PHENYLACETYLENE DERIVATIVES HAVING MGLUR5 RECEPTOR AFFINITY

The present invention relates to novel acetylene derivatives, their preparation, their use as pharmaceuticals and pharmaceutical compositions containing them.

More particularly the invention provides a compound of formula (I)

wherein

R ¹ represents hydrogen or C ₁ -C ₄ alkyl and

R ² represents an unsubstituted or substituted heterocycle or

R ¹ represents hydrogen or Ci-C ₄ alkyl and

R ² represents aryl or substituted aryl or

R ¹ and R ² together with the nitrogen atom form an unsubstituted or substituted heterocycle

R ³ represents (C^alkyl, (C _1-4 )alkoxy, tπfluoromethyl, halogen, cyano, nitro, -CHO, -COO(C _{1- 4} )alkyl, -CO(C^)alkyl;

n represents 0, 1 , 2, 3, 4 or 5;

R ⁴ represents OH and

R ⁵ and R ⁶ represent H or C ₁ -C ₄ alkyl or

R ⁴ and R ⁵ form a bond and

R ⁶ represent H or C ₁ -C ₄ alkyl or

R ⁴ and R ⁶ form a bond and R ⁵ represent H or C ₁ -C ₄ alkyl;

in free base or acid addition salt form.

In the present specification, the following definitions shall apply if no specific other definition is given:

"Alkyl" represents a straight-chain or branched-chain alkyl group, preferably represents a straight-chain or branched-chain C _1-12 alkyl, particularly preferably represents a straight-chain or branched-chain C _1-6 alkyl; for example, methyl, ethyl, n- or iso-propyl, n-, iso-, sec- or tert-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, n-nonyl, n-decyl, n-undecyl, n-dodecyl, with particular preference given to methyl, ethyl, n-propyl and iso-propyl.

"Alkandiyl" represents a straight-chain or branched-chain alkandiyl group bound by two different Carbon atoms to the molecule, it preferably represents a straight-chain or branched-chain C _1-12 alkandiyl, particularly preferably represents a straight-chain or branched-chain C _1-6 alkandiyl; for example, methandiyl (-CH ₂ -), 1 ,2-ethanediyl (-CH ₂ -CH ₂ -), 1 ,1-ethanediyl ((-CH(CH ₃ )-), 1 ,1-, 1,2- , 1 ,3-propanediyl and 1 ,1-, 1 ,2-, 1 ,3-, 1 ,4-butanediyl, with particular preference given to methandiyl, 1,1-ethanediyl, 1 ,2-ethanediyl, 1,3-propanediyl, 1 ,4-butanediyl.

Each alkyl part of "alkoxy", "alkoxyalkyl", "alkoxycarbonyl", "alkoxycarbonylalkyl" and "halogenalkyl" shall have the same meaning as described in the above-mentioned definition of "alkyl".

"Alkenyl" represents a straight-chain or branched-chain alkenyl group, preferably C _2-6 alkenyl, for example, vinyl, allyl, 1-propenyl, isopropenyl, 2-butenyl, 2-pentenyl, 2-hexenyl, etc. and preferably represents C _2-4 alkenyl.

"Alkendiyl" represents a straight-chain or branched-chain alkendiyl group bound by two different Carbon atoms to the molecule, it preferably represents a straight-chain or branched-chain C ₂ ^ alkandiyl; for example, -CH=CH-, -CH=C(CH ₃ )-, -CH=CH-CH ₂ -, -C(CH ₃ J=CH-CH ₂ -, - CH=C(CHa)-CH ₂ -, -CH=CH-C(CH ₃ )H-, -CH=CH-CH=CH-, -C(CH ₃ )=CH-CH=CH-, -CH=C(CH ₃ )- CH=CH-, with particular preference given to -CH=CH-CH ₂ -, -CH=CH-CH=CH-.

"Alkynyl" represents a straight-chain or branched-chain alkynyl group, preferably C _2-6 alkynyl, for example, ethenyl, propargyl, 1-propynyl, isopropenyl, 1- (2- or 3) butynyl, 1- (2- or 3) pentenyl, 1- (2- or 3) hexenyl, etc. .preferably represents C _2-4 alkynyl and particularly preferably represents ethynyl.

"Aryl" represents an aromatic hydrocarbon group, preferably a C _6-I o aromatic hydrocarbon group; for example phenyl, naphthyl, especially phenyl.

"Aralkyl" denotes an "Aryl" bound to an "Alkyl" (both as defined above) an represents, for example benzyl, α-methylbenzyl, 2-phenylethyl, α,α-dimethylbenzyl, especially benzyl.

Ηeterocycle" represents a saturated, partly saturated or aromatic ring system containing at least one hetero atom. Preferably, heterocycles consist of 3 to 11 ring atoms of which 1-3 ring atoms are hetero atoms. Heterocycles may be present as a single ring system or as bicyclic or tricyclic ring systems; preferably as single ring system or as benz-annelated ring system. Bicyclic or tricyclic ring systems may be formed by annelation of two or more rings, by a bridging atom, e.g. Oxygen, sulfur, nitrogen or by a bridging group, e.g. alkandediyl or alkenediyl. A Heterocycle may be substituted by one or more substituents selected from the group consisting of Oxo (=O), Halogen, Nitro, Cyano, Alkyl, Alkandiyl, Alkenediyl, Alkoxy, Alkoxyalkyl, Alkoxycarbonyl, Alkoxycarbonylalkyl, Halogenalkyl, Aryl, Aryloxy, Arylalkyl. Examples of heterocyclic moieties are: pyrrole, pyrroline, pyrrolidine, pyrazole, pyrazoline, pyrazolidine, imidazole, imidazoline, imidazolidine, triazole, triazoline, triazolidine, tetrazole, furane, dihydrofurane, tetrahydrofurane, furazane (oxadiazole), dioxolane, thiophene, dihydrothiophene, tetrahydrothiophene, oxazole, oxazoline, oxazolidine, isoxazole, isoxazoline, isoxazolidine, thiazole, thiazoline, thiazlolidine, isothiazole, istothiazoline, isothiazolidine, thiadiazole, thiadiazoline, thiadiazolidine, pyridine, piperidine, pyridazine, pyrazine, piperazine, triazine, pyrane, tetrahydropyrane, thiopyrane, tetrahydrothiopyrane, oxazine, thiazine, dioxine, morpholine, purine, pterine, and the corresponding benz-annelated heterocycles, e.g. indole, isoindole, cumarine, cumaronecinoline, isochinoline, cinnoline and the like.

"Hetero atoms" are atoms other than Carbon and Hydrogen, preferably Nitrogen (N), Oxygen (O) or Sulfur (S).

"Halogen" represents Fluoro, Chloro, Bromo or lodo, preferably represents Fluoro, Chloro or Bromo and particularly preferably represents Chloro.

Compounds of formula (I) exist in free or acid addition salt form. In this specification, unless otherwise indicated, language such as "compounds of formula (I)" is to be understood as embracing the compounds in any form, for example free base or acid addition salt form. Salts which are unsuitable for pharmaceutical uses but which can be employed, for example, for the

isolation or purification of free compounds of formula (I) , such as picrates or perchlorates, are also included. For therapeutic use, only pharmaceutically acceptable salts or free compounds are employed (where applicable in the form of pharmaceutical preparations), and are therefore preferred.

On account of the asymmetrical carbon atom(s) that may be present in the compounds of formula (I) and their salts, the compounds may exist in optically active form or in form of mixtures of optical isomers, e.g. in form of racemic mixtures or diastereomeric mixtures. All optical isomers and their mixtures, including the racemic mixtures, are part of the present invention. Preferred compounds of formula (I) have trans configuration in respect to R ⁴ and N

Preferred substituents, preferred ranges of numerical values or preferred ranges of the radicals present in the formula (I) and the corresponding intermediate compounds are defined below.

n preferably represents 0, 1 or 2.

n particularly preferably represents 1.

R ¹ preferably represents hydrogen or methyl.

R ¹ particularly preferably represents hydrogen.

R ³ preferably represents halogen, C _1-4 alkyl.

R ³ particularly preferably represents fluoro or methyl.

R ⁴ preferably represents OH.

R ⁵ preferably represents H.

R ⁶ preferably represents H.

R ² preferably represents an unsubstituted or substituted heterocycle having 3 - 11 ring atoms and 1 - 4 hetero atoms; the hetero atoms being selected from the group consisting of N, O, S, the substituents being selected from the group consisting of Oxo (=0),

Hydroxy, Halogen, Amino, Nitro, Cyano, C _1-4 Alkyl, C _1-4 Alkoxy, C _1-4 Alkoxyalkyl, C _1-4

Alkoxycarbonyl, C _1-4 Alkoxycarbonylalkyl, C _1-4 Halogenalkyl, C _6-10 Aryl, Halogen- C _6-10 Aryl, Ce- ₁ 0 Aryloxy, C _6-10 -ArYl-C _1-4 alkyl, furyl.

R ² further preferably represents phenyl or substituted phenyl, the substituents being selected from the group consisting of Hydroxy, Amino, Halogen, Nitro, Cyano, C ₁ ^ Alkyl, C _1-4

Alkoxy, C _1-4 Alkoxyalkyl, C _1^ , Alkoxycarbonyl, C _1-4 Alkoxycarbonylalkyl, C _1-4 Halogenalkyl, C _6-10 Aryl, Halogen- C _6-10 Aryl, C _6-10 Aryloxy, C _6-10 -ArYl-C _1-4 alkyl.

R ¹ and R ² together with the nitrogen atom further preferably form unsubstituted or substituted heterocycle having 3 - 11 ring atoms and 0 - 3 additional hetero atoms; the additional hetero atoms being selected from the group consisting of N, O, S; the substituents being selected from the group consisting of Oxo (=0), Hydroxy, Halogen, Amino, Nitro, Cyano, C ₁ U ₁ Alkyl, C _1-4 Alkoxy, C _1-4 Alkoxyalkyl, C _1-4 Alkoxycarbonyl, C ₁ ^ Alkoxycarbonylalkyl, C ₁ ^ Halogenalkyl, C _6-10 Aryl, Halogen- C _6-10 Aryl, C _6-10 Aryloxy, C _6-10 -ArYl-C _1-4 alkyl.

R ² particularly preferably represents an unsubstituted, a single or twofold substituted heterocycle having 5 - 10 ring atoms and 1 - 3 hetero atoms; the hetero atoms being selected from the group consisting of N, O, S; the substituents being selected from the group consisting of fluoro, chloro, methyl, ethyl, n-, i-propyl, n-, iso-, sec-, tert-butyl, phenyl, tolyl.

R ² particularly preferably represents an unsubstituted, a single or twofold substituted phenyl, the substituents being selected from the group consisting of fluoro, chloro, bromo.

R ¹ and R ² together with the nitrogen atom further particularly preferably form a single or twofold substituted heterocycle having 5 - 9 ring atoms and 0 - 2 additional hetero atoms; the additional hetero atoms being selected from the group consisting of N, O; the substituents being selected from the group consisting of methyl, ethyl, n-, i-propyl, n-, iso-, sec-, tert- butyl, phenyl, tolyl.

The abovementioned general or preferred radical definitions apply both to the end products of the formula (I) and also, correspondingly, to the starting materials or intermediates required in each case for the preparation. These radical definitions can be combined with one another at will, i.e. including combinations between the given preferred ranges. Further, individual definitions may not apply.

Preference according to the invention is given to compounds of the formula (I) which contain a combination of the meanings mentioned above as being preferred.

Particular preference according to the invention is given to compounds of the formula (I) which contain a combination of the meanings listed above as being particularly preferred.

Very particular preference according to the invention is given to the compounds of the formula (I) which contain a combination of the meanings listed above as being very particularly preferred.

Preferred are compounds of formula (V)

wherein R ¹ , R ² , R ³ are as defined above.

A further preferred group of compounds of formula (I) are compounds wherein R ³ is in the meta-position.

A further preferred group of compounds of formula (I) are compounds wherein the heterocycle of R ² is an aromatic heterocycle.

In a further aspect, the invention provides a process for the production of the compounds of formula (I) and their salts, which comprises the step of

a) for the production of a compound of formula (I) wherein i) R ⁴ represents hydroxy, R ¹ represents hydrogen or C ₁ -C ₄ alkyl and R ² represents an unsubstituted or substituted heterocycle or ii) R ¹ represents hydrogen or C ₁ -C ₄ alkyl and R ² represents aryl or substituted aryl, by reductive amination of a compound of formula (II)

wherein R ⁶ , R ⁵ , R ³ , n are as defined above, with a compound of formula (III)

N

^R1 (in) wherein R ¹ and R ² are as defined above, or

b) for the production of a compound of formula (I) wherein R ⁴ represents hydroxy, R ¹ and R ² together with the nitrogen atom form an unsubstituted or substituted heterocycle, by cyclocondensation of a compound of formula (IV)

c) for the production of a compound of formula (I) wherein R ⁴ represents hydroxy, R ¹ and R ² together with the nitrogen atom form an unsubstituted or substituted heterocycle, by Michael additon reaction of a compound of formula (V)

wherein R ⁶ , R ⁵ , R ² , R ¹ are as defined above, with a compound of formula (Vl)

wherein R and n are as defined above, or

d) for the production of a compound of formula (I) wherein i) R ⁴ and R ⁵ form a bond and R ⁶ represents hydrogen or C ₁ -C ₄ alkyl or ii) wherein R ⁴ and R ⁶ form a bond and R ⁵ represents hydrogen, by dehydrating a compound of formula (I) wherein R ⁴ is hydroxyl R ⁵ and R ⁶ are hydrogen or C ₁ -C ₄ alkyl,

and recovering the resulting compound of formula (I) in free base or acid addition salt form.

The reaction of processes a) b), c) and d) can be effected according to conventional methods, e.g. as described in the examples. Process c) is preferred for compounds wherein R ¹ and R ² together with the nitrogen form a heterocycle, especially preferably a substituted heterocycle. Process d) might be a side reaction of a previous reaction step, depending on pH, temperature and nature of substituents. In this case the compounds of formula one are isolated according to conventional methods, e.g. chromatography.

The reaction of process d) generally leads to a mixture of a compound of formula (I) wherein R ⁴ forms a single bond with R ⁵ and a compound of formula I wherein R ⁴ forms a single bond with R ⁶ , which are subsequently separated according to conventional methods. , e.g. as described in WO 03/047581.

A so obtained compound of formula (I) can be converted into another compound of formula (I) according to conventional methods.

Generally, the starting materials for manufacturing compounds of formula (I) are known or obtainable according to known processes. Certain starting materials, which are useful for the production of compounds of formula (I), are novel and subject of the present invention.

A compound of formula (II)

wherein R ⁶ , R ⁵ , R ³ , n are as defined above for compounds of formula (I).

A compound of formula (V)

(V) wherein R ⁶ , R ⁵ , R ² , R ¹ are as defined above, with a compound of formula (Vl)

A compound of formula (V) is obtainable by reacting a cycloehexenone of formula (VII)

wherein R ⁶ , R ⁵ , are as defined above, with an amine of formula (III) under basic conditions.

The following considerations apply to the individual reaction steps described above:

a) One or more functional groups, for example carboxy, hydroxy, amino, or mercapto, may need to be protected in the starting materials by protecting groups. The protecting groups employed may already be present in precursors and should protect the functional groups concerned against unwanted secondary reactions, such as acylations, etherifications, esterifications, oxidations, solvolysis, and similar reactions. It is a characteristic of protecting groups that they lend themselves readily, i.e. without undesired secondary reactions, to removal, typically by solvolysis, reduction, photolysis or also by enzyme activity, for example under conditions analogous to physiological conditions, and that they are not present in the end-products. The specialist knows, or can easily establish, which protecting groups are suitable with the reactions mentioned hereinabove and hereinafter. The protection of such functional groups by such protecting groups, the protecting groups themselves, and their removal reactions are described for example in standard reference works, such as J. F. W. McOmie, "Protective Groups in Organic Chemistry", Plenum Press, London and New York 1973, in T. W. Greene, "Protective Groups in Organic Synthesis", Wiley, New York 1981 , in "The Peptides"; Volume 3 (editors: E. Gross and J. Meienhofer), Academic Press, London and New York 1981 , in "Methoden der organischen Chemie" (Methods of organic chemistry),

Houben Weyl, 4th edition, Volume 15/1, Georg Thieme Verlag, Stuttgart 1974, in H.-D. Jakubke and H. Jescheit, "Aminosauren, Peptide, Proteine" (Amino acids, peptides, proteins), Verlag Chemie, Weinheim, Deerfield Beach, and Basel 1982, and in Jochen Lehmann, "Chemie der

Kohlenhydrate: Monosaccharide und Derivate" (Chemistry of carbohydrates: monosaccharides and derivatives), Georg Thieme Verlag, Stuttgart 1974.

b) Acid addition salts may be produced from the free bases in known manner, and vice-versa. Compounds of formula (I) in optically pure form can be obtained from the corresponding racemates according to well-known procedures, e.g. HPLC with chiral matrix. Alternatively, optically pure starting materials can be used.

c) Stereoisomeric mixtures, e.g. mixtures of diastereomers, can be separated into their corres- ponding isomers in a manner known per se by means of suitable separation methods. Dia- stereomeric mixtures for example may be separated into their individual diastereomers by means of fractionated crystallization, chromatography, solvent distribution, and similar procedures. This separation may take place either at the level of a starting compound or in a compound of formula I itself. Enantiomers may be separated through the formation of dia- stereomeric salts, for example by salt formation with an enantiomer-pure chiral acid, or by means of chromatography, for example by HPLC, using chromatographic substrates with chiral ligands.

d) Suitable diluents for carrying out the above- described are especially inert organic solvents. These include, in particular, aliphatic, alicyclic or aromatic, optionally halogenated hydrocarbons, such as, for example, benzine, benzene, toluene, xylene, chlorobenzene, dichlorobenzene, petroleum ether, hexane, cyclohexane, dichloromethane, chloroform, carbon tetrachloride; ethers, such as diethyl ether, diisopropyl ether, dioxane, tetrahydrofuran or ethylene glycol dimethyl ether or ethylene glycol diethyl ether; ketones, such as acetone, butanone or methyl isobutyl ketone; nitriles, such as acetonitrile propionitrile or butyronitrile; amides, such as N,N-dimethylformamide, N,N-dimethylacetamide, N-methyl-formanilide, N- methyl-pyrrolidone or hexamethylphosphoric triamide; esters, such as methyl acetate or ethyl acetate, sulphoxides, such as dimethyl sulphoxide, alcohols, such as methanol, ethanol, n- or i- propanol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, diethyelene glycol monomethyl ether, diethylene glycol monoethyl ether. Further, mixtures of diluents may be employed. Depending on the starting materials, reaction conditions and auxiliaries, water or diluents constaining water may be suitable. It is also possible to use one a starting material as diluent simultaneously.

e) Reaction temperatures can be varied within a relatively wide range. In general, the processes are carried out at temperatures between 0°C and 150 ⁰ C, preferably between 10 ⁰ C

and 120 ⁰ C. Deprotonation reactions can be varied within a relatively wide range. In general, the processes are carried out at temperatures between -150 ⁰ C and +50 ⁰ C, preferably between - 75°C and 0°C.

f) The reactions are generally carried out under atmospheric pressure. However, it is also possible to carry out the processes according to the invention under elevated or reduced pressure - in general between 0.1 bar and 10 bar.

g) Starting materials are generally employed in approximately equimolar amounts. However, it is also possible to use a relatively large excess of one of the components. The reaction is generally carried out in a suitable diluent in the presence of a reaction auxiliary, and the reaction mixture is generally stirred at the required temperature for a number of hours.

h) Work-up is carried out by customary methods (cf. the Preparation Examples).

Compounds of formula (I) and their pharmaceutically acceptable acid addition salts, hereinafter referred to as agents of the invention, exhibit valuable pharmacological properties and are therefore useful as pharmaceuticals.

In particular, the agents of the invention exhibit a marked and selective modulating, especially antagonistic, action at human metabotropic glutamate receptors (mGluRs). This can be determined in vitro for example at recombinant human metabotropic glutamate receptors, especially PLC-coupled subtypes thereof such as mGluR5, using different procedures like, for example, measurement of the inhibition of the agonist induced elevation of intracellular Ca ²⁺ concentration in accordance with L. P. Daggett et al., Neuropharm. Vol. 34, pages 871-886

(1995), P. J. Flor et al., J. Neurochem. Vol. 67, pages 58-63 (1996) or by determination to what extent the agonist induced elevation of the inositol phosphate turnover is inhibited as described by T. Knoepfel et al., Eur. J. Pharmacol. Vol. 288, pages 389-392 (1994), L. P. Daggett et al., Neuropharm. Vol. 67, pages 58-63 (1996) and references cited therein. Isolation and expression of human mGluR subtypes are described in US-Patent No. 5,521 ,297. Selected agents of the invention show IC50 values for the inhibition of the agonist (e.g. glutamate or quisqualate) induced elevation of intracellular Ca2+ concentration or the agonist (e.g. glutamate or quisqualate) induced inositol phosphate turnover, measured in recombinant cells expressing hmGluRδa of about 1nM to about 50 μM.

The agents of the invention are therefore useful in the prevention, treatment or delay of progression of disorders associated with irregularities of the glutamatergic signal transmission, of the gastro-intestinal and urinary tract and of nervous system disorders mediated full or in part by mGluR5.

Disorders associated with irregularities of the glutamatergic signal transmission are for example epilepsy, cerebral ischemias, especially acute ischemias, ischemic diseases of the eye, muscle spasms such as local or general spasticity, skin disorders, obesity disorders and, in particular, convulsions or pain.

Disorders of the gastro-intestinal tract include post-operative ileus, functional qastro-intestinal disorders (FGID) as for example functional dyspepsia (FD), gastro-esophageal reflux disease (GERD), irritable bowel syndrome (IBS), functional bloating, functional diarrhea, chronic constipation, functional disturbancies of the biliary tract as well as other conditions according to Gut 1999; Vol. 45 Suppl. II.

Disorders of the Urinary Tract comprise conditions associated with pain and/or discomfort of the urinary tract and overactive bladder (OAB).

Nervous system disorders mediated full or in part by mGluR5 are for example acute, traumatic and chronic degenerative processes of the nervous system, such as Parkinson's disease, senile dementia, Alzheimer's disease, Huntington's chorea, amyotrophic lateral sclerosis, multiple sclerosis and fragile X syndrome, psychiatric diseases such as schizophrenia and anxiety, depression, pain, itch and drug abuse. Anxiety related disorders includes panic disorders, social anxiety, obsessive compulsive disorders (OCD), post traumatic stress disorders (ATSD), generalized anxiety disorders (GAD), phobias.

The usefulness of the agents of the invention in the prevention, treatment or delay of progression of the above-mentioned disorders can be confirmed in a range of standard tests including those indicated below:

Activity of the agents of the invention in anxiety can be demonstrated in standard models such as the stress-induced hyperthermia in mice [cf. A. Lecci et al., Psychopharmacol. 101 , 255- 261]. At doses of about 0.1 to about 30 mg/kg p.o., selected agents of the invention reverse the stress-induced hyperthermia.

At doses of about 4 to about 50 mg/kg p.o., selected agents of the invention show reversal of Freund complete adjuvant (FCA) induced hyperalgesia [cf. J. Donnerer et al., Neuroscience 49, 693-698 (1992) and CJ. Woolf, Neuroscience 62, 327-331 (1994)].

For all the above mentioned indications, the appropriate dosage will of course vary depending upon, for example, the compound employed, the host, the mode of administration and the nature and severity of the condition being treated. However, in general, satisfactory results in animals are indicated to be obtained at a daily dosage of from about 0.5 to about 100 mg/kg animal body weight. In larger mammals, for example humans, an indicated daily dosage is in the range from about 5 to 1500 mg, preferably about 10 to about 1000 mg of the compound conveniently administered in divided doses up to 4 times a day or in sustained release form.

In accordance with the foregoing, the present invention also provides an agent of the invention for use as a pharmaceutical, e.g. in the prevention, treatment or delay of progression of disorders associated with irregularities of the glutamatergic signal transmission, of the gastrointestinal and urinary tract and of nervous system disorders mediated full or in part by mGluR5.

The invention also provides the use of an agent of the invention, in the prevention, treatment or delay of progression of disorders associated with irregularities of the glutamatergic signal transmission, of the gastro-intestinal and urinary tract and of nervous system disorders mediated full or in part by mGluR5.

Furthermore the invention provides the use of an agent of the invention for the manufacture of a pharmaceutical composition designed for the prevention, treatment or delay of progression of disorders associated with irregularities of the glutamatergic signal transmission, of the gastrointestinal and urinary tract and of nervous system disorders mediated full or in part by mGluR5.

In a further aspect the invention relates to a method of treating disorders mediated full or in part by mGluR5, which method comprises administering to a warm-blooded organism in need of such treatment a therapeutically effective amount of an agent of the invention.

Moreover the invention relates to a pharmaceutical composition comprising an agent of the invention in association with one or more pharmaceutical carrier or one or more pharmaceutically acceptable diluent.

The pharmaceutical compositions according to the invention are compositions for enteral, such as nasal, rectal or oral, or parenteral, such as intramuscular or intravenous, administration to warm-blooded animals (human beings and animals) that comprise an effective dose of the pharmacological active ingredient alone or together with a significant amount of a pharmaceutically acceptable carrier. The dose of the active ingredient depends on the species of warm-blooded animal, body weight, age and individual condition, individual pharmacokinetic data, the disease to be treated and the mode of administration.

The pharmaceutical compositions comprise from approximately 1% to approximately 95%, preferably from approximately 20% to approximately 90%, active ingredient. Pharmaceutical compositions according to the invention may be, for example, in unit dose form, such as in the form of ampoules, vials, suppositories, dragees, tablets or capsules.

The pharmaceutical compositions of the present invention are prepared in a manner known per se, for example by means of conventional dissolving, lyophilizing, mixing, granulating or confectioning processes.

The preferred agents of the invention include the (±)-(1R,3R)-3-(4-Chloro-phenylamino)-1-(3- chloro-phenylethynyl)-cyclohexanol free base or pharmaceutically acceptable acid addition salt form.

(±)-(1 R,3R)-3-(4-Chloro-phenylamino)-1-(3-chloro-phenylethynyl)-cy clohexanol inhibits the quisqualate-induced inositol phosphate turnover in hmGluRδ expressing cells with an IC ₅₀ concentration of 1600 nM.

With (±)-(1R,3R)-3-(4-Chloro-phenylamino)-1-(3-chloro-phenylethy nyl)-cyclohexanol, a stress- induced hyperthermia of 0.98 +/- 0.08 ⁰ C was reduced to 0.66 +/- 0.06 ⁰ C at 1 mg/kg p.o., to 0.43 +/- 10 ⁰ C at 3 mg/kg p.o.; to 0.58 +/- 0.06 ⁰ C at 10 mg/kg p.o. and to 0.33 +/- 0.04 ⁰ C at 30 mg/kg p.o. (p < 0.05; p < 0.0011 ; p < 0.01 ; p < 0.001 respectively).

Further, properly isotope-labeled agents of the invention exhibit valuable properties as histopathological labeling agents, imaging agents and/or biomarkers, hereinafter "markers", for the selective labeling of the metabotropic glutamate receptor subtype 5 (mGlu5 receptor). More particularly the agents of the invention are useful as markers for labeling the central and peripheral mGlu5 receptors in vitro or in vivo. In particular, compounds of the invention which

are properly isotopically labeled are useful as PET markers. Such PET markers are labeled with one or more atoms selected from the group consisting of ¹¹ C, ¹³ N, ¹⁵ 0, ¹⁸ F.

The agents of the invention are therefore useful, for instance, for determining the levels of receptor occupancy of a drug acting at the mGluδ receptor, or diagnostic purposes for diseases resulting from an imbalance or dysfunction of mGluδ receptors, and for monitoring the effectiveness of pharmacotherapies of such diseases.

In accordance with the above, the present invention provides an agent of the invention for use as a marker for neuroimaging.

In a further aspect, the present invention provides a composition for labeling brain and peripheral nervous system structures involving mGluδ receptors in vivo and in vitro comprising an agent of the invention.

In still a further aspect, the present invention provides a method for labeling brain and peripheral nervous system structures involving mGlu5 receptors in vitro or in vivo, which comprises contacting brain tissue with an agent of the invention.

The method of the invention may comprise a further step aimed at determining whether the agent of the invention labeled the target structure. Said further step may be effected by observing the target structure using positron emission tomography (PET) or single photon emission computed tomography (SPECT), or any device allowing detection of radioactive radiations.

The following non-limiting Examples illustrate the invention. A list of Abbreviations used is given below.

BOC tert-butoxycarbonyl n-BuLi n-butyl lithium

DCM dichloromethane

DMF N.N'-dimethylformamide

EDC 1 -ethyl-3-[3-(dimethylamino)propyl]-carbodiimide hydrochloride

EtOAc ethylacetate h hours

HCI hydrochloric acid

HOBt hydroxybenzotriazole

HPLC high pressure liquid chromatography min minutes

Mp melting point

MS mass spectroscopy MTBE methyl-tert.-butylether

Rf retention factor (Thin Layer Chromatography)

Rt retention time rt room temperature

TFA trifluoroacetic acid THF tetrahydrofuran

Example 1 : (±)-(1 R,3R)-3-(4-Chloro-phenvlamino)-1-(3-chloro-phenylethvnvl)-cv clohexanol

A solution of (±)-3-(3-Chloro-phenylethynyl)-3-hydroxy-cyclohexanone (500 mg, 2 mmol), 4- chloroaniline (256 mg, 2 mmol) and acetic acid (121 mg, 2 mmol) in DCM (30 ml) is treated with sodiumtriacetoxy borohydride (597 mg, 2.8 mmol) and stirred for 3 h at room temperature. The mixture is diluted with EtOAc, washed with sodium bicarbonate and brine, dried (Na2SO4) and the solvent evaporated to afford 324 mg of a red oil. This crude product was purified by chromatography on silica gel and treated with an excess of HCI in diethyl ether which afforded after evaporation of the solvent the hydrochloride of the title compound as an amorphous orange powder (112 mg, 14%). Mp: 153-163°C. MS (LC/MS): 361.3 [M+H].

The starting material was prepared as described hereafter: i) (±)-7-(3-Chloro-phenylethynyl)-1 ,4-dioxa-spiro[4.5]decan-7-ol: 1 -Chloro-3-ethynyl-benzene (6.4 g, 47.2 mmol) was dissolved in THF (250 ml) and cooled to -20 ⁰ C. A solution of n-BuLi in hexanes (29.5 ml, 1.6 M, 47.2 mmol) was added within 1 h and the solution stirred for an additional hour at this temperature. The mixture was then cooled to -78° and a solution of 1 ,4- Dioxa-spiro[4.5]decan-7-one (4.9 g, 31.4 mmol) in THF (100 ml) was added dropwise within 30'. The cooling bath was removed and the mixture was allowed to reach room temperature. EtOAc was added, the mixture was washed with aqueous sodium bicarbonate and brine, dried and evaporated to afford an orange oil (8.43 g). Chromatography on silica gel afforded the title compound as a yellow oil (4.65 g, 50%).

ii) (±)-3-(3-Chloro-phenylethynyl)-3-hydroxy-cyclohexanone: A solution of (±)-7-(3-Chloro- phenylethynyl)-1 ,4-dioxa-spiro[4.5]decan-7-ol (4.6 g, 15.88 mmol) and p-TsOH (61 mg) in acetone (100 ml) was stirred at room temperature for 24 h. Dilution with EtOAc, washing with aqueous sodium bicarbonate and brine, drying and evaporation of the solvents afforded the

crude product as a yellow oil (4.53 g). Chromatography on silica gel led to the pure title compound as a slightly yellowish oil (3.60 g, 91%).

Following the same procedure, the following compounds can be obtained: Example 1.1 : ((±)-1 R,3R)-1 -(3-Chloro-phenylethynyl)-3-(3,4-difluoro-phenylamino)-cyclo hexanol

MS (LC/MS): 362.3 [M+H]

TLC Rf: 0.11 (EtOAc/cyclohexane 1 :1)

Example 1.2: ((±)-1 R,3R)-1 -(3-Chloro-phenylethynyl)-3-(4-phenyl-thiazol-2-ylamino)- cyclohexanol

MS (LC/MS): 410.4 [M+H]

TLC Rf: 0.60 (EtOAc/cyclohexane 1 :1)

Example 1.3: ((±)-1 R.3R)-3-(4-Chloro-phenvlamino)-1-m-tolylethvnvl-cvclohexanol MS (LC/MS): 340.5 [M+H]

TLC Rf: 0.60 (EtOAc/cyclohexane 1 :1)

Example 1.4: ((±)-1 R,3R)-3-(3,4-Difluoro-phenylamino)-1 -m-tolylethynyl-cyclohexanol

MS (LC/MS): 342.1 [M+H] TLC Rf: 0.59 (EtOAc/cyclohexane 1:1)

Example 1.5: ((±)-1 R,3R)-3-(5-Methyl-1 H-pyrazol-3-ylamino)-1-m-tolylethynyl-yclohexanol

MS (LC/MS): 310.1 [M+H] TLC Rf: 0.41 (EtOAc/MeOH/Et ₃ N 90:9:1 )

Example 1.6: ((±)-1 R,3R)-1 -(3-Chloro-phenylethynyl)-3-(pyridin-2-ylamino)-cyclohexanol

MS (LC/MS): 327.4 [M+H] TLC Rf: 0.35 (EtOAc)

Example 1.7: ((±)-1 R,3R) -1 -(3-Chloro-phenylethynyl)-3-(pyridin-3-ylamino)-cyclohexanol

MS (LC/MS): 327.4 [M+H] TLC Rf: 0.34 (EtOAc)

Example 1.8: ((±)-1 R, 3R) -1-(3-Chloro-phenylethynyl)-3-(quinoxalin-6-ylamino)-cyclohe xanol MS (LC/MS): 378.3 [M+H]

TLC Rf: 0.37 (EtOAc/hexane 1 :1)

Example 1.9: ((±)-1 R.3R) -1-(3-Chloro-phenylethynyl)-3-(2,3-dihydro-benzo[1 ,4]dioxin-6- ylamino)-cyclohexanol MS (LC/MS): 384.3 [M+H]

TLC Rf: 0.46 (EtOAc/hexane 2:3)

Example 1.10: ((±)-1 R,3R) -1 -(3-Chloro-phenylethynyl)-3-(5-methyl-1 H-pyrazol-3-ylamino)- cyclohexanol MS (LC/MS): 330.4 [M+H]

TLC Rf: 0.54 (EtOAc/hexane 3:2)

Example 1.11 : ((±)-1 R,3R) -1-(3-Chloro-phenylethynyl)-3-(5-phenyl-1 H-pyrazol-3-ylamino)- cyclohexanol MS (LC/MS): 392.4 [M+H]

TLC Rf: 0.33 (EtOAc/hexane 3:2)

Example 1.12: ((±)-1 R.3R) -1-(3-Chloro-phenylethynyl)-3-(2,2-difluoro-benzo[1 ,3]dioxol-5- ylamino)-cyclohexanol MS (LC/MS): 406.1 [M+H]

TLC Rf: 0.41 (EtOAc/cyclohexane 1 :9)

Example 1.13: ((±)-1 R, 3R) -1-(3-Chloro-phenylethynyl)-3-(quinolin-8-ylamino)-cyclohexa nol

MS (LC/MS): 377.1 [M+H] TLC Rf: 0.45 (EtOAc/hexane 1 :2)

Example 1.14: ((±)-1 R.3R) -1-(3-Chloro-phenylethynyl)-3-(2,3-dihydro-imidazo[1 ,2-b]pyrazol-1- yl)-cyclohexanol

MS (LC/MS): 342.1 [M+H]

TLC Rf: 0.32 (EtOAc/hexane 2:1)

Example 1.15: (±)-(1 S,3S)-(1 R,3R)-1 -(3-Chloro-phenylethynyl)-3-(1 H-indazol-3-ylamino)- cyclohexanol

MS (LC/MS): 366.3 [M+H]

TLC Rf: 0.31 (EtOAc/cyclohexane 1:1)

Example 1.16: fS-O-Chloro-phenvlethvnvD-cvclohexvn-tδ-nnethvl^H-pvrazol-S -vD-amine MS (LC/MS): 312.3 [M+H]

TLC Rf: 0.53 (EtOAc/hexane 2:3)

Example 1.17: (±)-(1 S,3S)-(1 R,3R)-3-(Benzo[1 ,2,5]thiadiazol-5-ylamino)-1 -(3-chloro- phenylethynyl)-cyclohexanol MS (LC/MS): 384.1 [M+H]

TLC Rf: 0.51 (EtOAc/hexane 1 :4)

Example 1.18: (±)-(1 S,3S)-(1 R,3R)-1 -(3-Chloro-phenylethynyl)-3-(2-methyl-5-phenyl-2H- pyrazol-3-ylamino)-cyclohexanol MS (LC/MS): 406.1 [M+H]

TLC Rf: 0.51 (EtOAc/cyclohexane 1 :1)

Example 1.19: (±)-(1S,3S)-(1 R,3R)-1-(3-Chloro-phenylethynyl)-3-(5-furan-2-yl-1 H-pyrazol-3- ylamino)-cyclohexanol MS (LC/MS): 382.1 [M+H]

TLC Rf: 0.15 (EtOAc/cyclohexane 1 :1)

Example 1.20: (±)-(1S.3S)-πR.3R)-1-(3-Chloro-phenvlethvnvl)-3-(2.2.3.3-t etrafluoro-2.3- dihydro-benzo[1 ,4]dioxin-6-ylamino)-cyclohexanol MS (LC/MS): 456.1 [M+H]

TLC Rf: 0.33 (EtOAc/cyclohexane 1:9)

Example 1.21 : (±)-(1 S,3S)-1 -(3-Chloro-phenylethynyl)-3-(6-methoxy-pyridin-2-ylamino)- cyclohexanol

MS (LC/MS): 357.1 [M+H] TLC Rf: 0.40 (EtOAc/cyclohexane 1 :3)

Example 1.22: (±)-(1 S,3S)-1 -(3-Chloro-phenylethynyl)-3-(2,3-dihydro-[1 ,4]dioxino[2,3-b]pyridin- 6-ylamino)-cyclohexanol

MS (LC/MS): 385.1 [M+H]

Example 1.23: (±)-(1S.3S)-1-(3-Chloro-pheπvlethvnvn-3-(5-fluoro-Dvridin- 2-vlamino)- cyclohexanol

MS (LC/MS): 345.1 [M+H]

TLC Rf: 0.29 (EtOAc/cyclohexane 1 :4)

Example 1.24: (1S.3S)-1-(3-Chloro-phenvlethvnvn-3-(2.2-difluoro-benzon .3ldioxol-5-vlamino)- cyclohexanol

[α] _D = -154.5° (c=1.1 , MeOH) MS (LC/MS): 406.1 [M+H]

Example 1.25: (1 R,3R)-1-(3-Chloro-phenylethynyl)-3-(2,2-difluoro-benzo[1 ,3]dioxol-5-ylamino)- cyclohexanol

[α] _D = 158.4° (C=I ₁ MeOH) MS (LC/MS): 382.1 [M+H]

Example 1.26: (1S.3S)-1-(3-Chloro-phenvlethvnvn-3-(5-furan-2-vl-1 H-pvrazol-3-vlamiπo)- cyclohexanol

[α] _D = -189° (c=0.5, MeOH) M.p. = 83-88°C

Example 1.27: (1 R,3R)-1 -(3-Chloro-phenylethynyl)-3-(5-furan-2-yl-1 H-pyrazol-3-ylamino)- cyclohexanol

[α] _D = 186.4° (c=0.5, MeOH) M.p. = 78-85°

Example 1.28: nS.3S)-1-(3-Chloro-phenvlethvnvl)-3-(2.2.3.3-tetrafluoro-2.3 -dihvdro- benzo[1,4]dioxin-6-ylamino)-cyclohexanol

[α] _D = -156.8° (c=0.37, MeOH) TLC Rf: 0.33 (EtOAc/cyclohexane 1 :9)

Example 1.29: (1 R.3R)-1-(3-Chloro-phenvlethvnv[)-3-(2.2.3.3-tetrafluoro-2.3- dihvdro- benzo[1,4]dioxin-6-ylamino)-cyclohexanol

[α] _D = 133.8° (c=0.53, MeOH) TLC Rf: 0.33 (EtOAc/cyclohexane 1 :9)

Example 1.30: (1 R,3R)-1 -(3-Chloro-phenylethynyl)-3-(quinoxalin-6-ylamino)-cyclohexa nol. A solution of [(1R,3R)-3-(3-Chloro-phenylethynyl)-3-(4-methoxy-benzyloxy)- cyclohexyl]- quinoxalin-6-yl-amine (24.9 mg) in MeOH (1 ml) was cooled to 0° and treated with 4M HCI in dioxane (1.00 ml) in a dropwise manner. The solution was stirred at room temperature for 3 h, then poured onto ice/aqueous cone NH ₄ OH and the mixture extracted with Et ₂ O. The organic phase was dried and evaporated under reduced pressure. Purification by preparative thin layer chromatography afforded 10 mg of the title compound (53%). [α] _D = 485° (c=0.5, MeOH). MS (LC/MS): 378 [M+H].

The starting material was prepared as described hereafter:

i) (3-Oxo-cyclohexyl)-carbamic acid tert-butyl ester: A solution of 2-cyclohexen-1-on (14 ml, 150 mmol) and t-butylcarbamate (17 g, 145.11 mmol) in DCM (30 ml) was treated with bismuth nitrate pentahydrate (14 g, 28.8 mmol) and stirred at room temperature for 21 h. Dilution with further DCM, filtration over hyflo, washing of the filtrate with sodium bicarbonate solution and brine, drying of the organic phase with Na2SO4, filtration and evaporation of the solvent afforded 22.1 g of the crude product. Chromatography on silica gel (EtOAc/cyclohexanol 3:7), follocwed by crystallization from the same solvent system afforded (3-oxo-cyclohexyl)-carbamic acid tert-butyl ester (14.43 g, 47%).

ii) rac-[(1R,3R)-3-(3-Chloro-phenylethynyl)-3-hydroxy-cyclohexyl ]-carbamic acid tert-butyl ester: 1 -Chloro-3-ethynyl-benzene (9.0 ml, 71 mmol) was dissolved in THF (250 ml) and cooled to - 20°. A solution of n-BuLi in hexanes (44 ml, 1.6 M, 70 mmol) was added dropwise and the mixture stirred at -20° for 2 h. After cooling to -60°, a solution of (3-oxo-cyclohexyl)-carbamic

acid tert-butyl ester (15.15 g, 71 mmol) in THF (100 ml) was added slowly. The mixture was allowed to reach room temperature and then stirred for 16 h. Dilution of the mixture with EtOAc, washing with sodium bicarbonate solution and brine, drying of the organic phase with Na2SO4, filtration and evaporation of the solvent afforded a crude product as a mixture of cis and trans isomers. Careful chromatography on silica gel with EtOAc/cyclohexane 4:6 afforded first the desired rac-(R.R) isomer ('trans ¹ for -OH and -NH, 2.48 g, 10%), followed by the rac-(R.S) isomer ('cis' for -OH and -NH, 8 g).

iϋ) ( ⁺ )-[(1 R,3R)-3-(3-Chloro-phenylethynyl)-3-hydroxy-cyclohexyl]-carba mic acid tert-butyl ester: rac-[(1 R,3SR-3-(3-Chloro-phenylethynyl)-3-hydroxy-cyclohexyl]-carba mic acid tert-butyl ester (2.26 g) was separated into its enantiomers via HPLC using Chiralcel OD as stationary phase and hexanes/EtOH as eluent. 1.1 g of each enantiomer was isolated. [α] _D = +98.5° (c=0.5, MeOH) and -94.3° (c=0.6, MeOH), respectively.

iv) [(1 R,3R)-3-(3-Chloro-phenylethynyl)-3-(4-methoxy-benzyloxy)-cyc lohexyl]-carbamic acid tert- butyl ester: (+)-[(1R,3R)-3-(3-Chloro-phenylethynyl)-3-hydroxy-cyclohexyl ]-carbamic acid tert- butyl ester (3.50 g) was dissolved in THF (35 ml) and treated with NaH (800 mg) for 40 min. NaI (15.4 mg) and 4-methoxybenzyl bromide (2.51 g) were added and the mixture stirred for 16 h at room temperature. All volatiles were evaporate under reduced pressure, the residue triturated with silicagel (30 g) and cyclohexanol, and then filtered. The product was eluted from the silicagel with cyclohexanol/EtOAc 1 :1 to affort 4.7 g (70%) of the desired 4-methoxybenzyl ether.

v) (1 R,3R)-3-(3-Chloro-phenylethynyl)-3-(4-methoxy-benzyloxy)-cyc lohexylamine: [(1 R,3R)-3- (3-Chloro-phenylethynyl)-3-(4-methoxy-benzyloxy)-cyclohexyl] -carbamic acid tert-butyl ester (1.6 g) was dissolved in THF (27 ml) and treated with a solution of p-toluenesulfonic acid (660 mg) in EtOH (5 ml) for 9 h at reflux temperature. The mixture was distributed between cold 1 M Na ₂ CO ₃ and EtOAc, the phases separated, the organic phase dried over Na ₂ SO ₄ and evaporated. Flash chromatography afforded the desired primary amine (0.58 g, 46%).

vi) [(1R,3R)-3-(3-Chloro-phenylethynyl)-3-(4-methoxy-benzyloxy)- cyclohexyl]-quinoxalin-6-yl- amine: A solution of (1 R,3R)-3-(3-Chloro-phenylethynyl)-3-(4-methoxy-benzyloxy)- cyclohexylamine (34 mg), 6-bromoquinoxaline (23 mg), NaOt-Bu (13 mg), Pd ₂ (dba) ₃ ^' CHCI ₃ (1.9 mg) and BINAP (3.5 mg) in de-gassed toluene (2 ml) was stirred under Ar atmosphere for 1.5 h at 100°. The mixture was distributed between cold 1 M Na ₂ CO ₃ and EtOAc, the phases

separated, the aqueous phase ectracted with EtOAc, the combined organic phases dried over Na ₂ SO ₄ and evaporated. Chromatography afforded 38 mf of the desired product (83%).

Following the same procedure, the following compounds can be obtained:

Example 1.31 : (1 S,3S)-1 -(3-Chloro-phenylethynyl)-3-(quinoxalin-6-ylamino)-cyclohexa nol

MS (LC/MS): 378 [M+H]

TLC Rf: 0.14 (EtOAc/cyclohexane 1 :1)

Example 1.32: (1S,3S)-1-(3-Chloro-phenylethynyl)-3-(pyridin-2-ylamino)-cyc lohexanol

[α] _D = 193.8° (c=0.55, MeOH) MS (LC/MS): 327 [M+H]

Example 1.33: (1 R,3R)-1 -(3-Chloro-phenylethynyl)-3-(pyridin-2-ylamino)-cyclohexanol [α] _D = 179.8° (c=0.5, MeOH) MS (LC/MS): 327 [M+H]

Example 1.34: (1R,3R)-1-(3-Chloro-phenvlethvnvl)-3-(quinolin-8-vlamino)-cy clohexanol

[α] _D = 6.0° (c=0.5, MeOH) MS (LC/MS): 377 [M+H]

Example 1.35: (1 R,3R)-1-(3-Chloro-phenylethynyl)-3-(2,3-dihydro-[1 ,4]dioxino[2,3-b]pyridin-6- ylamino)-cyclohexanol

[α] _D = 242° (c=0.23, MeOH) MS (LC/MS): 385 [M+H]

Example 1.36: (1 R,3R)-1-(3-Chloro-phenylethynyl)-3-(5-fluoro-pyridin-2-ylami no)-cyclohexanol

MS (LC/MS): 345 [M+H] TLC Rf: 0.34 (EtOAc/cyclohexane 1 :2)

BcajτioJe_L37i (1 R,3R)-1-(3-Chloro-phenylethynyl)-3-(pyrimidin-2-ylamino)-cyc lohexanol MS (LC/MS): 328 [M+H]

TLC Rf: 0.21 (EtOAc/cyclohexane 1:1)

Example 1.38: (1 R,3R)-1 -(3-Chloro-phenylethynyl)-3-(5-trifluoromethyl-pyridin-2-yla mino)- cyclohexanol MS (LC/MS): 395 [M+H]

TLC Rf: 0.45 (EtOAc/cyclohexane 1 :2)

Example 1.39: (1 R,3R)-1 -(3-Chloro-phenylethynyl)-3-(pyrazin-2-ylamino)-cyclohexanol

MS (LC/MS): 328 [M+H] TLC Rf: 0.17 (EtOAc/cyclohexane 1:1)

Example 1.40: (1 R,3R)-1 -(3-Chloro-phenylethynyl)-3-(6-methoxy-pyridin-2-ylamino)- cyclohexanol

MS (LC/MS): 357 [M+H] TLC Rf: 0.28 (EtOAc/cyclohexane 1 :4)

Example 1.41 : (1 R.3R)-1-(3-Chloro-phenvlethvnvl)-3-(3-chloro-pvridin-2-vlami no)-cyclohexanol

MS (LC/MS): 361 [M+H] TLC Rf: 0.11 (EtOAc/cyclohexane 1 :4)

Example 1.42: (1 R,3R)-1 -(3-Chloro-phenylethynyl)-3-(5-chloro-pyridin-2-ylamino)-cyc lohexanol

MS (LC/MS): 361 [M+H]

TLC Rf: 0.12 (EtOAc/cyclohexane 1 :4)

Example 1.43: (1 R,3R)-1 -(3-Chloro-phenylethynyl)-3-(4-chloro-pyridin-2-ylamino)-cyc lohexanol

MS (LC/MS): 361 [M+H]

TLC Rf: 0.10 (EtOAc/cyclohexane 1 :4)

Example 1.44: (1 R,3R)-1 -(3-Chloro-phenylethynyl)-3-(6-chloro-pyridin-2-ylamino)-cyc lohexanol MS (LC/MS): 361 [M+H]

TLC Rf: 0.14 (EtOAc/cyclohexane 1 :4)

Example 1.45: (1 R.3R)-1-(3-Chloro-phenvlethvnvl)-3-(pvridazin-3-vlamino)-cvc lohexanol

MS (LC/MS): 328 [M+H] TLC Rf: 0.14 (EtOAc)

Example 1.46: (1 R,3R)-1-(3-Chloro-phenylethynyl)-3-(5-methyl-pyridin-2-ylami no)-cyclohexanol

MS (LC/MS): 341 [M+H]

TLC Rf: 0.11 (EtOAc/cyclohexane 1:2)

Example 1.47: (1 R,3R)-1 -(3-Chloro-phenylethynyl)-3-(pyrimidin-4-ylamino)-cyclohexan ol MS (LC/MS): 328 [M+H]

TLC Rf: 0.15 (EtOAc/cyclohexane 1:2)

Example 1.48: (1 R,3R)-1 -(3-Chloro-phenylethynyl)-3-(6-chloro-pyridin-3-ylamino)-cyc lohexanol

MS (LC/MS): 362 [M+H] TLC Rf: 0.22 (EtOAc/hexane 1 :3)

Example 1.49: : (1 R,3R)-1 -(3-Chloro-phenylethynyl)-3-(5-chloro-pyridin-3-ylamino)-cyc lohexanol

MS (LC/MS): 362 [M+H]

TLC Rf: 0.31 (EtOAc/hexane 1 :3)

Example 1.50: (1 R.SRM-O-Chloro-phenvlethvnvD-S-fpyrimidin-δ-vlamino^cvclohe xanol

MS (LC/MS): 328 [M+H]

TLC Rf: 0.18 (EtOAc/hexane 2:1 )

Example 1.51 : (1 R,3R)-1 -(3-Chloro-phenylethynyl)-3-(6-trifluoromethyl-pyridin-2-yla mino)- cyclohexanol

MS (LC/MS): 395 [M+H]

TLC Rf: 0.19 (EtOAc/cyclohexane 1 :4)

Example 1.52: (1 R,3R)-1-(3-Chloro-phenylethynyl)-3-(pyrimidin-5-ylamino)-cyc lohexanol

MS (LC/MS): 328 [M+H] TLC Rf: 0.24 (EtOAc)

Example 1.53: (1 R,3R)-1-(3-Chloro-phenvlethvnvl)-3-(5-fluoro-pyrimidin-2-vla mino)- cyclohexanol

MS (LC/MS): 346 [M+H]

TLC Rf: 0.61 (EtOAc/cyclohexane 1 :1)

Example 2: (1R,3R)-1-(3-Chloro-phenylethynyl)-3-imidazol-1-yl-cyclohexa nol: The pH of a solution of (1R,3R)-3-amino-1-(3-chloro-phenylethynyl)-cyclohexanol (268 mg, 1.07 mmol) in water (0.5 ml) is adjusted to pH=2 by addition of an aqueous 85% solution of H3PO4. Paraformaldehyde (32 mg, 1.07 mmol), Glyoxal (123 μl, 40% in water, 1.07 mmol) and water (1 ml) were added and the mixture heated to 80 ⁰ C. A saturated solution of NH4CI (195 μl) was added and the mixture stirred at 100 ⁰ C for 4 h. The reaction mixture was then cooled to 0 ⁰ C, treated with solid NaOH until the pH was basic and extracted two times with EtOAc. The extracts were washed with brine, dried over Na2SO4, filtered and evaporated to afford the crude product (266 mg). Chromatography on silica gel afforded the title compound as a white amorphous powder (66 mg, 20%). [α] _D = + 47.2° (c=0.25, MeOH) MS (LC/MS): 301.4 [M+H].

Following the same procedure, the following compounds can be obtained: BCaJ]ToJe-ZIi (I S, 3S)-1-(3-Chloro-phenylethynyl)-3-imidazol-1-yl-cyclohexanol [α] _D = -52.7° (c=0.5, MeOH) MS (LC/MS): 301.4 [M+H]

Example 2.2: (±)-(1R.3R)-3-lmidazol-1-vl-1-m-tolvlethvnvl-cvclohexanol

MS (LC/MS): 281.3 [M+H] TLC Rf: 0.52 (EtOAc/MeOH/Et ₃ N 70:27:3)

Example 3: (±)-(1S.3S)-1-(3-Chloro-phenvlethvnvl)-3-(2-methyl-imidazol -1-vl)-cvclohexanol

A solution of 1-chloro-3-ethynyl-benzene (410 mg, 3 mmol) in diethylether (15 ml) was cooled to

-65°. N-BuLi (1.9 ml, 3 mmol, 1.6 M in hexanes) was added dropwise and the mixture stirred for 30' at -65°. A solution of 3-(2-methyl-imidazol-1-yl)-cyclohexanone (446 mg, 2.5 mmol) in THF (2 ml) was added dropwise and the mixture stirred for 90' at -65°. The temperature was allowed to reach room temperature, and stirred for 3 h. The reaction mixture was partitioned between sat. aq. KHCO3 and EtOAc, the aq. phase extracted with EtOAc, the organic phases dried over Na2SO4, filtered and the solvents evaporated. Preparative thin layer chromatography of part of the crude mixture using EtOAc/EtOH/NH4OH 9:1 :0.1 as eluent afforded the racemic trans-

isomer (±)-(1S,3S)-1-(3-Chloro-phenylethynyl)-3-(2-methyl-imidazol -1-yl)-cyclohexanol (20 mg) along with the corresponding cis-isomer (see example 3.1 , 5 mg). MS (LC/MS): 315 [M+H]. TLC Rf: 0.29 (EtOAc/EtOH/NH4OH 9:1 :0.1).

The starting material was prepared as described hereafter:

3-(2-Methyl-imidazol-1-yl)-cyclohexanone: A mixture of cyclohex-2-enone (5.14 g, 53.5 mmol), 2-methyl-1 H-imidazole (4.39 g, 53.5 mmol) and bismuthnitrate pentahydrate (3.93 g, 8 mmol) was stirred at room temperature. After 1 h, DCM (4 ml) was added and stirring continued for 15 h. The mixture was filtered, partitioned between EtOAc and sat. aq. NaHCO3, the aq. phase extracted with EtOAc, the combined organic extracts dried over Na2SO4, filtered and the solvents evaporated. The crude residue was dissolved in cyclohexane/EtOAc 1 :1, silica gel (10 g) was added and the mixture filtered. The silica gel on the filter was washed first with EtOAc and then with EtOAc/MeOH 4:1. The EtOAc/MeOH 4:1 washings were collected and evaporated to afford the title compound (1.5 g, 16 %) of sufficient purity for subsequent steps.

Following the same procedure, the following compounds can be obtained:

Example 3.1 : (±)-πS.3R)-1-(3-Chloro-phenvlethvnvl)-3-(2-methvl-imidazol -1-vl)-cyclohexanol

MS (LC/MS): 315 [M+H] TLC Rf: 0.25 (EtOAc/EtOH/NH4OH 9:1 :0.1)

Example 3.2: (±)-(1 S.3S)-1-(3-Chloro-phenvlethvnvl)-3-(4-methvl-imidazol-1-vl)- cyclohexanol

MS (LC/MS): 315 [M+H] TLC Rf: 0.32 (EtOAc/EtOH/NH4OH 9:1 :0.1)

(±)-(1S,3R)-1-(3-Chloro-phenylethynyl)-3-(4-methyl-imidazol -1-yl)-cyclohexanol

MS (LC/MS): 315 [M+H]

TLC Rf: 0.21 (EtOAc/EtOH/NH4OH 9:1 :0.1 )

Example 3.4: (±H1S.3S)-1-(3-Chloro-phenvlethvnvl)-3-(2.4-dimethvl-imidaz ol-1-yl)- cyclohexanol

MS (LC/MS): 329 [M+H]

TLC Rf: 0.37 (EtOAc/EtOH/NH4OH 9:1 :0.1)

Example 3.5: (±H1S.3R)-1-(3-Chloro-phenvlethvnvl)-3-(2.4-dimethvl-imidaz ol-1-vl)- cyclohexanol

MS (LC/MS): 329 [M+H] TLC Rf: 0.27 (EtOAc/EtOH/NH4OH 9:1 :0.1)

Example 3.6: (±)-(1S.3S)-1-(3-Chloro-phenvlethvnvl)-3-(4-phenyl-imidazol -1-vl)-cvclohexanol

MS (LC/MS): 377 [M+H]

TLC Rf: 0.44 (EtOAc/EtOH/NH4OH 9:1 :0.1)

Example 3.7: (±)-(1S.3S)-1-(3-Chloro-phenylethvnvl)-3-(2-isopropyl-imida zol-1-vl)-cvclohexanol

MS (LC/MS): 343 [M+H]

TLC Rf: 0.29 (EtOAc/EtOH/NH4OH 9:1 :0.1)

Example 3.8: (±VdS.SSVS-Benzoimidazol-i-vl-i-O-chloro-phenvlethynvD-cvcl ohexanol MS (LC/MS): 351 [M+H]

TLC Rf: 0.38 (EtOAc/EtOH/NH4OH 9:1 :0.1)

Example 3.9: (±)-(1 S,3S)-1 -(3-Chloro-phenylethynyl)-3-[1 ,2,4]triazol-1 -yl-cyclohexanol

MS (LC/MS): 302 [M+H] TLC Rf: 0.36 (EtOAc/EtOH/NH4OH 9:1 :0.1 )