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Title:
UREA DERIVATIVES AND THEIR THERAPEUTIC USE
Document Type and Number:
WIPO Patent Application WO/2008/104756
Kind Code:
A1
Abstract:
A compound of formula (I) wherein R1 is C1-6 alkyl optionally substituted by OH, C1-4 alkyl, SH, C1-4 alkylthio, phenyl or indol-3-yl, wherein C1-4 alkyl and C1-4 alkylthio are optionally substituted by phenyl and indol-3-yl is optionally N-substituted by -SO2-C1-4 alkyl; either R2 and R3 are independently selected from H, C1-4 alkyl, C1-4 alkoxy, C3-8 carbocyclyl, heterocyclyl, aryl and heteroaryl, and C1-4 alkyl is optionally substituted by OH, C1-4 alkoxy, C3-8 carbocyclyl, heterocyclyl, aryl or heteroaryl; or NR2 R3 is heterocyclyl optionally substituted by OH, C1-4 alkyl or C1-4 alkoxy and optionally fused to a 5 or 6-membered aromatic or heteraromatic ring; R4 is H, C1-6 alkyl, C3-6 alkenyl, C3-6 alkynyl, C3-6 carbocyclyl or heterocyclyl; R5 is H, C1-4 alkyl, C3-6 carbocyclyl or C1-2 alkyl substituted by C3-6 carbocyclyl, and carbocyclyl is optionally substituted by methyl; or a pharmaceutically acceptable salt or solvate thereof. Such compounds have anti-bacterial activity.

Inventors:
CHANDLER STEPHEN JOHN (GB)
MURRAY PETER JOHN (GB)
Application Number:
GB2008/000640
Publication Date:
September 04, 2008
Filing Date:
February 26, 2008
Export Citation:
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Assignee:
SERENTIS LTD (GB)
CHANDLER STEPHEN JOHN (GB)
MURRAY PETER JOHN (GB)
International Classes:
C07C275/24; A61K31/17; A61P31/04
Foreign References:
US20020119962A12002-08-29
Other References:
DECICCO, C.P. ET AL.: "Amide surrogates of matrix metalloproteinase inhibitors: urea and sulfonamide mimics", BIOORG. MED. CHEM. LETT., vol. 7, no. 18, 1997, pages 2331 - 2336, XP002483572
HACKBARTH, C.J. ET AL: "N-Alkyl Urea hydroxamic acids as new class of peptide deformylase inhibitors with antibacterial activity", ANTIMICROBIAL AGENTS AND CHEMOTHERAPY, vol. 46, no. 9, 2002, pages 2752 - 2764, XP002483573
DATABASE BEILSTEIN [online] BEILSTEIN INSTITUTE FOR ORGANIC CHEMISTRY, FRANKFURT-MAIN, DE; XP002485596, Database accession no. 7050828, 7056080
DATABASE BEILSTEIN [online] BEILSTEIN INSTITUTE FOR ORGANIC CHEMISTRY, FRANKFURT-MAIN, DE; XP002485597, Database accession no. 3158391, 6343043
Attorney, Agent or Firm:
GILL JENNINGS & EVERY LLP (7 Eldon Street, London EC2M 7LM, GB)
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Claims:

Claims

1. A compound of formula (I)

(I) wherein R 1 is C 1-6 alkyl optionally substituted by OH, C 1-4 alkyl, SH, C 1-4 alkylthio, phenyl or indol-3-yl, wherein C 1-4 alkyl and C 1-4 alkylthio are optionally substituted by phenyl and indol-3-yl is optionally N-substituted by -SO 2 -C 1-4 alkyl; either R 2 and R 3 are independently selected from H, C 1-4 alkyl, C 1-4 alkoxy, C 3-8 carbocyclyl, heterocyclyl, aryl and heteroaryl, and C 1-4 alkyl is optionally substituted by OH, Ci -4 alkoxy, C 3-8 carbocyclyl, heterocyclyl, aryl or heteroaryl; or NR 2 R 3 is heterocyclyl optionally substituted by OH, C 1-4 alkyl or C 1-4 alkoxy and optionally fused to a 5 or 6-membered aromatic or heteraromatic ring; R 4 is H, C 1-6 alkyl, C 3-6 alkenyl, C 3-6 alkynyl, C 3-6 carbocyclyl or heterocyclyl;

R 5 is H, C 1-4 alkyl, C 3-6 carbocyclyl or C 1-2 alkyl substituted by C 3-6 carbocyclyl, and carbocyclyl is optionally substituted by methyl; or a pharmaceutically acceptable salt or solvate thereof. 2. A compound according to claim 1 , wherein R 1 is methyl, isopropyl, isobutyl, sec-butyl, -CH 2 -4-hydroxy-phenyl, -CH 2 -4-(C 1 . 4 alkoxy)-alkylphenyl, -CH 2 -indol-3-yl, -CH 2 -(λ/-SO 2 C 1 . 4 alkyl)-indol-3-yl, benzyl, -ethylphenyl, -CH 2 SH, -CH 2 -SC 1 . 4 alkyl, -CH 2 -SC 1 . 2 alkylphenyl, -CH 2 -CH 2 -S-Me, -CH 2 OH, -CH 2 -OC 1-2 alkylphenyl, -CH(Me)(OH), -CH(Me)OC 1-4 alkyl or -CH(Me)OCi -2 alkylphenyl; and either R 2 or R 3 are independently selected from H, C 1-6 alkyl, -Co -4 alkyl(C 1-4 alkoxy), -C 2 . 5 alkylhydroxy, -C 0 - 4 alkyl -Cs-βcarbocyclyl,

-Co^alkylheterocyclyl, -(C 0 - 4 alkyl)-aryl and -(C 0 - 4 alkyl)-heteroaryl, in which aryl and heteroaryl are optionally substituted by one or more groups selected from halogen, CN, -Ci- 4 alkyl, -Ci -4 fluoroalkyl, Ci -4 alkoxy, -Ci. 4 fluoroalkoxy, -N(C 0-4 alkyl)(C 0-4 alkyl) > -SO 2 Ci. 4 alkyl, -S0 2 N(C M alkyl)(Co- 4 alkyl), hydroxyl, -C(0)N(C 0 - 4 alkyl)(Co- 4 alkyl), C 2-4 alkenyl, C 2-4 alkynyl, -NC(O)C 0 -4alkyl, -NC(O)OCi -4 alkyl, -NHC(O)aryl, -0(Co-4alkyl)aryl, -NHC(O)heteroaryl, -O(C 0-4 alkyl)heteroaryl, -0(C 1-4 alkyl)alkoxy, -(Ci -4 alkyl)aryloxy and -(Ci- 4 alkyl)heteroaryloxy; or NR 2 R 3 is as defined in claim 1. 3. A compound according to claim 1 or claim 2, wherein R 1 is phenylethyl.

4. A compound according to any preceding claim, wherein R 2 is H.

5. A compound according to any preceding claim, wherein R 3 is methyl.

6. A compound according to any preceding claim, wherein R 4 is H.

7. A compound according to any preceding claim wherein R 5 is Ci -4 alkyl, C 3 . 6 carbocyclyl or Ci -2 alkyl substituted by C 3-6 carbocyclyl.

8. A compound according to claim 7, wherein R 5 is isobutyl or cyclopropylmethyl.

9. A compound according to claim 1, which is (S)-2-{3-[2-(hydroxyamino)-2- oxoethyl]-3-isobutylureido}-λ/-methyl-4-phenylbutanamide. 10. A compound according to claim 1, which is (S)-2-{3-(cyclopropylmethyl)- 3-[2-(hydroxyamino)-2-oxoethyl]ureido}-λ/-methyl-4-phenylbutanamide.

11. A compound according to any preceding claim, for use in therapy.

12. A compound according to claim 11 , wherein the therapy is of a disease associated with infection or colonisation by a pathogenic bacterium. 13. A pharmaceutical composition comprising a compound according to any preceding claim, in combination with one or more pharmaceutically acceptable diluents or carriers.

14. Use of a compound according to any of claims 1 to 10, for the manufacture of a medicament in the treatment of a disease associated with infection or colonisation by a pathogenic bacterium.

15. A compound of formula (II)

(H) wherein R 1 , R 2 , R 3 , R 4 and R 5 are as defined in any of claims 1 to 10, and L 1 is a leaving group.

Description:

UREA DERIVATIVES AND THEIR THERAPEUTIC USE Field of the Invention

The present invention relates to novel compounds that are urea derivatives and to their therapeutic use. Background of the Invention

A number of bacteria are pathogenic and are targets for therapy against the diseases they cause or exacerbate. One potential therapy is to target bacterial metalloprotease enzymes. It may be desirable to inhibit these enzymes in a selective manner since many metalloproteases have important roles in animals. In particular, in some circumstances it would be desirable to selectively inhibit bacterial metalloproteases (such as those of MA(E) subclan M4 family) over mammalian metalloproteases (such as those of MA(M) subclan M10 and M12 families) and, for example, to selectively inhibit bacterial metalloproteases (e.g. aureolysin) over animal (e.g. human) metalloproteases. All peptidases in the M4 family bind a single, catalytic zinc ion. A list of bacteria that produce metalloenzymes within the M4 family may be noted by reference to the website http://merops.sanqer.ac.uk.

Several metalloprotease-producing bacterial species are important human and animal pathogens. These include Aeromonas, Bacillus, Bordetella, Burkholderia, Serratia, Staphyloccus, Pseudomonas and Vibrio sp.

For example, Staphylococcus aureus has been found to colonise the skin lesions of more than 90% of atopic dermatitis (AD, sometimes referred to as eczema) patients (Leyden et al, AM Br. J. Dermatol. 90:525-530, 1974), while being present in only 5% of normal subjects. AD is a chronic, relapsing condition which is characterised by pruritus, erythema and inflammation. The bacterium has been shown to be important in the exacerbation and chronicity of AD through the release of toxins (e.g. enterotoxins A, B, C and D; toxic shock syndrome toxin), many of which are highly antigenic in nature, thus exacerbating the inflammatory responses in the skin (Leung, et al, J. CHn. Invest. 92 1374-80, 1993). One particular study in children found that 81% of patients had Staphylococcus aureus colonisation (compared to 4% of the control group), showing that disease severity could be correlated with colonisation by toxigenic strains (Bunikowski, et al, J. Allergy CHn. Immunol. 105(4):814-819, 2000).

Staphylococcus aureus colonisation and infections are also found in Netherton's Disease, a disease characterised by skin barrier disruption with several features in common with AD.

Targeting enzymes secreted by Staphylococcus aureus may be useful in treatment of AD and Netherton's disease. Aureolysin (EC 3.4.24.29) is a metalloprotease, which is secreted by Staphylococcus aureus (Dubin, G. Biol. Chem. 383:1075-1086, 2002). Aureolysin is a member of the thermolysin protein family, class M4, being dependent upon zinc and calcium for its activity, and has a low substrate specificity. Staphylococcus aureus is also found in a range of other diseases; for example, it is found commonly in lung infections, particularly in individuals with cystic fibrosis (CF), and in infections of traumatic or surgical lesions. It also causes impetigo & scalded skin syndrome.

Another example is the secreted M4 protease of Pseudomonas aeruginosa, pseudolysin (also known as LasB gene product or Las B elastase). Pseudolysin is the major virulence factor of Pseudomonas aeruginosa septicaemia, causing tissue damage (especially in the lung where elastin is degraded) and may compromise the immune system by degradation of immunoglobulins, complement components and serpins. Furthermore, patients suffering from CF are hyper-susceptible to chronic

Pseudomonas aeruginosa lung infections. In a healthy person, there is a constant flow of mucus over the surfaces of the air passages in the lungs. This removes debris and bacteria. In a patient with CF, this mucus is excessively thick and sticky and cannot perform this role properly. The sticky mucus also provides an ideal environment for bacterial growth. This can put a patient with CF at risk of bacterial chest infections and pneumonia.

Work with strains of Pseudomonas aeruginosa differing in secretion of pseudolysin, in a mouse model of diffuse panbronchiolitis, indicated that the enzyme is a potent inflammatory factor (Yanagihara.K., et al, J. Med. Microbiol. (2003) 52, 531-535), leading to the suggestion that control of release of pseudolysin by P. aeruginosa may be beneficial for patients with this condition. Pseudomonas aeruginosa can also cause keratitis.

Burkholderia cepacia, which produces the ZmpA metalloprotease, has emerged as a pathogen in patients with CF that may lead to rapid deterioration of lung function. Infection with B. cepacia complex bacteria may be highly transmissible in CF patients, and epidemics have been described in a number of CF centres, in the UK, the USA and Canada.

The Msp protease from Legionella sp. e.g. Legionella pneumophila, may have a role in the virulence of Legionaire's disease (Sahney, et al Med. Microbiol. (2001) 50, 517-525).

Vibriolysin from Vibrio cholerae plays a role in attachment of the bacterium to intestinal epithelium and may activate Vibrio toxins. Inhibiting vibriolysin may be an approach to the treatment of cholera infection.

Vibrio vulnificus can cause disease in those who eat contaminated seafood or have an open wound that is exposed to seawater. Among healthy people, ingestion of Vibrio vulnificus can cause vomiting, diarrhea, and abdominal pain. In immunocompromised persons, particularly those with chronic liver disease, Vibrio vulnificus can infect the bloodstream, causing a severe and life-threatening illness characterized by fever and chills, decreased blood pressure (septic shock) and blistering skin lesions. Vibrio vulnificus can also cause an infection of the skin when open wounds are exposed to warm seawater.

Serratia marcescens can cause conjunctivitis, keratitis, endophthalmitis and tear duct infections. It is common in the respiratory and urinary tracts of adults and the gastrointestinal system of children.

US5183900 discloses certain dipeptide analogues based on derivatives of 3-substituted succinic acid-1 -hydroxamate including ilomastat.

WO94/02447 discloses certain dipeptide analogues based on derivatives of 3-substituted 2-hydroxy-succinic acid 1 -hydroxamate including marimastat.

EP1030842 discloses solimastat, i.e. λ/1-[2,2-dimethyl-1S-(pyridin-2- ylcarbamoyO-propyll-λM-thydroxyl^fl-isobutyl-SS-methoxy-suc cinamide. WO95/19957 discloses certain dipeptide analogues based on derivatives of 3-substituted 2-hydroxy-succinic acid 1 -hydroxamate including 2S-hydroxy- 3f?-[1S(λ/,λ/-dimethylcarbamoyl)-2,2-dimethyl-propylcarbam oyl]-5-methyl- hexanohydroxamic acid.

WO95/19956 discloses certain dipeptide analogues based on derivatives of 3-substituted 2-hydroxy-succinic acid 1 -hydroxamate.

EP0664284 and Whittaker et al., Chemical Reviews, (1999), 99, 2735- 2776, disclose certain dipeptide analogues based on derivatives of 2- and 3- substituted succinic acid 1 -hydroxamate.

WO2007/025999 (published after the priority date claimed herein) discloses the treatment or prevention of an inflammatory skin condition which is characterised by colonisation with Staphylococcus aureus, comprising the topical administration of an aureolysin inhibitor. WO2007/025999 also discloses succinate derivatives as aureolysin inhibitors. Summary of the Invention

According to the present invention, novel compounds are of formula (I)

(I) wherein R 1 , R 2 , R 3 , R 4 and R 5 are as defined in claim 1 , or a pharmaceutically acceptable salt or solvate thereof, including all tautomers and stereoisomers thereof. More particularly:

R 1 is methyl, isopropyl, isobutyl, sec-butyl, -CH 2 -4-hydroxy-phenyl,

-CH 2 -4-(C 1-4 alkoxy)-phenyl, -CH 2 -indol-3-yl, -CH 2 -(λ/-SO 2 C 1 - 4 alkyl)-indol-3-yl, benzyl, -ethylphenyl, -CH 2 SH, -CH 2 -SCi -4 alkyl, -CH 2 -SCi -2 phenyl, -CH 2 -CH 2 -S-

Me, -CH 2 OH, -CH 2 OC 1-4 alkyl. -CH 2 -OCi -2 phenyl -CH(Me)(OH),

-CH(Me)OCi. 4 alkyl or -CH(Me)OCi -2 alkylphenyl;

R 2 is H; Ci -6 alkyl; -C 0 - 4 alkyl(Ci- 4 alkoxy), -C 2-5 alkylhydroxy;

C 0 - 4 alkyl -C 3-8 Ca^OCyCIyI; -Co^alkylheterocyclyl; -(C 0 - 4 alkyl)-aryl or -(C 0 - 4 alkyl)- heteroaryl; in which aryl and heteroaryl are optionally substituted by one or more groups selected from halogen; CN; -Ci -4 alkyl; -Ci -4 fluoroalkyl; C 1-4 alkoxy;

-C 1-4 fluoroalkoxy; -N(C 0 - 4 alkyl)(C 0 - 4 alkyl); -SO 2 Ci -4 alkyl; -SO 2 N(C 0-4 alkyl)

(Co- 4 alkyl); hydroxy; -C(O)N(C 0 - 4 alkyl)(C 0-4 alkyl); C 2-4 alkenyl; C 2-4 alkynyl;

-NC(O)C 0-4 alkyl; -NC(O)OCi -4 alkyl; -NHC(O)aryl; -O(C 0 - 4 alkyl)aryl; -NHC(O)heteroaryl; -O(C 0 - 4 alkyl)heteroaryl; -O(C 1 . 4 alkyl)alkoxy; (Ci. 4 alkyl)aryloxy and -(C 1-4 alkyl)heteroaryloxy;

R 3 is H; d-βalkyl; -C 2 . 4 alkyl(C 1-4 alkoxy), -C 2-5 alkylhydroxy; -C 0 - 4 alkyl -Ca-βcarbocyclyl; -Co^alkylheterocyclyl; -(Co -4 alkyl)-aryl or -(C 0-4 alkyl)- heteroaryl; in which aryl and heteroaryl are optionally substituted by one or more groups selected from halogen; CN; -Ci. 4 alkyl; -Ci -4 fluoroalkyl; C 1 ^aIkOXy; C 1-4 fluoroalkoxy; -N(C 0 - 4 alkyl)(C 0 - 4 alkyl); -SO 2 Ci -4 alkyl; -SO 2 N(C 0 - 4 alkyl) (Co- 4 alkyl); hydroxy; -C(0)N(C 0-4 alkyl)(Co- 4 alkyl); C 2-4 alkenyl; C 2-4 alkynyl; -NC(0)Co- 4 alkyl; -NC(O)OC 1-4 alkyl; -NHC(O)aryl; -O(C 0 - 4 alkyl)aryl; -NHC(O)heteroaryl; -O(C 0 - 4 alkyl)heteroaryl; -O(C 1-4 alkyl)alkoxy; -(C 1-4 alkyl)aryloxy and -(C 1-4 alkyl)heteroaryloxy; or R 2 and R 3 may be joined such that NR 2 R 3 together is a heterocyclyl group which may be optionally substituted by a group selected from hydroxy, C 1-4 alkyl and C 1-4 alkoxy and which may optionally be fused to a 5-6 membered aromatic or heteroaromatic ring;

R 4 is H; d-ealkyl; C 3-6 alkenyl; C 3 - 6 alkynyl; -C 0-4 alkyl (C 3-6 carbocyclyl) or -Co^alkylheterocyclyl; and

R 5 is H; Ci -4 alkyl; or -Co-aalkyl-Ca-βcarbocyclyl optionally substituted by methyl.

* is a stereogenic centre.

Compounds of the invention can be used in therapy of a disease or infection caused by pathogenic bacteria, e.g. an infection or disease given above. Description of the Invention

Throughout the description and the claims, the expression "alkyl", unless specifically limited, denotes a Ci -6 alkyl group, e.g. Ci -4 alkyl group. Alkyl groups may be straight-chain or branched. Suitable alkyl groups include, for example, methyl, ethyl, propyl (e.g. n-propyl and /sopropyl), butyl (e.g n-butyl, isobutyl, sec-butyl and tert-butyl), pentyl (e.g. n-pentyl) or hexyl (e.g. n-hexyl). The xpression "alk", for example in the expressions "alkoxy" and "thioalkyl" should be interpreted in accordance with the definition of "alkyl". Exemplary alkoxy groups include methoxy, ethoxy, propoxy (e.g. n-propoxy), butoxy (e.g. -butoxy),

pentoxy (e.g. n-pentoxy) and hexoxy (e.g. n-hexoxy). Exemplary thioalkyl groups include methylthio.

The expression "alkenyl", unless specifically limited, denotes a C 26 alkenyl group, e.g. a C 24 alkenyl group, which contains at least one double bond at any desired location and which does not contain any triple bonds. Alkenyl groups may be straight chain or branched. Exemplary alkenyl groups including one double bond include vinyl (i.e. ethenyl), propenyl and butenyl. Exemplary alkenyl groups including two double bonds include pentadienyl, e.g. (1 E, 3E)- pentadienyl. The expression "cycloalkyl", unless specifically limited, denotes a C 3-12 cycloalkyl group, suitably a C 3-10 cycloalkyl group, more suitably a C 3-8 cycloalkyl group, e.g. a C 3-6 cycloalkyl group, which may optionally be substituted by 1 to 3 methyl groups. Exemplary cycloalkyl groups include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl and cyclooctyl. Preferably, the number of ring carbon atoms is three to six.

The expression "cycloalkenyl", unless specifically limited, denotes a C 5-12 cycloalkenyl group, suitably a C 3-10 cycloalkenyl group, more suitably a C 5-8 cycloalkenyl group e.g. a C 5-6 cycloalkenyl group, which may optionally be substituted by 1 to 3 methyl groups. Exemplary cycloalkenyl groups include cyclopropenyl, cyclohexenyl, cycloheptenyl and cyclooctenyl. Preferably, the number of ring carbon atoms is five to six.

The expression "carbocyclyl", unless specifically limited, denotes any ring system in which all the ring atoms are carbon and which contains between three and 8 ring carbon atoms, suitably between three and six carbon atoms and in which the ring may optionally be substituted by 1 to 3 methyl groups. Carbocyclyl groups may be saturated or partially unsaturated, but do not include aromatic rings. Examples of carbocyclyl groups include monocyclic and bicyclic ring systems, in particular monocyclic ring systems. Other carbocyclyl groups include bridged ring systems (e.g. bicyclo[2.2.1]heptenyl). A specific example of a carbocyclyl group is a cycloalkyl group. A further example of a carbocyclyl group is a cycloalkenyl group.

The expression "heterocyclyl", unless specifically limited, refers to a carbocycyl group wherein one or more (e.g. 1, 2 or 3) ring atoms are replaced by

heteroatoms selected from N, S and O. A specific example of a heterocyclyl group is heteroalkyl, i.e. a cycloalkyl group (e.g. cyclopentyl or more particularly cyclohexyl) wherein one or more (e.g. 1 , 2 or 3, particularly 1 or 2, especially 1) ring atoms are replaced by heteroatoms selected from N, S or O. Exemplary heterocyclyl groups containing one hetero atom include pyrrolidine, tetrahydrofuran and piperidine, and exemplary heterocyclyl groups containing two hetero atoms include morpholine and piperazine. A further example of a heterocyclyl group is 2,2-dimethyl-1,3-dioxyl. A further specific example of a heterocyclyl group is heterocycloalkenyl i.e. a cycloalkenyl group (e.g. a cyclohexenyl group) wherein one or more (e.g. 1 , 2 or 3, particularly 1 or 2, especially 1) ring atoms are replaced by heteroatoms selected from N, S and O. An example of such a group is dihydropyranyl (e.g. 3,4-dihydro-2H-pyran-2-yl-). An example of a substituted heterocyclyl group is λ/-methylpiperazine.

The expression "aryl", unless specifically limited, denotes a C 6- i 2 aryl group, suitably a C 6- io aryl group, more suitably a C 6 -β aryl group. Aryl groups will contain at least one aromatic ring (e.g. one, two or three rings), but may also comprise partially or fully unsaturated rings. An example of a typical aryl group with one aromatic ring is phenyl. Examples of aromatic groups with two aromatic rings include naphthyl. Examples of aryl groups which contain partially or fully unsaturated rings include pentalene and indene.

The expression "heteroaryl", unless specifically limited, denotes an aryl residue, wherein one or more (e.g. 1, 2, 3, or 4, suitably 1 , 2 or 3) ring atoms are replaced by heteroatoms selected from N, S and O, or else a 5-membered aromatic ring containing one or more (e.g. 1 , 2, 3, or 4, suitably 1 , 2 or 3) ring atoms selected from N, S and O. Exemplary monocyclic heteroaryl groups include pyridine (e.g. pyridin-2-yl, pyridin-3-yl or pyridin-4-yl), pyrimidine, pyrrole, furan, thiophene, oxazole, pyrazole, imidazole (e.g. imidazol-1-yl, imidazol-2-yl or imidazol-4-yl), thiazole, isoxazole, pyrazole (e.g. pyrazol-3-yl), triazole (e.g. 1 ,2,3-triazole or 1 ,2,4-triazole), tetrazole, pyridazine, pyrazine and isothiazole. Exemplary bicyclic heteroaryl groups include quinoline, benzothiophene, indole (e.g. 1 H-indol-6-yl), benzimidazole, indazole, purine, chromene, benzodioxolane, benzodioxane (e.g. 2,3-dihydro-benzo[1,4]dioxin-6-yl) and benzodioxepine.

The expression "-alkylaryl", unless specifically limited, denotes an aryl residue which is connected via an alkylene moiety.

The expression "-alkylheteroaryl", unless specifically limited, denotes a heteroaryl residue which is connected via an alkylene moiety. The term "halogen" or "halo" comprises fluorine (F), chlorine (Cl) and bromine (Br).

When R 1 is -CH 2 -4-(C 1-4 alkoxy)-phenyl, examples include CH 2 -4-methoxy-phenyl and -CH 2 -4-ethoxy-phenyl.

When R 1 is -CH 2 -(λ/-Sθ 2 C 1-4 alkyl)-indol-3-yl, examples include -CH 2 -(A/- SO 2 Me)-indol-3-yl and -CH 2 -(λ/-SO 2 Et)-indol-3-yl.

When R 1 is -CH 2 -SCi -4 alkyl, examples include -CH 2 -SMe, -CH 2 -SEt and - CH 2 -SPr.

When R 1 is -CH 2 -SCi -2 phenyl, examples include -CH 2 -S-CH 2 Ph and -CH 2 -S-CH 2 CH 2 Ph. When R 1 is -CH 2 OC 1 . 4 alkyl, examples include -CH 2 OMe, CH 2 OEt and

-CH 2 OPr.

When R 1 is -CH 2 -OC 1-2 alkyl phenyl, examples include -CH 2 -O-CH 2 Ph and -CH 2 -O-CH 2 CH 2 Ph.

When R 1 is -CH(Me)OC 1 . 4 alkyl, examples include -CH(Me)OMe, -CH(Me)OEt and -CH(Me)OPr.

When R 1 is -CH(Me)OCi- 2 alkylphenyl, examples include -CH(Me)OCH 2 Ph and -CH(Me)OCH 2 CH 2 Ph.

When R 2 or R 3 is C 1-6 alkyl, examples include methyl, ethyl, propyl (e.g. n-propyl, isopropyl), butyl (n-butyl, isobutyl, sec-butyl and te/f-butyl), pentyl and hexyl.

When R 2 or R 3 is -C 0 - 4 alkyl(C 1-4 alkoxy), examples include methoxy, ethoxy, propoxy, butoxy, methoxyethyl, methoxypropyl, methoxybutyl, ethoxyethyl, propoxymethyl, propoxypropyl and butoxymethyl.

When R 2 or R 3 is -C 2 . 5 alkylhydroxy, examples include hydroxyethyl, hydroxypropyl, hydroxybutyl and hydroxypentyl.

When R 2 or R 3 is -C 0 - 4 alkyl-C 3 - 8 carbocyclyl, examples include -C 0 - 4 alkyl- C 3 . 8 cycloalkyl and When R 2 or R 3 is

examples include cyclopropyl, cyclopropylmethyl, cyclopentyl, cyclohexylmethyl, cyclopropylethyl, cyclohexyl and cyclopropylbutyl.

When R 2 or R 3 is examples include cyclopentenylmethyl, cyclohexenyl, cyclohexenylmethyl and cyclohexenylethyl. When R 2 or R 3 is -Co^alkylheterocyclyl, examples include

-alkylheterocycloalkyl and -alkylheterocycloalkenyl. Examples include tetrahydrofuranyl, piperidinyl, -methyltetrahydrofuranyl, -methylpyrrolidin-2-yl,

-methylpiperidin-2-yl and -ethylmorpholinyl.

When R 2 or R 3 is -Co- 4 alkyl-aryl, examples include phenyl, 4-fluorophenyl, benzyl, 2-phenylethyl, 2-phenylpropyl, 3-phenylpropyl, tolylmethyl, 2-tolylethyl,

2-tolylpropyl, 3-tolylpropyl, fluorobenzyl, 2-(2-fluorophenyl)ethyl,

2-(2-fluorophenyl)propyl, 3-(2-f luorophenyl)propyl, naphthylen-1 -ylmethyl,

2-(naphthalen-2-yl)ethyl, 3-(naphthalen-2-yl)propyl and

3-(naphthalen-1 -yl)propyl. When R 2 or R 3 is -Co^alkyl-heteroaryl, examples include pyrazolyl, pyrazinyl, pyridinyl, thiadiazolyl, furan-3-ylmethyl, thiophen-2-ylethyl, pyrrolylethyl, indolylmethyl, benzofuran-3-ylmethyl, benzothiophenylmethyl,

(5-methylfuran-3-yl)methyl, (methylthiophenyl)methyl, (methylpyrrolyl)methyl,

(methylindolyl)methyl (for example, (5-methyl-1H-indol-3-yl)methyl), (methylbenzofuranyl)methyl, (methylbenzofuranyl)ethyl (for example,

2-(2-methylbenzofuran-3-yl)ethyl) and (methylbenzothiophenyl)methyl (for example (3-methylbenzo[6]thiophen-6-yl)methyl).

When R 2 and R 3 are joined such that NR 2 R 3 is a heterocyclyl group, examples include piperidinyl. When R 4 is Ci -6 alkyl, examples include methyl, ethyl, propyl (e.g. π-propyl, isopropyl) and butyl (e.g. n-butyl, isobutyl, sec-butyl and te/t-butyl). When R 4 is C 3-6 alkenyl, examples include propen-2-yl, buten-2-yl, buten-3-yl and hexen-4-yl.

When R 4 is C 3 - 6 alkynyl, examples include propyn-2-yl, butyn-2-yl, butyn-3-yl and hexyn-3-yl.

When R 4 is -Co- 4 alkyl(C 3 . 6 cycloalkyl), examples include cyclopropyl, cyclopentyl, cyclohexyl, -methylcyclopropyl, -ethylcyclopentyl, -propylcyclohexyl and -propylcyclopropyl.

When R 4 is -Co^alkylheterocyclyl, examples include -alkyl- heterocycloalkyl and -alkyl-heterocycloalkenyl. Examples include tetrahydrofuranyl, piperidinyl, -methyltetrahydrofuranyl, -methylpyrrolidin-2-yl, -methylpiperidin-2-yl and -ethylmorpholinyl. When R 5 is C 1-4 alkyl, examples include methyl, ethyl, propyl (e.g.

/7-propyl, isopropyl) and butyl (e.g. n-butyl, isobutyl, sec-butyl and tert-butyl).

When R 5 is -C 0- 2alkyl-C 3- 6carbocyclyl optionally substituted by methyl, examples include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, -methylcyclopropyl, -methyl(methyl-cyclopropyl), -ethylcyclopropyl, -propylcyclopropyl; and -methylcyclobutyl.

Preferably, R 1 is phenylethyl.

Preferably, R 2 is H.

Preferably, R 3 is Ci -4 alkyl. Most suitably, R 3 is methyl.

In one embodiment of the invention, R 4 is hydrogen. In another embodiment of the invention, R 4 is methyl.

When R 5 is Ci -4 alkyl, it is preferably isobutyl. When R 5 is -C 0 - 2 alkyl-C 3 - 6 carbocyclyl, it is preferably -methylcyclopropyl. Preferably, R 5 is -C 1-4 alkyl (e.g. isobutyl) -or -Co^alkyl-Ca-sCycloalkyl (e.g. -methylcyclopropyl). Most preferably, R 5 is C 1-4 alkyl, especially isobutyl. The molecular weight of the compounds of formula (I) is preferably less than 800, more preferably less than 600, even more preferably less than 500.

Specific compounds of the invention which may be mentioned are those included in the Examples and pharmaceutically acceptable salts thereof.

Compounds described herein may contain one or more asymmetric centres and may thus give rise to enantiomers and diastereomers. The present invention includes all such possible enantiomers, diastereomers as well as their racemic mixtures, their substantially pure resolved enantiomers, all possible geometric isomers, and pharmaceutically acceptable salts thereof. The above formula (I) is shown without a definitive stereochemistry at certain positions. The present invention includes all stereoisomers of formula (I) and pharmaceutically acceptable salts thereof. Further, mixtures of stereoisomers as well as isolated specific stereoisomers are also included. During the course of the synthetic procedures used to prepare such compounds, or in using racemization or

epimerization procedures known to those skilled in the art, the products of such procedures can be a mixture of stereoisomers. Suitably, the configuration at the stereogenic centre labelled * is (S) (as defined by the Cahn-lngold-Prelog R/S rules) except where R 1 is CH 2 SH, -CH 2 -SC 1-4 alkyl or -CH 2 -SC 1-2 phenyl when the configuration is (R)) (i.e. the amino acid for which the moiety is claimed would traditionally be defined as (L)).

The compounds of the invention may also exhibit atropisomerism, the present invention includes all atropisomers of formula (I) and mixtures thereof.

When a tautomer of the compound of formula (I) exists, the present invention includes any possible tautomers and pharmaceutically acceptable salts thereof, and mixtures thereof, except where specifically drawn or stated otherwise. The term "pharmaceutically acceptable salts" refers to salts prepared from pharmaceutically acceptable non-toxic bases or acids.

When the compound of formula (I) and pharmaceutically acceptable salts thereof exist in the form of solvates or polymorphic forms, the present invention includes any possible solvates and polymorphic forms. A type of a solvent that forms the solvate is not particularly limited so long as the solvent is pharmacologically acceptable. For example, water, ethanol, propanol or acetone can be used. Compounds of formula (I) may be prepared by a process comprising reaction of a compound of formula (II)

(II) wherein L 1 is a leaving group (e.g. alkoxy, such as methoxy), with hydroxylamine. Suitable conditions include stirring (e.g. at room temperature) in a polar aprotic organic solvent (e.g. dioxane or dimethylacetamide).

Compounds of formula (II) may be prepared by a process comprising reaction of a compound of formula (III)

(III) with a compound of formula (IV)

(IV) wherein L 2 and L 3 represent leaving groups, followed by reaction with a compound of formula (V)

(V) or a protected derivative thereof.

L 2 and L 3 may, for example, both represent -OCCI 3 , in which case compound (IV) is triphosgene. Suitable conditions for reaction of compound (III) with compound (IV) include stirring at room temperature in a polar aprotic solvent (e.g. tetrahydrofuran) in the presence of a base (e.g. triethylamine). Suitably, this is followed by addition of compound (V) to the intermediate formed in situ, i.e. addition of compound (V) to the intermediate formed in situ by reaction of compound (III) with compound (IV).

Compounds of formula (III) may be prepared from the corresponding amine NH 2 R 5 by reaction with a compound of formula (Vl)

wherein L 4 is a leaving group (e.g. halogen, such as Br). Suitable reaction conditions include reaction of the amine NHR 5 with (Vl) in a polar aprotic solvent

(e.g. dimethylsulfoxide or tetrahydrofuran) in the presence of a base (e.g. an amine such as triethylamine).

Compounds of formula (V) may be prepared by reaction of compound (VII)

(VII) wherein L 5 is OH or a leaving group such as alkoxy (e.g. methoxy) with the corresponding amine NHR 2 R 3 . When L 5 is OH, suitable conditions include those conventionally used for coupling an acid to an amine (e.g. in the presence of HOBt, DCC and triethylamine in an inert solvent such as DCM). The amine of compound (VII) may if desired be protected during this process by conversion to a suitable derivative, such as a carbamate, e.g. a Boc or a Cbz derivative, followed by deprotection. When L 5 is alkoxy, suitable conditions include those given above for reaction of compounds of formula (III) with NH 2 R 5 .

Compounds of formula (VII) may be prepared from compounds of formula (VIII)

(VIII) by alkylation, including reductive alkylation, of the suitably-protected amino acid (when L 5 is OH), or alternatively by alkylation, including reductive alkylation of the suitably protected amino acid ester (when L 5 is alkoxy). Compounds of formula (Vila), i.e. compounds of formula (VII) wherein L 5 is OH, and R 4 is Me as shown below, may be conveniently prepared by one or more methods designed for the preparation of optically pure λ/-methyl amino acids. One such process is described by G.V. Reddy et al., Tetrahedron Lett., 1998, 39, 1985-1986, starting from λ/-Cbz (or /V-Boc) alpha-amino acids. Reaction of these compounds with paraformaldehyde gives the oxazolidinones

(IX) which are cleaved under hydrogenolytic conditions to give the λ/-methyl amino acid (or the λ/-Boc-λ/-methyl amino acid).

(IX) (Vila)

Compounds of formula (VIII) include natural amino acids acid (e.g. L-AIa, L-VaI, L-Leu, L-IIe, L-Tyr, L-Trp, L-Phe, L-Cys, L-Met, L-Ser, L-Thr) as well as the corresponding D-amino acids. Compounds of formula (VIII) in which R 1 is -CH 2 -4-(Ci-4alkoxy)phenyl, -CH 2 -(λ/-Sθ2Ci.4alkyl)indol-3-yl, -ethylphenyl, -CH 2 -SC 1-4 alkyl, -CH 2 -SCi -2 phenyl, -CH 2 OC i -4 alkyl, -CH 2 -OCi -2 phenyl

-CH(Me)OCi -4 alkyl or -CH(Me)OCi -2 alkylphenyl may be prepared by a process comprising derivatising the corresponding amino acid, if necessary employing an appropriate protecting strategy for the acid and/or amine.

Alternatively, certain compounds of formula (V) in which R 4 is not H may be synthesised from compounds of formula (X)

(X) e.g. by alkylation, including reductive alkylation.

Thus, compounds of formula (X) may be reacted with a suitable aldehyde or ketone (e.g. cyclopropanecarboxaldehyde (C 3 H 5 CHO) in the case where R 4 is cyclopropylmethyl) to form an imine under dehydrating conditions, and then reduced, e.g. by catalytic hydrogenation or chemically with sodium cyanoborohydride (NaCNBH 3 ) or with sodium triacetoxyborohydride (Na(AcO) 3 BH).

Compounds of formula (X) may be prepared from compounds of formula (VIII) by standard methods for amide preparation. Exemplary conditions include

combining the suitably protected amino acid (VIII), wherein L 5 is OH, and the desired amine NHR 2 R 3 in the presence of HOBt and DCC.

If desired, intermediate compounds may be protected by the use of conventional protecting groups. Protecting groups and means for their removal are described in "Protective Groups in Organic Synthesis", by Theodora W.

Greene and Peter G. M. Wuts, published by John Wiley & Sons Inc; 4 th Rev Ed.,

2006, ISBN-10: 0471697540.

Compound of formula (IV) and (VII) are either known or may be prepared by conventional methods known per se. Novel intermediate compounds, e.g. compounds of formula (II), are a further aspect of the invention, including all salts and solvates thereof (as well as all tautomers and stereoisomers thereof).

The methods, uses and compositions are expected to be useful in veterinary applications (i.e. wherein the mammal is a domestic or livestock mammal e.g. cat, dog, horse, pig etc). However the principal expected use or method is in pharmaceutical applications (i.e. wherein the mammal is a human).

Since the compounds of formula (I) are intended for pharmaceutical use they are preferably provided in substantially pure form, for example at least 60% pure, more suitably at least 75% pure, especially at least 98% pure (% are on a weight for weight basis).

Pharmaceutical compositions containing compounds of the invention may be adapted for administration for any convenient route of administration which is appropriate for the target condition. The compositions include compositions suitable for oral, rectal, topical (e.g. to the skin or lung), and parenteral (including subcutaneous, intramuscular, and intravenous) administration, although the most suitable route in any given case will depend on the particular host, and nature and severity of the conditions for which the active ingredient is being administered. The pharmaceutical compositions may be conveniently presented in unit dosage form and prepared by any of the methods well known in the art of pharmacy.

Thus the invention also encompasses a pharmaceutical composition comprising a compound of formula (I), or a pharmaceutically acceptable salt thereof, in combination with one or more pharmaceutically acceptable diluents or

carriers. Such compositions may be prepared by intimately mixing the ingredients.

The pharmaceutical compositions can be presented as discrete units suitable for oral administration such as capsules, cachets or tablets each containing a predetermined amount of the active ingredient. Further, the compositions can be presented as a powder, as granules, as a solution, as a suspension in an aqueous liquid, as a non-aqueous liquid, as an oil-in-water emulsion, or as a water-in-oil liquid emulsion. In addition to the common dosage forms set out above, the compound of formula (I), or a pharmaceutically acceptable salt thereof, may also be administered by controlled release means and/or delivery devices. The compositions may be prepared by any of the methods of pharmacy. In general, such methods include a step of bringing into association the active ingredient with the carrier that constitutes one or more necessary ingredients. In general, the compositions are prepared by uniformly and intimately admixing the active ingredient with liquid carriers or finely divided solid carriers or both. The product can then be conveniently shaped into the desired presentation.

The pharmaceutical carrier employed can be, for example, a solid, liquid, or liquefied gas. Examples of solid carriers include lactose, terra alba, sucrose, talc, gelatin, agar, pectin, acacia, magnesium stearate, and stearic acid. Examples of liquid carriers are sugar syrup, peanut oil, olive oil, and water. Examples of liquefied gaseous carriers include 1 ,1,1,2-tetrafluoroethane, and 1 ,1 ,1 ,2,3,3,3-heptafluoro-n-propane.

In preparing the compositions for oral dosage form, any convenient pharmaceutical media may be employed. For example, water, glycols, oils, alcohols, flavoring agents, preservatives, coloring agents, and the like may be used to form oral liquid preparations such as suspensions, elixirs and solutions; while carriers such as starches, sugars, microcrystalline cellulose, diluents, granulating agents, lubricants, binders, disintegrating agents, and the like may be used to form oral solid preparations such as powders, capsules and tablets. Because of their ease of administration, tablets and capsules are the preferred oral dosage units whereby solid pharmaceutical carriers are employed.

Optionally, tablets may be coated by standard aqueous or nonaqueous techniques.

A tablet containing the composition of this invention may be prepared by compression or molding, optionally with one or more accessory ingredients or adjuvants. Compressed tablets may be prepared by compressing, in a suitable machine, the active ingredient in a free-flowing form such as powder or granules, optionally mixed with a binder, lubricant, inert diluent, surface active or dispersing agent. Molded tablets may be made by molding in a suitable machine, a mixture of the powdered compound moistened with an inert liquid diluent. Each tablet preferably contains from about 0.05 mg to about 5 g of the active ingredient and each cachet or capsule preferably containing from about 0.05 mg to about 5 g of the active ingredient.

For example, a formulation intended for the oral administration to humans may contain from about 0.5 mg to about 5 g of active agent, compounded with an appropriate and convenient amount of carrier material which may vary from about 5 to about 95% of the total composition. Unit dosage forms will generally contain between from about 1 mg to about 2 g of the active ingredient, typically 25, 50, 100, 200, 300, 400, 500, 600, 800, or 1000 mg.

Pharmaceutical compositions of this invention can be in a form suitable for rectal administration wherein the carrier is a solid. It is preferable that the mixture forms unit dose suppositories. Suitable carriers include cocoa butter and other materials commonly used in the art. The suppositories may be conveniently formed by first admixing the composition with the softened or melted carrier(s) followed by chilling and shaping in molds. In addition to the aforementioned carrier ingredients, the pharmaceutical formulations described above may include, as appropriate, one or more additional carrier ingredients such as diluents, buffers, flavouring agents, binders, surface-active agents, thickeners, lubricants, preservatives (including anti-oxidants) and the like. Furthermore, other adjuvants can be included to render the formulation isotonic with the blood of the intended recipient.

The topical formulation will preferably maximise surface exposure and minimise systemic exposure to the active ingredient(s).

Compounds according to the invention may, if desired, be administered topically to the skin. When said formulation is a gel it typically comprises a hydrophilic polymer such as cross-linked polyethylene glycol, cross-linked starch or polyvinyl pyrrolidone. An ointment, cream or lotion typically contains an aqueous phase and an oleaginous phase in admixture. Alternatively, the formulation may be entirely oleaginous in the form of an oil, ointment, gel or spray. The formulation may additionally contain one or more emollients, emulsifiers, thickeners and/or preservatives, particularly when it is a cream or ointment. Emollients suitable for inclusion in creams or ointments are typically long chain alcohols, for example a C 8 -22 alcohol such as cetyl alcohol, stearyl alcohol and cetearyl alcohol, hydrocarbons such as petrolatum light mineral oil and plant oils (such as corn oil, coconut oil, olive oil, cotton seed oil and sunflower seed oil) or acetylated lanolin. The total amount of emollient in the formulation is preferably about 5 wt% to about 30 wt%, and more preferably about 5 wt% to about 10 wt% based on the total weight of the formulation. The emulsifier is typically a nonionic surface active agent, e.g., polysorbate 60 (available from ICI Americas), sorbitan monostearate, polyglyceryl-4 oleate and polyoxyethylene(4)lauryl ether. Generally the total amount of emulsifier is about 2 wt% to about 14 wt%, and more preferably about 2 wt% to about 6 wt% by weight based on the total weight of the formulation. Pharmaceutically acceptable thickeners, such as Veegum (available from R. T. Vanderbilt Company, Inc.), and long chain alcohols (i.e. C 8 - 22 alcohols such as cetyl alcohol, stearyl alcohol and cetearyl alcohol) can be used. The total amount of thickener present is preferably about 3 wt% to about 12 wt% based on the total weight of the formulation.

Preservatives such as methylparaben, propylparaben and benzyl alcohol can be present in the formulation. The appropriate amount of such preservative(s) is known to those skilled in the art.

Optionally, an additional solubilizing agent such as benzyl alcohol, lactic acid, acetic acid, stearic acid or hydrochloric acid can be included in the formulation. If an additional solubilizing agent is used, the amount present is preferably about 1 wt% to about 12 wt% based on the total weight of the formulation. Optionally, the formulation can contain a humectant such as

glycerin and a skin penetration enhancer such as butyl stearate, urea and DMSO.

It is known to those skilled in the art that a single ingredient can perform more than one function in a cream, i.e., cetyl alcohol can serve both as an emollient and as a thickener. When said formulation is a cream, the cream typically consists of an oil phase and a water phase mixed together to form an emulsion. Preferably, the cream comprises an oil-in-water emulsion. Preferably, the amount of water present in a cream of the invention is about 45 wt% to about 85 wt% based on the total weight of the cream. Where the formulation is an ointment, it typically comprises a pharmaceutically acceptable ointment base such as petrolatum, or polyethylene glycol 400 (available from Union Carbide) in combination with polyethylene glycol 3350 (available from Union Carbide). The amount of ointment base present in an ointment of the invention is preferably about 60 wt% to about 95 wt% based on the total weight of the ointment. In an exemplary embodiment of a topical skin composition, the formulation is a cream which comprises an oil-in-water cream base comprising isostearic acid, cetyl alcohol, stearyl alcohol, white petrolatum, polysorbate 60, sorbiton monostearate, glycerin, xanthum gum, purified water, benzyl alcohol, methylparaban and propyl-paraban. Topical administration to the skin may also be achieved by use of an aerosol formulation. Aerosol formulations comprise the active ingredient suspended or dissolved in a suitable aerosol propellant, such as a chlorofluorocarbon (CFC) or a hydrofluorocarbon (HFC). Suitable CFC propellants include trichloromonofluoromethane (propellant 11), dichlorotetrafluoromethane (propellant 114), and dichlorodifluoromethane (propellant 12). Suitable HFC propellants include tetrafluoroethane (HFC-134a) and heptafluoropropane (HFC-227). The propellant comprises 40 to 90% by weight of the total inhalation composition. A yet further suitable propellant is ethanol. Preferably, for incorporation into the aerosol propellant, the active ingredient, or a pharmaceutically acceptable salt thereof, will be processed into respirable particles as described for the dry powder formulations. The particles are then suspended in the propellant, typically being coated with a surfactant to

enhance their dispersion properties. Such surfactants include sorbitan trioleate, oleyl alcohol, oleic acid, lecithin or oils derived from natural sources, such as, corn oil, olive oil, cotton seed oil coconut oil and sunflower seed oil are useful in keeping the suspended particles form agglomerating. Compounds according to the invention may alternatively, if desired, be administered to the lungs via a number of routes. They may be administered intranasally, for example in the form of an aerosol or other atomisable formulation using an appropriate intranasal delivery device, e.g. a nasal spray such as those known in the art, or by inhalation, which is preferred, especially for use with a nebulizer.

Thus the invention includes (A) a compound of formula (I), or a pharmaceutically acceptable salt thereof, in inhalable form, e.g. in an aerosol or other atomisable composition or in inhalable particulate, e.g. micronised, form, (B) an inhalable medicament comprising a compound of formula I in inhalable form; (C) a pharmaceutical product comprising a compound of formula (I) in inhalable form in association with an inhalation device; and (D) an inhalation device containing a compound of formula (I) in inhalable form.

Suitable aerosol formulations for topical administration to the lungs are as described above in relation to aerosol formulations for topical administration to the skin.

In another embodiment, the inhalation route of administration is in a powder form. The active ingredient may be used as a powder with a particle size of 0.5 to 10 μm, preferably 0.5-5 μm, which can be produced by a variety of conventional techniques, such as jet-milling, spray-drying, solvent precipitation, and the like. One widely used formulation approach is to mix the fine active drug particles with a coarse bulking powder with a particle size of 10 to 500 μm. The bulking powder is selected from saccharides, preferably lactose, sucrose, glucose, galactose, fructose, trehalose and raffinose, most preferably lactose. Preferably the particle size of the finely-divided solid powder should for physiological reasons be less than 25 μm and preferably less than about 10 μm in diameter. The particle size of the powder for inhalation therapy should most preferably be in the range of 2 to 10 μm.

As a further aspect of the invention, a compound for use in the present invention may be prepared as a formulation suitable for nebulisation. Such formulations contain excipients physiologically compatible with the bronchial epithelium, usually consisting of co-solvents, preservatives, chelating agents, pH and tonicity regulators and surfactants. Suitable excipients include but are not limited to, propylene glycol, ethanol, glycerin, benzalkonium chloride, sodium edentate, ascorbic acid, citric acid, hydrochloric acid, sodium hydroxide, sodium chloride, oleic acid, and lecithin. The nebulised formulation may be prepared by standard manufacturing techniques. As a further aspect of the invention, a compound for use in the present invention, or a pharmaceutically acceptable salt thereof, may be prepared in a lyophilised form for subsequent reconstitution in a physiologically acceptable vehicle for inhalation immediately prior administration. The lyophilised formulation may include the following optional additional excipients, lactose, mannitol and glucose. The lyophilised product may be prepared by a aseptic process first involving dissolving the active ingredient and excipients in an aqueous vehicle. The resulting solution is then filled in glass vials and subsequently freeze dried. The lyophilized compound of the invention suitably includes lactose, suitably in a ratio of compound of the invention or a salt form: lactose of 1 :1 to 1 :10.

As a further aspect of the invention, a formulation for use in the present invention, preferably a nebulized formulation of a compound of the invention or a pharmaceutically acceptable salt thereof, may be taste-masked by various approaches including addition of suitable further excipients either in the solution formulation or as an ingredient in the lyophilized form or vehicle for reconstitution. Suitable excipients for taste-masking according to the invention include but not limited to, saccharine sodium, aspartame, menthol and polyalcohols such as sorbitol and xylitol. The taste-masked formulation may be prepared by known and standard techniques, e.g. according to the methods described in WO2005/037246.

Pharmaceutical compositions of the present invention suitable for parenteral administration may be prepared as solutions or suspensions of the active compounds in water. A suitable surfactant can be included such as, for

example, hydroxypropylcellulose. Dispersions can also be prepared in glycerol, liquid polyethylene glycols, and mixtures thereof in oils. Further, a preservative can be included to prevent the detrimental growth of microorganisms.

Pharmaceutical compositions of the present invention suitable for injectable use include sterile aqueous solutions or dispersions. Furthermore, the compositions can be in the form of sterile powders for the extemporaneous preparation of such sterile injectable solutions or dispersions. In all cases, the final injectable form must be sterile and must be effectively fluid for easy syringability. The pharmaceutical compositions must be stable under the conditions of manufacture and storage; thus, preferably should be preserved against the contaminating action of microorganisms such as bacteria and fungi. The carrier can be a solvent or dispersion medium containing, for example, water, ethanol, polyol (e.g. glycerol, propylene glycol and liquid polyethylene glycol), vegetable oils, and suitable mixtures thereof. Pharmaceutical compositions of the present invention can be in a form suitable for topical use such as, for example, an aerosol, oil, gel, cream, ointment, lotion, dusting powder, or the like. Further, the compositions can be in a form suitable for use in transdermal devices. The formulations may be aqueous or non-aqueous. These formulations may be prepared, using a compound of formula (I), or a pharmaceutically acceptable salt thereof, via conventional processing methods. As an example, a cream or ointment is prepared by admixing hydrophilic material and water, together with about 5wt% to about 10wt% of the compound, to produce a cream or ointment having a desired consistency. Compositions containing a compound of formula (I), or pharmaceutically acceptable salts thereof, may also be prepared in powder or liquid concentrate form.

The compounds of formula (I), or pharmaceutically acceptable salts thereof, can also be included in pharmaceutical compositions in combination with one or more other therapeutically active compounds.

Generally, dosage levels on the order of 0.01 mg/kg to about 150 mg/kg of body weight per day are useful in the treatment of the above-indicated

conditions, or alternatively about 0.5 mg to about 7 g per patient per day. For example, the conditions may be effectively treated by the administration of from about 0.01 to 50 mg of the compound per kilogram of body weight per day, or alternatively about 0.5 mg to about 2.5 g per patient per day. It is understood, however, that the specific dose level for any particular patient will depend upon a variety of factors including the age, body weight, general health, sex, diet, time of administration, route of administration, rate of excretion, drug combination and the severity of the particular disease undergoing therapy. The inhibitor may, for example in the case of inhibitors of aureolysin for the treatment of AD, be administered in conjunction with further medicaments, such as conventional therapies for the treatment or prevention of inflammatory skin conditions, for example steroids (such as hydrocortisone, clobetasone butyrate, betamethasone valerate, hydrocortisone butyrate, clobetasol propionate, fluticasone propionate, mometasone furoate and dexamethasone), non-steroidal anti-inflammatory drugs, macrolide immunosuppressants (such as cyclosporine A, tacrolimus and pimecrolimus), leukotriene antagonists and phosphodiesterase inhibitors.

The inhibitor may, for example, in the case of inhibitors of M4 proteases for the treatment of CF, be administered in conjunction with further medicaments, such as conventional therapies for the treatment or prevention of CF, for example, a suitable DNase drug substances including dornase alfa (Pulmozyme™).

For example the further medicament may be an antibiotic substance which is bacteriocidal or bacteriostatic for Staphylococcus aureus, Pseudomonas aeruginosa, Burkholderia cepacia, Legionella sp., Vibrio cholerae.QT any other M4 protease-producing bacteria.

These further treatments may be administered by any convenient route. For example, oral, rectal, topical (e.g. to the skin or lung), and parenteral (including subcutaneous, intramuscular, and intravenous) administration.

Combination treatments may be administered simultaneously, sequentially or separately, by the same or by different routes. In one embodiment, the further medicament may be administered orally. In another

embodiment, the further medicament may be administered topically, e.g. in a combined preparation with the inhibitor.

A compound of the invention that is a M4 inhibitor, in one embodiment, does not significantly inhibit mammalian metalloproteases of the MA(M) subclan, for example M10 & M12 families. By "does not significantly inhibit" it is meant that the strength of inhibition (e.g. as measured by IC 5 o) of the inhibitor against mammalian metalloproteases of the MA(M) subclan, for example M10 & M12 families, is at least 5 times, preferably at least 10 times, e.g. at least 50 times, weaker than the strength of inhibition of the inhibitor against M4 proteases. By inhibition, it is meant that the IC 50 value is less than 15 μM in the M4 protease assays, preferably less than 0.5 μM.

Compounds of the invention are expected to be useful in the treatment of a range of diseases associated with infection or colonisation by metalloprotease- producing pathogenic bacteria such as Aeromonas, Bacillus, Bordetella, Burkholderia, Legionella, Serratia, Staphyloccυs, Pseudomonas and Vibrio sp. For example, compounds of the invention are expected to be useful in the treatment of diseases associated with infection or colonisation by:

• Aeromonas sp. (e.g. A. hydrophila, A. caviae & A. sobria cause gastroenteritis in healthy individuals or septicemia in individuals with impaired immune systems or various malignancies).

• Bacillus sp. (e.g. B. cereυs in food poisoning, B. anthracis in anthrax).

• Bordetella sp. (e.g. respiratory tract infections).

• Burkholderia cepacia (e.g. lung infections in CF sufferers).

• Legionella sp. (e.g. Legionnaire's disease). • Serratia sp. (e.g. Serratia marcescens in urinary tract infections, wound infections, and pneumonia).

• Staphylococcus aureus (e.g. conditions such as CF or atopic dermatitis, especially where colonisation or infection results in aggravation of the underlying condition and an increase in the inflammatory response). • Pseudomonas aeruginosa (e.g. septicaemia, and lung infections in CF sufferers)

• Vibrio cholerae (e.g. cholera)

The following Examples illustrate the invention. Example 1

(S)-2-{3-[2-(hydroxyamino)-2-oxoethyl]-3-isobutylureido}- λ/-methyl-4- phenylbutanamide 1.

(a) (S)-methyl 2-amino-4-phenylbutanoate hydrochloride 2.

To a stirred solution of L-Homophe-OH (5.0 g, 27.9 mmol) in MeOH (25 ml) was added thionyl chloride (2.26 ml, 30.69 mmol) at O 0 C. The mixture was allowed to warm to RT then heated at 65 0 C for 2h. After concentration in vacuo the residue was triturated with Et 2 O (10 ml), collected by suction filtration, washed with Et 2 O (5 ml) and air dried to give the title compound (6.11g, 95%). LCMS (3min) purity= 97%, tr=1.08, m/z 194 [M+H] + . (b) (S)-2-amino-λ/-methyl-4-phenylbutanamide 3.

To a solution of 8M MeNH 2 in EtOH (8.7 ml, 69.6 mmol) was added (S)- methyl 2-amino-4-phenylbutanoate hydrochloride 2 (4.0 g, 17.4 mmol) at RT and the mixture was stirred overnight. The reaction mixture was concentrated in

vacuo, Et 2 O (5 ml x 3) was added and evaporation in vacuo repeated three times. The solid was suspended in DCM (30 ml), washed with saturated aq. NaHCO 3 (10 ml) and water (10 ml), dried (Na 2 SO 4 ), filtered and concentrated in vacuo to give the title compound as a white solid (2.77 g, 83%). LCMS (3 min) purity= 94%, t r 1.05, m/z 193 [M+H], 1 H NMR (MeOD) δ 1.65 (1 H 1 m), 1.85 (1 H, m), 2.55 (2 H, m), 2.60 (3 H, s, CONHMe), 3.15 (1 H, m), 7.00-7.20 (5 H, m, Ar). (c) Methyl 2-(isobutylamino)acetate 4.

To a stirred solution of isobutylamine (3.3 ml, 33 mmol) in DMSO (50 ml) was added a pre-mixed solution of bromomethyl acetate (5 g, 33 mmol) and triethylamine (4.6 ml, 33 mmol) drop wise. The reaction mixture was stirred at room temperature for 6 hours, after which time saturated ammonium chloride (50 ml) was added. The reaction mixture was extracted with diethyl ether (2 x 100 ml), the organic layers were combined, washed with brine (100 ml) and then dried (MgSO 4 ), filtered and concentrated in vacuo to afford the crude product as a colourless oil. Flash column chromatography (EtOAc: Heptane, 50:50) afforded the title compound as a colourless oil (1.03 g, 22% yield). LCMS (3min) t r 0.26, m/z 146 [M+H]. (d) (S)-methyl 2-{1-isobutyl-3-[1-(methylamino)-1-oxo-4-phenylbutan-2- yl]ureido}acetate 5.

To a solution of methyl 2-(isobutylamino)acetate 4 (1.0 g, 0.007 mol) in THF (10 ml) was added NaH (60% dispersion in oil, 0.3 g, 0.0076 mol) in one

portion, and the resulting solution was stirred at room temperature for 10 mintues. Triphosgene (0.67 g, 2.2 mmol) was added portionwise and the reaction mixture was stirred for a further 10 minutes. To this suspension was added a solution of (S)-2-amino-λ/-methyl-4-phenylbutanamide 3 (1.32 g, 7.0 mmol) in THF (3 ml) in one portion and stirring was continued for 12 hours. The reaction mixture was partitioned between water (20 ml) and ethyl acetate (20 ml), the organic layer was separated, and washed with brine (20 ml) and then dried (MgSO 4 ), filtered and concentrated in vacuo to afford the title compound as a yellow oil (1.8 g, 82% yield). The mixture was taken on without further purification. LCMS (3min) t r 1.82, m/z 364 [M+H].

(e) (S)-2-{3-[2-(hydroxyamino)-2-oxoethyl]-3-isobutylureido}-λ/ -methyl-4- phenylbutanamide 1.

Aqueous hydroxylamine (50% solution, 0.32 g, 4.9 mmol) was added in one portion to a solution of (S)-methyl 2-{1-isobutyl-3-[1-(methylamino)-1-oxo-4- phenylbutan-2-yl]ureido}acetate 5 (1.8 g, 4.9 mmol) in dioxane (5ml). The reaction mixture was stirred at room temperature for 3 hours, after which time a further portion of hydroxylamine (0.32 g, 4.9 mmol) was added. The reaction mixture was stirred at room temperature for 24 hours, and the reaction mixture was concentrated in vacuo and purified by trituration with methanol to afford the title compound (47.5 mg, 3% yield) as a white solid. LCMS (3 min) purity= 91%, tr 1.51 , m/z 365 [M+H], 1 H NMR (DMSO) δ 10.45 (1H, s), 8.79, (1H, s), 7.67 (1H, d), 7.06-6.93 (5H, m), 6.35 (1H, d), 3.87-3.81 (1H, m), 3.68-3.56 (2H, m), 2.92- 2.86 (1H, m), 2.76-2.71 (1H, m), 2.45-2.32 (5H, m), 1.81-1.73 (1H, m), 1.64-1.54 (2H, m), 0.61 (6H, t).

Example 2

(S)-2-{3-(cyclopropylmethyl)-3-[2-(hydroxyamino)-2-oxoeth yl]ureido}-/V- methyl-4-phenylbutanamide 6.

(a) Methyl 2-(cyclopropylmethylamino)acetate 7.

7

To a stirred solution of aminomethylcyclopropane (2.3 g, 3.3 mmol) in DMSO (50 ml) was added a pre-mixed solution of bromomethyl acetate (5 g, 3.3 mmol) and triethylamine (4.6 ml, 3.3 mmol) drop wise. The reaction mixture was stirred at room temperature for 6 hours, and then saturated ammonium chloride

(50 ml) was added. The reaction mixture was extracted with diethyl ether (2 x

100 ml), the organic layers were combined, washed with brine (100 ml) and then dried (MgSO 4 ), filtered and concentrated in vacuo to afford the crude product as a colourless oil. Flash column chromatography (EtOAc: Heptane, 50:50) afforded the title compound as a colourless oil (1.35 g, 30% yield). LCMS (3 min) t r 0.28, m/z 144 [M+H].

(b) (S)-methyl 2-{1 -(cyclopropylmethyl)-3-[1 -(methylamino)-i -oxo-4- phenylbutan-2-yl]ureido}acetate 8.

To a solution of methyl 2-(cyclopropylmethylamino)acetate 7 (1.0 g, 7.0 mmol) in THF (10 ml) was added NaH (60% dispersion in oil, 0.3 g, 7.6

mmol) in one portion and the resulting solution was stirred at room temperature for 10 mintues. Triphosgene (0.67 g, 2.2 mmol) was then added portionwise and the reaction mixture was stirred for a further 10 minutes. To this suspension was added a solution of (S)-2-amino-λ/-methyl-4-phenylbutanamide 3 (1.32 g, 7.0 mmol) in THF (3 ml) in one portion and stirring was continued for 12 hours. The reaction mixture was partitioned between water (20 ml) and ethyl acetate (20 ml), and the organic layer was separated, washed with brine (20 ml) and then dried (MgSO 4 ), filtered and concentrated in vacuo to afford the title compound as a yellow oil (1.5 g, 60% yield). The mixture was taken on without further purification. LCMS (3 min) t r 1.74, m/z 362 [M+H].

(c) (S)-2-{3-(cyclopropylmethyl)-3-[2-(hydroxyamino)-2-oxoethyl] ureido}-λ/ methyl-4-phenylbutanamide 6.

Aqueous hydroxylamine (50% solution, 0.12 g, 1.8 mmol) was added in one portion to a solution of (S)-methyl 2-{1-(cyclopropylmethyl)-3-[1- (methylamino)-1-oxo-4-phenylbutan-2-yl]ureido}acetate 8 (0.34 g, 0.9 mmol) in dioxane (5 ml). The reaction mixture was stirred at room temperature for 3 hours, after which time a further portion of hydroxylamine (0.12 g, 1.8 mmol) was added. The reaction mixture was stirred at room temperature for 24 hours, and was concentrated in vacuo and purified by preparative HPLC to afford the title compound (9.1 mg, 3% yield) as a white solid. LCMS (3 min) purity= 95%, t r 1.43, m/z 363 [M+H], 1 H NMR (MeOD) δ 7.30-7.18 (5H, m), 4.27-4.24 (1H, m), 4.41-3.99 (2H 1 q), 3.37-3.28 (1H, m), 3.18-3.13 (1H, m), 2.81-2.64 (5H, m), 2.22- 2.14 (1H 1 m), 2.06-1.94 (1H, m), 1.05-0.99 (1 H, m), 0.61-0.55 (2H, m), 0.31-0.26 (2H 1 m).

Biological data

Inhibitory activity against purified aureolysin type Il (BioCentrum Ltd) and LasB (Calbiochem) was assessed in mixtures (0.1 ml) containing 90 mM MOPS buffer pH 6.8, 4.5 mM calcium chloride, 0.045% Brij 35, 10 μM Mca-Pro-Leu- Gly-Leu-Dap(Dnp)-Ala-Arg-amide (Bachem), enzyme and 2% dimethyl sulphoxide vehicle with or without inhibitor. Compound activity against human MMPs (e.g. hMMP-9) (Calbiochem) was assessed in the same way except that the buffer used was 90 mM Tris-HCI pH 7.5 @ 25 9 C, 90 mM sodium chloride, 9

mM calcium chloride and 0.045% Brij 35. Reactions were incubated at 37 8 C for 1 hour, stopped with 0.1 ml 0.5 M acetic acid and the fluorescence measured using 320 nm excitation and 405 nm emission. The compound concentration eliciting a 50% decrease in enzyme activity under assay conditions (the IC 50 value) was determined by curve fitting (XLfit, IDBS Ltd). Results were obtained as follows:

IC 5 O value (uM) or % inhibition at 100 uM

Example No

Aureolysin type Il LasB hMMP-9

1 0.36 0.049 49%

2 10 2.3 22%