbocycle which is partially unsaturated, said carbocycle being optionally substituted by 1 substituent -Z-R ^d and 1-4 substituents each independently selected from -Z-R ^f ;

Het ¹ is a 3 to 8-membered saturated or partially unsaturated monocyclic heterocycle, containing 1 or 2 heteroatoms selected from O and N, said heterocycle being optionally substituted by 1 substituent -Z-R ^d and 1-4 substituents each independently selected from -Z-R ^f ;

Het ² is a 6 to 12-membered saturated or partially unsaturated multicyclic heterocycle containing 1-3 heteroatoms selected from O, S and N, said heterocycle being optionally substituted by 1 substituent -Z-R ^d and 1-4 substituents each independently selected from -Z-R ^f ;

Het ³ is (i) a 6-membered aromatic heterocycle containing 1-3 N atoms or (ii) a 5-membered aromatic heterocycle containing either (a) 1-4 N atoms or (b) 1 O or S atom and 0-3 N atoms, said heterocycle being optionally substituted by 1 substituent -Z-R ^d and 1-4 substituents each independently selected from -Z-R ^e ; Het ⁴ is (i) a 10-membered bicyclic aromatic heterocycle containing 1-4 N atoms or (ii) a 9- membered bicyclic aromatic heterocycle containing either (a) 1-4 N atoms or (b) 1 O or S atom and 0-3 N atoms or (iii) an 8-membered bicyclic aromatic heterocycle containing (a) 1-4 N atoms or (b) 1 O or S atom and 1-3 N atoms or (c) 2 O or S atoms and 0-2 N atoms, said heterocycle being optionally substituted by 1 substituent -Z-R ^d and 1-4 substituents each independently selected from -Z-R ^e ;

Z is a bond, -CO- or C ₁ -C ₆ alkylene;

R ^d is Aryl ³ , Aryl ⁴ , Het ⁵ , Het ⁶ , Het ⁷ or Het ⁸ ;

R ^e is C ₁ -C ₆ alkyl, C ₃ -C ₈ cycloalkyl, halo, -CN, -OR ⁶ , -NR ⁷ R ⁸ , -SR ⁶ , -SOR ⁹ , -SO ₂ R ⁹ , -COR ⁶ , -OCOR ⁶ , -COOR ⁶ , -NR ⁶ COR ⁶ , -CONR ⁷ R ⁸ , -NR ⁶ SO ₂ R ⁹ , -SO ₂ NR ⁷ R ⁸ , -NR ⁶ CONR ⁷ R ⁸ , -NR ⁶ COOR ⁹ or -NR ⁶ SO ₂ NR ⁷ R ⁸ ;

R ^f is C ₁ -C ₆ alkyl, C ₃ -C ₈ cycloalkyl, halo, oxo, -OR ⁶ , -NR ⁷ R ⁸ , -SR ⁶ , -SOR ⁹ , -SO ₂ R ⁹ , -COR ⁶ , -OCOR ⁶ , -COOR ⁶ , -NR ⁶ COR ⁶ , -CONR ⁷ R ⁸ , -NR ⁶ SO ₂ R ⁹ , -SO ₂ NR ⁷ R ⁸ , -NR ⁶ CONR ⁷ R ⁸ , -NR ⁶ COOR ⁹ or -NR ⁶ SO ₂ NR ⁷ R ⁸ ;

Aryl ³ is phenyl or naphthyl, said phenyl and naphthyl being optionally substituted with 1-5 substituents selected from C ₁ -C ₆ alkyl, C ₃ -C ₈ cycloalkyl, halo, -CN, -OR ⁶ , -NR ⁷ R ⁸ , -SR ⁶ , -SOR ⁹ , -SO ₂ R ⁹ , -COR ⁶ , -OCOR ⁶ , -COOR ⁶ , -NR ⁶ COR ⁶ , -CONR ⁷ R ⁸ , -NR ⁶ SO ₂ R ⁹ , -SO ₂ NR ⁷ R ⁸ , -NR ⁶ CONR ⁷ R ⁸ , -NR ⁶ COOR ⁹ and -NR ⁶ SO ₂ NR ⁷ R ⁸ ;

Aryl ⁴ is a 3 to 8-membered monocyclic or 6 to 12-membered bicyclic carbocycle which is partially unsaturated, said carbocycle being optionally substituted by 1-5 substituents selected from C ₁ -C ₆ alkyl, C ₃ -C ₈ cycloalkyl, halo, oxo, -OR ⁶ , -NR ⁷ R ⁸ , -SR ⁶ , -SOR ⁹ , -SO ₂ R ⁹ , -COR ⁶ , -OCOR ⁶ , -COOR ⁶ , -NR ⁶ COR ⁶ , -CONR ⁷ R ⁸ , -NR ⁶ SO ₂ R ⁹ , -SO ₂ NR ⁷ R ⁸ , -NR ⁶ CONR ⁷ R ⁸ , -NR ⁶ COOR ⁹ and -NR ⁶ SO ₂ NR ⁷ R ⁸ ;

Het ⁵ is a 3 to 8-membered saturated or partially unsaturated monocyclic heterocycle, containing 1 or 2 heteroatoms selected from O and N, said heterocycle being optionally substituted by 1-5 substituents selected from C ₁ -C ₆ alkyl, C ₃ -C ₈ cycloalkyl, halo, oxo, -OR ⁶ , -NR ⁷ R ⁸ , -SR ⁶ , -SOR ⁹ , -SO ₂ R ⁹ , -COR ⁶ , -OCOR ⁶ , -COOR ⁶ , -NR ⁶ COR ⁶ , -CONR ⁷ R ⁸ , -NR ⁶ SO ₂ R ⁹ , -SO ₂ NR ⁷ R ⁸ , -NR ⁶ CONR ⁷ R ⁸ , -NR ⁶ COOR ⁹ and -NR ⁶ SO ₂ NR ⁷ R ⁸ ; Het ⁶ is a 6 to 12-membered saturated or partially unsaturated multicyclic heterocycle containing 1-3 heteroatoms selected from O, S and N, said heterocycle being optionally substituted by 1-5 substituents selected from d-C ₆ alkyl, C ₃ -C ₈ cycloalkyl, halo, oxo, -OR ⁶ , -NR ⁷ R ⁸ , -SR ⁶ , -SOR ⁹ , -SO ₂ R ⁹ , -COR ⁶ , -OCOR ⁶ , -COOR ⁶ , -NR ⁶ COR ⁶ , -CONR ⁷ R ⁸ , -NR ⁶ SO ₂ R ⁹ , -SO ₂ NR ⁷ R ⁸ , -NR ⁶ CONR ⁷ R ⁸ , -NR ⁶ COOR ⁹ and -NR ⁶ SO ₂ NR ⁷ R ⁸ ;

Het ⁷ is (i) a 6-membered aromatic heterocycle containing 1-3 N atoms or (ii) a 5-membered aromatic heterocycle containing either (a) 1-4 N atoms or (b) 1 O or S atom and 0-3 N atoms, said heterocycle being optionally substituted with 1-4 substituents selected from C ₁ -C ₆ alkyl, C ₃ - C ₈ cycloalkyl, halo, -CN, -OR ⁶ , -NR ⁷ R ⁸ , -SR ⁶ , -SOR ⁹ , -SO ₂ R ⁹ , -COR ⁶ , -OCOR ⁶ , -COOR ⁶ , -NR ⁶ COR ⁶ , -CONR ⁷ R ⁸ , -NR ⁶ SO ₂ R ⁹ , -SO ₂ NR ⁷ R ⁸ , -NR ⁶ CONR ⁷ R ⁸ , -NR ⁶ COOR ⁹ and -NR ⁶ SO ₂ NR ⁷ R ⁸ ;

Het ⁸ is (i) a 10-membered bicyclic aromatic heterocycle containing 1-4 N atoms or (ii) a 9- membered bicyclic aromatic heterocycle containing either (a) 1-4 N atoms or (b) 1 O or S atom and 0-3 N atoms, or (iii) an 8-membered bicyclic aromatic heterocycle containing (a) 1-4 N atoms or (b) 1 O or S atom and 1-3 N atoms or (c) 2 O or S atoms and 0-2 N atoms, said heterocycle being optionally substituted with 1-5 substituents selected from C ₁ -C ₆ alkyl, C ₃ -C ₈ cycloalkyl, halo, -CN, -OR ⁶ , -NR ⁷ R ⁸ , -SR ⁶ , -SOR ⁹ , -SO ₂ R ⁹ , -COR ⁶ , -OCOR ⁶ , -COOR ⁶ , -NR ⁶ COR ⁶ , -CONR ⁷ R ⁸ , -NR ⁶ SO ₂ R ⁹ , -SO ₂ NR ⁷ R ⁸ , -NR ⁶ CONR ⁷ R ⁸ , -NR ⁶ COOR ⁹ and -NR ⁶ SO ₂ NR ⁷ R ⁸ ;

R ⁶ is H, C ₁ -C ₆ alkyl or C ₃ -C ₈ cycloalkyl, said C ₁ -C ₆ alkyl and C ₃ -C ₈ cycloalkyl being optionally substituted by -OH or C ₁ -C ₆ alkoxy;

R ⁷ and R ⁸ are each independently H, C ₁ -C ₆ alkyl or C ₃ -C ₈ cycloalkyl or are taken together with the nitrogen atom to which they are attached to form a A-, 5- or 6-membered saturated heterocyclic ring containing 1-2 nitrogen atoms or 1 nitrogen and 1 oxygen atom, said heterocyclic ring being optionally substituted by one or more C ₁ -C ₆ alkyl or C ₃ -C ₈ cycloalkyl groups; and

R ⁹ is C ₁ -C ₆ alkyl or C ₃ -C ₈ cycloalkyl, said C ₁ -C ₆ alkyl and C ₃ -C ₈ cycloalkyl being optionally substituted by -OH or C ₁ -C ₆ alkoxy;

wherein, in each instance, said C ₁ -C ₆ alkyl, C ₁ -C ₆ alkylene, C ₃ -C ₈ cycloalkyl and C ₆ -C ₁₂ bicycloalkyl may have one or more hydrogen atoms replaced with a fluorine atom; with the proviso that the compound of formula (I) is not 3-[(1 ,2-dihydro-2-oxo-3-pyridinyl)amino]- 4-[[(1 R)-1 ,2,2-trimethylpropyl]amino]cyclobut-3-ene-1 ,2-dione.

In the following preferred embodiments, any groups not specifically defined have the same meaning as given in embodiment E1 above. In each case, where relevant, the compound 3- [(i ^-dihydro^-oxo-S-pyridinyOaminoH-^I R^I ^^-trimethylpropylJaminolcyclobut-S-ene-i ^- dione is disclaimed.

The invention also provides, as preferred embodiment E2, a compound of formula (I), or a pharmaceutically acceptable salt thereof, or a pharmaceutically acceptable solvate of said compound or salt, wherein R ² is:

wherein R ³ , R ⁴ and R ⁵ are each independently H, -CN, halo, Ci-C ₆ alkyl, C ₃ -C ₈ cycloalkyl, -(C ₁ - C ₆ alkylene)-(Aryl ¹ ), -NR ⁶ SO ₂ -(C ₁ -C ₆ alkyl), -NR ⁶ -(C _r C ₆ alkyl), -NR ⁶ CONR ⁶ -(d-C ₆ alkyl), -NR ⁶ CO-(C ₃ -C ₈ cycloalkyl), -NR ⁶ CO-(C ₁ -C ₆ alkyl), -SO-(C ₁ -C ₆ alkyl), -S-(C ₁ -C ₆ alkyl), -SO ₂ -(C ₁ - C ₆ alkyl), -SO ₂ -(Aryl ¹ ), -SO ₂ -(Het ¹ ), -SO ₂ NR ⁶ -(d-C ₆ alkyl), -SO ₂ -(C ₃ -C ₈ cycloalkyl), -0-(C ₁ -C ₆ alkyl), -CONH ₂ , -CONR^(C ₁ -C ₆ alkyl), -CONR ⁶ ^C ₁ -C ₆ alkylene)-(C ₃ -C ₈ cycloalkyl), -CONR ⁶ - (Het ¹ ), -CONR ⁶ -(Het ² ), -CO-(Het ¹ ), Aryl ¹ , Het ³ , -COOH, -CO-(Het ² ), -CONR ⁶ (C ₃ -C ₈ cycloalkyl), - CONR^(C ₁ -C ₆ alkylene)-(Aryl ¹ ), -CONR ⁶ -(C _r C ₆ alkylene)-(Het ¹ ), -CONR ⁶ -(d-C ₆ alkylene)- (Het ³ ) or -CONR ⁶ -(Het ³ ), said C ₁ -C ₆ alkyl and C ₃ -C ₈ cycloalkyl, in each case, being optionally substituted by 1-5 substituents selected from -CN, -OR ⁶ , -NR ⁷ R ⁸ , -SR ⁶ , -SOR ⁹ , -SO ₂ R ⁹ , -COR ⁶ , - OCOR ⁶ , -COOR ⁶ , -NR ⁶ COR ⁶ , -CONR ⁷ R ⁸ , -NR ⁶ SO ₂ R ⁹ , -SO ₂ NR ⁷ R ⁸ , -NR ⁶ CONR ⁷ R ⁸ , -NR ⁶ COOR ⁹ and -NR ⁶ SO ₂ NR ⁷ R ⁸ ;

or, alternatively, where R ³ and R ⁴ are attached to adjacent carbon atoms, R ⁵ is H, and R ³ and R ⁴ are taken together with the carbon atoms to which they are attached to form a 5 or 6- membered ring which may be aromatic or partially saturated and which may be carbocyclic or contain up to two heteroatoms selected from N and O, said ring being optionally substituted by 1-3 substituents selected from halo; wherein, in each instance, said CrC ₆ alkyl, CrC ₆ alkylene and C ₃ -C ₈ cycloalkyl may have one or more hydrogen atoms replaced with a fluorine atom.

The invention also provides, as preferred embodiment E3, a compound of formula (I), or a pharmaceutically acceptable salt thereof, or a pharmaceutically acceptable solvate of said compound or salt, wherein R ² is:

wherein R ³ , R ⁴ and R ⁵ are each independently H, -CN, halo, Ci-C ₆ alkyl, C ₃ -C ₈ cycloalkyl, -(C ₁ - C ₆ alkylene)-(Aryl ¹ ), -NR ⁶ SO ₂ -(C ₁ -C ₆ alkyl), -NR ⁶ -(C _r C ₆ alkyl), -NR ⁶ CONR ⁶ -(C _r C ₆ alkyl), -NR ⁶ CO-(C ₃ -C ₈ cycloalkyl), -NR ⁶ CO-(C ₁ -C ₆ alkyl), -SO-(C ₁ -C ₆ alkyl), -S-(C ₁ -C ₆ alkyl), -SO ₂ -(C ₁ - C ₆ alkyl), -SO ₂ -(Aryl ¹ ), -SO ₂ -(Het ¹ ), -SO ₂ NR ⁶ -(d-C ₆ alkyl), -SO ₂ -(C ₃ -C ₈ cycloalkyl), -0-(C ₁ -C ₆ alkyl), -CONH ₂ , -CONR ⁶ -(C _r C ₆ alkyl), -CONR ⁶ -(C _r C ₆ alkylene)-(C ₃ -C ₈ cycloalkyl), -CONR ⁶ - (Het ¹ ), -CONR ⁶ -(Het ² ), -CO-(Het ¹ ), Aryl ¹ or Het ³ , said C ₁ -C ₆ alkyl and C ₃ -C ₈ cycloalkyl, in each case, being optionally substituted by 1-5 substituents selected from -CN, -OR ⁶ , -CONR ⁷ R ⁸ , - NR ⁷ R ⁸ and -COOR ⁶ ;

or, alternatively, where R ³ and R ⁴ are attached to adjacent carbon atoms, R ⁵ is H, and R ³ and R ⁴ are taken together with the carbon atoms to which they are attached to form a 5 or 6- membered ring which may be aromatic or partially saturated and which may be carbocyclic or contain up to two heteroatoms selected from N and O, said ring being optionally substituted by 1-3 substituents selected from halo;

wherein, in each instance, said C ₁ -C ₆ alkyl, C ₁ -C ₆ alkylene and C ₃ -C ₈ cycloalkyl may have one or more hydrogen atoms replaced with a fluorine atom.

The invention also provides, as preferred embodiment E4, a compound of formula (I), or a pharmaceutically acceptable salt thereof, or a pharmaceutically acceptable solvate of said compound or salt, wherein R ² is:

wherein R ³ , R ⁴ and R ⁵ are each independently H, -CN, halo, Ci-C ₆ alkyl, C ₃ -C ₈ cycloalkyl, -(C ₁ - C ₆ alkylene)-(Aryl ¹ ), -NR ⁶ SO ₂ -(C ₁ -C ₆ alkyl), -NR ⁶ -(C _r C ₆ alkyl), -NR ⁶ CONR ⁶ -(C _r C ₆ alkyl), -NR ⁶ CO-(C ₃ -C ₈ cycloalkyl), -NR ⁶ CO-(C ₁ -C ₆ alkyl), -SO-(C ₁ -C ₆ alkyl), -S-(C ₁ -C ₆ alkyl), -SO ₂ -(C ₁ - C ₆ alkyl), -SO ₂ -(Aryl ¹ ), -SO ₂ -(Het ¹ ), -SO ₂ NR ⁶ -(C _r C ₆ alkyl), -SO ₂ -(C ₃ -C ₈ cycloalkyl), -0-(C ₁ -C ₆ alkyl), -CONH ₂ , -CONR^(C ₁ -C ₆ alkyl), -CONR^(C ₁ -C ₆ alkylene)-(C ₃ -C ₈ cycloalkyl), -CONR ⁶ - (Het ¹ ), -CONR ⁶ -(Het ² ), -CO-(Het ¹ ), Aryl ¹ or Het ³ , said C ₁ -C ₆ alkyl and C ₃ -C ₈ cycloalkyl, in each case, being optionally substituted by 1-5 substituents selected from -CN, -OR ⁶ , -CONR ⁷ R ⁸ , - NR ⁷ R ⁸ and -COOR ⁶ ;

or, alternatively, where R ³ and R ⁴ are attached to adjacent carbon atoms, R ⁵ is H, and R ³ and R ⁴ are taken together with the carbon atoms to which they are attached to form a 5 or 6- membered ring which may be aromatic or partially saturated and which may be carbocyclic or contain up to two heteroatoms selected from N and O, said ring being optionally substituted by 1-3 substituents selected from halo;

wherein, in each instance, said C ₁ -C ₆ alkyl, C ₁ -C ₆ alkylene and C ₃ -C ₈ cycloalkyl may have one or more hydrogen atoms replaced with a fluorine atom.

The invention also provides, as preferred embodiment E5, a compound of formula (I), or a pharmaceutically acceptable salt thereof, or a pharmaceutically acceptable solvate of said compound or salt, wherein R ² is:

wherein R ³ , R ⁴ and R ⁵ are each independently H, C ₁ -C ₆ alkyl, -CONR^CrCe alkyl), -CO(Het ¹ ), or -SO ₂ NR ⁶ -(C _r C ₆ alkyl). The invention also provides, as preferred embodiment E6, a compound of formula (I), or a pharmaceutically acceptable salt thereof, or a pharmaceutically acceptable solvate of said compound or salt, wherein R ² is:

wherein R ³ is H, C ₁ -C ₆ alkyl, -CONR ⁶ -(d-C ₆ alkyl), -CO(Het ¹ ), or -SO ₂ NR ⁶ -(C _r C ₆ alkyl);

R ⁴ is H; and

R ⁵ is H.

The invention also provides, as preferred embodiment E7, a compound of formula (I), or a pharmaceutically acceptable salt thereof, or a pharmaceutically acceptable solvate of said compound or salt, wherein R ² is:

wherein R ³ , R ⁴ and R ⁵ are each independently H, methyl, -CON(CH ₃ ) ₂ ,

(carboxypyrrolidinyl)carbonyl, (hydroxypiperidinyl)carbonyl or (methylpiperazinyl)carbonyl.

The invention also provides, as preferred embodiment E8, a compound of formula (I), or a pharmaceutically acceptable salt thereof, or a pharmaceutically acceptable solvate of said compound or salt, wherein R ² is:

wherein R ³ is H, methyl, -CON(CH ₃ ) ₂ , (carboxypyrrolidinyl)carbonyl, (hydroxypyrrolidinyl)carbonyl or (methylpiperazinyl)carbonyl;

R ⁴ is H; and

R ⁵ is H.

The invention also provides, as preferred embodiment E9, a compound of formula (I), or a pharmaceutically acceptable salt thereof, or a pharmaceutically acceptable solvate of said compound or salt, wherein R ² is 2-hydroxypyrid-3-yl or 2-hydroxy-6-methylpyrid-3-yl.

The invention also provides, as preferred embodiment E10, a compound of formula (I), or a pharmaceutically acceptable salt thereof, or a pharmaceutically acceptable solvate of said compound or salt, wherein R ² is:

wherein R ³ is H, d-C ₆ alkyl or C ₃ -C ₈ cycloalkyl;

R ⁴ is H; and

R ^b is H, CN or C ₁ -C ₆ alkyl.

The invention also provides, as preferred embodiment E11 , a compound of formula (I), or a pharmaceutically acceptable salt thereof, or a pharmaceutically acceptable solvate of said compound or salt, wherein R ² is:

wherein R ³ is H, methyl or cyclopropyl;

R ⁴ is H; and

R ⁵ is H, CN or methyl.

The invention also provides, as preferred embodiment E12, a compound of formula (I), or a pharmaceutically acceptable salt thereof, or a pharmaceutically acceptable solvate of said compound or salt, wherein R ² is 2-hydroxypyridin-3-yl, 2-hydroxy-6-methylpyridin-3-yl, 2- hydroxy-4-cyanopyridin-3-yl, 2-hydroxy-5-fluoropyridin-3-yl, 2-hydroxy-6-cyclopropylpyridin-3-yl or 2-hydroxy-4-methylpyridin-3-yl.

The invention also provides, as preferred embodiment E13, a compound of formula (I), or a pharmaceutically acceptable salt thereof, or a pharmaceutically acceptable solvate of said compound or salt, wherein R ² is as defined in any one of embodiments E1 , E2, E3, E4, E5, E6, E7, E8, E9, E10, E11 and E12 and R ¹ is C ₁ -C ₆ alkyl, C ₃ -C ₈ cycloalkyl, Aryl ¹ , Aryl ² , Het ¹ , Het ² , - CO-(Aryl ¹ ) or -SO ₂ -( Aryl ¹ ), said CrC ₆ alkyl and C ₃ -C ₈ cycloalkyl being optionally substituted by 1 to 3 substituents independently selected from -CN, halo, -NH ₂ , -SH, -CONH ₂ , -SO ₂ NH ₂ , - NR ⁶ CONH ₂ , -OCONH ₂ and -X-R ^a ; wherein, in each instance, said Ci-C ₆ alkyl and C ₃ -C ₈ cycloalkyl may have one or more hydrogen atoms replaced with a fluorine atom.

The invention also provides, as preferred embodiment E14, a compound of formula (I), or a pharmaceutically acceptable salt thereof, or a pharmaceutically acceptable solvate of said compound or salt, wherein R ² is as defined in any one of embodiments E1 , E2, E3, E4, E5, E6, E7, E8, E9, E10, E11 and E12 and R ¹ is C ₁ -C ₆ alkyl, C ₃ -C ₈ cycloalkyl, Aryl ¹ , Aryl ² , Het ¹ , Het ² , - CO-(Aryl ¹ ) or -SO ₂ -( Aryl ¹ ), said CrC ₆ alkyl and C ₃ -C ₈ cycloalkyl being optionally substituted by 1 to 3 substituents independently selected from -NH ₂ , -NR^(C ₁ -C ₆ alkyl), -O-(C _r C ₆ alkyl), C ₃ -C ₈ cycloalkyl, Aryl ¹ , Het ¹ , Het ² , Het ³ , Het ⁴ , -SO ₂ -(Het ¹ ), -(C ₁ -C ₆ alkylene)-(Het ¹ ), -(C ₁ -C ₆ alkylene)- (Aryl ¹ ), -0-(C ₁ -C ₆ alkylene)-(Aryl ¹ ) and hydroxyl(C ₃ -C ₈ cycloalkyl); wherein, in each instance, said CrC ₆ alkyl and C ₃ -C ₈ cycloalkyl may have one or more hydrogen atoms replaced with a fluorine atom.

The invention also provides, as preferred embodiment E15, a compound of formula (I), or a pharmaceutically acceptable salt thereof, or a pharmaceutically acceptable solvate of said compound or salt, wherein R ² is as defined in any one of embodiments E1 , E2, E3, E4, E5, E6,

E7, E8, E9, E10, E11 and E12 and R ¹ is C _r C ₆ alkyl optionally substituted by 1 to 3 substituents independently selected from -NH ₂ , -NR ⁶ -(Ci-C ₆ alkyl), -O-(C _r C ₆ alkyl), C ₃ -C ₈ cycloalkyl, Aryl ¹ ,

Het ¹ , Het ² , Het ³ , Het ⁴ , -SO ₂ -(Het ¹ ), -(C ₁ -C ₆ alkylene)-(Het ¹ ), -(C ₁ -C ₆ alkylene)-(Aryl ¹ ), -0-(C ₁ -C ₆ alkylene)-(Aryl ¹ ) and hydroxyl(C ₃ -C ₈ cycloalkyl); wherein, in each instance, said C ₁ -C ₆ alkyl and

C ₃ -C ₈ cycloalkyl may have one or more hydrogen atoms replaced with a fluorine atom.

The invention also provides, as preferred embodiment E16, a compound of formula (I), or a pharmaceutically acceptable salt thereof, or a pharmaceutically acceptable solvate of said compound or salt, wherein R ² is as defined in any one of embodiments E1 , E2, E3, E4, E5, E6, E7, E8, E9, E10, E1 1 and E12 and R ¹ is C ₁ -C ₆ alkyl optionally substituted by 1 to 3 substituents independently selected from Aryl ¹ , Het ³ and Het ⁴ .

The invention also provides, as preferred embodiment E17, a compound of formula (I), or a pharmaceutically acceptable salt thereof, or a pharmaceutically acceptable solvate of said compound or salt, wherein R ² is as defined in any one of embodiments E1 , E2, E3, E4, E5, E6, E7, E8, E9, E10, E1 1 and E12 and R ¹ is C ₁ -C ₃ alkyl substituted by 1 substituent selected from Aryl ¹ , Het ³ , Het ⁴ and C ₁ -C ₃ alkyl.

The invention also provides, as preferred embodiment E18, a compound of formula (I), or a pharmaceutically acceptable salt thereof, or a pharmaceutically acceptable solvate of said compound or salt, wherein R ² is as defined in any one of embodiments E1 , E2, E3, E4, E5, E6, E7, E8, E9, E10, E11 and E12 and R ¹ is C ₁ -C ₃ alkyl optionally substituted by 1 substituent selected from furanyl, imidazo[2,1-b][1 ,3]thiazolyl, phenyl, pyridinyl, C ₁ -C ₃ alkyl and pyrimidinyl, said furanyl, imidazo[2,1-b][1 ,3]thiazolyl, phenyl, pyridinyl and pyrimidinyl being optionally substituted by methyl.

The invention also provides, as preferred embodiment E19, a compound of formula (I), or a pharmaceutically acceptable salt thereof, or a pharmaceutically acceptable solvate of said compound or salt, wherein R ² is as defined in any one of embodiments E1 , E2, E3, E4, E5, E6, E7, E8, E9, E10, E11 and E12 and R ¹ is (methylfuranyl)propyl, (imidazo[2,1- b][1 ,3]thiazolyl)propyl, (phenyl)propyl, pyridinylpropyl, methylbutyl or pyrimidinylpropyl. The invention also provides, as preferred embodiment E20, a compound of formula (I), or a pharmaceutically acceptable salt thereof, or a pharmaceutically acceptable solvate of said compound or salt, wherein R ² is as defined in any one of embodiments E1 , E2, E3, E4, E5, E6, E7, E8, E9, E10, E11 and E12 and R ¹ is 1-(5-methylfuran-2-yl)propyl, 1-(imidazo[2,1- b][1 ,3]thiazol-6-yl)propyl, 1-(phenyl)propyl, 1-(pyridin-2-yl)propyl, 3-methylbut-2-yl or 1- (pyrimidin-3-yl)propyl.

The invention also provides, as preferred embodiment E21 , a compound of formula (I), or a pharmaceutically acceptable salt thereof, or a pharmaceutically acceptable solvate of said compound or salt, wherein R ² is as defined in any one of embodiments E1 , E2, E3, E4, E5, E6, E7, E8, E9, E10, E1 1 and E12 and R ¹ is (a) -CHR ^x R ^y , wherein R ^x is C ₁ -C ₅ alkyl or C ₃ -C ₈ cycloalkyl, said C ₁ -C ₅ alkyl being optionally substituted by methoxy and R ^y is Het ³ , Het ⁴ , phenyl, -CH ₂ OCH ₂ Ph or C ₃ -C ₈ cycloalkyl, said Het ³ , Het ⁴ and phenyl being optionally substituted by C ₁ - C ₆ alkyl, halo, C ₁ -C ₆ alkoxy, -CN or C ₃ -C ₈ cycloalkyl; or (b) C ₃ -C ₈ cycloalkyl optionally substituted by phenyl or benzyl, said phenyl or benzyl being optionally substituted by halo; or (c) t-butyl, 3-methylbut-2-yl, isopropyl or pent-3-yl; wherein, in each instance, said C ₁ -C ₅ alkyl, C ₁ - C ₆ alkyl and C ₃ -C ₈ cycloalkyl may have one or more hydrogen atoms replaced with a fluorine atom.

The invention also provides, as preferred embodiment E22, a compound of formula (I), or a pharmaceutically acceptable salt thereof, or a pharmaceutically acceptable solvate of said compound or salt, wherein R ² is as defined in any one of embodiments E1 , E2, E3, E4, E5, E6, E7, E8, E9, E10, E1 1 and E12 and R ¹ is (a) -CHR ^x R ^y , wherein R ^x is methyl, ethyl, propyl, isopropyl, methoxymethyl or cyclopropyl and R ^y is -CH ₂ OCH ₂ Ph, cyclopropyl, phenyl, pyrimidinyl, pyrazinyl, furanyl, imidazo[2,1-b]thiazolyl, thiazolyl, pyridyl or pyrimidinyl, said phenyl, pyrimidinyl, pyrazinyl, furanyl, imidazo[2,1-b]thiazolyl, thiazolyl, pyridyl and pyrimidinyl being optionally substituted by C ₁ -C ₆ alkyl, halo, C ₁ -C ₆ alkoxy, -CN or C ₃ -C ₈ cycloalkyl; or (b) cyclopropyl, cyclobutyl, cyclopentyl or cyclohexyl, each being optionally substituted by phenyl, fluorophenyl, chlorobenzyl or benzyl; or (c) t-butyl, 3-methylbut-2-yl, isopropyl or pent-3-yl; wherein said C ₁ -C ₆ alkyl, C ₃ -C ₈ cycloalkyl, methyl, ethyl, propyl, isopropyl, methoxymethyl and cyclopropyl may have one or more hydrogen atoms replaced with a fluorine atom.

The invention also provides, as preferred embodiment E23, a compound of formula (I), or a pharmaceutically acceptable salt thereof, or a pharmaceutically acceptable solvate of said compound or salt, wherein R ² is as defined in any one of embodiments E1 , E2, E3, E4, E5, E6,

E7, E8, E9, E10, E11 and E12 and R ¹ is 1-phenylprop-1-yl, 1-pyridylprop-1-yl, 1-pyrazinylprop- 1-yl, 3-methylbut-2-yl, 1-pyrimidinylprop-i-yl, 1-(methylphenyl)prop-1-yl, 1-

(trifluoromethylphenyl)prop-i-yl, 1-(methoxyphenyl)prop-1-yl, 1-(dimethylphenyl)prop-1-yl, 1- (methylfuranyl)prop-i-yl, 1-((methyl)(isopropyl)furanyl)prop-1-yl, 1-phenylbut-1-yl, 1- (isopropylfuranyl)prop-i-yl, (fluorophenyl)(isopropyl)methyl, (trifluoromethyl)(furanyl)methyl, ter- butyl, (trifluoromethyl)(methoxyphenyl)methyl, 1-phenylbut-1-yl, (chloromethyl)(methyl)methyl, (chlorophenylmethyOcyclopropyl, 1-(imidazo[2,1-b]thiazolyl)prop-1-yl,

(trifluoromethyl)(phenyl)methyl, 1-(trifluoromethylphenyl)prop-1-yl, 1-(fluorophenyl)prop-1-yl, 1- (cyclopropylphenyl)prop-i-yl, 1-phenyl-2-methoxyprop-1-yl, difluorophenylcyclopentyl, phenylcyclopentyl, isopropyl, 1 -thiazolyl prop- 1 -yl , 1-(difluorophenyl)prop-1-yl, pent-3-yl, cyclopentyl, cyclohexyl, benzylcyclobutyl, 1-thiazolylprop-1-yl (phenyl)(isopropyl)methyl, (methyl)(methylisoxazolyl)methyl, (isopropyl)(triazolyl)methyl, phenylcyclopenyl,

(methyl)((diflouro)(methyl)phenyl)methyl, (methyl)(pyridyl)methyl, fluorophenylcyclopentyl, 1- (difluorophenyl)prop-i-yl, dicyclopropylmethyl, 1-(fluorophenyl)prop-1-yl, 2-methyl-3-phenylprop- 3-yl, (phenyl)(cyclopropyl)methyl, (methyl)((difluoro)(methyl)phenyl)methyl, 1- ((fluoro)(methyl)phenyl)prop-1-yl, (isopropyl)(methoxyphenyl)methyl, 1-pyrimidinylprop-1-yl, 1- (dimethylphenyl)prop-i-yl, 1-(methylphenyl)prop-1-yl, 1-((fluoro)(methoxy)phenyl)prop-1-yl, 1- ((fluoro)(trifluoromethyl)prop-1-yl, (cyclopropylXdifluorophenyOmethyl, 1-chlorophenylprop-i-yl, 1 -cyanophenylprop-1 -yl, 1 -(benzyloxymethyl)prop-i -yl, ((methyl)(chloro)phenyl)(methyl)methyl or 1-methoxyphenylprop-1-yl.

The present invention also provides: a method of treating a disease or condition mediated at least in part by activation of the CXCR-2 receptor, in a subject in need of such treatment, comprising administering to the subject a therapeutically effective amount of a compound of formula (I), or a pharmaceutically acceptable salt thereof, or a pharmaceutically acceptable solvate of said compound or salt; the use of a compound of formula (I), or a pharmaceutically acceptable salt thereof, or a pharmaceutically acceptable solvate of said compound or salt, for the manufacture of a medicament for treating a disease or condition mediated at least in part by activation of the CXCR-2 receptor; a compound of formula (I), or a pharmaceutically acceptable salt thereof, or a pharmaceutically acceptable solvate of said compound or salt, for use as a medicament; a compound of formula (I), or a pharmaceutically acceptable salt thereof, or a pharmaceutically acceptable solvate of said compound or salt, for use in the treatment of a disease or condition mediated at least in part by activation of the CXCR-2 receptor; a pharmaceutical composition comprising a compound of formula (I), or a pharmaceutically acceptable salt thereof, or a pharmaceutically acceptable solvate of said compound or salt, and a pharmaceutically acceptable excipient; a pharmaceutical composition for the treatment of a disease or condition mediated at least in part by activation of the CXCR-2 receptor comprising a compound of formula (I), or a pharmaceutically acceptable salt thereof, or a pharmaceutically acceptable solvate of said compound or salt.

The disease or condition mediated at least in part by activation of the CXCR-2 receptor is preferably an inflammatory disease, particularly an inflammatory respiratory condition such as allergic rhinitis, nasal congestion, rhinorrhea, perennial rhinitis, nasal inflammation, asthma of all types, chronic obstructive pulmonary disease (COPD), acute COPD exacerbations, chronic or acute bronchoconstriction, chronic bronchitis, small airways obstruction, emphysema, chronic eosinophilic pneumonia, acute respiratory distress syndrome (ARDS), exacerbation of airways hyper-reactivity consequent to other drug therapy, airways disease that is associated with pulmonary hypertension, acute lung injury (ALI), bronchiectasis, cystic fibrosis, idiopathic pulmonary fibrosis, bronchiolitis obliterans syndrome, bronchopulmonary dysplasia or sinusitis, most particularly asthma or chronic obstructive pulmonary disease.

Types of asthma include atopic asthma, non-atopic asthma, allergic asthma, atopic bronchial IgE-mediated asthma, bronchial asthma, essential asthma, true asthma, intrinsic asthma caused by pathophysiologic disturbances, extrinsic asthma caused by environmental factors, essential asthma of unknown or inapparent cause, bronchitic asthma, emphysematous asthma, exercise- induced asthma, allergen induced asthma, cold air induced asthma, occupational asthma, infective asthma caused by bacterial, fungal, protozoal, or viral infection, non-allergic asthma, incipient asthma, wheezy infant syndrome and bronchiolytis.

The treatment of asthma includes palliative treatment for the symptoms and conditions of asthma such as wheezing, coughing, shortness of breath, tightness in the chest, shallow or fast breathing, nasal flaring (nostril size increases with breathing), retractions (neck area and between or below the ribs moves inward with breathing), cyanosis (gray or bluish tint to skin, beginning around the mouth), runny or stuffy nose, and headache.

Other diseases and conditions of interest include rhumatoid arthritis, osteoarthritis, systemic lupus erthythematosus, psoriasis, allergic conjunctivitis, atopic dermatitis, pruritus, cancer, endometriosis, inflammatory bowel disease (including Crohn's disease and ulcerative colitis), gastric ulceration, septic shock, endotoxic shock, sepsis, toxic shock syndrome, meningitis, stroke, cardiac and renal reperfusion injury, glomerulo-nephritis, glomerulo-thrombosis, atherosclerosis, Alzheimer's disease, graft versus host reaction, allograft rejection, wound healing, spinal cord injury, multiple sclerosis, acute inflammatory pain, chronic inflammatory pain, acute neuropathic pain, chronic neuropathic pain and HIV infection. The present invention also provides any of the uses, methods or compositions as defined above wherein the compound of formula (I), or pharmaceutically acceptable salt thereof, or pharmaceutically acceptable solvate of said compound or salt, is used in combination with another pharmacologically active compound, particularly one of the functionally-defined classes or specific compounds listed below. Generally, the compounds of the combination will be administered together as a formulation in association with one or more pharmaceutically acceptable excipients.

Suitable agents for use in combination therapy with a compound of formula (I), or pharmaceutically acceptable salt thereof, or pharmaceutically acceptable solvate of said compound or salt, particularly in the treatment of respiratory disease include:

• a 5-lipoxygenase activating protein (FLAP) antagonist;

• a leukotriene antagonist (LTRA) such as an antagonist of LTB ₄ , LTC ₄ , LTD ₄ , LTE ₄ , CySLT ₁ or CysLT ₂ , e.g. montelukast or zafirlukast; • a histamine receptor antagonist, such as a histamine type 1 receptor antagonist or a histamine type 2 receptor antagonist, e.g. loratidine, fexofenadine, desloratidine, levocetirizine, methapyrilene or cetirizine;

• an α1 -adrenoceptor agonist or an α2-adrenoceptor agonist, e.g. phenylephrine, methoxamine, oxymetazoline or methylnorephrine; • a muscarinic M3 receptor antagonist, e.g. tiotropium or ipratropium;

• a PDE inhibitor, such as a PDE3 inhibitor, a PDE4 inhibitor or a PDE5 inhibitor, e.g. theophylline, sildenafil, vardenafil, tadalafil, ibudilast, cilomilast or roflumilast;

• sodium cromoglycate or sodium nedocromil;

• a cyclooxygenase (COX) inhibitor, such as a non-selective inhibitor (e.g. aspirin or ibuprofen) or a selective COX-2 inhibitor (e.g. celecoxib or valdecoxib);

• a glucocorticosteroid, e.g. fluticasone, mometasone, dexamethasone, prednisolone, budesonide, ciclesonide or beclamethasone;

• an anti-inflammatory monoclonal antibody, e.g. infliximab, adalimumab, tanezumab, ranibizumab, bevacizumab or mepolizumab; • a β2 agonist, e.g. salmeterol, albuterol, salbutamol, fenoterol or formoterol, particularly a long-acting β2 agonist;

• an intigrin antagonist, e.g. natalizumab;

• an adhesion molecule inhibitor, such as a VLA-4 antagonist;

• a kinin Bi or B ₂ receptor antagonist; • an immunosuppressive agent, such as an inhibitor of the IgE pathway (e.g. omalizumab) or cyclosporine;

• a matrix metalloprotease (MMP) inhibitor, such as an inhibitor of MMP-9 or MMP-12; • a tachykinin NK ₁ , NK ₂ or NK ₃ receptor antagonist;

• a protease inhibitor, such as an inhibitor of elastase, chymase or catheopsin G;

• an adenosine A _2a receptor agonist;

• an adenosine A _2b receptor antagonist; • a urokinase inhibitor;

• a dopamine receptor agonist (e.g. ropinirole), particularly a dopamine D2 receptor agonist (e.g. bromocriptine);

• a modulator of the NFKB pathway, such as an IKK inhibitor;

• a modulator of a cytokine signalling pathway such as an inhibitor of syk kinase, JAK kinase, p38 kinase, SPHK-1 kinase, Rho kinase, EGF-R or MK-2;

• a mucolytic, mucokinetic or anti-tussive agent

• an antibiotic;

• an antiviral agent;

• a vaccine; • a chemokine;

• an epithelial sodium channel (ENaC) blocker or Epithelial sodium channel (ENaC) inhibitor;

• a nucleotide receptor agonist, such as a P2Y2 agonist;

• a thromboxane inhibitor; • niacin;

• a 5-lipoxygenase (5-LO) inhibitor, e.g. Zileuton;

• an adhesion factor, such as VLAM, ICAM or ELAM;

• a CRTH2 receptor (DP ₂ ) antagonist;

• a prostaglandin D ₂ receptor (DP-i) antagonist; • a haematopoietic prostaglandin D2 synthase (HPGDS) inhibitor;

• interferon-β;

• a soluble human TNF receptor, e.g. Etanercept;

• a HDAC inhibitor;

• a phosphoinositotide 3-kinase gamma (PI3Kγ) inhibitor; • a phosphoinositide 3-kinase delta (PI3K™) inhibitor; and

• a CXCR-1 receptor antagonist; including the pharmaceutically acceptable salts of the specifically named compounds and the pharmaceutically acceptable solvates of said specifically named compounds and their salts. Besides being useful for human treatment, compounds of formula (I) are also useful for veterinary treatment of companion animals, exotic animals and farm animals.

When used in the present application, the following abbreviations have the meanings set out below:

APCI (in relation to mass spectrometry) is atmospheric pressure chemical ionization;

BOP is (benzotriazol-1-yloxy)tris(dimethylamino)phosphonium hexafluorophosphate;

CaIc is calculated;

CDCI ₃ is deuterochloroform; CO ₂ Et is ethyl carboxylate;

DCC is N,N'-dicyclohexylcarbodiimide;

DCM is dichloromethane;

DEA is diethylamine;

DIPEA is N,N-diisopropylethylamine; DMA is N,N-dimethylacetamide;

DMF is dimethylformamide;

DMSO-d ₆ is fully deuterated dimethyl sulphoxide;

EDC/EDCI is N-(3-Dimethylaminopropyl)-N'-ethylcarbodiimide hydrochloride;

ES (in relation to mass spectrometry) is electrospray; Et is ethyl; h is hour(s);

HATU is N,N,N',N'-tetramethyl-O-(7-azabenzotriazol-1-yl)uronium hexafluorophosphate;

HBTU is N,N,N',N'-tetramethyl-O-(1 H-benzotriazol-1-yl)uronium hexafluorophosphate;

HCI is hydrochloric acid; 1 H NMR or ¹ H NMR is proton nuclear magnetic resonance;

HOAt is 1-hydroxy-7-azabenzotriazole;

HOBt is 1-hydroxybenzotriazole;

HPLC is high performance liquid chromatography;

H ₂ SO ₄ is sulphuric acid; IPA is isopropyl alcohol; iPr is isopropyl;

K ₂ CO ₃ is potassium carbonate;

KMnO ₄ is potassium permanganate;

LCMS is liquid chromatography mass spectrometry; LRMS is low resolution mass spectrometry;

NMM is 4-methylmorpholine;

Me is methyl; MeCN is acetonitrile; MeOD-Cl ₄ is fully deuterated methanol; MgSO ₄ is magnesium sulfate; min is minute(s); MS is mass spectroscopy; NaCI is sodium chloride; Obs is observed; Pd(OAc) ₂ is palladium(ll)acetate RT is retention time; TBTU is O-(benzotriazol-1-yl)-N,N,N',N'-tetramethyluronium tetrafluoroborate; TEA is triethylamine; TFA is trifluoroacetic acid; THF is tetrahydrofuran.

Unless otherwise defined herein, scientific and technical terms used in connection with the present invention have the meanings that are commonly understood by those of ordinary skill in the art.

The phrase "therapeutically effective" is intended to qualify the amount of compound or pharmaceutical composition, or the combined amount of active ingredients in the case of combination therapy. This amount or combined amount will achieve the goal of treating the relevant condition.

The term "treatment," as used herein to describe the present invention and unless otherwise qualified, means administration of the compound, pharmaceutical composition or combination to effect preventative, palliative, supportive, restorative or curative treatment. The term treatment encompasses any objective or subjective improvement in a subject with respect to a relevant condition or disease.

The term "preventive treatment," as used herein to describe the present invention, means that the compound, pharmaceutical composition or combination is administered to a subject to inhibit or stop the relevant condition from occurring in a subject, particularly in a subject or member of a population that is significantly predisposed to the relevant condition.

The term "palliative treatment," as used herein to describe the present invention, means that the compound, pharmaceutical composition or combination is administered to a subject to remedy signs and/or symptoms of a condition, without necessarily modifying the progression of, or underlying etiology of, the relevant condition.

The term "supportive treatment," as used herein to describe the present invention, means that the compound, pharmaceutical composition or combination is administered to a subject as a part of a regimen of therapy, but that such therapy is not limited to administration of the compound, pharmaceutical composition or combination. Unless otherwise expressly stated, supportive treatment may embrace preventive, palliative, restorative or curative treatment, particularly when the compounds or pharmaceutical compositions are combined with another component of supportive therapy.

The term "restorative treatment," as used herein to describe the present invention, means that the compound, pharmaceutical composition or combination is administered to a subject to modify the underlying progression or etiology of a condition. Non-limiting examples include an increase in forced expiratory volume in one second (FEV 1 ) for lung disorders, decreased rate of a decline in lung function over time, inhibition of progressive nerve destruction, reduction of biomarkers associated and correlated with diseases or disorders, a reduction in relapses, improvement in quality of life, reduced time spent in hospital during an acute exacerbation event and the like.

The term "curative treatment," as used herein to describe the present invention, means that compound, pharmaceutical composition or combination is administered to a subject for the purpose of bringing the disease or disorder into complete remission, or that the disease or disorder is undetectable after such treatment.

The term "selective", when used to describe a functionally-defined receptor ligand or enzyme inhibitor means selective for the defined receptor or enzyme subtype as compared with other receptor or enzyme subtypes in the same family. For instance, a selective PDE5 inhibitor is a compound which inhibits the PDE5 enzyme subtype more potently than any other PDE enzyme subtype. Such selectivity is preferably at least 2 fold (as measured using conventional binding assays), more preferably at least 10 fold, most preferably at least 100 fold.

The term "alkyl", alone or in combination, means an acyclic, saturated hydrocarbon group of the formula C _n H _2n +i which may be linear or branched. Examples of such groups include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, pentyl, iso-amyl and hexyl. Unless otherwise specified, an alkyl group comprises from 1 to 6 carbon atoms. The term "alkylene" means a bivalent acyclic, saturated hydrocarbon group of the formula C _n H _2n which may be linear or branched. Example of such groups include -CH ₂ -, -CH(CH ₃ )-, -CH ₂ CH ₂ -, -CH(CH ₃ )CH ₂ -, -CH(CH ₃ )CH(CH ₃ )- and -CH ₂ CH ₂ CH ₂ -. Unless otherwise specified, an alkylene group comprises from 1 to 6 carbon atoms.

The carbon atom content of alkyl and various other hydrocarbon-containing moieties is indicated by a prefix designating a lower and upper number of carbon atoms in the moiety, that is, the prefix C-C _j indicates a moiety of the integer "i" to the integer "j" carbon atoms, inclusive. Thus, for example, C ₁ -C ₆ alkyl refers to alkyl of one to six carbon atoms, inclusive.

The term "hydroxy," as used herein, means an OH radical.

Het ¹ and Het ⁵ are saturated or partially saturated (i.e. non aromatic) heterocycles and may be attached via a ring nitrogen atom (when the heterocycle is attached to a carbon atom) or a ring carbon atom (in all cases). Equally, when substituted, the substituent may be located on a ring nitrogen atom (if the substituent is joined through a carbon atom) or a ring carbon atom (in all cases). Specific examples include oxiranyl, aziridinyl, oxetanyl, azetidinyl, tetrahydrofuranyl, pyrrolidinyl, tetrahydropyranyl, piperidinyl, 1 ,4-dioxanyl, morpholinyl, piperazinyl, azepanyl, oxepanyl, oxazepanyl and diazepinyl.

Het ² and Het ⁶ are saturated or partially saturated heterocycles and may be attached via a ring nitrogen atom (when the heterocycle is attached to a carbon atom) or a ring carbon atom (in all cases). Equally, when substituted, the substituent may be located on a ring nitrogen atom (if the substituent is joined through a carbon atom) or a ring carbon atom (in all cases). Het ² and Het ⁶ are multicyclic heterocyclic groups, containing two or more rings. Such rings may be joined so as to create a bridged, fused or spirofused ring system, as illustrated with two six-membered rings below (heteroatoms not shown):

fused spirofused bridged

Het ² and Het ⁶ may be fully saturated or partially unsaturated, i.e. they may have one or more degrees of unsaturation but may not be fully aromatic. In the case of a fused ring system, one of the rings may be aromatic but not both of them. An example of Het ² is tropanyl (azabicyclo[3.2.1 Joctanyl).

Het ³ and Het ⁷ are aromatic heterocycles and may be attached via a ring carbon atom (in all cases) or a ring nitrogen atom with an appropriate valency (when the heterocycle is attached to a carbon atom). Equally, when substituted, the substituent may be located on a ring carbon atom (in all cases) or a ring nitrogen atom with an appropriate valency (if the substituent is joined through a carbon atom). Specific examples include thienyl, furanyl, pyrrolyl, pyrazolyl, imidazoyl, oxazolyl, isoxazolyl, thiazolyl, isothiazolyl, triazolyl, oxadiazolyl, thiadiazolyl, tetrazolyl, pyridyl, pyridazinyl, pyrimidinyl and pyrazinyl.

Het ⁴ and Het ⁸ are aromatic heterocycles and may be attached via a ring carbon atom (in all cases) or a ring nitrogen atom with an appropriate valency (when the heterocycle is attached to a carbon atom). Equally, when substituted, the substituent may be located on a ring carbon atom (in all cases) or a ring nitrogen atom with an appropriate valency (if the substituent is joined through a carbon atom). Het ⁴ and Het ⁸ are aromatic and are therefore necessarily fused bicycles. Specific examples include imidazo[2, 1-b][1 ,3]thiazolyl, benzofuranyl, benzothienyl, indolyl, benzimidazolyl, indazolyl, benzotriazolyl, pyrrolo[2,3-b]pyridyl, pyrrolo[2,3-c]pyridyl, pyrrolo[3,2-c]pyridyl, pyrrolo[3,2-b]pyridyl, imidazo[4,5-b]pyridyl, imidazo[4,5-c]pyridyl, pyrazolo[4,3-d]pyridyl, pyrazolo[4,3-c]pyridyl, pyrazo Io [3, 4-c] pyridyl, pyrazolo[3,4-b]pyridyl, isoindolyl, indazolyl, purinyl, indolizinyl, imidazo[1 ,2-a]pyridyl, imidazo[1 ,5-a]pyridyl, pyrazolo[1 ,5-a]pyridyl, pyrrolo[1 ,2-b]pyridazinyl, imidazo[1 ,2-c]pyrimidinyl, quinolinyl, isoquinolinyl, cinnolinyl, quinazolinyl, quinoxalinyl, phthalazinyl, 1 ,6-naphthyridinyl, 1 ,7- naphthyridinyl, 1 ,8-naphthyridinyl, 1 ,5-naphthyridinyl, 2,6-naphthyridinyl, 2,7-naphthyridinyl, pyrido[3,2-d]pyrimidinyl, pyrido[4,3-d]pyrimidinyl, pyrido[3,4-d]pyrimidinyl, pyrido[2,3- d]pyrimidinyl, pyrido[2,3-d]pyrazinyl, pyrido[3,4-b]pyrazinyl, pyrimido[5,4-d]pyrimidinyl, pyrazino[2,3-b]pyrazinyl and pyrimido[4,5-d]pyrimidine.

Aryl ² and Aryl ⁴ are each a 3 to 8-membered monocyclic or a 6 to 12-membered bicyclic carbocycle which is partially unsaturated. The 6 to 12-membered bicyclic carbocycle may be fused, spirofused or bridged (see above). In this context, partially unsaturated means that the carbocycle includes at least one double bond but is not, as a whole, aromatic. A 6-membered monocyclic carbocycle with three double bonds would therefore not fall within the definition since it would amount to a phenyl group. Nor would a 10-membered bicyclic carbocycle with two fused six-membered rings and five double bonds fall within the definition since it would amount to a naphthyl group. In the case of a fused bicyclic carbocycle, however, it is possible for one of the rings to be atomatic. The carbocycle may be attached through a fully saturated or an unsaturated carbon atom. Some examples of Aryl ² and Aryl ⁴ are as follows:

The term "cycloalkyl" means a means a monocyclic, saturated hydrocarbon group of the formula C _n H _2n - _I - Examples include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, and cycloheptyl. Unless otherwise specified, a cycloalkyl group comprises from 3 to 8 carbon atoms.

The term bicycloalkyl means a bicyclic, saturated hydrocarbon group of the formula C _n H _2n - ₃ in which the two rings are joined in a fused, spiro-fused or bridged manner (see above). The following groups are illustrative of C ₅ -Ci ₂ bicycloalkyl (note that as drawn, these groups have an extra hydrogen atom where the linking bond would be):

The moieties C ₁ -C ₆ alkyl, C ₁ -C ₆ alkylene, C ₃ -C ₈ cycloalkyl and C ₆ -C ₁₂ bicycloalkyl, whether these groups are named individually or as part of a composite group, may have one or more hydrogen atoms replaced by a fluorine atom. Thus, for example, the C ₁ alkyl group methyl may be substituted with 1-3 fluorine atoms to form -CH ₂ F, -CHF ₂ or CF ₃ .

The term "oxo" means a doubly bonded oxygen.

The term "alkoxy" means a radical comprising an alkyl radical that is bonded to an oxygen atom, such as a methoxy radical. Examples of such radicals include methoxy, ethoxy, propoxy, isopropoxy, butoxy and tert-butoxy.

As used herein, the terms "co-administration", "co-administered" and "in combination with", referring to a combination of a compound of formula (I) and one or more other therapeutic agents, includes the following:

• simultaneous administration of such a combination of a compound of formula (I) and a further therapeutic agent to a patient in need of treatment, when such components are formulated together into a single dosage form which releases said components at substantially the same time to said patient, • substantially simultaneous administration of such a combination of a compound of formula(l) and a further therapeutic agent to a patient in need of treatment, when such components are formulated apart from each other into separate dosage forms which are taken at substantially the same time by said patient, whereupon said components are released at substantially the same time to said patient,

• sequential administration of such a combination of a compound of formula (I) and a further therapeutic agent to a patient in need of treatment, when such components are formulated apart from each other into separate dosage forms which are taken at consecutive times by said patient with a significant time interval between each administration, whereupon said components are released at substantially different times to said patient; and

• sequential administration of such a combination of a compound of formula (I) and a further therapeutic agent to a patient in need of treatment, when such components are formulated together into a single dosage form which releases said components in a controlled manner.

The term 'excipient' is used herein to describe any ingredient other than a compound of formula (I). The choice of excipient will to a large extent depend on factors such as the particular mode of administration, the effect of the excipient on solubility and stability, and the nature of the dosage form. The term "excipient" encompasses diluent, carrier or adjuvant.

One way of carrying out the invention is to administer a compound of formula (I) in the form of a prodrug. Thus, certain derivatives of a compound of formula (I) which may have little or no pharmacological activity themselves can, when administered into or onto the body, be converted into a compound of formula (I) having the desired activity, for example by hydrolytic cleavage, particularly hydrolytic cleavage promoted by an esterase or peptidase enzyme. Such derivatives are referred to as 'prodrugs'. Further information on the use of prodrugs may be found in 'Prodrugs as Novel Delivery Systems', Vol. 14, ACS Symposium Series (T. Higuchi and W. Stella) and 'Bioreversible Carriers in Drug Design', Pergamon Press, 1987 (Ed. E. B. Roche, American Pharmaceutical Association). Reference can also be made to Nature Reviews/Drug Discovery, 2008, 7, 355 and Current Opinion in Drug Discovery and Development, 2007, 10, 550.

Prodrugs in accordance with the invention can, for example, be produced by replacing appropriate functionalities present in the compounds of formula (I) with certain moieties known to those skilled in the art as 'pro-moieties' as described, for example, in 'Design of Prodrugs' by H. Bundgaard (Elsevier, 1985). Thus, a prodrug in accordance with the invention is (a) an ester or amide derivative of a carboxylic acid in a compound of formula (I); (b) an ester, carbonate, carbamate, phosphate or ether derivative of a hydroxyl group in a compound of formula (I); (c) an amide, imine, carbamate or amine derivative of an amino group in a compound form formula (I); (d) a thioester, thiocarbonate, thiocarbamate or sulphide derivatives of a thiol group in a compound of formula (I); or (e) an oxime or imine derivative of a carbonyl group in a compound of formula (I).

Some specific examples of prodrugs in accordance with the invention include:

(i) where the compound of formula (I) contains a carboxylic acid functionality

(-COOH), an ester thereof, such as a compound wherein the hydrogen of the carboxylic acid functionality of the compound of formula (I) is replaced by Ci-Cs alkyl (e.g. ethyl) or (C ₁ -C ₈ alkyl)C(=O)OCH ₂ - (e.g. ^t BuC(=O)OCH ₂ -);

(ii) where the compound of formula (I) contains an alcohol functionality (-OH), an ester thereof, such as a compound wherein the hydrogen of the alcohol functionality of the compound of formula (I) is replaced by -CO(C ₁ -C ₈ alkyl) (e.g. methylcarbonyl) or the alcohol is esterified with an amino acid;

(iii) where the compound of formula (I) contains an alcohol functionality (-OH), an ether thereof, such as a compound wherein the hydrogen of the alcohol functionality of the compound of formula (I) is replaced by (C ₁ -C ₈ alkyl)C(=O)OCH ₂ - or -CH ₂ OP(=O)(OH) ₂ ;

(iv) where the compound of formula (I) contains an alcohol functionality (-OH), a phosphate thereof, such as a compound wherein the hydrogen of the alcohol functionality of the compound of formula (I) is replaced by -P(=O)(OH) ₂ or -P(=0)(0Na) ₂ or -P(=O)(O ^" ) ₂ Ca ²⁺ ;

(v) where the compound of formula (I) contains a primary or secondary amino functionality (-NH ₂ or -NHR where R ≠ H), an amide thereof, for example, a compound wherein, as the case may be, one or both hydrogens of the amino functionality of the compound of formula (I) is/are replaced by (C-ι-C ₁₀ )alkanoyl, -COCH ₂ NH ₂ or the amino group is derivatised with an amino acid;

(vi) where the compound of formula (I) contains a primary or secondary amino functionality (-NH ₂ or -NHR where R ≠ H), an amine thereof, for example, a compound wherein, as the case may be, one or both hydrogens of the amino functionality of the compound of formula (I) is/are replaced by -CH ₂ OP(=O)(OI-l) ₂ .

Certain compounds of formula (I) may themselves act as prodrugs of other compounds of formula (I). It is also possible for two compounds of formula (I) to be joined together in the form of a prodrug. In certain circumstances, a prodrug of a compound of formula (I) may be created by internally linking two functional groups in a compound of formula (I), for instance by forming a lactone.

References below to compounds of formula (I) are taken to include the compounds themselves and prodrugs thereof. The invention includes such compounds of formula (I) as well as pharmaceutically acceptable salts of such compounds and pharmaceutically acceptable solvates of said compounds and salts.

Pharmaceutically acceptable salts of the compounds of formula (I) include acid addition and base salts.

Suitable acid addition salts are formed from acids which form non-toxic salts. Examples include the acetate, adipate, aspartate, benzoate, besylate, bicarbonate/carbonate, bisulfate/sulfate, borate, camsylate, citrate, cyclamate, edisylate, esylate, formate, fumarate, gluceptate, gluconate, glucuronate, hexafluorophosphate, hibenzate, hydrochloride/chloride, hydrobromide/bromide, hydroiodide/iodide, isethionate, lactate, malate, maleate, malonate, mesylate, methylsulfate, naphthylate, 2-napsylate, nicotinate, nitrate, orotate, oxalate, palmitate, pamoate, phosphate/hydrogen phosphate/dihydrogen phosphate, pyroglutamate, saccharate, stearate, succinate, tannate, tartrate, tosylate, trifluoroacetate, naphatlene-1 ,5-disulfonic acid and xinofoate salts.

Suitable base salts are formed from bases which form non-toxic salts. Examples include the aluminium, arginine, benzathine, calcium, choline, diethylamine, diolamine, glycine, lysine, magnesium, meglumine, olamine, potassium, sodium, tromethamine and zinc salts.

Hemisalts of acids and bases may also be formed, for example, hemisulfate and hemicalcium salts. For a review on suitable salts, see Handbook of Pharmaceutical Salts: Properties, Selection, and Use by Stahl and Wermuth (Wiley-VCH, 2002).

Pharmaceutically acceptable salts of compounds of formula (I) may be prepared by one or more of three methods: (i) by reacting the compound of formula (I) with the desired acid or base; (ii) by removing an acid- or base-labile protecting group from a suitable precursor of the compound of formula (I) or by ring-opening a suitable cyclic precursor, for example, a lactone or lactam, using the desired acid or base; or

(iii) by converting one salt of the compound of formula (I) to another by reaction with an appropriate acid or base or by means of a suitable ion exchange column.

All three reactions are typically carried out in solution. The resulting salt may precipitate out and be collected by filtration or may be recovered by evaporation of the solvent. The degree of ionisation in the resulting salt may vary from completely ionised to almost non-ionised.

The compounds of formula (I), and pharmaceutically acceptable salts thereof, may exist in unsolvated and solvated forms. The term 'solvate' is used herein to describe a molecular complex comprising the compound of formula (I), or a pharmaceutically acceptable salt thereof, and one or more pharmaceutically acceptable solvent molecules, for example, ethanol. The term 'hydrate' is employed when said solvent is water.

A currently accepted classification system for organic hydrates is one that defines isolated site, channel, or metal-ion coordinated hydrates - see Polymorphism in Pharmaceutical Solids by K.

R. Morris (Ed. H. G. Brittain, Marcel Dekker, 1995). Isolated site hydrates are ones in which the water molecules are isolated from direct contact with each other by intervening organic molecules. In channel hydrates, the water molecules lie in lattice channels where they are next to other water molecules. In metal-ion coordinated hydrates, the water molecules are bonded to the metal ion.

When the solvent or water is tightly bound, the complex will have a well-defined stoichiometry independent of humidity. When, however, the solvent or water is weakly bound, as in channel solvates and hygroscopic compounds, the water/solvent content will be dependent on humidity and drying conditions. In such cases, non-stoichiometry will be the norm.

Also included within the scope of the invention are multi-component complexes (other than salts and solvates) wherein the drug and at least one other component are present in stoichiometric or non-stoichiometric amounts. Complexes of this type include clathrates (drug-host inclusion complexes) and co-crystals. The latter are typically defined as crystalline complexes of neutral molecular constituents which are bound together through non-covalent interactions, but could also be a complex of a neutral molecule with a salt. Co-crystals may be prepared by melt crystallisation, by recrystallisation from solvents, or by physically grinding the components together - see Chem Commun, X7_, 1889-1896, by O. Almarsson and M. J. Zaworotko (2004). For a general review of multi-component complexes, see J Pharm Sci, 64 (8), 1269-1288, by Haleblian (August 1975).

The compounds of the invention may exist in a continuum of solid states ranging from fully amorphous to fully crystalline. The term 'amorphous' refers to a state in which the material lacks long range order at the molecular level and, depending upon temperature, may exhibit the physical properties of a solid or a liquid. Typically such materials do not give distinctive X-ray diffraction patterns and, while exhibiting the properties of a solid, are more formally described as a liquid. Upon heating, a change from solid to liquid properties occurs which is characterised by a change of state, typically second order ('glass transition'). The term 'crystalline' refers to a solid phase in which the material has a regular ordered internal structure at the molecular level and gives a distinctive X-ray diffraction pattern with defined peaks. Such materials when heated sufficiently will also exhibit the properties of a liquid, but the change from solid to liquid is characterised by a phase change, typically first order ('melting point').

The compounds of formula (I) may also exist in a mesomorphic state (mesophase or liquid crystal) when subjected to suitable conditions. The mesomorphic state is intermediate between the true crystalline state and the true liquid state (either melt or solution). Mesomorphism arising as the result of a change in temperature is described as 'thermotropic' and that resulting from the addition of a second component, such as water or another solvent, is described as 'lyotropic'. Compounds that have the potential to form lyotropic mesophases are described as 'amphiphilic' and consist of molecules which possess an ionic (such as -COO Na ⁺ , -COO K ⁺ , or - SO ₃ Na ⁺ ) or non-ionic (such as -N ^~ N ⁺ (CH ₃ ) ₃ ) polar head group. For more information, see Crystals and the Polarizing Microscope by N. H. Hartshorne and A. Stuart, 4 ^th Edition (Edward Arnold, 1970).

Hereinafter all references to compounds of formula (I) include references to pharmaceutically acceptable salts, solvates, multi-component complexes and liquid crystals thereof and to solvates, multi-component complexes and liquid crystals of pharmaceutically acceptable salts thereof.

The compounds of formula (I) may exhibit polymorphism and/or one or more kinds of isomerism (e.g. optical, geometric, anisotropic or tautomeric isomerism). The compounds of formula (I) may also be isotopically labelled. Such variation is implicit to the compounds of formula (I) defined as they are by reference to their structural features and therefore within the scope of the invention.

Compounds of formula (I) containing one or more asymmetric carbon atoms can exist as two or more stereoisomers. Where a compound of formula (I) contains an alkenyl or alkenylene group, geometric cis/trans (or ZIE) isomers are possible. Where structural isomers are interconvertible via a low energy barrier, tautomeric isomerism ('tautomerism') can occur. This can take the form of proton tautomerism in compounds of formula (I) containing, for example, an imino, keto, or oxime group, or so-called valence tautomerism in compounds which contain an aromatic moiety. It follows that a single compound may exhibit more than one type of isomerism.

The pharmaceutically acceptable salts of compounds of formula (I) may also contain a counterion which is optically active (e.g. d-lactate or l-lysine) or racemic (e.g. dl-tartrate or dl- arginine).

Cis/trans isomers may be separated by conventional techniques well known to those skilled in the art, for example, chromatography and fractional crystallisation.

Conventional techniques for the preparation/isolation of individual enantiomers include chiral synthesis from a suitable optically pure precursor or resolution of the racemate (or the racemate of a salt or derivative) using, for example, chiral high pressure liquid chromatography (HPLC). Alternatively, the racemate (or a racemic precursor) may be reacted with a suitable optically active compound, for example, an alcohol, or, in the case where the compound of formula (I) contains an acidic or basic moiety, a base or acid such as 1-phenylethylamine or tartaric acid. The resulting diastereomeric mixture may be separated by chromatography and/or fractional crystallization and one or both of the diastereoisomers converted to the corresponding pure enantiomer(s) by means well known to a skilled person. Chiral compounds of formula (I) (and chiral precursors thereof) may be obtained in enantiomerically-enriched form using chromatography, typically HPLC, on an asymmetric resin with a mobile phase consisting of a hydrocarbon, typically heptane or hexane, containing from 0 to 50% by volume of isopropanol, typically from 2% to 20%, and from 0 to 5% by volume of an alkylamine, typically 0.1 % diethylamine. Concentration of the eluate affords the enriched mixture. Chiral chromatography using sub-and supercritical fluids may be employed. Methods for chiral chromatography useful in some embodiments of the present invention are known in the art (see, for example, Smith, Roger M., Loughborough University, Loughborough, UK; Chromatographic Science Series (1998), 75 (Supercritical Fluid Chromatography with Packed Columns), pp. 223-249 and references cited therein). In some relevant examples herein, columns were obtained from Chiral Technologies, Inc, West Chester, Pennsylvania, USA, a subsidiary of Daicel ^® Chemical Industries, Ltd., Tokyo, Japan.

When any racemate crystallises, crystals of two different types are possible. The first type is the racemic compound (true racemate) referred to above wherein one homogeneous form of crystal is produced containing both enantiomers in equimolar amounts. The second type is the racemic mixture or conglomerate wherein two forms of crystal are produced in equimolar amounts each comprising a single enantiomer. While both of the crystal forms present in a racemic mixture have identical physical properties, they may have different physical properties compared to the true racemate. Racemic mixtures may be separated by conventional techniques known to those skilled in the art - see, for example, Stereochemistry of Organic Compounds by E. L. Eliel and S. H. Wilen (Wiley, 1994).

By way of example, one situation in which tautomerism can arise with the compounds of formula (I) is a result of the R ² group being a 2-hydroxypyridine. The hydroxyl proton can be located on the oxygen atom of the hydroxyl group or the pyridine nitrogen atom as follows:

It must be emphasised that whilst, for conciseness, the compounds of formula (I) have been drawn herein in a single tautomeric form, the different tautomers are equivalent to each other and all possible tautomeric forms are included within the scope of the invention.

The present invention includes all pharmaceutically acceptable isotopically-labelled compounds of formula (I) wherein one or more atoms are replaced by atoms having the same atomic number, but an atomic mass or mass number different from the atomic mass or mass number which predominates in nature. Isotopically-labelled compounds of formula (I) can generally be prepared by conventional techniques known to those skilled in the art or by processes analogous to those described in the accompanying Examples and Preparations using an appropriate isotopically-labelled reagent in place of the non-labelled reagent previously employed. In particular, hydrogen atoms may be replaced by deuterium atoms since such deuterated compounds are sometimes more resistant to metabolism. Also included within the scope of the invention are active metabolites of compounds of formula (I), that is, compounds formed in vivo upon administration of the drug, often by oxidatation or dealkylation. Some examples of metabolites in accordance with the invention include

(i) where the compound of formula (I) contains a methyl group, an hydroxymethyl derivative thereof (-CH ₃ -> -CH ₂ OH):

(ii) where the compound of formula (I) contains an alkoxy group, an hydroxy derivative thereof (-OR -> -OH);

(iii) where the compound of formula (I) contains a tertiary amino group, a secondary amino derivative thereof (-NRR -> -NHR or -NHR);

(iv) where the compound of formula (I) contains a secondary amino group, a primary derivative thereof (-NHR -> -NH ₂ );

(v) where the compound of formula (I) contains a phenyl moiety, a phenol derivative thereof (-Ph -> -PhOH); and

(vi) where the compound of formula (I) contains an amide group, a carboxylic acid derivative thereof (-CONH ₂ -> COOH).

For administration to human patients, the total daily dose of a compound of formula (I) is typically in the range of 0.01 mg to 500mg depending, of course, on the mode of administration. In another embodiment of the present invention, the total daily dose of a compound of formula (I) is typically in the range of 0.1 mg to 300mg. In yet another embodiment of the present invention, the total daily dose of a compound of formula (I) is typically in the range of 1 mg to 30mg. The total daily dose may be administered in single or divided doses and may, at the physician's discretion, fall outside of the typical range given herein. These dosages are based on an average human subject having a weight of about 65kg to 70kg. The physician will readily be able to determine doses for subjects whose weight falls outside this range, such as infants and the elderly.

In the case of dry powder inhalers and aerosols, the dosage unit is determined by means of a prefilled capsule, blister or pocket or by a system that utilises a gravimetrically fed dosing chamber. Units in accordance with the invention are typically arranged to administer a metered dose or "puff' containing from 1 to 5000 μg of drug. The overall daily dose will typically be in the range 1μg to 20mg which may be administered in a single dose or, more usually, as divided doses throughout the day.

A compound of formula (I) can be administered per se, or in the form of a pharmaceutical composition, which, as active constituent contains an efficacious dose of at least one compound of the invention, in addition to customary pharmaceutically innocuous excipients and/or additives.

Pharmaceutical compositions suitable for the delivery of compounds of the present invention and methods for their preparation will be readily apparent to those skilled in the art. Such compositions and methods for their preparation may be found, for example, in Remington's Pharmaceutical Sciences, 19th Edition (Mack Publishing Company, 1995).

Compounds of formula (I) are preferably administered orally. Oral administration may involve swallowing, so that the compound enters the gastrointestinal tract, or buccal or sublingual administration may be employed by which the compound enters the blood stream directly from the mouth. Formulations suitable for oral administration include solid formulations such as tablets, capsules containing particulates, liquids, or powders, lozenges (including liquid-filled), chews, multi- and nano-particulates, gels, solid solution, liposome, films, ovules, sprays and liquid formulations.

In respect of the present invention, in all its embodiments, oral administration is preferred. Oral administration in the form of a tablet or capsule is particularly preferred.

Liquid formulations include suspensions, solutions, syrups and elixirs. Such formulations may be employed as fillers in soft or hard capsules and typically comprise a carrier, for example, water, ethanol, polyethylene glycol, propylene glycol, methylcellulose, or a suitable oil, and one or more emulsifying agents and/or suspending agents. Liquid formulations may also be prepared by the reconstitution of a solid, for example, from a sachet.

Compounds of formula (I) may also be used in fast-dissolving, fast-disintegrating dosage forms such as those described in Expert Opinion in Therapeutic Patents, 11 (6), 981-986, by Liang and Chen (2001 ).

For tablet dosage forms, depending on dose, the drug may make up from 1 weight % to 80 weight % of the dosage form, more typically from 5 weight % to 60 weight % of the dosage form. In addition to the drug, tablets generally contain a disintegrant. Examples of disintegrants include sodium starch glycolate, sodium carboxymethyl cellulose, calcium carboxymethyl cellulose, croscarmellose sodium, crospovidone, polyvinylpyrrolidone, methyl cellulose, microcrystalline cellulose, lower alkyl-substituted hydroxypropyl cellulose, starch, pregelatinised starch and sodium alginate. Generally, the disintegrant will comprise from 1 weight % to 25 weight %. In one embodiment of the present invention, the disintegrant will comprise from 5 weight % to 20 weight % of the dosage form. Binders are generally used to impart cohesive qualities to a tablet formulation. Suitable binders include microcrystalline cellulose, gelatin, sugars, polyethylene glycol, natural and synthetic gums, polyvinylpyrrolidone, pregelatinised starch, hydroxypropyl cellulose and hydroxypropyl methylcellulose. Tablets may also contain diluents, such as lactose (monohydrate, spray-dried monohydrate, anhydrous and the like), mannitol, xylitol, dextrose, sucrose, sorbitol, microcrystalline cellulose, starch and dibasic calcium phosphate dihydrate. Tablets may also optionally comprise surface active agents, such as sodium lauryl sulfate and polysorbate 80, and glidants such as silicon dioxide and talc. When present, surface active agents may comprise from 0.2 weight % to 5 weight % of the tablet, and glidants may comprise from 0.2 weight % to 1 weight % of the tablet. Tablets also generally contain lubricants such as magnesium stearate, calcium stearate, zinc stearate, sodium stearyl fumarate, and mixtures of magnesium stearate with sodium lauryl sulfate. Lubricants generally comprise from 0.25 weight % to 10 weight %. In one embodiment of the present invention, lubricants comprise from 0.5 weight % to 3 weight % of the tablet. Other possible ingredients include anti-oxidants, colourants, flavouring agents, preservatives and taste-masking agents.

Exemplary tablets contain up to about 80% drug, from about 10 weight % to about 90 weight % binder, from about 0 weight % to about 85 weight % diluent, from about 2 weight % to about 10 weight % disintegrant, and from about 0.25 weight % to about 10 weight % lubricant.

Tablet blends may be compressed directly or by roller to form tablets. Tablet blends or portions of blends may alternatively be wet-, dry-, or melt-granulated, melt congealed, or extruded before tabletting. The final formulation may comprise one or more layers and may be coated or uncoated; it may even be encapsulated. Formulations of tablets are discussed in Pharmaceutical Dosage Forms: Tablets, Vol. 1 , by H. Lieberman and L. Lachman (Marcel Dekker, New York, 1980).

Consumable oral films for human or veterinary use are typically pliable water-soluble or water- swellable thin film dosage forms which may be rapidly dissolving or mucoadhesive and typically comprise a compound of formula (I), a film-forming polymer, a binder, a solvent, a humectant, a plasticiser, a stabiliser or emulsifier, a viscosity-modifying agent and a solvent. Some components of the formulation may perform more than one function. The film-forming polymer may be selected from natural polysaccharides, proteins, or synthetic hydrocolloids and is typically present in the range 0.01 to 99 weight %, more typically in the range 30 to 80 weight %. Other possible ingredients include anti-oxidants, colorants, flavourings and flavour enhancers, preservatives, salivary stimulating agents, cooling agents, co-solvents (including oils), emollients, bulking agents, anti-foaming agents, surfactants and taste-masking agents. Films in accordance with the invention are typically prepared by evaporative drying of thin aqueous films coated onto a peelable backing support or paper. This may be done in a drying oven or tunnel, typically a combined coater dryer, or by freeze-drying or vacuuming.

Solid formulations for oral administration may be formulated to be immediate and/or modified release. Modified release includes delayed, sustained, pulsed, controlled, targeted and programmed release. Suitable modified release formulations for the purposes of the invention are described in US Patent No. 6,106,864. Details of other suitable release technologies such as high energy dispersions and osmotic and coated particles are to be found in Pharmaceutical Technology On-line, 25(2), 1-14, by Verma et al (2001 ). The use of chewing gum to achieve controlled release is described in WO-A-00/35298.

Compounds of formula (I) may also be administered directly into the blood stream, into muscle, or into an internal organ. Such parenteral administration includes intravenous, intraarterial, intraperitoneal, intrathecal, intraventricular, intraurethral, intrasternal, intracranial, intramuscular and subcutaneous administration. Suitable devices for parenteral administration include needle (including microneedle) injectors, needle-free injectors and infusion techniques.

Compounds of the invention may also be administered topically to the skin or mucosa, that is, dermally or transdermally.

The compounds of formula (I) can also be administered intranasally or by inhalation, typically in the form of a dry powder (either alone, as a mixture, for example, in a dry blend with lactose, or as a mixed component particle, for example, mixed with phospholipids, such as phosphatidylcholine) from a dry powder inhaler, as an aerosol spray from a pressurised container, pump, spray, atomiser (preferably an atomiser using electrohydrodynamics to produce a fine mist), or nebuliser, with or without the use of a suitable propellant, such as 1 ,1 ,1 ,2-tetrafluoroethane or 1 ,1 ,1 ,2,3,3,3-heptafluoropropane, or as nasal drops. For intranasal use, the powder may comprise a bioadhesive agent, for example, chitosan or cyclodextrin.

The pressurised container, pump, spray, atomizer, or nebuliser contains a solution or suspension of the compound of formula (I) comprising, for example, ethanol, aqueous ethanol, or a suitable alternative agent for dispersing, solubilising, or extending release of the compound, a propellant as solvent and an optional surfactant, such as sorbitan trioleate, oleic acid, or an oligolactic acid.

Prior to use in a dry powder or suspension formulation, the drug product is micronised to a size suitable for delivery by inhalation (typically less than 5 microns). This may be achieved by any appropriate comminuting method, such as spiral jet milling, fluid bed jet milling, supercritical fluid processing to form nanoparticles, high pressure homogenisation, or spray drying.

Capsules (made, for example, from gelatin or hydroxypropylmethylcellulose), blisters and cartridges for use in an inhaler or insufflator may be formulated to contain a powder mix of the compound of the invention, a suitable powder base such as lactose or starch and a performance modifier such as l-leucine, mannitol, or magnesium stearate. The lactose may be anhydrous or in the form of the monohydrate, preferably the latter. Other suitable excipients include dextran, glucose, maltose, sorbitol, xylitol, fructose, sucrose and trehalose.

A suitable solution formulation for use in an atomiser using electrohydrodynamics to produce a fine mist may contain from 1 μg to 20mg of the compound of the invention per actuation and the actuation volume may vary from 1 μl to 10Oμl. A typical formulation may comprise a compound of formula (I), propylene glycol, sterile water, ethanol and sodium chloride. Alternative solvents which may be used instead of propylene glycol include glycerol and polyethylene glycol.

Suitable flavours, such as menthol and levomenthol, or sweeteners, such as saccharin or saccharin sodium, may be added to those formulations of the invention intended for intranasal administration. Formulations for intranasal administration may be formulated to be immediate and/or modified release using, for example, PGLA. Modified release includes delayed, sustained, pulsed, controlled, targeted and programmed release.

Compounds of formula (I) may also be administered directly to the eye or ear, typically in the form of drops of a micronised suspension or solution in isotonic, pH-adjusted, sterile saline.

Compounds of formula (I) may be combined with soluble macromolecular entities, such as cyclodextrin and suitable derivatives thereof or polyethylene glycol-containing polymers, in order to improve their solubility, dissolution rate, taste, bioavailability and/or stability when using any of the aforementioned modes of administration. Drug-cyclodextrin complexes, for example, are found to be generally useful for most dosage forms and administration routes. Both inclusion and non-inclusion complexes may be used. As an alternative to direct complexation with the drug, the cyclodextrin may be used as an auxiliary additive, i.e. as a carrier, diluent, or solubiliser. Most commonly used for these purposes are alpha-, beta- and gamma- cyclodextrins, examples of which may be found in international patent publications WO-A- 91/1 1172, WO-A-94/02518 and WO-A-98/55148.

Inasmuch as it may desirable to administer a combination of active compounds, for example, for the purpose of treating a particular disease or condition, it is within the scope of the present invention that two or more pharmaceutical compositions, at least one of which contains a compound of formula (I), may conveniently be combined in the form of a kit suitable for coadministration of the compositions. Thus, a kit of the invention comprises two or more separate pharmaceutical compositions, at least one of which contains a compound of formula (I), and means for separately retaining said compositions, such as a container, divided bottle, or divided foil packet. An example of such a kit is the familiar blister pack used for the packaging of tablets, capsules and the like. Such a kit is particularly suitable for administering different dosage forms, for example, oral and parenteral, for administering separate compositions at different dosage intervals, or for titrating the separate compositions against one another. To assist compliance, the kit typically comprises directions for administration and may be provided with a so-called memory aid.

All the compound of formula (I) can be made by the specific and general experimental procedures described below in combination with the common general knowledge of one skilled in the art (see, for example, Comprehensive Organic Chemistry, Ed. Barton and Ollis, Elsevier; Comprehensive Organic Transformations: A Guide to Functional Group Preparations, Larock, John Wiley and Sons). In the general methods that follow, R ¹ and R ² have the meanings given in embodiment E1 described above unless otherwise stated.

A compound of formula (I) may be prepared as shown in Scheme 1 by reacting an amine of formula R ² NH ₂ with a compound of formula (III) or by reacting an amine of formula R ¹ NH ₂ with a compound of formula (IV). In compounds of formula (III) and (IV), R ¹⁰ and R ¹¹ are each C ₁ -C ₆ alkyl, preferably ethyl. In either case, the reaction is typically carried out in the presence of an inert solvent or mixture of inert solvents (e.g. ethanol, dimethyl sulphoxide, toluene, N, N- dimethylformamide, propionitrile, acetonitrile), optionally in the presence of a suitable base (e.g. triethylamine, diisopropylethylamine, potassium carbonate, potassium hydrogen carbonate, sodium hydrogen carbonate) at an elevated temperature (e.g. between 8O ⁰ C and 120 ⁰ C). The reaction typically takes 12 to 48 hours to reach completion. In a preferred procedure, a solution of the two starting materials in ethanol is treated with diisopropylamine and, where necessary, heated (e.g. at reflux).

Compounds of formula (III) and (IV) may be prepared by reacting an amine of formula R ¹ NH ₂ or R ² NH ₂ , respectively, with a compound of formula (II). Typically, the reaction is carried out in the presence of a suitable inert solvent or mixture of inert solvents (e.g. ethanol, dimethyl sulphoxide, toluene, N,N-dimethylformamide, propionitrile, acetonitrile). Optionally, a base such as triethylamine, diisopropylethylamine, potassium carbonate, potassium hydrogen carbonate or sodium hydrogen carbonate may be added and the reaction may be accelerated by the application of heat. In a preferred procedure, the reaction is carried out in ethanol at room temperature.

Scheme 1

(IV)

Alternatively compounds of formula (I) may be prepared as shown in Scheme 2 by reacting an amide of formula (V) with a heteroaryl halide of formula R ² X, where X is chloride, bromide or iodide (for instance, a compound of formula (XII) or (XIV) - see below). The reaction is typically carried out in the presence of a suitable palladium catalyst (e.g. tris(dibenzylideneacetone)dipalladium/2-dicyclohexylphosphin o-2'-(N,N-dimethylamino)biphenyl of formula Pd ₂ (dba) ₃ /{DavePhos} ₂ ) in the presence of a solvent or mixture of solvents (e.g. tetrahydrofuran, toluene, acetonitrile, hexane) and in the presence of a base (e.g. triethylamine, diisopropylethylamine, potassium carbonate, potassium hydrogen carbonate, cesium carbonate). Preferably, the reaction is carried out at a temperature of from 7O ⁰ C to 1 1O ⁰ C for 4 to 16 hours. In the case where R ² X contains a potentially reactive moiety such as a hydroxyl or amino group, this group is preferably protected using a suitable protecting group (see, for example, 'Protective Groups in Organic Synthesis' by Theorora Greene and Peter Wuts, third edition, 1999, John Wiley and Sons) which may be later removed.

The amide of formula (V) may be prepared by reaction of a compound of formula (III) with ammonia. Typically, the reaction is carried out in the presence of a suitable inert solvent or mixture of inert solvents (e.g. ethanol, dimethyl sulphoxide, toluene, N,N-dimethylformamide, propionitrile, acetonitrile) and the reaction may be accelerated by the application of heat. In a preferred procedure, the reaction is carried out in ethanol at room temperature.

Scheme 2

Where the compound R ² NH ₂ is of formula (Vl) (keto tautomer shown), it may be prepared as shown in Scheme 3, by deprotection of a compound of formula (VII). The group P ¹ represents a suitable alcohol protecting group, and both the choice of protecting group and suitable conditions for its removal are within the scope of the skilled person's common general knowledge (see, for example, 'Protective Groups in Organic Synthesis' by Theorora Greene and Peter Wuts, third edition, 1999, John Wiley and Sons). Preferably, P ¹ is methyl or benzyl. In a typical reaction, where P ¹ is methyl, a solution of the compound of formula (VII) in dichloromethane is treated with boron tribromide at a temperature of from O ⁰ C to 4O ⁰ C for 0.5 to 6 hours.

A compound of formula (VII) may be prepared by the reduction of a compound of formula (VIII). In a typical procedure the compound of formula (VIII) is hydrogenated using a metal catalyst or combination of catalysts (e.g palladium on carbon, platinium oxide or Raney-Nickel ^® ) in the presence of a solvent (e.g. methanol, ethanol, ethyl acetate, tetrahydrofuran) with a hydrogen source (e.g. ammonium formate, formic acid, hydrogen) at a temperature of from 2O ⁰ C to 9O ⁰ C, for 1 to 6 hours.

A compound of formula (VIII) may be prepared by reaction of a compound of formula (IX), wherein L ¹ is a suitable leaving group such as is a halide, with a compound M-R ³ , wherein M is a suitable metallic derivative such as a zincate, boronic acid, boronate ester, stannane, or magnesium derivative. In a typical procedure, the compound of formula (IX) and the metallic derivative M-R ³ are reacted together in the presence of a suitable palladium catalyst (e.g. palladium acetate/tri-orffto-tolylphosphine of formula Pd(OAc) ₂ Z(P(O-ToI) ₃ J ₂ ) in the presence of a solvent or mixture of solvents (e.g. toluene, acetonitrile, hexane) and in the presence of a base (e.g. triethylamine, diisopropylethylamine, potassium carbonate, potassium hydrogen carbonate). Preferably, the reaction is carried out at a temperature of from 7O ⁰ C to 1 1O ⁰ C for 4 to 16 hours.

Scheme 3

(IX) (VIII) (VII) (Vl)

Compounds of formula (II), R ¹ NH ₂ , R ² NH ₂ , (III), R ² X, and (IX) are either commercially available or can easily be prepared by the skilled person from commercially available starting materials using common functional group transformation known in the common general knowledge and described in text books of synthetic organic chemistry such as 'Comprehensive Organic Transformations' by Richard Larock (1999, VCH Publishers Inc.).

The skilled person will appreciate that the individual steps of the general methods described above can be reversed in many instances to provide alternative routes to compounds of formula (I). Compounds of formula (I) can likewise be interconverted (e.g. from a compound of formula (I) in which R ³ is an ester or acid to a compound of formula (I) in which R ³ is an amide).

The following experimental details illustrate specifically how certain compounds of formula (I) may be prepared. All Examples are compounds of formula (I). Preparations are intermediates useful in the synthesis of compounds of formula (I).

General methods used

One or more of the following nine general preparative methods were used in the experiments described below.

Method (i): A carboxylic acid (e.g. Preparation 16 or 37, 130μmol) was dissolved in dimethylformamide (80OuL). HATU (130μmol) and DIPEA (300μmol) were added and the reaction mixture was stirred at 25 ⁰ C for 30 minutes. A solution of an amine reactant (0.5M in dimethylformamide, 20OuL, 100μmol) was added and the reaction mixture was heated to 5O ⁰ C for 16 hours. The reaction mixture was concentrated in vacuo then purified by preparative HPLC.

Method (ii): A 0.15M solution of compound of formula (IV) (e.g. Preparation 1 ) in dimethylsulfoxide (0.5ml_, 75μmol) was added to an amine of formula R ¹ NH ₂ (75μmol). DIPEA (150μmol) was added and the reaction mixture was sealed and heated at 6O ⁰ C for 2 hours. The reaction mixture was purified preparative HPLC.

Method (iii): A 0.1 M solution of compound of formula (IV) (e.g. Preparation 1 ) in ethanol (1.OmL, 100μmol) was added to amine of formula R ¹ NH ₂ (100μmol). Cesium fluoride (200μmol) was added and the reaction mixture was sealed and heated at 8O ⁰ C for 16 hours. The reaction mixture was concentrated in vacuo and then purified by preparative HPLC.

Method (iv): A 0.1 M solution of a compound of formula (IV) (e.g. Preparation 1 ) in ethanol (75OuL, 75μmol) was added to an amine of formula R ¹ NH ₂ (200μmol). DIPEA (39uL, 225μmol) was added and the reaction mixture was sealed and heated at 3O ⁰ C for 48 hours. The reaction mixture was concentrated in vacuo and then purified by preparative HPLC. Method (v): A compound of formula (IV) (e.g. Preparation 1 , 33mg, 100μmol) dissolved in 533uL of ethanol was added to an amine of formula R ¹ NH ₂ (100μmol). DIPEA (133uL) was added and the reaction mixture was sealed and heated at 3O ⁰ C for 48 hours. The reaction mixture was concentrated in vacuo and then purified by preparative HPLC. Method (vi): A solution of a compound of formula (IV) (e.g. Preparation 1 , 100μmol) in dimethylsulfoxide was added to an amine of formula R ¹ NH ₂ (100μmol). Cesium fluoride (30mg, 200μmol) was added and the reaction mixture was sealed and heated under microwave radiation for 30 minutes at 100 ⁰ C. The reaction mixture was filtered, concentrated in vacuo and then purified by preparative HPLC. Method (vii): A compound of formula (IV) (e.g. Preparation 1 ) (100μmol) in dimethylsulfoxide was added to an amine of formula R ¹ NH ₂ (100μmol). Cesium fluoride (30mg, 200μmol) was added and the reaction mixture was sealed and heated at 8O ⁰ C for 16 hours. The reaction mixture was filtered, concentrated in vacuo and then purified by preparative HPLC. Method (viii): A solution of a compound of formula (IV) (e.g. Preparation 38, 100μmol) in dimethylsulfoxide was added to an amine of formula R ¹ NH ₂ (100μmol). Potassium hydroxide (1 1mg, 200μmol) was added and the reaction mixture was sealed and heated under microwave radiation for 40 minutes at 17O ⁰ C. The reaction mixture was filtered, concentrated in vacuo and then purified by preparative HPLC.

Method (ix): 4-(2-Ethoxy-3,4-dioxocyclobut-1-enylamino)-3-hydroxy-Λ/,Λ/ -dimethyl picolinamide (Preparation 1 1 , 100mg, 0.328mmol) and an amine of formula R ¹ NH ₂ (0.393mmol, 1.2eq) were combined with ethanol (1.5mL) with or without DIPEA (126.9mg, 0.983mmol) and the reaction mixture was stirred at room temperature for 16 hours. The reaction mixture was concentrated in vacuo and purified by preparative HPLC, trituration with an appropriate solvent or preparative thin layer chromatography on silica.

Analytical HPLC One or more of the following analytical HPLC Methods were used in the experiments described below.

Preparative HPLC

One or more of the following preparative HPLC Methods were used in the experiments described below.

Mobile Phase Solvent A: Water +0.1 % Solvent A: Water +0.1 % trifluoroacetic acid trifluoroacetic acid Solvent B: Acetonitrile Solvent B: Acetonitrile

Preparative HPLC Method 10

Column: Sunfire Prep C18 (100mm x 30 mm, 5 μm) System: Waters Auto purification system Detector: Photo Diode Array

Preparative HPLC Method 11

Column: Sunfire Prep C18 (100mm x 30 mm, 5 μ) System: Waters Auto purification system Detector: Photo Diode Array and MS

Preparative HPLC Method 12

Column: Sunfire Prep C18 (100mm x 30 mm, 5 μ) System: Waters Auto purification system Detector: Photo Diode Array

Preparative HPLC Method 13

Column: Sunfire Prep C18 (100mm x 30 mm, 5 μ) System: Waters Auto purification system Detector: Photo Diode Array and MS

Preparative HPLC Method 14

Column: Sunfire Prep C18 (100mm x 30 mm, 5 μ) System: Waters Auto purification system Detector: Photo Diode Array

Preparative HPLC Method 15

Column: Sunfire Prep C18 (100mm x 30 mm, 5 μ) System: Waters Auto purification system Detector: Photo Diode Array

Preparative HPLC Method 16

Column: Sunfire Prep C18 (100mm x 30 mm, 5 μ) System: Waters Auto purification system Detector: Photo Diode Array and MS

Preparative HPLC Method 17

Column: Sunfire Prep C18 (100mm x 30 mm, 5 μ) System: Waters Auto purification system Detector: Photo Diode Array

Preparation 1

3-Ethoxy-4-(2-oxo-1 ,2-dihvdropyridin-3-ylamino)cvclobut-3-ene-1 ,2-dione

To a stirred solution of 1 ,2-diethoxycyclobutenedione (1.OmL, 6.8mmol) in absolute ethanol (5mL) at O ⁰ C was added dropwise over 30 minutes a suspension of 3-amino-2-hydroxy-pyridine (500mg, 4.5mmol) in absolute ethanol (5mL). Upon complete addition, the resultant mixture was allowed to warm to room temperature, stirred over 16 hours and then concentrated in vacuo to give a brown residue. The residue was purified by column chromatography on silica gel eluting with dichloromethane:methanol (gradient elution, 100:0 to 90:10 by volume) to furnish the title compound as a brown solid, 290mg.

¹ H NMR (400MHz, CD ₃ OD): δ = 1.49 (3H, m), 4.83 (2H, m), 6.38 (1 H, m), 7.20 (1 H, m), 7.81 (1 H, m) ppm. LRMS (ES): m/z 233 [M-H] ^" . Preparation 2

Ethvl 2-chloro-2-ethvl-3-oxobutanoate

Sulfuryl chloride (69g, 0.51 mol) was added at room temperature to a stirred solution of ethyl 2- ethylacetoacetate (79g, 0.5mol) in dichloromethane (40OmL). The mixture was stirred for 1 hour and poured into water. The organic layer was washed with saturated aqueous sodium chloride solution and dried over magnesium sulfate, and the solvent was removed in vacuo. The residual oil was distilled under a water-jet pump vacuum at b.p. 105-110°C/15mmHg to yield the title compound as a colorless oil, 72g.

Preparation 3 3-Chloropentan-2-one

A mixture of ethyl 2-chloro-2-ethyl-3-oxobutanoate (Preparation 2, 72g, 0.6mol), concentrated H ₂ SO ₄ (29Og, 3mol) and water (29OmL) was refluxed with vigorous stirring for a total of 24 hours. The reaction mixture was then diluted with water (2L) and subjected to extraction with chloroform (3x15OmL). The combined organic phases were washed with water (30OmL) and saturated aqueous sodium chloride solution (30OmL) and dried over magnesium sulfate. The solvent was removed in vacuo, and the residue was distilled at b.p. 130-134 ⁰ C to give the title compound as a colourless oil, 52g.

Preparation 4

2-(2-Oxopentan-3-yl)isoindoline-1 ,3-dione

A mixture of 3-chloropentan-2-one (Preparation 3, 12Og, 1 mol) and potassium phthalimide (185g, 1 mol) in DMF (50OmL) was stirred in a flask immersed in a boiling water bath for 6 hours. The mixture was cooled and poured into water (3L). The precipitate that formed was separated by filtration and air-dried to give the title compound as fine, light-yellow crystals, 193g.

Preparation 5 2-(1-Bromo-2-oxopentan-3-vDisoindoline-1 ,3-dione

Bromine (13Og, O.δmol) was added dropwise at room temperature to a stirred solution of 2-(2- oxopentan-3-yl)isoindoline-1 ,3-dione (Preparation 4, 185g, O.δmol) in chloroform (1 L). The mixture was stirred at room temperature for 3 hours and the resultant soution was then concentrated to dryness in vacuo. The solid formed was suspended in water (400ml), filtered and washed with further water until washings were neutral. The solid was then crystallised from ethanol (400ml) to yield the title compound as white crystals, 195g.

Preparation 6 2-Amino-3-[3-(1 ,3-dioxo-1 ,3-dihydro-2/-/-isoindol-2-yl)-2-oxopentyl1-1 ,3-thiazol-3-ium bromide

2-Aminothiazole (52g, 0.52mol) was added to a solution of 2-(1-bromo-2-oxopentan-3- yl)isoindoline-1 ,3-dione (Preparation 5, 15Og, 0.49mol) in acetone (1 L). The solution was left overnight and then filtered to give the title compound as white crystals, 163g.

Preparation 7

2-(1-(lmidazor2,1-blthiazol-6-vDpropyD-isoindoline-1 ,3-dione

A mixture of 2-amino-3-[3-(1 ,3-dioxo-1 ,3-dihydro-2H-isoindol-2-yl)-2-oxopentyl]-1 ,3-thiazol-3- ium bromide (Preparation 6, 163g, 0.4mol) and DMF (30OmL) was stirred at 110 ⁰ C for 1.5 hours and then poured into water (3L). Solid potassium carbonate was added to the resulting mixture until a pH of 9-10 was reached. The precipitate which formed was filtered, washed with water until washings were neutral and then air-dried to give the title compound as light-yellow crystals, 105 g.

Preparation 8

1-(lmidazo[2,1-b1thiazol-6-ylpropan-1 -amine dihvdrochloride

Hydrazine hydrate (17mL, 0.34mol) was added to a suspension of 2-(1-(imidazo[2,1-b]thiazol-6- yl)propyl)-1 H-isoindoline-1 ,3-dione (Preparation 7, 105g, 0.34mol) in ethanol (40OmL). The mixture was stirred under reflux for 2 hours and then cooled. Concentrated aqueous HCI (13OmL) was added and the mixture was refluxed for a further 2 hours. Then the mixture was cooled and filtered and the precipitate was washed on the filter with water (200 mL). The combined filtrates were concentrated to dryness in vacuo, and the residue was dissolved in water (30OmL). Charcoal (15-2Og) was added, and the mixture was refluxed for 1 hour and filtered. The aqueous solution was evaporated in vacuo, and the residue was crystallized from 90% ethanol to give the title compound as yellow crystals, 54g. 1H NMR (400MHz, d ₆ -DMSO): δ = 0.88 (3H, t), 1.90-2.15 (2H, m), 4.35 (1 H, m), 7.46 (1 H, d), 8.07 (1 H, s), 8.13 (1 H, d), 8.75 (3H, s) ppm. LRMS (ES) : m/z 265 [M-NH ₂ J ⁺ .

Preparation 9 3-Amino-6-methylpyridin-2-ol

A solution of 2-hydroxy-6-methyl-3-nitropyridine (100mg, 0.650mmol) in methanol (10.OmL) was hydrogenated using an H-Cube™ flow reactor (Pd/C cartridge, 1 ml/min flow rate, full H ₂ mode, 5O ⁰ C). The solution was then concentrated in vacuo and the title compound was isolated as a white solid, 36 mg. ¹ H NMR (400MHz, DMSOd ₆ ): δ = 2.02 (3H, s), 4.68 (2H, bs), 5.72 (1 H, d), 6.34 (1 H, d), 1 1.23 (1 H, bs) ppm.

Preparation 10

(S)-3-Ethoxy-4-(3-methylbutan-2-ylamino)cyclobut-3-ene-1 ,2-dione

To a stirred solution of 3,4-diethoxycyclobut-3-ene-1 ,2-dione (1.85ml_, 12.6mmol) in absolute ethanol (35.OmL) was added (S)-3-methylbutan-2-amine (1.34 ml_, 11.5 mmol). The reaction mixture was stirred at room temperature for 1.5 hours and then concentrated in vacuo to give a yellow solid. Recrystallisation from ethyl acetate/ heptane furnished the title compound as an off-white solid, 1.93g.

¹ H NMR (400MHz, CDCI ₃ ): δ = 0.93 (6H, d), 1.22 (3H, d), 1.46 (3H, t), 1.75 (1 H, m), 3.6 (1 H, m), 4.8 (2H, m), 6.00 (1 H, m) ppm.

Preparation 11

(S)-3-Amino-4-(3-methylbutan-2-ylamino)cvclobut-3-ene-1 ,2-dione

(S)-3-Ethoxy-4-(3-methylbutan-2-ylamino)cyclobut-3-ene-1 ,2-dione (Preparation 10, 250mg,

1.18mmol) was dissolved in 2.OmL of absolute ethanol. Ammonia solution (2M solution in ethanol, 2.37mL, 4.73mmol) was added. The reaction mixture was stirred at room temperature for 4 days. The reaction mixture was filtered and the resultant solid was dried to give the title compound as a white solid, 215mg.

¹ H NMR (400MHz, DMSO-d ₆ ): δ= 0.86 (6H, m), 1.12 (3H, d), 1.69 (1 H, m), 3.86 (1H, bs), 7.08-

7.54(2H, m) ppm. LRMS (ES): m/z 181 [M-H] ^" . Preparation 12

(f?)-3-Ethoxy-4-(1-phenylpropylamino)cyclobut-3-ene-1 ,2-dione

To a stirred solution of 3,4-diethoxycyclobut-3-ene-1 ,2-dione (2.32g, 13.7mmol) in absolute ethanol (40 ml_), at room temperature, was added, in a single portion, (R)-1-phenylpropan-1- amine (1.85g, 13.7mmol). The resulting solution was stirred at room temperature for 16 hours and then concentrated in vacuo to give a colourless oil. The oil was dissolved in ethyl acetate and the resulting solution was washed with 10% aqueous citric acid solution and water. The organic phase was further washed with saturated aqueous sodium hydrogen carbonate, then water and finally saturated aqueous sodium chloride solution. The organic phase was then dried over magnesium sulfate and concentrated in vacuo to furnish the title compound as a clear oil, 3.22g.

¹ H NMR (400MHz, CDCI ₃ ): δ = 0.95 (3H, t), 1.40 (3H, t), 1.87-2.03 (2H, m) , 4.58 (1 H, bs), 4.73 (2H, q), 6.69 (1 H, bs), 7.25-7.37 (5H, m) ppm.

Preparation 13

3-Amino-4-(1-phenyl-propylamino)-cvclobut-3-ene-1 ,2-dione

(R)-3-Ethoxy-4-(1-phenylpropylamino)cyclobut-3-ene-1 ,2-dione (Preparation 12, 580mg, 2.24mmol) was dissolved in absolute ethanol (1OmL). Ammonia solution (7M in methanol,

O.δmL, 5.59mmol) was added and the reaction mixture was stirred at room temperature overnight. A precipitate had formed which was filtered and washed with methanol (2 x 2OmL) to furnish the title compound as a solid, 260mg.

¹ H NMR (400MHz, DMSOd ₆ ): δ= 0.88 (3H, t), 1.86 (2H, m), 4.94 (1 H, m), 7.24-7.40 (5H, m), 7.44 (1 H m), 7.77 (1 H m) ppm.

LRMS (ES): m/z 229 [M-H] ^" . Preparation 14

Λ/,Λ/,Λ/-Trimethylpyrimidin-4-aminium chloride

To a solution of trimethylamine (957mmol) in toluene (33OmL) at 0 ⁰ C was added a solution of A- chloropyrimidine (19.Og, 165.9mmol) in toluene at O ⁰ C. The mixture was allowed to warm to room temperature and stirred overnight. The precipitate which formed was filtered, washed with diethyl ether (2 * 5OmL) and dried in vacuo to furnish the title compound as a solid, 13.5g. ¹ H NMR (400MHz, DMSOd ₆ ): δ= 3.60 (9H, s), 8.28 (1 H, d), 9.30 (1 H, d), 9.42 (1 H, s) ppm.

Preparation 15

Pyrimidine-4-carbonitrile

To a suspension of Λ/,Λ/,Λ/-trimethylpyrimidin-4-aminium chloride (Preparation 14, 13.3g, 76.6mmol) in dichloromethane (76mL), at O ⁰ C, was added dropwise a solution of tetraethylammonium cyanide (13.2g, 84.2mmol) in dichloromethane (76mL). The mixture was allowed to warm to room temperature and stirred for 1 hour. Water (10OmL) was added, the organic phase was separated and the aqueous phase was extracted with dichloromethane (2 x 10OmL). The combined organic layers were dried over sodium sulfate and concentrated in vacuo to give a crude residue. Purification by column chromatography on silica gel eluting with 10-20% ethyl acetate in hexane gave the title compound as a liquid (7.0 g). 1H NMR (400MHz, CDCI ₃ ): δ = 7.66 (1 H, d), 8.99 (1 H, d), 9.36 (1 H, s) ppm.

Preparation 16

1-(Pyrimidine-4-yl)propan-1-one

Ethyl magnesium bromide (3.0M in diethyl ether, 19mL) was added slowly by dropwise addition to a solution of pyrimidine-4-carbonitrile (Preparation 15, 6g, 57.1 mmol) in diethyl ether at 0 ⁰ C. The reaction mixture was allowed to warm to room temperature and stirred for 2 hours. The reaction mixture was treated with hydrochloric acid solution (2N, 6OmL) and stirred for 0.5 hours at room temperature. The reaction was neutralised with saturated aqueous sodium hydrogen carbonate solution and extracted with diethyl ether (3 * 50 ml_). The organic extracts were combined, washed with saturated aqueous sodium chloride solution, dried over sodium sulfate and concentrated in vacuo to give a crude residue. Purification by column chromatography on silica gel, eluting with 1 % to 10% ethyl acetate in hexane, gave the title compound as a liquid, 2.5g.

¹ H NMR (400MHz, CDCI ₃ ): δ= 1.20 (3H, t), 3.20 (2H, q), 7.87 (1 H, d), 8.96 (1 H, d), 9.33 (1 H, s) ppm.

Preparation 17

1-(Pyrimidine-4-yl)propan-1 -amine

To a solution of 1-(pyrimidine-4-yl)propan-1-one (Preparation 16, 2.5g, 18.4mmol) in methanol (144ml_) was added ammonium acetate (21.2g, 275mmol) and the mixture was stirred for 2 hours at room temperature. The reaction mixture was cooled to 0 ⁰ C and sodium cyanoborohydride (8.65g, 137mmol) was added portionwise. The reaction mixture was allowed to warm to room temperature and stirred overnight. The reaction mixture was concentrated in vacuo, diluted with water, basified to pH 13-14 by the addition of 5% aqueous sodium hydroxide solution and extracted with dichloromethane (6 * 5OmL). The combined organic extracts were dried over sodium sulfate and concentrated in vacuo and the crude residue was purified by column chromatography on silica gel eluting first with a mixture of dichloromethane and ammonia (1-2%) then dichloromethane, ammonia and 1-5% methanol to give the free amine 1- (pyrimidine-4-yl)propan-1 -amine, 1.2g. 1H NMR (400MHz, DMSOd ₆ ): δ= 0.85 (3H, t), 1.50-1.75 (2H, m), 3.75 (1 H, m), 7.56 (1 H, d), 8.71 (1 H, d), 9.06 (1 H, s) ppm. LRMS (ES): m/z 138 [M+H] ⁺ Preparation 18

5-Bromo-6-methoxynicotinonitrile

Sodium acetate (1.53g, 18.65mmol) was added to a mixture of 6-methoxynicotinonitrile (2.5g, 18.65mmol) and acetic acid (7ml_). Bromine (5.89g, 36.92mmol) was added and the reaction mixture was heated at 8O ⁰ C for 18 hours. The reaction mixture was diluted with water and extracted with diethyl ether. The organic phase was washed with 4M aqueous sodium hydroxide solution and 5% sodium thiosulfate solution, dried over anhydrous sodium sulfate and concentrated in vacuo to afford crude product. Column chromatographic purification on silica gel, eluting with 2% ethyl acetate in hexane, afforded the title compound (1g, 25%). 1H NMR (400MHz, DMSOd ₆ ): δ = 4.07 (s, 3H), 8.02 (s, 1 H), 8.41 (s, 1 H) ppm.

Preparation 19

(RVδ-fS^-Dioxo^-d-phenylpropylamino^vclobut-i-enylaminoV e-methoxynicotinonitrile

5-Bromo-6-methoxynicotinonitrile (Preparation 18, l OO.Omg, 0.469mmol), 3-amino-4-(1-phenyl- propylamino)-cyclobut-3-ene-1 ,2-dione (Preparation 13, 1 18.9mg, 0.316mmol) and dry tetrahydrofuran (3ml_) were mixed and degassed using argon. Bis(dibenzylideneacetone)palladium(0) (85.96mg, 0.093mmol) and dicyclohexylphosphoryl N-N dimethyl amine bi-phenyl (30.30mg, 0.093 mmol) were added and the reaction mixture was heated by microwave for 2 hours. The reaction mixture was filtered through Celite and washed with ethyl acetate. The organic phase was washed with water and brine, dried using anhydrous sodium sulfate and concentrated in vacuo to give crude product. Column chromatographic purification on silica gel, eluting with 2% methanol in dichloromethane, afforded the title compound. (40mg, 35%) ¹ H NMR (400MHz, CDCI ₃ ): δ = 0.95 (m, 3H), 1.90-2.00 (m, 2H), 3.83 (s, 3H), 5.29 (s, 1 H) 7.25- 7.32 (m, 5H), 7.95 (m, 1 H), 8.22 (m, 1 H) ppm, 2 exchangeables not observed. LRMS m/z 363.4 [M+H] ⁺ .

Preparation 20

(RVS-fδ-Fluoro^-methoxypyridin-S-ylaminoM-fi-phenylpropy lamino^vclobut-S-ene-i ^-dione

3-Bromo-5-fluoro-2-methoxypyridine (100mg, 0.485mmol), 3-amino-4-(1-phenyl-propylamino)- cyclobut-3-ene-1 ,2-dione (Preparation 13, 122.95mg, 0.533mmol) and dry tetrahydrofuran (3ml_) were mixed and degassed using argon. Bis(dibenzylideneacetone)palladium(0) (88.81 mg, 0.097mmol) and dicyclohexylphosphoryl N-N dimethyl amine bi-phenyl (38.17mg, 0.097mmol) were added and the reaction mixture was heated with microwave radiation for 2 hours. The reaction mixture was filtered through Celite and washed with ethyl acetate. The organic phase was washed with water and brine, dried using anhydrous sodium sulfate and concentrated in vacuo to give crude product. Column chromatographic purification on silica gel, eluting with 30% ethyl acetate in hexane, afforded the title compound (356mg, 73%). 1H NMR (400MHz, CDCI ₃ ): δ = 0.94 (m, 3H), 1.88-2.03 (m, 2H), 3.68 (s. 3H), 5.12 (bs, 1 H), 7.25-7.32 (m, 5H), 7.45 (s, 1 H), 7.91-7.93 (m, 1 H) ppm, 2 exchangeables not observed. LRMS m/z 356.2 [M+H] ⁺ .

Preparation 21 δ-Cvclopropyl^-methoxy-S-nitropyridine

θ-Chloro^-methoxy-S-nitropyridine (1.Og, 5.3mmol), cyclopropylboronic acid (592mg, 6.89mmol) and potassium phosphate (3.94g, 18.55mmol) were mixed with toluene (18.5ml_) and water (1.85mL). Tricyclohexylphosphine (148.6mg, 0.55mmol) and palladium(ll) acetate (59.48mg, 0.265mmol) were added. The reaction mixture was heated at reflux for 5 hours. Ethyl acetate was added then the resultig mixture was washed with water (6OmL) and brine and dried using anhydrous sodium sulfate. The organic phase was concentrated in vacuo to give crude product which was purified by column chromatographic purification of silica gel, eluting with 1.5 to 2% ethyl acetate in hexane, to afford the title compound as a brown solid (950mg, 98%). 1H NMR (400MHz, CDCI ₃ ): δ = 1.07-1.12 (m, 2H), 1.17-1.24 (m, 2H), 2.02 (m, 1 H), 4.03 (s, 3H), 6.88 (d, 1 H), 8.18 (d, 1 H) ppm.

Preparation 22

6-Cvclopropyl-2-methoxypyridin-3-amine

6-Cyclopropyl-2-methoxy-3-nitropyridine (Preparation 21 , 400mg, 2.06mmol), iron powder (575.3, 10.03mmol) and calcium chloride (228.6mg, 2.06mmol) were combined with ethanol (8.24ml_) and water (2.06ml_) and the resulting mixture was heated at reflux for 1 hour. The reaction mixture was filtered through Celite and the filtrate was concentrate in vacuo. The crude compound was dissolved in ethyl acetate (10OmL) and the resulting solution was washed with water (4OmL) and brine. The organic pgase was dried over anhydrous sodium sulfate and concentrated in vacuo to afford the title compound as a brown solid (280mg, 77%). 1H NMR (400MHz, CDCI ₃ ): δ = 0.80 (m ,2H), 0.89 (m, 2H), 1.82 (m, 1H), 3.54 (br s, 2H), 3.92 (s, 3H), 6.56 (d, 1 H), 6.77 (d, 1 H) ppm. Preparation 23

(R)-3-(6-Cvclopropyl-2-methoxypyridin-3-ylamino)-4-(1-phe nylpropylamino)cyclobut-3-ene-1 ,2- dione.

θ-Cyclopropyl^-methoxypyridin-S-amine (Preparation 22, 350mg, 2.13mmol) and (R)-3-ethoxy- 4-(1-phenylpropylamino)cyclobut-3-ene-1 ,2-dione (Preparation 12, 276.3mg, 1.065mmol) were dissolved in ethanol (2.OmL). Diisopropylethylamine (413. Omg, 3.20mmol) was added and the reaction mixture was heated at reflux for 48 hours. The reaction was concentrated in vacuo and the crude product was purified by column chromatography on silica gel, eluting with 10 to 40 % ethyl acetate in hexane, to afford the title compound as a brown solid (220mg, 27%). 1H NMR (400MHz, CDCI ₃ ): δ = 0.80-0.87 (m, 4H), 0.91-0.95 (t, 3H), 1.77-1.83 (m, 1 H), 1.86- 1.98 (m, 2H), 3.71 (s, 3H), 5.10 (m, 1 H), 6.56 (d, 1 H), 7.27-7.36 (m, 5H), 7.63 (m, 1 H) ppm, 2 exchangeables not observed.

Preparation 24

3-Ethoxy-4-(4-methyl-2-oxo-1 ,2-dihvdropyridin-3-ylamino)cvclobut-3-ene-1 ,2-dione

3-Amino-4-methylpyridin-2(1 H)-one (see WO-2004/063155, 50mg, 0.4mmol) and 3,4- diethoxycyclobut-3-ene-1 ,2-dione (69mg, 0.4mmol) were combined with ethanol (5ml_) and the mixture was heated at reflux for 8 hours. A precipitate formed which was collected by filtration and triturated with diethyl ether to afford the title compound as a yellow solid (50mg, 51 %). ¹ H NMR (400MHz, DMSOd ₆ ): δ = 1.31-1.37 (m, 3H), 2.1 1 (s, 3H), 4.64 (m, 2H), 6.10 (m, 1 H), 7.20 (m, 1 H), 9.94 (br s , 1 H), 11.74 (br s , 1 H) ppm. LRMS m/z 249.4 [M+H] ⁺ . Preparation 25

(S)-3-Ethoxy-4-(1-phenylpropylamino)cyclobut-3-ene-1 ,2-dione

To a stirred solution of 3,4-diethoxycyclobut-3-ene-1 ,2-dione (5.46g, 32.1 mmol) in absolute ethanol (80 ml_), at room temperature, was added dropwise (S)-1-phenylpropan-1-amine (3.95, 29.2mmol) over 5 minutes. The resultant solution was stirred at room temperature for 3 hours and then concentrated in vacuo to give a brown oil. The crude product was purified by column chromatography on silica gel eluting with a gradient of from 25% to 100% 2-methoxy-2- methylpropane in heptane to afford a yellow oil. This oil was dissolved in ethyl acetate and pentane added to give a white precipitate which was filtered and dried to afford the title compound as a white solid (4.3Og, 57%).

¹ H NMR (400MHz, CDCI ₃ ): δ = 0.95 (t, 3H), 1.40 (t, 3H), 1.87-2.03 (m, 2H) , 4.58 (bs, 1 H), 4.73 (q, 2H), 6.50 (bs, 1 H), 7.25-7.37 (m, 5H) ppm.

Preparation 26

1-(3-Fluoro-5-methylphenyl)propylamine

Step A: To a stirred solution of 3-fluoro-5-methylbenzoic acid (7.5g, 32.43mmol) in dichloromethane (5OmL) was added oxalyl chloride (7.86ml_, 97.31 mmol), at O ⁰ C, followed by a few drops of dimethylformamide and the reaction mixture was stirred at room temperature for 2 hours. The solvent was removed in vacuo and the residue was dried for a further 30 minutes under vacuum. The material thus obtained was dissolved in dichloromethane (5OmL). O,N- Dimethyhydroxylamine hydrochloride (4.74g, 48.64mmol) was added along with DIPEA (14.12mL, 81.09mmol) and the reaction was stirred at room temperature overnight. The mixture was diluted with dichloromethane and water, the phases were separated and the organic phase was washed with water (twice) and brine, dried using anhydrous sodium sulfate and concentrated in vacuo. Purification by silica column chromatography eluting with 15% ethyl acetate in hexane gave 5.6g of 3-fluoro-N-methoxy-5,N-dimethylbenzamide. LRMS: m/z 198 [M+H].

Step B: Ethyl magnesium bromide (3.0M in diethyl ether, 38ml_, 113.70mmol) was added dropwise at O ⁰ C to a solution of the product of Step A (5.6g, 28.42mmol) in tetrahydrofuran (10OmL) and the reaction mixture was stirred at room temperature for 30 minutes. The reaction was quenched with aqueous ammonium chloride and then extracted with ethyl acetate. The ethyl acetate extract was washed with brine, dried over magnesium sulfate and concentrated in vacuo. Purification by silica column chromatography eluting with 5% ethyl acetate in hexane gave 3.5g of 1-(3-fluoro-5-methylphenyl)propan-1-one.

¹ H-NMR (400MHz, CDCI ₃ ): δ = 1.19-1.22 (t, 3H), 2.3 (s, 3H), 2.92-2.97 (m, 3H), 7.07 (d, 1 H), 7.42 (d, 1 H), 7.5 (s, 1 H) ppm.

Step C: A mixture of the product of step B (3.5g, 21.08mmol), titanium(IV) isopropoxide (17.4, 63.25mmol) and 7M ammonia in methanol (15.05mL, 10.54mmol) was stirred at room temperature for 6 hours, sodium borohydride (1.196g, 31.62mmol) was added at O ⁰ C (caution: effervescence) and the resulting mixture was stirred at room temperature overnight. The almost solid mixture was diluted with aqueous ammonia solution (6OmL), stirred for 15 minutes, filtered and washed with ethyl acetate. The two phase filtrate was separated and the aqueous phase was washed with further ethyl acetate. The combined organic extracts were washed with 2N HCI. The aqueous phase was basified with saturated aqueous sodium carbonate and then re- extracted with ethyl acetate. The ethyl acetate extract was washed with brine, dried using magnesium sulfate and concentrated in vacuo to afford the title compound (1.5g). 1H-NMR (400MHz, DMSOd ₆ ): δ = 0.7-0.8 (t, 3H), 1.4-1.5 (m, 2H), 2.29 (s, 3H), 3.65-3.68 (m, 1 H), 6.8-6.9 (m, 3H) ppm, 2 exchangeables not observed.

The following compounds were prepared using the method of Preparation 26 from starting materials as described in the table.

Preparation 37

1 -(3-Methylphenyl)propan-1 -one

A mixture of 1-(3-bromophenyl)propan-1-one (8.Og, 37.55mmol), trimethylboroxine (4.71g, 37.55mmol), potassium carbonate (15.65g, 112.65mmol), 1 ,4-dioxane (18.OmL) and water (18.OmL) was degassed and purged with argon for 30 minutes. (1 ,1 '- Bis(diphenylphosphino)ferrocene)dichloropalladium(ll) complex with dichloromethane (3.06g, 3.755mmol) was added and the resulting mixture was heated at reflux overnight. The reaction was cooled and filtered through Celite. The filtrate was diluted with ethyl acetate, washed with water and brine, dried over anhydrous magnesium sulfate and concentrated in vacuo. The residue was purified by silica column chromatography eluting with 1.5% ethyl acetate in hexane to afford the title compound (5.Og).

¹ H NMR (400MHz, CDCI ₃ ): δ = 1.19-1.22 (t, 3H), 2.4 (s, 3H), 2.95-3.00 (m, 2H), 7.30 (m, 2H), 7.70 (d, 2H) ppm.

Preparation 38

1-(4-Cvclopropylphenyl)propan-1-one

To a mixture of 1-(4-bromophenyl)propan-1-one (5.Og, 23.38mmol), cyclopropylboronic acid (3.9g, 35.07mmol), potassium phosphate (17.37g, 81.83mmol) and toluene (10OmL) was added water (1OmL), tricyclohexylphosphine (0.0653mg, 2.33mmol) and palladium(ll) acetate (260mg, 1.16mmol) and the reaction mixture was heated at reflux under an argon atmosphere for 3 hours. The reaction was cooled, diluted with ethyl acetate, washed with water and brine, dried over anhydrous sodium sulfate and concentrated in vacuo. Purification by silica column chromatography eluting with 2% ethyl acetate in hexane gave the title compound (3.8g). 1H NMR (400MHz, CDCI ₃ ): δ = 0.74-0.82 (m, 2H), 0.90-1.00 (m, 2H), 1.10-1.20 (t, 3H), 1.80- 1.90 (m, 1 H), 2.92-2.97 (m, 2H), 7.00-7.10 (d, 2H), 7.83-7.85 (d, 2H) ppm. Preparation 39 i-O-CyclopropylphenvDpropan-i-one

The title compound (1.9g) was prepared in an analogous fashion to Preparation 38 starting with 1-(3-bromophenyl)propan-1-one (3.Og, 17.24mmol).

¹ H NMR (400MHz, DMSOd ₆ ): δ = 0.71-0.74 (m, 2H), 0.93-1.00(m, 2H), 1.18-1.22 (t, 3H), 1.90- 1.97 (m, 1 H), 2.90-3.00 (m, 2H), 7.20 (d, 1 H), 7.30 (t, 1 H), 7.60 (s, 1 H), 7.7 (d, 1 H) ppm.

Preparation 40 Cvclopropyl(2,6-difluorophenyl)methanol

A solution of n-butyllithium (2.5M in hexanes, 350 mmol, 140 ml_) was added dropwise to a solution 1 ,3-difluorobenzene (39.9 g, 350 mmol) in tetrahydrofuran (100OmL) at -78°C. After 1 hour, a solution of cyclopropylcarboxaldehyde (29.4 g, 420 mmol) in tetrahydrofuran (200 ml_) was added to the reaction mixture, dropwise, at -78°C. After addition, the reaction mixture was warmed gradually to room temperature and stirred overnight. The reaction mixture was cooled to O ⁰ C, and 6OmL of saturated aqueous ammonium chloride was added. The aqueous layer was extracted with ethyl acetate (30OmL) and the combined organic extracts were washed with brine, dried over anhydrous sodium sulfate and concentrated in vacuo to afford the title compound as a crude oil (65.3 g).

Preparation 41

2-[Azido(cvclopropyl)methyl1-1 ,3-difluorobenzene

Diphenyl phosphoryl azide (1 15.6 g, 420 mmol) and 1 ,8-diazabicyclo[5.4.0]undec-7-ene (63 ml_, 420 mmol) were added to a solution of cyclopropyl(2,6-difluorophenyl)methanol (Preparation 40, 65 g, 350 mmol) in 28OmL of toluene sequentially at O ⁰ C. The reaction mixture was warmed to room temperature and then heated at 40 ⁰ C overnight. The reaction mixture was cooled to O ⁰ C and 10OmL of brine was added. The layers were separated and the organic layer was dried over anhydrous sodium sulfate. Concentration followed by chromatography gave the title compound (62.5 g).

Preparation 42 1-Cyclopropyl-1-(2,6-difluorophenyl) methylamine

Palladium (20% wt. % on activated carbon, 6.3g) was added to a solution of 2- [azido(cyclopropyl)methyl]-1 ,3-difluorobenzene (Preparation 41 ) (62.5g, 300 mmol) in ethanol (25OmL) and ethyl acetate (25OmL). The reaction mixture was stirred at room temperature under hydrogen (1 atmosphere) for 40 hours. The palladium was filtered off and the filtrate was concentrated in vacuo. Chromatography afforded the title compound (28.9 g, 53 %) as white solid.

Preparation 43 N-Methylpyrrolidine-2-carboxamide

The title compound was prepared from racemic proline as described by Shendage, D. M., et al. in J. Am. Chem. Soc, 61 , 3675-3678.

Preparation 44

2,2,2-Trifluoro-N-methylethanamine hydrochloride

To a solution of lithium aluminiumhydride (69g, 1.8mol) in 100OmL of ether was added a solution of 2,2,2-trifluoro-N-methylacetamide (86g, 0.6mol) in ether at 0 ⁰ C and the reaction mixture was stirred at room temperature overnight. Sodium sulfate decahydrate was added to the mixture at -10 ⁰ C and the resulting suspension was filtered. Dry HCI gas was then bubbled into the filtrate to give a white solid. Isolation of the solid followed by recrystallization from methanol/ diethyl ether provided the title compound as a white solid (73g, 80.7% yield).

Preparation 45 tert-Butyl 3-(methylsulfonyloxy)azetidine-1-carboxylate

tert-Butyl 3-hydroxyazetidine-i-carboxylate (71g, 0.41 mol) was dissolved in dichloromethane (70OmL). Triethylamine (1 14ml_, 0.82 mol) was added and the solution was cooled in an ice bath before the addition of methanesulfonyl chloride (33.4ml_, 0.43 mol) as a solution in dichloromethane (10OmL). The reaction mixture was stirred at room temperature overnight and evaporated. The residue was dissolved in ether (50OmL), triethylamine hydrochloride was filtered off, and the filtrate was evaporated. The residue was purified by column chromatography on silica gel eluting with hexane:ethyl acetate (3:1 ) to afford the title compound (80 g, 78%).

¹ H NMR (400 MHz, DMSOd ₆ ): δ = 1.38 (s, 9H), 3.23 (s, 3H), 3.90-3.94 (m, 2H), 4.19-4.24 (m, 2H), 5.22-5.28 (m, 1 H) ppm.

Preparation 46 tert-Butyl 3-iodoazetidine-1-carboxylate

tert-Butyl 3-(methylsulfonyloxy)azetidine-1-carboxylate (Preparation 45, 8Og, 0.318 mol) and potassium iodide (159g, 0.96 mol) were mixed in dimethylformamide (500 mL). The reaction mixture was stirred at 110 ⁰ C for 7 hours. The solvent was evaporated and the resulting residue was suspended in water (1 L). The product was extracted with ethyl acetate (80OmL). The combined extracts were washed with water, dried using anhydrous sodium sulfate and concentrated in vacuo. The residue was purified by column chromatography on silica gel eluting with ethyl acetate :hexane (1 :4) to afford the title compound (64.6 g, 72%). 1H NMR (400 MHz, DMSOd ₆ ): δ = 1.38 (s, 9H), 4.05-4.09 (m, 2H), 4.61-4.64 (m, 3H) ppm.

Preparation 47 tert-Butyl S-pyrimidin-δ-ylazetidine-i-carboxvlate

A 50OmL three-necked flask equipped with a drop funnel and thermometer was charged with zinc dust (11.1 g, 0.17 mol). Dry tetrahydrofuran (15OmL) was added. The mixture was degassed, and the flask was filled with argon. Dibromoethane (1 mL) was added in a flow of argon at room temperature. The mixture was kept at 60-65 ⁰ C for 15 min and then cooled to room temperature. Trimethylsilyl chloride (1 mL) was added, and the mixture was stirred for 1 hour. A solution of tert-butyl 3-iodoazetidine-i-carboxylate (Preparation 46, 28.3g, 0.1 mol) in dry tetrahydrofuran (75mL) was added dropwise and the reaction mixture was stirred for 1 hour and then degassed. Pd(PPh ₃ ) ₄ (1g) and a solution of 5-bromopyrimidine (19.1g, 0.12 mol) in THF (100 mL) were added. The mixture was degassed again, heated at reflux for 6 hours and filtered through Celite. After evaporation of the solvent, ethyl acetate (30OmL) was added and the resulting mixture was washed with a solution of sodium hydrogencarbonate (5Og) in water (50OmL). The layers were separated, the aqueous layer was extracted with ethyl acetate and the combined organic extractions were dried with sodium sulfate and concentrated in vacuo. The residue was purified by column chromatography on silica gel, eluting with ethyl acetate to afford the title compound (15.1 , 64%).

Preparation 48 2-(Azetidin-3-yl)pyrimidine hydrochloride

tert-Butyl S-pyrimidin-δ-ylazetidine-i-carboxylate (Preparation 47, 17.8 g, 0.078 mol) was dissolved in methanol (25ml_) and 4M HCI in dioxane (9OmL) was added at 20 ⁰ C. After 2 hours the precipitate which had formed was separated by filtration, washed with dioxane (10OmL), THF (10OmL), and ether (10OmL) and dried to afford the title compound (12.5g, 79%). 1H NMR (400 MHz, DMSOd ₆ ): δ = 4.16-4.32 (m, 5H), 7.48 (dd, 1 H), 8.86 (d, 1 H), 9.11 (s, 2H), 9.33 (s, 1 H), 9.78 (s, 1 H) ppm.

Preparation 49

3-(Azetidin-3-yl)pyridazine hydrochloride

The title compound was prepared from 3-chloropyridazine (see WO-2007/113232) and

Preparation 46 using an analogous procedure to that described for Preparations 47 and 48

(3.7g, 54%).

¹ H NMR (400MHz, DMSOd ₆ ): δ = 4.13-4.22 (m, 2H), 4.26-4.36 (m, 3H), 8.00 (dd, 1 H), 8.65 (d, 1 H, 6 Hz), 8.81 (d, 1 H, 6 Hz), 9.01 (s, 1 H), 9.52 (br. s, 1 H), 9.74 (br. s, 1 H) ppm.

Preparation 50

5-(Azetidin-3-yl)pyrimidine hydrochloride

The title compound was prepared from 5-bromopyrimidine and Preparation 46 using an analogous procedure to that described for Preparations 47 and 48 (5.2 g, 39%). 1H NMR: (400 MHz, DMSO- d ₆ ): δ = 4.15-4.22 (m, 3H), 4.24-4.30 (m, 2H), 9.02 (s, 2H), 9.17 (s, 1 H), 9.41-9.57 (s, 1 H), 9.59-9.75 (s, 1 H) ppm. Preparation 51

2-(Benzylcarbamoyl)nicotinic acid

To a solution of furo[3,4-b]pyridine-5,7-dione (1 18 g, 0.789mol) in dry 1 , 4-dioxane (60 ml_) were added dropwise benzylamine (88.2ml_, 0.824mol) and triethylamine (159.4g, 1.58mol) successively. Then the mixture was stirred at 3O ⁰ C overnight. The solvents were removed by evaporation to give a syrup. The syrup was dried in vacuo at 6O ⁰ C for 2 hours and used in subsequent reactions directly.

Preparation 52

6-Benzyl-5H-pyrrolo[3, 4-blpyήdine-5, 7(6H)-dione

To 2-(benzylcarbamoyl)nicotinic acid (Preparation 51 ) (202.7 g, 0.789 mol) was added acetic anhydride (30OmL), toluene (30OmL) and trifluoro-acetic acid (3OmL) successively. Then the mixture was heated to 100-110 ⁰ C and stirred at this temperature overnight. Another portion of toluene (20OmL) was added. Then the mixture was cooled to O ⁰ C slowly. The solid formed in the mixture was filtered, washed with toluene (15OmL) and dried in vacuo to afford the title compound as an off-white solid (153.4 g 81 %).

Preparation 53

6-Benzyl-6,7-dihvdro-5H-pyrrolo[3,4-b1pvridine

To a refluxing suspension of lithium aluminium hydride (24.5 g, 0.645 mol) in dry tetrahydrofuran (30OmL) was added a suspension of 6-benzyl-5H-pyrrolo[3,4-b]pyridine-5,7(6H)-dione (Preparation 52, 76.8 g, 0.322 mol) in dry tetrahydrofuran (40OmL) with vigorous stirring. After the addition of the 6-benzyl-5H-pyrrolo[3,4-b]pyridine-5,7(6H)-dione was complete, the mixture was stirred for another 20 minutes. The mixture was cooled to O ⁰ C and quenched with 15% aqueous sodium hydroxide solution and stirred for 1 hour. The mixture was filtered, washed with ethyl acetate (12OmL), dried over anhydrous sodium sulfate and concentrated in vacuo. The residue was purified by column chromatography on silica gel eluting with dichloromethane:methanol (gradient elution 80:1 to 40:1 ) to afford the title compound as an orange liquid (13.8 g, 20%).

Preparation 54 tert-Butyl 5H-pyrrolo[3,4-b1pyridine-6(7H)-carboxylate

A mixture of 6-benzyl-6,7-dihydro-5H-pyrrolo[3,4-b]pyridine (Preparation 53, 27.5 g, 0.131 mol), di-tert-butyl dicarbonate (57 g, 0.262 mol), 20% Pd(OH) ₂ /C (2.0 g) and methanol (70OmL) was stirred at 6O ⁰ C in an autoclave under 15 atmospheres of hydrogen overnight. The catalyst was filtered off and the filtrate was concentrated. The residue was purified by column chromatography on silica gel eluting with petroleum etheπethyl acetate (gradient elution 40:1 to

20:1 ) to afford the title compound as a colourless oil (3 g, 10 %).

Preparation 55

6,7-Dihvdro-5H-pyrrolo[3,4-b1pyridine hydrochloride

To a solution of tert-butyl-5H-pyrrolo[3,4-b]pyridine-6(7H)-carboxylate (Preparation 54, 4.9 g, 0.022 mol) in methanol (1 OmL) was added dropwise a saturated solution of hydrogen chloride in 1 , 4-dioxane (5OmL) at O ⁰ C. The reaction mixture was stirred at room temperature for 3 hours. The solvent was concentrated in vacuo to afford the title compound as a grey solid (4.2 g, 98 %).

Preparation 56

2,3-Dihvdro-1 H-pyrrolo[3,4-c1pyridine hydrochloride

The title compound was prepared from furo[3,4-c]pyridine-1 ,3-dione using an analogous procedure to that described for Preparation 55. Preparation 57

3-Azabicyclo[3.2.01heptane

^\

NH

^y

The title compound was prepared by deprotection of benzyl 3-azabicyclo[3.2.0]heptane-3- carboxylate (see Salomon, R. G., et al., Tet. Lett., 1984, 30, 3167) by standard methods.

Preparation 58 cis-2-(3,5-Difluorophenyl)cyclopentanamine

The title compound was prepared as described by Shepherd, T. A., et al., J. Med. Chem., 2002, 45, 2101.

Preparation 59

Trans-2-(4-fluorophenyl)cyclopentanamine

The title compound was prepared as described by Shepherd, T. A., et al., J. Med. Chem., 2002,

45, 2101 from 4-fluorophenyl magnesium bromide.

Preparation 60 (1 S,2R)-2-(3,5-Difluorophenyl)cyclopentanamine

The title compound was prepared as described by Shepherd, T. A., et al., J. Med. Chem., 2002, 45, 2101 from 3,5-fluorophenyl magnesium bromide.

Preparation 61 (R)-piperidine-3-carboxamide

The title compound was prepared as described in WO-2006/123257, starting from (R)-3- carbamoyl-piperidine-l-carboxylic acid tert-butyl ester.

Preparation 62

(R)-1-(4-Chloro-3-methylphenyl)ethanamine hydrochloride

The title compound was prepared as described by Colyer, J. T., et al.; J. Org. Chem., 2006, 71 , 6859 starting from 4-chloro-3-methylbenzaldehyde.

Preparation 63

(R)-1-(2,4-Difluoro-5-methylphenyl)ethanamine hydrochloride

The title compound was prepared using the method of Colyer, J. T., et al., J. Org. Chem., 2006, 71 , 6859 starting from 2,4-difluoro-5-methylbenzaldehyde.

Preparation 64

1-(5-Methylisoxazol-3-yl)ethanamine

The title compound was prepared using the method described by Ghosh, A. K., et al., J. Med. Chem., 2007, 50, 2399-2407 starting from ethyl δ-methylisoxazole-S-carboxylate.

Preparation 65 Ethyl 1 -benzylcvclobutanecarboxylate

To a solution of lithium bis(trimethylsilyl)amide solution (287ml_, 0.28 mol) in tetrahydrofuran (50OmL) was added dropwise a solution of ethyl cyclobutanecarboxylate (35g, 0.273 mol) in tetrahydrofuran (5OmL) while keeping the temperature between -6O ⁰ C and -65 ⁰ C. After the addition, the reaction mixture was stirred at -6O ⁰ C to -65 ⁰ C for 2 hours. A solution of benzyl bromide (49g, 0.287 mol) in tetrahydrofuran (5OmL) was added dropwise and the resulting mixture was stirred at -6O ⁰ C to -65 ⁰ C for 1 hour and at room temperature for 3 hours. The reaction was quenched by the addition of saturated ammonium chloride aqueous solution (20OmL) and the organic phase was separated. The aqueous layer was extracted with ethyl acetate (1.8L). The combined organic layers were washed with brine, dried over anhydrous sodium sulfate and concentrated in vacuo. The residue was purified by column chromatography on silica gel eluting with petroleum etheπethyl acetate (100:1 ) to afford the title compound as a yellow liquid (39 g, 63%).

Preparation 66

1 -Benzylcyclobutanecarboxylic acid

To a solution of ethyl i-benzylcyclobutanecarboxylate (Preparation 65, 56g, 0.26 mol) in methanol:tetrahydrofuran:water (250mL:125mL:63mL) was added lithium hydroxide hydrate (32.3g, 0.77mol), in portions, at O ⁰ C. After the addition was complete, the reaction mixture was heated at 5O ⁰ C for 8 hours. The volatiles were removed and water was added. The aqueous solution was washed with petroleum ether to remove impurities. The aqueous layer was acidified with cone. HCI until the solution was at pH 2 and then extracted with dichloromethane (60OmL). The combined organic layers were washed with brine, dried using anhydrous sodium sulfate and concentrated in vacuo to afford the title compound as a white solid (46 g, 94%). Preparation 67

1 -Benzylcyclobutanecarbonyl azide

1-Benzylcyclobutanecarboxylic acid (Preparation 66, 30 g, 0.16 mol) was suspended in water (3OmL) and acetone (45OmL) was added. A solution of triethylamine (28.5 mL, 0.21 mol) in acetone (5OmL) was added dropwise at O ⁰ C followed by a solution of ethyl chloroformate (20.1 mL, 0.21 mol) in acetone (5OmL). The resulting mixture was stirred at O ⁰ C for 30 min and a solution of sodium azide (15.6 g, 0.24 mol) in water (10OmL) was added dropwise. The resulting mixture was stirred at O ⁰ C for one hour. The reaction mixture was poured onto crushed ice and thoroughly extracted with ether. The combined ether extracts were washed with water, dried using anhydrous sodium sulfate and concentrated in vacuo to afford the title compound as a yellow liquid (27.6 g, 80%).

Preparation 68 tert-Butyl 1 -benzylcyclobutylcarbamate

A solution of 1 -benzylcyclobutanecarbonyl azide (Preparation 67, 55.2 g, 0.26 mol) in toluene (50OmL) was heated at reflux for 1 hour. After the reaction mixture was cooled to room temperature, t-butanol (12OmL) was added in one portion. The resulting mixture was stirred at reflux overnight. The reaction mixture was concentrated in vacuo to dryness to afford the title compound (50 g, 73%) as a yellow liquid, which was used in further experiments without further purification.

Preparation 69

1-Benzylcvclobutanamine hydrochloride

tert-Butyl i-benzylcyclobutylcarbamate (Preparation 68, 50 g, 0.19 mol) was added to 50OmL of HCI in dioxane at O ⁰ C. After the addition was complete, the reaction mixture was stirred at room temperature for 1 hour. The reaction mixture was concentrated in vacuo to dryness. The residue was diluted with water and washed with ethyl acetate (45OmL) to remove impurities. The aqueous solution was basified with solid potassium hydroxide until the solution was pH 12 and then extracted with dichloromethane (45OmL). The combined organic layers were washed with brine, dried using anhydrous sodium sulfate and concentrated in vacuo to afford the title compound as a brown liquid (30 g, 100%).

Preparation 70 tert-Butyl 3-cvanoazetidine-i-carboxylate

Sodium cyanide (47.3 g, 0.966 mol) was added to a stirred solution of tert-butyl 3- (methylsulfonyloxy)azetidine-i-carboxylate (Preparation 45, 121.4 g, 0.483 mol) in dimethylsulfoxide (17OmL). The reaction mixture was heated to 100-105 ⁰ C and stirred at this temperature for 100 hours. The reaction mixture was diluted with water (1.5L) and extracted with ether (2.4L). The combined organic extracts were washed with water (1 L) and brine (0.6L), dried over anhydrous magnesium sulfate and concentrated in vacuo. The residue was purified by chromatography on silica gel eluting with hexane:ethyl acetate (3:1 ) to afford the title compound as a white crystalline solid (61.5 g, 70.0%).

¹ H NMR (400 MHz, CDCI ₃ ): 5 = 4.20-4.10 (m, 4H), 3.40-3.32 (m, 1 H), 1.41 (s, 9H) ppm.

Preparation 71

1 -(tert-Butoxycarbonyl)azetidine-3-carboxylic acid

A solution of sodium hydroxide (27.5 g) in water (30OmL) was added to solution of tert-butyl 3- cyanoazetidine-1-carboxylate (Preparation 70, 25.1 g, 0.138 mol) in methanol (30OmL). The mixture was heated at reflux for 5 hours. The methanol was evaporated and the residuary aqueous solution was neutralized with 10% citric acid and extracted with dichloromethane (2.1 L). The combined organic extracts were dried over magnesium sulfate and concentrated in vacuo to afford the title compound as a white crystalline solid (22.3 g, 80.8%). ¹ H NMR (400 MHz, DMSO-d ₆ ): δ = 4.01-3.97 (m, 2H), 3.87-3.84 (m, 2H), 3.36-3.28 (m, 1 H), 1.37 (S ₁ 9H) ppm.

Preparation 72 tert-Butyl S-fmethoxyfmethvDcarbamovDazetidine-i-carboxylate

Carbonyldiimidazole (24.4 g, 0.150 mol) was added in portions to a solution of 1-(tert- butoxycarbonyl)azetidine-3-carboxylic acid (Preparation 71 , 22.3 g, 0.1 11 mol) in tetrahydrofuran (25OmL). The mixture was stirred at room temperature for 1.5 hours. A suspension of Λ/,O-dimethylhydroxylamine hydrochloride (15.O g, 0.154 mol) in a mixture of acetonitrile (30OmL) and triethylamine (22 mL, 0.162 mol) was added. The resulting mixture was stirred at room temperature for 24 hours. The solvents were evaporated and water (30OmL) and ethyl acetate (80OmL) were added to the residue. The organic layer was separated, washed with 5% aqueous citric acid (40OmL), water (30OmL) and brine (30OmL), dried over anhydrous magnesium sulfate and concentrated in vacuo to afford the title compound as a pale yellow oil (28.15 g, 100%).

¹ H NMR (400 MHz, CDCI ₃ ): δ = 4.12-4.09 (m, 2H), 4.03-3.99 (m, 2H), 3.64-3.56 (m, 1 H), 3.63 (s, 3H), 3.17 (s, 3H), 1.40 (s, 9H) ppm.

Preparation 73 tert-Butyl 3-acetylazetidine-1 -carboxylate

A solution of tert-butyl 3-(methoxy(methyl)carbamoyl)azetidine-1-carboxylate (Preparation 72, 27.1 g, 0.111 mol) in tetrahydrofuran (20OmL) was added dropwise to a 1.4 M solution of methylmagnesium bromide in a 25:75 mixture of tetrahydrofuran and toluene (99.0 mL, 0.139 mol, 1.25 eq) over 40 minutes. The reaction temperature was kept at ~0°C. After the addition, the mixture was stirred at 10-15 ⁰ C for 2 hours and then at room temperature for 1 hour. The mixture was cooled to 0 ⁰ C and 10% aqueous citric acid (15OmL) was added. The organic layer was separated and the aqueous layer was extracted with ethyl acetate (60OmL). The organic layers were combined, washed with brine (50OmL) and dried using anhydrous sodium sulfate to give a residue which was purified by chromatography on silica gel, eluting with chloroform, to afford the title compound (20.6 g, 93.4%).

¹ H NMR (400 MHz, CDCI ₃ ): δ = 4.04-4.02 (m, 4H), 3.43-3.35 (m, 1 H), 2.16 (s, 3H), 1.42 (s, 9H) ppm.

Preparation 74

4-(Azetidin-3-yl)pyrimidine

Step A: A solution of tert-butyl 3-acetylazetidine-1-carboxylate (Preparation 73, 20.6 g,

0.103 mol) in N-N-dimethylformamide dimethyl acetal was refluxed for 45 hours. The reaction mixture was evaporated and then co-evaporated with toluene (40OmL) to leave a residue that was used in step B without further purification.

Step B: Formamidine hydrochloride (4.96 g, 0.062 mol) and a solution of the product from Step A in methanol (75 mL) were added in series to a solution of sodium methylate (3.33 g, 0.062 mol) in absolute methanol (75 mL). The mixture was refluxed for 50 hours. The solvent was exchanged for dioxane and the mixture was refluxed for another 40 hours. The solvent was evaporated and water (150 mL) and ethyl acetate (250 mL) were added to the residue. The organic layer was separated and the aqueous layer was extracted with ethyl acetate (50OmL). The combined organic extracts were dried over anhydrous magnesium sulfate and concentrated to give a residue that was purified by chromatography on silica gel, eluting with ethyl acetate, to afford tert-butyl 3-pyrimidin-4-ylazetidine-1-carboxylate (2.0 g, 20.6%). 1H NMR (400 MHz, DMSOd ₆ ): δ = 9.18 (d, 1 H), 8.73 (d, 1 H), 7.48 (dd, 1 H), 4.21-4.17 (m, 2H), 4.02-3.98 (m, 2H), 3.96-3.88 (m, 1 H), 1.39 (s, 9H) ppm.

Step C: Trifluoroacetic acid (9.9mL, 14.7 g, 0.13 mol) was added to a cooled solution of tert- butyl 3-pyrimidin-4-ylazetidine-1-carboxylate (product of Step B, 1.9 g, 0.008 mol) in dichloromethane (1OmL) at 0-5 ⁰ C. The mixture was stirred with cooling for 30 min and then stirred at room temperature for 1 hour. The solvent was removed in vacuo and the residue was azetroped with dichloromethane (10OmL) and methanol (10OmL) to afford the title compound as a brown syrup (2.42 g, 99%).

¹ H NMR (400 MHz, DMSO- d ₆ ): δ = 9.33 (br. s, 1 H), 9.00 (br. s, 1 H), 9.24 (d, 1 H), 8.78 (d, 1 H), 7.52 (dd, 1 H), 4.33-4.19 (m, 5H) ppm. Example 1

(f?)-3-(2-Hvdroxypyridin-3-ylamino)-4-(1-(5-methylfuran-2 -yl)propylamino)cvclobut-3-ene-1 ,2- dione

3-Ethoxy-4-(2-hydroxypyridin-3-ylamino)cyclobut-3-ene-1 ,2-dione (Preparation 1 , 290mg, 1.2mmol) was added in a single portion to a stirred solution of (1R)-1-(5-methyl-2-furyl)propan- 1 -amine (prepared as described in WO-2002/083624; 340mg, 2.5mmol) in absolute ethanol (6ml_) at room temperature. The resultant suspension was stirred at room temperature for 18 hours and then concentrated in vacuo. The residue was dissolved in ethyl acetate (10OmL) and the resulting solution was washed with water (3 ^χ 100mL) and saturated aqueous sodium chloride (3 ^χ 100mL), dried (sodium sulfate) and concentrated in vacuo. The residue was purified by column chromatography on silica gel eluting with dichloromethane:methanol (gradient elution, 100:0 to 95:5 by volume) to furnish the title compound as a brown solid, 166 mg. 1H NMR (400MHz, CD ₃ OD): δ = 0.99 (3H, t), 1.87-2.10 (2H, m), 2.26 (3H, s), 5.20 (1 H, t), 5.96 (1 H, m), 6.20 (1 H, d), 6.34-6.40 (1 H, m), 7.09 (1 H, m), 8.20 (1 H, d) ppm. LRMS (ES) : m/z 324 [M-H] ^" .

Example 2 3-[(2-Hvdroxypyridin-3-yl)amino1-4-[(1-imidazo[2,1-b1[1 ,31thiazol-6-ylpropyl)amino1 cvclobut-3- ene-1 ,2-dione

3-Ethoxy-4-(2-hydroxypyridin-3-ylamino)cyclobut-3-ene-1 ,2-dione (Preparation 1 , 17mg, 0.075mmol) was dissolved in dimethylsulfoxide (0.5ml) and (1-imidazo[2,1-fcι][1 ,3]thiazol-6- ylpropyl)amine dihydrochloride (Preparation 8, 19mg, 0.075mmol) was added followed by N, N- diisopropylethylamine (26μL, 0.15mmol). The resultant mixture was shaken at 6O ⁰ C for 18 hours. The crude mixture was purified by HPLC (Preparative Method 5 using a gradient of 36 to 66% B over 12 minutes; Analytical Method C; RT 2.017 mins; m/z 370 [MH] ⁺ ) to give the desired product.

Example 3 S-^-Oxo-i ^-dihydropyridin-S-vDaminoM-lfdRVI-phenylpropyllaminojcvclob ut-S-ene-i ^- dione

3-Ethoxy-4-(2-hydroxypyridin-3-ylamino)cyclobut-3-ene-1 ,2-dione (Preparation 1 , 50mg,

0.21 mmol) was added in a single portion to a stirred solution of (R)-(+)-1-phenylpropylamine

(58mg, 0.43mmol) in absolute ethanol (6ml_) and the reaction mixture was stirred at room temperature for 18 hours. The resultant suspension was filtered, washing with further ethanol, to yield the title compound as a white solid, 65mg.

¹ H NMR (400MHz, d ₆ -DMSO): δ = 0.89 (3H, t), 1.8-1.95 (2H, m), 5.09 (1 H, m), 6.23 (1 H, m),

7.07 (1 H, m), 7.25-7.45 (5H, m), 8.00 (1 H, m), 8.90 (1 H, m), 9.47 (1 H, br s), 11.94 (1 H, br s) ppm.

LRMS (ES) : m/z 326 [M-H] ^" .

Example 4

3-[(2-Hvdroxy-6-methylpyridin-3-yl)amino1-4-{[(1 R)-1-(5-methyl-2-furyl)propyl1amino) cvclobut-3- ene-1 ,2-dione

A solution of (R)-3-ethoxy-4-(1-(5-methylfuran-2-yl)propylamino)cyclobut-3 -ene-1 ,2-dione (prepared as described in WO-2002/083624, 15mg, 0.058mmol) in ethanol (1.5mL) was added to 3-amino-6-methylpyridin-2-ol (Preparation 9, 36 mg, 0.29mmol) followed by Hunigs base (0.15mL, 0.87mmol) and the resultant solution was stirred at reflux for 24 hours. The reaction was then allowed to cool to room temperature and concentrated in vacuo to give a crude residue. The residue was purified by column chromatography on silica gel eluting with heptane:ethyl acetate (90:10 by volume) to furnish the title compound as a solid, 31 mg. 1H NMR (400MHz, CD ₃ OD): δ = 1.00 (3H, t), 1.86-2.10 (2H, m), 2.26 (6H, m), 5.19 (1 H, t), 5.95 (1 H, m), 6.14 (1 H, m), 6.19 (1 H, m), 8.07 (1 H, d) ppm. LRMS (ES) : m/z 340 [M-H] ^" .

Example 5

S-^-Hvdroxypyridin-S-vDaminoM-fd-pyridin^-ylpropyDaminoic yclobut-S-ene-i ^-dione

To a mixture of 3-ethoxy-4-(2-hydroxypyridin-3-ylamino)cyclobut-3-ene-1 ,2-dione (Preparation 1 , 50mg, 0.21 mmol) and ethanol (1 ml_) was added 1-(pyridin-2-yl)propan-1 -amine (58mg, 0.43mmol) and Hunig's base (0.1 1 mL, 0.64mmol) and the resultant solution was stirred at room temperature. After 3 hours the reaction mixture was concentrated in vacuo to give a crude residue. The residue was purified by column chromatography on silica gel eluting with dichloromethane:methanol (gradient elution, 100:0 to 90:10 by volume) to furnish the title compound as a solid, 42 mg.

¹ H NMR (400MHz, CDCI ₃ ): δ = 0.97 (3H, t), 1.86-2.1 1 (2H, m), 5.46 (1 H, m), 6.53 (1 H, t), 7.15 (1 H, m), 7.38 (1 H, m), 7.58 (1 H, m), 7.86 (1 H, m), 8.48-8.64 (2H, m) ppm. LRMS (ES) : m/z 325 [M+H] ⁺ .

The following tabulated Examples are of the formula:

(ii)

(ii)

B

(ii)

to

m/z (ii)

(ii)

to

m/z (v)

(v)

(vi)

title

to

m/z

(vi)

was 4

(vii)

to

m/z

(vii)

B (vi)

(vi)

B

(vi)

m/z

(vi)

B Example 39

(RVδ-CS^-Dioxo^-d-phenylpropylamino^vclobut-i-enylaminoV e-oxo-i .e-dihvdropyridine-S- carbonitrile

(R)-5-(3,4-Dioxo-2-(1-phenylpropylamino)cyclobut-1-enylam ino)-6-methoxynicotinonitrile (Preparation 19, 70mg, 0.193mmol) was dissolved in dry dichloromethane and cooled to O ⁰ C. Boron tribromide (1 M solution in dichloromethane, 0.772ml_, 0.772mmol) was added and the reaction mixture was stirred at room temperature for 4 hours. The reaction mixture was quenched with ice:saturated ammonium chloride solution:aqueous ammonia (30:65:5). 2N Hydrochloric acid was added until a pH of 4 was reached, the layers were separated and the aqueous phase was extracted with further dichloromethane. The combined organic phases were washed with water and brine, dried over anhydrous sodium sulfate and concentrated in vacuo to give crude product that was purified by preparative HPLC Method 1. HPLC MS Method F: retention time 2.13 minutes. LRMS(ES): m/z 326.117 M+H] ⁺ .

Example 40

(R)-3-(5-Fluoro-2-oxo-1 ,2-dihvdropyridin-3-ylamino)-4-(1-phenylpropylamino)cyclobut -3-ene- 1 ,2-dione

(R)-3-(5-Fluoro-2-methoxypyridin-3-ylamino)-4-(1-phenylpr opylamino)cyclobut-3-ene-1 ,2-dione (Preparation 20, 356mg, LOOmmo) was dissolved in dry dichloromethane and cooled to O ⁰ C. Boron tribromide (1 M solution in dichloromethane, 5mL, 5.00mmol) was added and the reaction mixture was stirred at room temperature for 8 hours. The reaction mixture was quenched with ice:saturated ammonium chloride solution:aqueous ammonia (60:130:10). 2N Hydrochloric acid was added until the solution was pH 4, the layers were separated and the aqueous phase was extracted with further dichloromethane. The combined organic phases were washed with water and brine, dried over anhydrous sodium sulfate and concentrated in vacuo to give crude product which was washed with diethyl ether to afford the title compound as a brown solid (43mg, 13%). ¹ H NMR (400MHz, DMSOd ₆ ): δ = 0.86 (t, 3H), 1.84-1.87 (m, 2H), 5.03-5.07 (m, 1 H), 7.19-7.39 (m, 6H), 8.16-8.19 (m, 1 H) ₁ 8.98 (m, 1 H), 9.60 (br s, 1 H), 1 1.93 (s, 1 H) ppm. LRMS: m/z 342.2 [M+H] ⁺ .

Example 41 ene-1 ,2-dione

(R)-3-(6-Cyclopropyl-2-methoxypyridin-3-ylamino)-4-(1-phe nylpropylamino)cyclobut-3-ene-1 ,2- dione (Preparation 23, 100mg, 0.265mmol) was dissolved in 2,4,6-collidine (1 mL). Lithium iodide (177mg, 1.32mmol) was added and the reaction mixture was heated at 135 ⁰ C overnight. Solvent was removed in vacuo and the crude compound was purified by column chromatography on silica gel eluting with 0.5 to 2% methanol in dichloromethane, followed by diethyl ether trituration, to afford the title compound as a brown solid (30mg, 31 %). 1H NMR (400MHz, DMSO-d ₆ ): δ = 0.77 (s, 2H), 0.87-0.91 (m, 4H), 1.07-1.1 1 (m, 1 H), 1.78-1.90 (m, 3H), 5.07-5.09 (m, 1 H), 5.87-5.89 (m, 1 H), 7.28-7.41(m, 5H), 7.90 (d, 1 H), 8.83 (d, 1 H), 9.40 (s, 1 H), 12.06 (s, 1 H) ppm. LRMS: m/z 364.3 [M+H] ⁺ .

Example 42 (R)-3-(4-Methyl-2-oxo-1 ,2-dihvdropyridin-3-ylamino)-4-(1-phenylpropylamino)cyclobut -3-ene- 1 ,2-dione

3-Ethoxy-4-(4-methyl-2-oxo-1 ,2-dihydropyridin-3-ylamino)cyclobut-3-ene-1 ,2-dione (Preparation 24, 50mg, 0.2mmol) and (R)-1-phenylpropan-1-amine (54mg, 0.4mmol) were combined with ethanol (1 mL) and the mixture was heated at reflux for 1 hour. The solvent was removed in vacuo to give crude product that was purified by preparative HPLC Method 1. HPLC MS Method F: retention time 2.39 minutes. LRMS(ES): m/z 338.14 [M+H] ⁺ .

The following further Examples can be prepared analogously, substituting appropriate starting materials where necessary and making appropriate changes to experimental conditions informed by common general knowledge.

3-{[1-(2-methoxyphenyl)propyl]amino}-4-[(2-oxo-1 ,2-dihydropyridin-3-

Example 43 yl)amino]cyclobut-3-ene-1 ,2-dione

3-[(2-oxo-1 ,2-dihydropyridin-3-yl)amino]-4-({1-[2-(2,2,2-

Example 44 trifluoroethoxy)phenyl]ethyl}amino)cyclobut-3-ene-1 ,2-dione

3-{[1-(2-methylphenyl)propyl]amino}-4-[(2-oxo-1 ,2-dihydropyridin-3-

Example 45 yl)amino]cyclobut-3-ene-1 ,2-dione

3-[(2-oxo-1 ,2-dihydropyridin-3-yl)amino]-4-{[(1S)-1-

Example 46 phenylethyl]amino}cyclobut-3-ene-1 ,2-dione

3-{[1-(4-fluorophenyl)-2-methylpropyl]amino}-4-[(2-oxo-1 ,2-dihydropyridin-

Example 47 3-yl)amino]cyclobut-3-ene-1 ,2-dione

3-[(2-oxo-1 ,2-dihydropyridin-3-yl)amino]-4-[(1-

Example 48 phenylcyclopropyl)amino]cyclobut-3-ene-1 ,2-dione

3-{[1-(4-methyl-1 ,3-thiazol-2-yl)ethyl]amino}-4-[(2-oxo-1 ,2-dihydropyridin-

Example 49 3-yl)amino]cyclobut-3-ene-1 ,2-dione

3-({cyclopropyl[2-fluoro-3-(trifluoromethyl)phenyl]methyl }amino)-4-[(2-oxo-

Example 50 1 ,2-dihydropyridin-3-yl)amino]cyclobut-3-ene-1 ,2-dione

3-[(2-oxo-1 ,2-dihydropyridin-3-yl)amino]-4-{[(1S)-1-(1 ,3-thiazol-2-

Example 51 yl)ethyl]amino}cyclobut-3-ene-1 ,2-dione

3-[(1-ethylpropyl)amino]-4-[(2-oxo-1 ,2-dihydropyridin-3-yl)amino]cyclobut-

Example 52 3-ene-1 ,2-dione

Example 53 3-[(1-isobutylcyclopropyl)amino]-4-[(2-oxo-1 ,2-dihydropyridin-3- yl)amino]cyclobut-3-ene-1 ,2-dione

3-[(3-methyl-1-phenylbutyl)amino]-4-[(2-oxo-1 ,2-dihydropyridin-3-

Example 54 yl)amino]cyclobut-3-ene-1 ,2-dione

3-[(2-oxo-1 ,2-dihydropyridin-3-yl)amino]-4-[(1-

Example 55 phenylcyclobutyl)amino]cyclobut-3-ene-1 ,2-dione

3-[( 1 -cyclopropylethyl)amino]-4-[(2-oxo- 1 ,2-d ihydropyrid in-3-

Example 56 yl)amino]cyclobut-3-ene-1 ,2-dione

3-{[1-(1-methyl-1 H-pyrazol-4-yl)ethyl]amino}-4-[(2-oxo-1 ,2-dihydropyridin-

Example 57 3-yl)amino]cyclobut-3-ene-1 ,2-dione

3-[(2-oxo-1 ,2-dihydropyridin-3-yl)amino]-4-({1-[4-(2,2,2-

Example 58 trifluoroethoxy)phenyl]ethyl}amino)cyclobut-3-ene-1 ,2-dione

3-[(3-bromopyridin-4-yl)amino]-4-[(2-oxo-1 ,2-dihydropyridin-3-

Example 59 yl)amino]cyclobut-3-ene-1 ,2-dione

3-[(2-oxo-1 ,2-dihydropyridin-3-yl)amino]-4-({1-[3-(2,2,2-

Example 60 trifluoroethoxy)phenyl]ethyl}amino)cyclobut-3-ene-1 ,2-dione

3-[(2-oxo-1 ,2-dihydropyridin-3-yl)amino]-4-{[1-(1 ,3-thiazol-5-

Example 61 yl)ethyl]amino}cyclobut-3-ene-1 ,2-dione

3-{[1-(3-ethyl-1 ,2,4-oxadiazol-5-yl)ethyl]amino}-4-[(2-oxo-1 ,2-

Example 62 dihydropyridin-3-yl)amino]cyclobut-3-ene-1 ,2-dione

3-[(2-oxo-1 ,2-dihydropyridin-3-yl)amino]-4-{[(1 R)-1-

Example 63 phenylethyl]amino}cyclobut-3-ene-1 ,2-dione

3-[(2-methylcyclopentyl)amino]-4-[(2-oxo-1 ,2-dihydropyridin-3-

Example 64 yl)amino]cyclobut-3-ene-1 ,2-dione

3-{[2-fluoro-1-(1 H-tetrazol-5-yl)ethyl]amino}-4-[(2-oxo-1 ,2-dihydropyridin-

Example 65 3-yl)amino]cyclobut-3-ene-1 ,2-dione

3-[(1-isopropylcyclopropyl)amino]-4-[(2-oxo-1 ,2-dihydropyridin-3-

Example 66 yl)amino]cyclobut-3-ene-1 ,2-dione

3-{[2-methyl-1-(1 H-tetrazol-5-yl)propyl]amino}-4-[(2-oxo-1 ,2-

Example 67 dihydropyridin-3-yl)amino]cyclobut-3-ene-1 ,2-dione 3-{[(1 R)-1-methylbutyl]amino}-4-[(2-oxo-1 ,2-dihydropyridin-3-

Example 68 yl)amino]cyclobut-3-ene-1 ,2-dione

3-{[1-(4-methoxybenzyl)cyclopropyl]amino}-4-[(2-oxo-1 ,2-dihydropyridin- Example 69 3-yl)amino]cyclobut-3-ene-1 ,2-dione

3-{[(1S)-1-(5-amino-1 ,3,4-oxadiazol-2-yl)-2,2-dimethylpropyl]amino}-4-[(2- Example 70 oxo-1 ,2-dihydropyridin-3-yl)amino]cyclobut-3-ene-1 ,2-dione

3-[(2-oxo-1 ,2-dihydropyridin-3-yl)amino]-4-{[(1S)-1-(2H-tetrazol-5- Example 71 yl)ethyl]amino}cyclobut-3-ene-1 ,2-dione

S-^θ-dimethylcyclohexy^amino^-^-oxo-i ^-dihydropyridin-S- Example 72 yl)amino]cyclobut-3-ene-1 ,2-dione

3-{[(1 R)-1-(4-fluorophenyl)ethyl]amino}-4-[(2-oxo-1 ,2-dihydropyridin-3- Example 73 yl)amino]cyclobut-3-ene-1 ,2-dione

3-{[1-(4-chloro-2-methylphenyl)ethyl]amino}-4-[(2-oxo-1 ,2-dihydropyridin- Example 74 3-yl)amino]cyclobut-3-ene-1 ,2-dione

3-[(2-oxo-1 ,2-dihydropyridin-3-yl)amino]-4-{[1-(1 H-tetrazol-5- Example 75 yl)ethyl]amino}cyclobut-3-ene-1 ,2-dione

3-{[1-(1 H-imidazol-4-yl)-2-methylpropyl]amino}-4-[(2-oxo-1 ,2- Example 76 dihydropyridin-3-yl)amino]cyclobut-3-ene-1 ,2-dione

(3R)-3-({3,4-dioxo-2-[(2-oxo-1 ,2-dihydropyridin-3-yl)amino]cyclobut-1-en- Example 77 1 -yl}amino)butanenitrile

3-{[2-(4-fluorophenyl)-1-methylethyl]amino}-4-[(2-oxo-1 ,2-dihydropyridin- Example 78 3-yl)amino]cyclobut-3-ene-1 ,2-dione

3-{[1-(2,3-dichlorophenyl)-2-methylpropyl]amino}-4-[(2-ox o-1 ,2- Example 79 dihydropyridin-3-yl)amino]cyclobut-3-ene-1 ,2-dione

3-{[(1 R,2S)-2-fluorocyclopentyl]amino}-4-[(2-oxo-1 ,2-dihydropyridin-3- Example 80 yl)amino]cyclobut-3-ene-1 ,2-dione

3-[(3-methylcyclopentyl)amino]-4-[(2-oxo-1 ,2-dihydropyridin-3-

Example 81 yl)amino]cyclobut-3-ene-1 ,2-dione

Example 82 3-{[(1S)-1-(3,5-dimethoxyphenyl)ethyl]amino}-4-[(2-oxo-1 ,2- dihydropyridin-3-yl)amino]cyclobut-3-ene-1 ,2-dione

3-{[2,2-dimethyl-1-(2H-tetrazol-5-yl)propyl]amino}-4-[(2- oxo-1 ,2-

Example 83 dihydropyridin-3-yl)amino]cyclobut-3-ene-1 ,2-dione

3-{[1-(5-methyl-1 H-pyrazol-4-yl)ethyl]amino}-4-[(2-oxo-1 ,2-dihydropyridin-

Example 84 3-yl)amino]cyclobut-3-ene-1 ,2-dione

3-{[(1 R,2R)-2-fluorocyclopentyl]amino}-4-[(2-oxo-1 ,2-dihydropyridin-3-

Example 85 yl)amino]cyclobut-3-ene-1 ,2-dione

3-[(2-oxo-1 ,2-dihydropyridin-3-yl)amino]-4-[(1-

Example 86 propylcyclopropyl)amino]cyclobut-3-ene-1 ,2-dione

S-lti^-cyclopropylphenyOpropyllaminoJ^-^-oxo-i ^-dihydropyridin-S-

Example 87 yl)amino]cyclobut-3-ene-1 ,2-dione

3-({1-[3,5-bis(trifluoromethyl)phenyl]propyl}amino)-4-[(2 -oxo-1 ,2-

Example 88 dihydropyridin-3-yl)amino]cyclobut-3-ene-1 ,2-dione

3-[(2-oxo-1 ,2-dihydropyridin-3-yl)amino]-4-[(1-pyrimidin-4-

Example 89 ylpropyl)amino]cyclobut-3-ene-1 ,2-dione

4-[1-({3,4-dioxo-2-[(2-oxo-1 ,2-dihydropyridin-3-yl)amino]cyclobut-1-en-1-

Example 90 yl}amino)ethyl]benzonitrile

3-[(2-oxo-1 ,2-dihydropyridin-3-yl)amino]-4-({1-[4-

Example 91 (trifluoromethyl)phenyl]propyl}amino)cyclobut-3-ene-1 ,2-dione

3-[(2-oxo-1 ,2-dihydropyridin-3-yl)amino]-4-({1-[3-

Example 92 (trifluoromethyl)phenyl]propyl}amino)cyclobut-3-ene-1 ,2-dione

3-{[(1 R,2R)-2-(3,5-difluorophenyl)cyclopentyl]amino}-4-[(2-oxo-1 ,2-

Example 93 dihydropyridin-3-yl)amino]cyclobut-3-ene-1 ,2-dione

3-[(2-oxo-1 ,2-dihydropyridin-3-yl)amino]-4-({1-[2-

Example 94 (trifluoromethyl)phenyl]propyl}amino)cyclobut-3-ene-1 ,2-dione

3-{[1-(4-fluorophenyl)propyl]amino}-4-[(2-oxo-1 ,2-dihydropyridin-3-

Example 95 yl)amino]cyclobut-3-ene-1 ,2-dione

3-{[(1 R,2R)-2-(4-fluorophenyl)cyclopentyl]amino}-4-[(2-oxo-1 ,2-

Example 96 dihydropyridin-3-yl)amino]cyclobut-3-ene-1 ,2-dione S-^S^-dioxo^-I^IR^I-phenylpropyljaminoJcyclobut-i-en-i-y^ami nol-N-

Example 97 methyl-6-oxo-1 ,6-dihydropyridine-2-carboxamide

5-[(3,4-dioxo-2-{[(1R)-1-phenylpropyl]amino}cyclobut-1-en -1-yl)amino]- Example 98 N,N-dimethyl-6-oxo-1 ,6-dihydropyridine-2-carboxamide

3-[(2-oxo-1 ,2-dihydropyridin-3-yl)amino]-4-[(1-pyrimidin-4- Example 99 ylpropyl)amino]cyclobut-3-ene-1 ,2-dione

3-[(5-methyl-2-oxo-1 ,2-dihydropyridin-3-yl)amino]-4-{[(1 R)-1- Example 100 phenylpropyl]amino}cyclobut-3-ene-1 ,2-dione

3-[(6-benzyl-2-oxo-1 ,2-dihydropyridin-3-yl)amino]-4-{[(1 R)-1- Example 101 phenylpropyl]amino}cyclobut-3-ene-1 ,2-dione

3-[(5-cyclopropyl-2-oxo- 1 ,2-d ihyd ropyrid i n-3-yl )am i no]-4-{[( 1 R)- 1 - Example 102 phenylpropyl]amino}cyclobut-3-ene-1 ,2-dione

3-{[(1R)-1-(2-methylpyridin-4-yl)ethyl]amino}-4-[(2-oxo-1 ,2-dihydropyridin- Example 103 3-yl)amino]cyclobut-3-ene-1 ,2-dione

3-[(2-oxo-1 ,2-dihydropyridin-3-yl)amino]-4-[(2,2,2-trifluoro-1-pyridin- 3- Example 104 ylethyl)amino]cyclobut-3-ene-1 ,2-dione

3-[(2-oxo-1 ,2-dihydropyridin-3-yl)amino]-4-[(1-pyridin-3- Example 105 ylcyclopropyl)amino]cyclobut-3-ene-1 ,2-dione

3-{[1-(1-naphthyl)ethyl]amino}-4-[(2-oxo-1 ,2-dihydropyridin-3- Example 106 yl)amino]cyclobut-3-ene-1 ,2-dione

3-[(2-oxo-1 ,2-dihydropyridin-3-yl)amino]-4-[(1-quinolin-6- Example 107 ylethyl)amino]cyclobut-3-ene-1 ,2-dione

3-{[1-(3-methoxyphenyl)cyclopropyl]amino}-4-[(2-oxo-1 ,2-dihydropyridin- Example 108 3-yl)amino]cyclobut-3-ene-1 ,2-dione

3-[(2-oxo-1 ,2-dihydropyridin-3-yl)amino]-4-{[(1 R)-1-pyrazin-2- Example 109 ylethyl]amino}cyclobut-3-ene-1 ,2-dione

3-[(2-oxo-1 ,2-dihydropyridin-3-yl)amino]-4-({1-[4-(2,2,2-

Example 110 trifluoroethoxy)phenyl]ethyl}amino)cyclobut-3-ene-1 ,2-dione

Example 111 3-[(2-methylphenyl)amino]-4-[(2-oxo-1 ,2-dihydropyridin-3- yl)amino]cyclobut-3-ene-1 ,2-dione

3-[(1-cyclopentylcyclopropyl)amino]-4-[(2-oxo-1 ,2-dihydropyridin-3-

Example 112 yl)amino]cyclobut-3-ene-1 ,2-dione

3-[(2-isopropylpyrimidin-5-yl)amino]-4-[(2-oxo-1 ,2-dihydropyridin-3-

Example 113 yl)amino]cyclobut-3-ene-1 ,2-dione

3-{[1-(4-methyl-1 ,3-thiazol-2-yl)ethyl]amino}-4-[(2-oxo-1 ,2-dihydropyridin-

Example 114 3-yl)amino]cyclobut-3-ene-1 ,2-dione

3-[(2-oxo-1 ,2-dihydropyridin-3-yl)amino]-4-{[2-(2,2,2-

Example 115 trifluoroethoxy)phenyl]amino}cyclobut-3-ene-1 ,2-dione

3-[(2-oxo-1 ,2-dihydropyridin-3-yl)amino]-4-{[1-(1 ,3-thiazol-5-

Example 116 yl)ethyl]amino}cyclobut-3-ene-1 ,2-dione

3-[(1-isobutylcyclopropyl)amino]-4-[(2-oxo-1 ,2-dihydropyridin-3-

Example 117 yl)amino]cyclobut-3-ene-1 ,2-dione

3-[(2-oxo-1 ,2-dihydropyridin-3-yl)amino]-4-[(1-

Example 118 phenylcyclobutyl)amino]cyclobut-3-ene-1 ,2-dione

4-[1-({3,4-dioxo-2-[(2-oxo-1 ,2-dihydropyridin-3-yl)amino]cyclobut-1-en-1-

Example 119 yl}amino)ethyl]benzenesulfonamide

3-{[1-(2-chlorophenyl)ethyl]amino}-4-[(2-oxo-1 ,2-dihydropyridin-3-

Example 120 yl)amino]cyclobut-3-ene-1 ,2-dione

3-[(2-oxo-1 ,2-dihydropyridin-3-yl)amino]-4-{[(1S)-1-pyrazin-2-

Example 121 ylethyl]amino}cyclobut-3-ene-1 ,2-dione

3-[(2-oxo-1 ,2-dihydropyridin-3-yl)amino]-4-{[(1 R)-1-pyridin-2-

Example 122 ylethyl]amino}cyclobut-3-ene-1 ,2-dione

3-[(2-oxo-1 ,2-dihydropyridin-3-yl)amino]-4-{[(1S)-1-quinolin-4-

Example 123 ylethyl]amino}cyclobut-3-ene-1 ,2-dione

3-[(1-imidazo[1 ,2-a]pyridin-2-ylpropyl)amino]-4-[(2-oxo-1 ,2-dihydropyridin-

Example 124 3-yl)amino]cyclobut-3-ene-1 ,2-dione

3-[(2-oxo-1 ,2-dihydropyridin-3-yl)amino]-4-(tetrahydrofuran-3-

Example 125 ylamino)cyclobut-3-ene-1 ,2-dione 3-{[1-(4-fluorophenyl)cyclobutyl]amino}-4-[(2-oxo-1 ,2-dihydropyridin-3-

Example 126 yl)amino]cyclobut-3-ene-1 ,2-dione

3-{[1-(4-chlorophenyl)ethyl]amino}-4-[(2-oxo-1 ,2-dihydropyridin-3- Example 127 yl)amino]cyclobut-3-ene-1 ,2-dione

3-[(2-oxo-1 ,2-dihydropyridin-3-yl)amino]-4-{[(1S)-1-(1 ,3-thiazol-2- Example 128 yl)ethyl]amino}cyclobut-3-ene-1 ,2-dione

3-[(2-oxo-1 ,2-dihydropyridin-3-yl)amino]-4-{[(1S)-1- Example 129 phenylethyl]amino}cyclobut-3-ene-1 ,2-dione

3-[(2-oxo-1 ,2-dihydropyridin-3-yl)amino]-4-[(1-pyridin-4- Example 130 ylethyl)amino]cyclobut-3-ene-1 ,2-dione

3-[(2-oxo-1 ,2-dihydropyridin-3-yl)amino]-4-[(1- Example 131 phenylcyclopropyl)amino]cyclobut-3-ene-1 ,2-dione

3-{[1-(3,4-difluorophenyl)-1-methylethyl]amino}-4-[(2-oxo -1 ,2- Example 132 dihydropyridin-3-yl)amino]cyclobut-3-ene-1 ,2-dione

3-({cyclopropyl[2-fluoro-3-(trifluoromethyl)phenyl]methyl }amino)-4-[(2-oxo- Example 133 1 ,2-dihydropyridin-3-yl)amino]cyclobut-3-ene-1 ,2-dione

3-[(2-oxo-1 ,2-dihydropyridin-3-yl)amino]-4-{[(1 R)-1-pyridin-4- Example 134 ylethyl]amino}cyclobut-3-ene-1 ,2-dione

3-{[(1 R)-2-methoxy-1-phenylethyl]amino}-4-[(2-oxo-1 ,2-dihydropyridin-3- Example 135 yl)amino]cyclobut-3-ene-1 ,2-dione

S-flHS-chlorophenyOcyclopropyllaminoJ^-^-oxo-i ^-dihydropyridin-S- Example 136 yl)amino]cyclobut-3-ene-1 ,2-dione

3-{[1-(3-ethyl-1 ,2,4-oxadiazol-5-yl)ethyl]amino}-4-[(2-oxo-1 ,2- Example 137 dihydropyridin-3-yl)amino]cyclobut-3-ene-1 ,2-dione

3-{[1-(5-methylisoxazol-3-yl)ethyl]amino}-4-[(2-oxo-1 ,2-dihydropyridin-3- Example 138 yl)amino]cyclobut-3-ene-1 ,2-dione

3-{[(1S)-2-methyl-1-(4H-1 ,2,4-triazol-3-yl)propyl]amino}-4-[(2-oxo-1 ,2-

Example 139 dihydropyridin-3-yl)amino]cyclobut-3-ene-1 ,2-dione

Example 140 3-{[2-cyclopropyl-1-(3-fluoro-4-methylphenyl)ethyl]amino}-4- [(2-oxo-1 ,2- dihydropyridin-3-yl)amino]cyclobut-3-ene-1 ,2-dione

3-[(2-oxo-1 ,2-dihydropyridin-3-yl)amino]-4-[(2,2,2-trifluoro-1-pyridin- 2-

Example 141 ylethyl)amino]cyclobut-3-ene-1 ,2-dione

3-{[(1 R)-1-(1-naphthyl)ethyl]amino}-4-[(2-oxo-1 ,2-dihydropyridin-3-

Example 142 yl)amino]cyclobut-3-ene-1 ,2-dione

3-{[1-(4-fluorophenyl)-2-methylpropyl]amino}-4-[(2-oxo-1 ,2-dihydropyridin-

Example 143 3-yl)amino]cyclobut-3-ene-1 ,2-dione

N^-ti^lS^-dioxo^-^-oxo-i ^-dihydropyridin-S-yOaminojcyclobut-i-en-

Example 144 1 -yl}amino)ethyl]phenyl}-1 ,1 ,1 -trif luoromethanesulfonamide

3-[(2-oxo-1 ,2-dihydropyridin-3-yl)amino]-4-({1-[3-(2,2,2-

Example 145 trifluoroethoxy)phenyl]ethyl}amino)cyclobut-3-ene-1 ,2-dione

3-{[1-(3,4-dichlorophenyl)ethyl]amino}-4-[(2-oxo-1 ,2-dihydropyridin-3-

Example 146 yl)amino]cyclobut-3-ene-1 ,2-dione

3-[(2-oxo-1 ,2-dihydropyridin-3-yl)amino]-4-{[(1 R,2R)-2-

Example 147 phenylcyclopentyl]amino}cyclobut-3-ene-1 ,2-dione

4-[1-({3,4-dioxo-2-[(2-oxo-1 ,2-dihydropyridin-3-yl)amino]cyclobut-1-en-1-

Example 148 yl}amino)ethyl]-2-(trifluoromethyl)benzonitrile

3-{[1-(3-chlorophenyl)-1-methylethyl]amino}-4-[(2-oxo-1 ,2-dihydropyridin-

Example 149 3-yl)amino]cyclobut-3-ene-1 ,2-dione

S-^-oxo-i ^-dihydropyridin-S-yOaminoH-^i-phenylbutyOaminojcyclobut-

Example 150 3-ene-1 ,2-dione

3-[(2-oxo-1 ,2-dihydropyridin-3-yl)amino]-4-({1-[2-

Example 151 (trifluoromethyl)phenyl]ethyl}amino)cyclobut-3-ene-1 ,2-dione

3-[( 1 -cyclopropylethyl)amino]-4-[(2-oxo- 1 ,2-d ihydropyrid in-3-

Example 152 yl)amino]cyclobut-3-ene-1 ,2-dione

3-[(2-oxo-1 ,2-dihydropyridin-3-yl)amino]-4-{[(1 R)-1-quinolin-4-

Example 153 ylethyl]amino}cyclobut-3-ene-1 ,2-dione

3-[(2-oxo-1 ,2-dihydropyridin-3-yl)amino]-4-({1-[2-(2,2,2-

Example 154 trifluoroethoxy)phenyl]ethyl}amino)cyclobut-3-ene-1 ,2-dione 4-[1-({3,4-dioxo-2-[(2-oxo-1 ,2-dihydropyridin-3-yl)amino]cyclobut-1-en-1-

Example 155 yl}amino)ethyl]benzonitrile

3-{[cyclopropyl(4-methoxyphenyl)methyl]amino}-4-[(2-oxo-1 ,2- Example 156 dihydropyridin-3-yl)amino]cyclobut-3-ene-1 ,2-dione

3-[(2-oxo-1 ,2-dihydropyridin-3-yl)amino]-4-{[(1 R)-1- Example 157 phenylethyl]amino}cyclobut-3-ene-1 ,2-dione

S-^S^-dioxo^-I^IR^I-phenylpropyljaminoJcyclobut-i-en-i-yO aminol-N- Example 158 methyl-6-oxo-1 ,6-dihydropyridine-3-carboxamide

3-[(2-oxo-6-phenyl-1 ,2-d ihyd ropyrid in-3-yl)am ino]-4-{[( 1 R)-1 - Example 159 phenylpropyl]amino}cyclobut-3-ene-1 ,2-dione

S-^i-ethylpropyOaminol^-^-oxo-i ^-dihydropyridin-S-yOaminojcyclobut- Example 160 3-ene-1 ,2-dione

3-[(2-oxo-1 ,2-dihydropyridin-3-yl)amino]-4-{[(1S)-1- Example 161 phenylpropyl]amino}cyclobut-3-ene-1 ,2-dione

3-[(2-oxo-1 ,2-dihydropyridin-3-yl)amino]-4-{[(1S)-1- Example 162 phenylpropyl]amino}cyclobut-3-ene-1 ,2-dione

3-{[(1S)-1 ,2-dimethylpropyl]amino}-4-[(2-oxo-1 ,2-dihydropyridin-3- Example 163 yl)amino]cyclobut-3-ene-1 ,2-dione

3-(cyclohexylamino)-4-[(2-oxo-1 ,2-dihydropyridin-3-yl)amino]cyclobut-3- Example 164 ene-1 ,2-dione

S-lti^-chlorobenzyOcyclopropyllaminoJ^-^-oxo-i ^-dihydropyridin-S- Example 165 yl)amino]cyclobut-3-ene-1 ,2-dione

3-{[1-(4-fluorophenyl)propyl]amino}-4-[(2-oxo-1 ,2-dihydropyridin-3- Example 166 yl)amino]cyclobut-3-ene-1 ,2-dione

3-{[1-methyl-2-(6-methylpyridin-2-yl)ethyl]amino}-4-[(2-o xo-1 ,2- Example 167 dihydropyridin-3-yl)amino]cyclobut-3-ene-1 ,2-dione

3-[(2-imidazo[2,1-b][1 ,3]thiazol-6-yl-1-methylethyl)amino]-4-[(2-oxo-1 ,2-

Example 168 dihydropyridin-3-yl)amino]cyclobut-3-ene-1 ,2-dione

Example 169 3-{[1-(2-methyl-1 ,3-thiazol-4-yl)ethyl]amino}-4-[(2-oxo-1 ,2-dihydropyridin- 3-yl)amino]cyclobut-3-ene-1 ,2-dione

3-{[1-(1 ,5-dimethyl-1 H-pyrazol-4-yl)ethyl]amino}-4-[(2-oxo-1 ,2-

Example 170 dihydropyridin-3-yl)amino]cyclobut-3-ene-1 ,2-dione

3-[(2-oxo-1 ,2-dihydropyridin-3-yl)amino]-4-[(1-pyridin-2- Example 171 ylcyclopropyl)amino]cyclobut-3-ene-1 ,2-dione

3-{[1-(6-methylpyridin-3-yl)ethyl]amino}-4-[(2-oxo-1 ,2-dihydropyridin-3- Example 172 yl)amino]cyclobut-3-ene-1 ,2-dione

3-{[1-(3,5-dimethyl-1 H-pyrazol-4-yl)ethyl]amino}-4-[(2-oxo-1 ,2- Example 173 dihydropyridin-3-yl)amino]cyclobut-3-ene-1 ,2-dione

3-{[(1 R)-1-(methoxymethyl)propyl]amino}-4-[(2-oxo-1 ,2-dihydropyridin-3- Example 174 yl)amino]cyclobut-3-ene-1 ,2-dione

3-{[2-(1 H-indazol-3-yl)-1-methylethyl]amino}-4-[(2-oxo-1 ,2-dihydropyridin- Example 175 3-yl)amino]cyclobut-3-ene-1 ,2-dione

3-{[1-(4-methyl-4H-1 ,2,4-triazol-3-yl)ethyl]amino}-4-[(2-oxo-1 ,2- Example 176 dihydropyridin-3-yl)amino]cyclobut-3-ene-1 ,2-dione

3-[(2-oxo-1 ,2-dihydropyridin-3-yl)amino]-4-(tetrahydro-2H-pyran-3- Example 177 ylamino)cyclobut-3-ene-1 ,2-dione

3-{[(1R)-1-(5-methyltetrahydrofuran-2-yl)propyl]amino}-4- [(2-oxo-1 ,2- Example 178 dihydropyridin-3-yl)amino]cyclobut-3-ene-1 ,2-dione

3-{[(1R)-1-(5-methyltetrahydrofuran-2-yl)propyl]amino}-4- [(2-oxo-1 ,2-

Example 179 dihydropyridin-3-yl)amino]cyclobut-3-ene-1 ,2-dione

Example 180 3-anilino-4-[(2-oxo-1 ,2-dihydropyridin-3-yl)amino]cyclobut-3-ene-1 ,2-dione

3-[(2-methoxyphenyl)amino]-4-[(2-oxo-1 ,2-dihydropyridin-3- Example 181 yl)amino]cyclobut-3-ene-1 ,2-dione

3-[(2,3-dichlorophenyl)amino]-4-[(2-oxo-1 ,2-dihydropyridin-3-

Example 182 yl)amino]cyclobut-3-ene-1 ,2-dione

3-[(2-chlorophenyl)amino]-4-[(2-oxo-1 ,2-dihydropyridin-3-

Example 183 yl)amino]cyclobut-3-ene-1 ,2-dione Example 184 3-[(2-bromophenyl)amino]-4-[(2-oxo-1 ,2-dihydropyridin-3- yl)amino]cyclobut-3-ene-1 ,2-dione

3-[(2-oxo-1 ,2-dihydropyridin-3-yl)amino]-4-{[2-

Example 185 (trifluoromethoxy)phenyl]amino}cyclobut-3-ene-1 ,2-dione

3-[(3-chloro-2-fluorophenyl)amino]-4-[(2-oxo-1 ,2-dihydropyridin-3-

Example 186 yl)amino]cyclobut-3-ene-1 ,2-dione

3-{[2-(difluoromethoxy)phenyl]amino}-4-[(2-oxo-1 ,2-dihydropyridin-3-

Example 187 yl)amino]cyclobut-3-ene-1 ,2-dione

3-[(2-methoxyphenyl)amino]-4-[(2-oxo-1 ,2-dihydropyridin-3-

Example 188 yl)amino]cyclobut-3-ene-1 ,2-dione

3-[(2-oxo-1 ,2-dihydroquinolin-3-yl)amino]-4-{[(1R)-1-

Example 189 phenylpropyl]amino}cyclobut-3-ene-1 ,2-dione

The following compounds are also examples of compounds of formula (I):

31146

106

Biological Data

CXCR2 membrane i binding filtration assay

10Ox stock solutions of test compounds were first prepared in 100% DMSO then diluted 10-fold with CXCR2 assay buffer (5OmM Hepes, pH 7.4, 5mM MgCI ₂ , 1 mM CaCI ₂ , 0.2% BSA, solution filter sterilized prior to use). A 1 nM stock of [ ¹²⁵ I] IL-8 (Perkin Elmer) is prepared in CXCR2 assay buffer. Frozen stock aliquots of hCXCR2-CHO over-expressing membranes are thawed on ice before diluting in assay buffer to a concentration of 31.25 μg/ml in room temperature assay buffer, immediately prior to use. Total Binding of [ ¹²⁵ I] IL-8 is defined in the presence of test compound vehicle (10% DMSO in assay buffer).

Assays are performed in 96 well 1 ml polypropylene deep well plates. Total assay volume is 200μl. Test compounds are profiled as 10-point, half-log increment IC ₅₀ curves in singlicate to a maximum final assay concentration of 10μM. The final assay concentration of [ ¹²⁵ I] IL-8 is 0.1 nM in all wells. The final assay concentration of DMSO is 1% in all wells. All wells contain 0.5ug of hCXCR2-CHO membrane suspension. Test compound or vehicle are added to the plate first (20ul/well). 20μl of 1 nM [ ¹²⁵ I] IL-8 is added to all wells. Finally, 160 μl of membrane suspension (3.125 μg/ml) is added to all wells in the plate. Assay plates are sealed and shaken for 22.5 hours at room temperature. Separation of free and receptor bound [ ¹²⁵ I] IL-8 is achieved by vacuum filtration, followed by 3 x 1 ml with wash buffer (5OmM Hepes, pH 7.4,50OmM NaCI, 0.1 % BSA), onto 96-well GF/C filter plates (Perkin Elmer), using a Packard filtermate harvester. Filter plates are pre-soaked for 2 hours with 0.33% PEI and primed with 5OmM Hepes, pH 7.4, 0.5% BSA, before filtration of the assay. Following filtration, the GF/C plates are dried for 2 hours at 45 ⁰ C. Before the addition of 50μl/well of 'Microscint 0' scintillation cocktail (Perkin Elmer). CPM/well are determined by reading on a Packard Topcount NXT counter. [ ¹²⁵ I] IL-8 binding (cpm) in the presence of test compound is plotted versus compound concentration (on a Log scale) to determine an IC ₅₀ from the resultant sigmoid curve. IC ₅₀ values are corrected to K ₁ values by applying the Cheng Prussoff equation:

Cheng-Prussoff equation: Ki = IC50 1 + [L]/Kd

Where IC ₅₀ is the concentration of test compound , inhibiting specific radioligand binding by 50%. [L] is the free radioligand concentration and K _D and K, are the equilibrium dissociation constants of [ ¹²⁵ l]-IL-8 and test compound respectively.

CXCR2 membrane binding scintillation proximity assay

100X stock solutions of test compounds are first prepared in 100% DMSO then diluted 10-fold with CXCR2 assay buffer (5OmM Hepes, pH 7.4, 5mM MgCI ₂ , 1 mM CaCI ₂ , 0.2% BSA, 0.05% pluronic F127, solution filter sterilised prior to use). A 1 nM stock of [ ¹²⁵ I] IL-8 (Perkin Elmer) is prepared in CXCR2 assay buffer. WGA PVT SPA beads are resuspended in CXCR2 assay buffer at 50mg/ml. Frozen stock aliquots of hCXCR2-CHO over-expressing membranes are thawed on ice and precoupled at 20ug protein/mg bead in 0.5x final volume CXCR2 assay buffer for 2 hours at 4oC. Precoupled bead/membrane mix is centrifuged at 2000rpm for 3 minutes and resuspended in final volume of CXCR2 assay buffer. Total Binding of [ ¹²⁵ I] IL-8 is defined in the presence of test compound vehicle (10% DMSO in assay buffer). Non-specific binding of [ ¹²⁵ I] IL-8 is defined in the presence of a final assay concentration of 4μM PF- 05058078. PF-05058078 is prepared as a 40OuM stock solution in 100% DMSO before diluting to a 10X stock of 40μM in CXCR2 assay buffer.

Assays are performed in 96 well non binding surface polystyrene plates. Total assay volume is 100μl. Test compounds are profiled as 10-point, half-log increment IC ₅₀ curves in singlicate to a maximum final assay concentration of 40μM. The final assay concentration of [ ¹²⁵ I] IL-8 is 0.1 nM in all wells. The final assay concentration of DMSO is 1 % in all wells. All wells contain 10ug of hCXCR2-HEK membrane precoupled with WGA PVT SPA bead. Test compound, vehicle or PF-05058078 are added to the plate first (10ul/well). 10μl of 1 nM [ ¹²⁵ I] IL-8 is added to all wells. Finally, 80 μl of membrane/bead suspension is added to all wells in the plate. Assay plates are sealed and shaken for 1 hour at room temperature. Plates are incubated for a further 9 hours. CPM/well are determined by reading on a Packard Topcount NXT counter. Specific binding of [ ¹²⁵ l]-IL-8 is calculated by subtracting non-specific binding from total binding values. Test compound data are expressed as a percentage of specific binding. Percentage specific binding in the presence of test compound is plotted versus compound concentration (on a Log scale) to determine an IC ₅₀ from the resultant sigmoid curve.

Human neutrophil chemotaxis assay 1

Human neutrophil isolation: Peripheral blood from healthy donors is collected by venipuncture in 4% (w/v) EDTA (9 parts blood: 1 part EDTA). The red blood cells are removed by sedimentation on 6% (w/v) Dextran (Sigma) for 40 minutes. The granulocytes in the supernatant are separated from the peripheral blood mononuclear cells using Ficoll-Paque PLUS (Amersham Biosciences) density gradient centrifugation at 400xg for 35 minutes. Contaminating red blood cells are removed using hypotonic shock lysis with ice-cold sterile water for 30 seconds followed by restoration of osmalarity with double strength PBS and the final granulocyte pellet is resuspended in ice cold assay buffer (RPMI + 2OmM Hepes + 2mM L-Glutamine + 0.1 % (w/v) BSA). The isolated leukocyte preparations are typically 85-95% neutrophils.

Human neutrophils are diluted in assay buffer to 8x10 ⁴ cells/well and added along with compound (or 1 % DMSO - final assay concentration) to the top chamber of a 96-well Multiscreen migration plate (Millipore, containing a 3μm polycarbonate filter). Chemo-attractant (1 nM IL-8 or 3nM GROα) in assay buffer is added along with compound (or 1 % DMSO) to the bottom chamber. Both halves are pre-incubated at 37 ⁰ C for 60 minutes prior to sandwiching the plate together. The chemotaxis assay is run for a further 60 minutes at 37 ⁰ C. The number of cells that migrate into the bottom chamber are determined using cell lysis in the presence of a fluorescent DNA dye (CyQuant Picogreen, Invitrogen). The samples are transferred onto a black clear-bottom 96-well plate and the fluorescence read using a Fusion plate reader (Packard, excitation filter 485nm, emission filter 535nm). The raw relative fluorescence units are converted into % of max stimulation using Basal (absence of chemo-attractant) and max (1 nM IL-8 or 3nM GROα) control wells on every plate.

Human neutrophil chemotaxis assay 2

Human neutrophil isolation: Peripheral blood from healthy donors is collected by venipuncture in 4% (w/v) EDTA/HBSS(-) (9 parts blood:1 part EDTA). The red blood cells are removed by sedimentation on 4% (w/v) Dextran/HBSS(-) (Pharmacosmos) for 40 minutes. The granulocytes in the supernatant are separated from the peripheral blood mononuclear cells using Ficoll-Paque PLUS (Amersham Biosciences) density gradient centrifugation at 400xg for 35 minutes. Contaminating red blood cells are removed using hypotonic shock lysis with ice- cold sterile water for 30 seconds followed by restoration of osmalarity with double strength PBS and the final granulocyte pellet is re-suspended in ice cold assay buffer (HBSS(+) +1 OmM D- Glucose + 0.1 % (w/v) BSA). The isolated leukocyte preparations are typically 85-95% neutrophils.

Human neutrophils are diluted in assay buffer to 8x10 ⁶ cells/well and added along with compound (or 1 % DMSO - final assay concentration) to the top chamber of a 96-well Multiscreen migration plate (Millipore, containing a 3μm polycarbonate filter). Chemoattractant (1 nM IL-8 or 3nM GROa) in assay buffer is added along with compound (or 1 % DMSO) to the bottom chamber. Both halves are pre-incubated at 37°C for 60 minutes prior to sandwiching the plate together. The chemotaxis assay is run for a further 60 minutes at 37°C. The number of cells that migrate into the bottom chamber are determined using cell lysis in the presence of a fluorescent DNA dye (CyQuant Picogreen, Invitrogen). The samples are transferred onto a black clear-bottom 96-well plate and the fluorescence read using a Fusion plate reader (Packard, excitation filter 485nm, emission filter 535nm). The raw relative fluorescence units are converted into % of max stimulation using Basal (absence of chemoattractant) and max (1 nM IL-8 or 3nM GROa) control wells on every plate.

Results