WO2007039782A1 - Tetrazole derivatives as modulators of metabotropic glutamate receptors - Google Patents

Abstract

The present invention relates to new compounds of formula (I) wherein Y1 and Y2 selected from the group consisting of hydrogen, halogen atom, C1-4 alkyl, C1-4 alkoxy or cyano group, X is oxygen or two hydrogen atoms; Z is -(CH2)n- group or S; n is 1 or 2; R is selected from the group consisting of optionally substituted C1-7 alkyl, C1-4 haloalkyl, C1-4 hydroxyalkyl, C1-3OC1-3 alkyl, C1-4 cyanoalkyl, C0-2(NR1R2)alkyl, C1-4-alkylCOOC1-4-alkyl, C1-4-alkylOCOC1-4-alkyl, C1-4-alkylNHCOC1-4-alkyl, C2-7 alkenyl, C2-7 alkynyl, CH2O-(CH2)1-3-OCH3; an optionally substituted C3-7 cycloalkyl; phenyl; C3-7 saturated or unsaturated heterocyclyl or heteroaryl group containing 1-4 heteroatom; R1 and R2 are independently selected from hydrogen, C1-7 alkyl or C1-6 alkanoyl group - and/or enantiomers and/or racemates and/or diastereomers and/or geometric isomers and/or pharmaceutically acceptable salts thereof formed with acids and bases, to the process for producing said compounds, to pharmaceutical compositions containing said compounds and to their use in the prevention and/or treatment of mGluR5 receptor-mediated disorders.

Description

TETRAZOLE DERIVATIVES AS MODULATORS OF METABOTROPIC GLUTAMATE RECEPTORS

FIELD OF THE INVENTION

The present invention relates to a new class of compounds, the processes for their preparation, the pharmaceutical formulations containing these compounds, as well as the process of treatments with these compounds.

BACKGROUND OF THE INVENTION

A major excitatory neurotransmitter in the mammalian central nervous system (CNS) is the glutamate molecule, which binds to neurons in the CNS and thereby activating cell surface receptors. These receptors can be divided into two major classes, ionotropic and metabotropic glutamate receptors, based on the structural features of the receptor proteins. Metabotropic glutamate receptors (mGluRs) are G protein-coupled receptors that activate a variety of intracellular second messenger systems following the binding of glutamate. Activation of mGluRs in intact mammalian neurons elicits one or more of the following responses: activation of phospholipase C; increases in phosphoinositide (PI) hydrolysis; intracellular calcium release; activation of phospholipase D; activation or inhibition of adenyl cyclase; increases or decreases in the formation of cyclic adenosine monophosphate (cAMP); activation of guanylyl cyclase; increases in the formation of cyclic guanosine monophosphate (cGMP); activation of phospholipase A2; increases in arachidonic acid release; and increases or decreases in the activity of voltage- and ligand-gated ion channels. (Schoepp et al., Trends Pharmcol. Sci. 14:13 (1993), Schoepp, Neurochem. Int. 24:439 (1994), Pin et al., Neuropharmacology 34:1 (1995), Bordi and Ugolini, Prog. Neurobiol. 59:55 (1999).

Eight distinct mGluR subtypes, termed mGluRl through mGluR8, have been identified by molecular cloning. Nakanishi, Neuron 13:1031 (1994), Pin et al., Neuropharmacology 34: (1995), Knopfel et al., J. Med. Chem. 38:1417 (1995). Further receptor diversity occurs via expression of alternatively spliced forms of certain mGluR subtypes. Pin et al., PNAS 89:10331 (1992), Minakami et al., BBRC 199:1136 (1994), JoIy et al., J. Neurosci. 15:3970 (1995). Metabotropic glutamate receptor subtypes may be subdivided into three groups,

Group I, Group II, and Group III mGluRs, based on amino acid sequence homology, the second messenger systems utilized by the receptors, and by their pharmacological characteristics. Group I mGluR comprises mGluRl, mGluR5 and their alternatively spliced variants.

Attempts at elucidating the physiological roles of Group I mGluRs suggest that activation of these receptors elicits neuronal excitation. Evidence indicates that this excitation is due to direct activation of postsynaptic mGluRs, but it also has been suggested that activation of presynaptic mGluRs occurs, resulting in increased neurotransmitter release. (Pin et al, Neuropharmacology 34:1(1995), Watkins et al., Trends Pharmacol. Sci. 15:33 (1994).

Metabotropic glutamate receptors have been implicated in a number of normal processes in the mammalian CNS. Activation of mGluRs has been shown to be required for induction of hippocampal long-term potentiation and cerebellar long-term depression. Bashir et al., Nature 363:347 (1993), Bortolotto et al., Nature 368:740 (1994), Aiba et al., Cell 79:365 (1994), Aiba et al., Cell 79:377 (1994). A role for mGluR activation in nociception and analgesia also has been demonstrated. Meller et al., Neuroreport 4: 879 (1993), Bordi and Ugolini, Brain Res. 871:223 (1999).

Further, Group I metabotropic glutamate receptors and mGluR5 in particular, have been suggested to play roles in a variety of pathophysiological processes and disorders affecting the CNS. These include stroke, head trauma, anoxic and ischemic injuries, hypoglycemia, epilepsy, neurodegenerative disorders such as Alzheimer's disease and pain (Schoepp et al., Trends Pharmacol. Sci. 14:13 (1993), Cunningham et al., Life Sci. 54:135 (1994), Hollman et al., Ann. Rev. Neurosci. 17:31 (1994), Pin et al., Neuropharmacology 34:1 (1995), Knopfel et al., J. Med. Chem. 38:1417 (1991), Spooren et al., Trends Pharmacol. Sci. 22:331 (2001), Gasparini et al. Curr. Opin. Pharmacol. 2:43 (2002), Neugebauer Pain 98:1 (2002)). MGluR5-selective compounds such as 2-methyl-6-(phenylethynyl)-pyridine ("MPEP") are effective in animal models of mood disorders, including anxiety and depression (W.PJ.M Spooren et al., Br. J. Pharmacol. Exp. Ther., 295:1267-1275 (2000); E. Tatarczynska et al, Brit. J. Pharmacol., 132:1423-1430 (2001); A. Klodzynska et al, Pol. J. Pharmacol, 132:1423-1430 (2001)). Most of the pathology in these conditions is thought to be due to excessive glutamate-induced excitation of CNS neurons. As Group I mGluRs appear to increase glutamate-mediated neuronal excitation via postsynaptic mechanisms and enhanced presynaptic glutamate release, their activation probably contributes to the pathology. Therefore, selective antagonists of Group I niGluR receptors could be therapeutically beneficial, especially as neuroprotective agents, analgesics or anticonvulsants. Compounds that have the above mentioned pharmacological activity are described by various researchers.

International Patent Application WO 99 45006 describes heterocyclic compounds including some 2,5-disubstituted tetrazole derivates and their use as inhibitors of rotamase enzymes, especially FKBP- 12 and FKBP-52. These compounds moderate neuronal regeneration and outgrowth and can be used for treating neurological disorders arising from neurodegenerative diseases and nerve damage.

International Patent Application WO 03 029210 claims novel heteroaryl-substituted tetrazoles as modulators of metabotropic glutamate receptor-5 (mGluR5). The specified compound is 2-[2-(3-chlorophenyl)-2H-tetrazol-5-yl]pyridine. International Patent Application WO 03 077918 describes di-aryl substituted tetrazole modulators of mGluR5. It relates to new compounds of 1,3-bisaryltetrazole derivatives, compositions containing them and the method of treating a range of CNS disorders with these compounds, such as pain, including inflammatory pain, anxiety, depression, Parkinson's disease, obesity, bipolar disorders, circadian rhythm disorders and epilepsy.

However there remains a need for novel compounds and composition that exhibit an activity at metabotropic glutamate receptors (mGluRs), especially at the mGluR5 receptor.

SUMMARY OF THE INVENTION

Compounds of the present invention are represented by formula (I)

- wherein

Y₁ and Y₂ selected from the group consisting of hydrogen, halogen atom, C_1-4 alkyl, C_1-4 alkoxy or cyano group,

X is oxygen or two hydrogen atoms;

Z is -(CH₂)n- group or S; n is 1 or 2;

R is selected from the group consisting of optionally substituted C_1-7 alkyl, C_1-4 haloalkyl, C_1-4 hydroxyalkyl, C_1-3OC_1-3 alkyl, C_1-4 cyanoalkyl, Q^CNR^alkyl, C_1-4-alkylCOOC_1-4-alkyl, C_1-4-alkylOCOC_1-4-alkyl,

C_1-4-alkylNHCOC_1-4-alkyl, C_2-7 alkenyl, C_2-7 alkynyl, CH₂O-(CH₂)_I-3-OCH₃; an optionally substituted C_3-7 cycloalkyl; phenyl; C_3-7 saturated or unsaturated heterocyclyl or heteroaryl group containing 1-4 heteroatom(s); R and R are independently selected from hydrogen, C_1-7 alkyl or C_1-6 alkanoyl group — and/or enantiomers and/or racemates and/or diastereomers and/or geometric isomers and/or pharmaceutically acceptable salts thereof formed with acids and bases.

Another aspect of the present invention provides processes for the synthesis of compounds of formula (I). A further aspect of the present invention provides pharmaceutical formulations containing a therapeutically effective amount of a compound of formula (I) or diastereomers or salts or hydrates or solvates thereof as active ingredient and pharmaceutically acceptable diluents, excipients and/or inert carriers.

A further aspect of the present invention provides the use of a compound of formula (I) for the prevention and/or treatment of mGluR5 receptor mediated disorders, particularly neurological disorders, psychiatric disorders, acute and chronic pain and neuromuscular dysfunctions of the lower urinary tract.

A further aspect of the present invention provides the use of a compound of formula (I) for the manufacture of a medicament for the prevention and/or treatment of mGluR5 receptor- mediated disorders, particularly neurological disorders, psychiatric disorders, acute and chronic pain and neuromuscular dysfunctions of the lower urinary tract.

A further aspect of the present invention provides methods of prevention and/or treatment of mGluR5 receptor-mediated disorders with a compound of formula (I), which means administering to a mammal to be treated - including human - effective amount/amounts of compounds of formula (I) of the present invention as such or as medicament.

These and other aspects of the present invention are described in detail herein.

DETAILED DESCRIPTION OF THE INVENTION

Compounds of the present invention are represented by formula (I)

*

- wherein

Y₁ and Y₂ selected from the group consisting of hydrogen, halogen atom, C_1-4 alkyl, C_1-4 alkoxy or cyano group, X is oxygen or two hydrogen atoms; Z is -(CH₂)n- group or S; n is 1 or 2; R is selected from the group consisting of optionally substituted C_1-7 alkyl, C_1-4 haloalkyl, C₁^ hydroxyalkyl, C_1-3OCi_-3 alkyl, C_1-4 cyanoalkyl, Co^CNR^^alkyl, C_1-4-alkylCOOC_1-4-alkyl, C_1-4-alkylOCOC_1-4-alkyl, C_1-4-alkylNHCOC_1-4-alkyl, C_2-7alkenyl, C_2-7 alkynyl, CH₂O-(CH₂)_L3-OCH₃; an optionally substituted C_3-7 cycloalkyl; phenyl; C_3-7 saturated or unsaturated heterocyclyl or heteroaryl group containing 1-4 heteroatom(s);

R and R are independently selected from hydrogen, C_1-7 alkyl or C_1-6 alkanoyl group - and/or enantiomers and/or racemates and/or diastereomers and/or geometric isomers and/or pharmaceutically acceptable salts thereof formed with acids and bases.

In one subset of formula (I) are compounds wherein

Y₁ and Y₂ selected from the group consisting of hydrogen, halogen atom, Ci_-4 alkyl, C_1-4 alkoxy or cyano group;

X is oxygen or two hydrogen atoms; Z is -(CH₂)n- group or S; n is 1 or 2;

R is selected from the group consisting of optionally substituted C_1-7 alkyl, Ci_-4 haloalkyl, C_1-4 hydroxyalkyl, C_1-3OCi_-3 alkyl, C_1-4 cyanoalkyl, Co^CNR^alkyl, C_1-4-alkylCOOC_1-4-alkyl, C_1-4-alkylOCOCi_-4-alkyl, C_1-4-alkylNHCOC_1-4-alkyl, C_2-7 alkenyl, C_2-7 alkynyl, CH₂O-(CH₂)_1-3-OCH₃;

C_3-7 cycloalkyl, which is optionally substituted by one or more substituent(s) selected from the group of C_1-7 alkyl, cyano, acetamido or oxo group,

C_3-7 saturated or unsaturated heterocyclyl group, which is optionally substituted by one or more substituent(s) selected from C_1-7 alkyl or oxo group, wherein the 1-4 heteroatom is independently selected from the group of N, O, S; phenyl group, which is optionally substituted by one or more substituent(s) selected from the group of Ci_-7 alkyl, C_2-7 alkenyl, C_2-7 alkynyl or cyano group; heteroaryl group, which is optionally substituted by one or more substituent(s) selected from halogen atom, C_1-7 alkyl, acetamido, Ci_-4 alkoxy, cyano, Ci_-4 thioalkyl, or Ci_-4 alkanoyl group, wherein the 1-4 heteroatom is independently selected from the group of N, O, S;

R¹ and R² are independently selected from hydrogen, Ci_-7 alkyl or C_1-6 alkanoyl group - and/or enantiomers and/or racemates and/or diastereomers and/or geometric isomers and/or pharmaceutically acceptable salts thereof formed with acids and bases.

In one embodiment within this subset are compounds wherein Y₁ and Y₂ selected from the group consisting of hydrogen, halogen atom, C_1-4 alkyl, C_1-4 alkoxy or cyano group; X is oxygen or two hydrogen atoms; Z is -(CH₂)n- group or S; n is 1 or 2; R is selected from the group consisting of optionally substituted C_1-7 alkyl, C_1-4 haloalkyl, C_1-4 hydroxyalkyl, C_1-3OC_1-3 alkyl, C_1-4 cyanoalkyl, Co^CNR^alkyl, C_1-4-alkylCOOC_1-4-alkyl, C_1-4-alkylOCOC_1-4-alkyl, C_1-4-alkylNHCOC_1-4-alkyl, C_2-7alkenyl, C_2-7alkynyl, CH₂O-(CH₂)i.₃-OCH₃; C_3-7 cycloalkyl, which is optionally substituted by one or more substituent(s) selected from the group consisting of C_1-7 alkyl, cyano, acetamido or oxo group,

C_3-7 saturated or unsaturated heterocyclyl which is optionally substituted by one or more substituent(s) selected from C_1-7 alkyl or oxo group, wherein the 1-4 heteroatom is independently selected from the group of N, O, S; phenyl group, which is optionally substituted by one or more substituent(s) selected from the group of C_1-7 alkyl, C_2-7 alkenyl, C_2-7 alkynyl or cyano group; a heteroaryl group, which is selected from the group of furyl, thiophenyl, pyrrolyl, pyrazolyl, imidazolyl, pyridinyl, pyrazinyl, thiazolyl, thiadiazolyl, izoxazolyl group and is optionally substituted by one or more substituent(s) selected from halogen, C_1-7 alkyl, acetamido, C_1-4 alkoxy, cyano, C_1-4 thioalkyl, or C_1-4 alkanoyl group; R¹ and R² are independently selected from hydrogen, C_1-7 alkyl or C_1-6 alkylcarbonyl group - and/or enantiomers and/or racemates and/or diastereomers and/or geometric isomers and/or pharmaceutically acceptable salts thereof formed with acids and bases.

Listed below are definitions of various terms used in the specification and claims to describe the present invention.

For the avoidance of doubt it is to be understood that where in this specification a group is qualified by 'hereinbefore defined', 'defined hereinbefore' or "defined above' the said group encompasses the first occurring and broadest definition as well as each and all of the other definitions for that group

For the avoidance of doubt it is to be understood that in this specification "C_1-7" means a carbon containing linear or branched group having 1, 2, 3, 4, 5, 6 or 7 carbon atoms.

As used herein the term "alkyl" as well as other groups having the prefix "alk" such as, for example, alkoxy, alkanoyl, alkenyl, alkynyl and the like, means carbon chains which may be linear or branched or combinations thereof. Examples of alkyl groups include methyl, ethyl, propyl, isopropyl, butyl, sec- and tert-butyl, pentyl, hexyl, heptyl and the like. In this specification, unless stated otherwise, the term "alkenyl" includes both straight and branched chain alkenyl groups. The term "C_2-7 alkenyl" refers to an alkenyl group having 2 to 7 carbon atoms and one to three double bonds, and may be, but is not ■limited to vinyl, allyl, propenyl, isopropenyl, butenyl, isobutenyl, crotyl, pentenyl, isopentenyl or hexenyl. In this specification, unless stated otherwise the term "alkynyl" includes both straight and branched chain alkynyl groups. The term "C_2-7 alkynyl" refers to an alkylnyl group having 2 to 7 carbon atoms and one or two triple bonds, and may be, but is not limited to ethynyl, propargyl, butynyl, isobutynyl, pentynyl, isopentynyl or hexynyl.

In this specification, unless stated otherwise, the term "cycloalkyl" refers to an optionally substituted, saturated cyclic hydrocarbon ring system. The term C_3-7 cycloalkyl" may be cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl or cycloheptyl.

The term "hetero" unless specifically stated otherwise includes one or more O, S, or

N atoms. For example, heterocyclyl and heteroaryl include ring systems that contain one or more C, O, S, or N atoms in the ring, including mixtures of such atoms. Examples of heteroaryl rings include pyridinyl, quinolinyl, isoquinolinyl, pyridazinyl, pyrimidinyl, pyrazinyl, quinoxalinyl, furyl, benzofuryl, dibenzofuryl, thienyl, benzthienyl, pyrrolyl, indolyl, pyrazolyl, indazolyl, oxazolyl, benzoxazolyl, isoxazolyl, thiazolyl, benzothiazolyl, isothiazolyl, imidazolyl, benzimidazolyl, oxadiazolyl, thiadiazolyl, triazolyl, and tetrazolyl.

Examples of heterocyclyl rings include azetidinyl, pyrrolidinyl, piperidinyl, piperazinyl, morpholinyl, tetrahydrofuranyl, imidazolinyl, pyrrolidin-2-one, ρiperidin-2-one, and thiomorpholinyl groups.

The term "halogen" includes fluorine, chlorine, bromine and iodine atoms. In this specification, unless stated otherwise, the term "halo" may be fluoro, chloro, bromo or iodo.

In this specification, unless stated otherwise, the term "haloalkyl" means an alkyl group as defined above, wherein at least one or up to all of the hydrogen atoms are replaced with a halogen. The term "C_1-6 haloalkyl" may include, but is not limited to fluoromethyl, difluoromethyl, trifluoromethyl, fluoroethyl, difluoroethyl, bromopropyl. The term "OC_1-6 haloalkyl" may include, but is not limited to fluoromethoxy, difluoromethoxy, trifluoromethoxy, fluoro ethoxy, difluoroethoxy group.

The term "alkanoyl" may include, but is not limited to formyl and acetyl group. The term "optionally substituted" is intended to include both substituted and unsubstituted groups. Thus, for example, optionally substituted cycloalkyl could represent a methylcyclohexyl or a cyclohexyl ring.

The term "pharmaceutically acceptable salts" refers to salts prepared from pharmaceutically acceptable non-toxic bases or acids. When the compound of the present invention is acidic, its corresponding salt can be conveniently prepared from pharmaceutically acceptable non-toxic bases, including inorganic bases and organic bases. Among the salts formed with bases especially important are the salts formed with alkali metals, e.g. sodium, potassium, alkali-earth metals, e.g. calcium and magnesium, as well as with ammonia or organic amines. The latter bases can have further substituents, e.g. hydroxy or amino groups, which can influence e.g. the solubility and the handling of the product. Both organic and inorganic acids can be used for the formation of acid addition salts. Suitable inorganic acids can be e.g. hydrochloric acid, sulfuric acid and phosphoric acid. Representatives of monovalent organic acids can be e.g. formic acid, acetic acid, trifluoroacetic acid, propionic acid, and different butyric acids, valeric acids and capric acids. Representatives of bivalent organic acids can be e.g. oxalic acid, malonic acid, maleic acid, fumaric acid and succinic acid. Other organic acids can also be used, such as hydroxy acids e.g. citric acid, tartaric acid, or aromatic carboxylic acids e.g. benzoic acid or salicylic acid, as well as aliphatic and aromatic sulfonic acids e.g. methanesulfonic acid and p-toluenesulfonic acid. Especially valuable group of the acid addition salts is in which the acid component itself does not have therapeutical effect in the applied dose or it does not have unfavorable influence on the effect of the active ingredient. These acid addition salts are pharmaceutically acceptable acid addition salts. The reason why acid addition salts, which do not belong to the pharmaceutically acceptable acid addition salts belong to the present invention is, that in given case they can be advantageous in the purification and isolation of the desired compounds.

The term "activated acid" means a carboxylic acid (RCOOH) which is activated with EDC in the presence of a base such as sodium hydrogen carbonate or TEA.

Compounds described herein contain one or more double bonds and may thus give rise to cis/trans isomers as well as other conformational isomers. The present invention includes all such possible isomers as well as mixtures of such isomers.

Compounds described herein can contain one or more asymmetric centers and may thus give rise to diastereomers and optical isomers. The present invention includes all such possible diastereomers as well as their racemic mixtures and their substantially pure enantiomers.

Especially important compounds of formula (I) of the present invention are the following:

(5-Bromo-furan-2-yl)-{2-[2-(3-chloro-phenyl)-2H-tetrazol-5-yl]-piperidin-l-yl}-methanone,

Cyclobutyl-[2-(2-m-tolyl-2H-tetrazol-5-yl)-ρiperidin-l-yl]-methanone,

Cyclobutyl-{2R-[2-(3-chloro-phenyl)-2H-tetrazol-5-yl]-piperidin-l-yl}-methanone, {2R-[2-(3-chloro-ρhenyl)-2H-tetrazol-5-yl]-pyrrolidin- 1 -yl} - 1 -(5-methyl-thiophen-2-yl)- methanone,

Cyclopentyl-{2-[2-(3-chloro-phenyl)-2H-tetrazol-5-yl]-piperidin-l-yl}-methanone, Cyclopentyl-[2-(2-m-tolyl-2H-tetrazol-5-yl)-ρiperidin-l-yl]-methanone, {2-[2-(3 -Chloro-phenyl)-2H-tetrazol-5-yl]-ρyrrolidin- 1 -yl} - 1 -(5-methyl-furan-2-yl)- methanone,

{2-[2-(3-Chloro-phenyl)-2H-tetrazol-5-yl]-ρiperidin-l-yl}-l-(5-methyl-thioρhen-2-yl)- methanone,

1 - {2R-[2-(3 -Chloro-phenyl)-2H-tetrazol-5-yl]-piperidin- 1 -yl} -hept-7-yn- 1 -one,

(5-Bromo-thioρhen-2-yl)- {2-[2-(3-chloro-ρhenyl)-2H-tetrazol-5-yl]-piρeridin- 1 -yl} - 1 - methanone, l-{2-[2-(3-Chloro-phenyl)-2H-tetrazol-5-yl]-piperidin-l-yl}-2-methyl-propan-l-one, [2-(2-m-Tolyl-2H-tetrazol-5-yl)-piρeridin- 1 -yl]- 1 -(5-methyl-thiophen-2-yl)-methanone, {2-[2-(3 -Chloro-phenyl)-2H-tetrazol-5-yl]-ρiρeridin- 1 -yl} - 1 -(4,5-dimethyl-furan-2-yl)- methanone,

3-[2-(3-Chloro-phenyl)-2H-tetrazol-5-yl]-piperidine-l-carboxylic acid dimetliylamide, Cycloheptyl-{2-[2-(3-chloro-phenyl)-2H-tetrazol-5-yl]-piperidin-l-yl}-methanone, 2-[2-(3-Chloro-phenyl)-2H-tetrazol-5-yl]-piperidine-l-carboxylic acid dimethylamide, {2-[2-(3 -Chloro-phenyl)-2H-tetrazol-5-yl]-piperidin- 1 -yl} - 1 -furan-3 -yl)-methanone, (5-Bromo-thiophen-2-yl)-[2-(2-m-tolyl-2H-tetrazol-5-yl)-pyrrolidin- 1 -yl] -methanone, (5-Bromo-furan-2-yl)-{2-[2-(3-bromo-phenyl)-2H-tetrazol-5-yl]-piperidin-l-yl}-methanone, {2-[2-(3-Bromo-phenyl)-2H-tetrazol-5-yl] -piperidin- 1 -yl} - 1 -(5-methyl-furan-2-yl)- methanone,

[2-(2-m-Tolyl-2H-tetrazol-5-yl)-piperidin-l-yl]-l-(5-methyl-furan-2-yl)-methanone, (5-Bromo-furan-2-yl)-{4-[2-(3-chloro-phenyl)-2H-tetrazol-5-yl]-thiazolidin-3-yl}-methanone, {4-[2-(3-Chloro-ρhenyl)-2H-tetrazol-5-yl]-thiazolidin-3-yl}-(5-niethyl-thioρhen-2-yl)- methanone, 2-{2-[2-(3-Chloro-phenyl)-2H-tetrazol-5-yl]-piperidin-l-ylmethyl}-pyridine, and pharmaceutically acceptable salts thereof formed with acids and bases.

Pharmaceutical formulations

The present invention provides in a further aspect pharmaceutical compositions comprising a compound represented by formula (I) and/or enantiomers and/or racemates and/or diastereomers and/or geometric isomers and/or salts thereof as an active ingredient and one or more pharmaceutically acceptable carrier. Compounds of formula (I) and/or enantiomers and/or racemates and/or diastereomers and/or geometric isomers and/or salts thereof may be administered by any convenient method, for example by oral, parenteral (including subcutaneous, intramuscular, and intravenous), buccal, sublingual, nasal, rectal or transdermal administration and the pharmaceutical compositions adapted accordingly. Pharmaceutical compositions may be conveniently presented in unit dosage form and prepared by any of the methods well known in the art of pharmacy. Compounds of formula (I) and/or enantiomers and/or racemates and/or diastereomers and/or geometric isomers and/or salts thereof which are active when given orally can be formulated as liquids or solids, for example syrups, suspensions or emulsions, tablets, capsules and lozenges. Liquid formulations of compounds of formula (I) and/or enantiomers and/or racemates and/or diastereomers and/or geometric isomers and/or salts thereof generally consist of a suspension or solution of a compound of formula (I) or physiologically acceptable salts thereof in a suitable liquid carrier(s) for example an aqueous solvent, such as water, ethanol or glycerine, or a non-aqueous solvent, such as polyethylene glycol or an oil. The formulation may also contain a suspending agent, preservative, flavoring or coloring agent.

A composition in the solid form of a tablet can be prepared using any suitable pharmaceutical carrier(s) routinely used for preparing solid formulations. Examples of solid carriers include lactose, terra alba, sucrose, talc, gelatine, agar, pectin, acacia, magnesium stearate, stearic acid etc. 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.

A composition in the solid foπn of a capsule can be prepared using routine encapsulation procedures. For example, pellets containing the active ingredient can be prepared using standard carriers and then filled into a hard gelatine capsule; alternatively, a dispersion or suspension can be prepared using any suitable pharmaceutical carrier(s), for example aqueous gums, celluloses, silicates or oils and the dispersion or suspension then filled into a soft gelatine capsule.

Typical parenteral compositions consist of a solution or suspension of the compound of formula (I) and/or enantiomers and/or racemates and/or diastereomers and/or geometric isomers and/or salts thereof in a sterile aqueous carrier or parenterally acceptable oil, for example polyethylene glycol, polyvinyl pyrrolidone, lecithin, arachis oil or sesame oil.

Alternatively, the solution can be lyophilized and then reconstituted with a suitable solvent just prior to administration. Compositions of the present invention for nasal administration containing a compound of formula (I) and/or enantiomers and/or racemates and/or diastereomers and/or geometric isomers and/or salts thereof may conveniently be formulated as aerosols, drops, gels and powders. Aerosol formulations of the present invention typically comprise a solution or fine suspension of the compound of formula (I) in a physiologically acceptable aqueous or nonaqueous solvent and are usually presented in a single or multidose quantities in sterile form is a sealed container, which can take the form of a cartridge or refill for use with an atomizing device. Alternatively, the sealed container may be a unitary dispensing device, such as a single dose nasal inhaler or an aerosol dispenser fitted with a metering valve which is intended for disposal once the contents of the container have been exhausted. Where the dosage form comprises an aerosol dispenser, it will contain a propellant which can be a compressed gas, such as compressed air or an organic propellant, such as a fluorochlorohydro carbon. The aerosol dosages form can also take the form of a pump- atomiser. Compositions of the present invention containing a compound of formula (I) are suitable for buccal or sublingual administration including tablets, lozenges and pastilles, wherein the active ingredient is formulated with a carrier, such as sugar and acacia, tragacanth, or gelatine, glycerin etc.

Compositions of the present invention containing a compound of formula (I) and/or enantiomers and/or racemates and/or diastereomers and/or geometric isomers and/or salts thereof for rectal administration are conveniently formulated in the form of suppositories containing a conventional suppository base, such as 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 moulds.

Compositions of the present invention containing a compound of formula (I) and/or enantiomers and/or racemates and/or diastereomers and/or geometric isomers and/or salts thereof for transdermal administration include ointments, gels and patches.

Compositions of the present invention containing a compound of formula (I) and/or enantiomers and/or racemates and/or diastereomers and/or geometric isomers and/or salts thereof is preferably in the unit dose form, such as tablet, capsule or ampoule. Each dosage unit of the present invention for oral administration contains preferably from 0.1 to 500 mg of a compound of formula (I) and/or enantiomers and/or racemates and/or diastereomers and/or geometric isomers and/or salts thereof.

Each dosage unit of the present invention for parenteral administration contains preferably from 0.1 to 500 mg of a compound of formula (I) and/or enantiomers and/or racemates and/or diastereomers and/or geometric isomers and/or salts thereof.

Physiologically acceptable compounds of formula (I) and/or enantiomers and/or racemates and/or diastereomers and/or geometric isomers and/or salts thereof can be administered in a daily dosage regimen. In the treatment of mGluR5 mediated disorders, such as schizophrenia, anxiety, depression, panic, bipolar disorders, and circadian disorders or chronic and acute pain disorders the dosage levels from about 0.01 mg/kg to about 140 mg/kg of body weight per day are useful or alternatively about 0.5 mg to about 7 g per patient per day.

The amount of active ingredient that may be combined with the carrier materials to produce a single dosage form will vary depending upon the host treated and the particular mode of administration. For example, a formulation intended for oral administration to humans may conveniently 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 percent of the total composition. Unit dosage forms will generally contain between from about 1 mg to about 1000 mg of the active ingredient, typically 25 mg,

50 mg, 100 mg, 200 mg, 25-300 mg, 400 mg, 500 mg, 600 mg, 800 mg or 1000 mg.

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.

Medical use

Compounds of formula (I) of the present invention have been found to exhibit biological activity at mGluR5 receptors and are expected to be useful in the treatment of mGluR5 mediated disorders. W

15

It has been found that compounds according to the present invention or salts thereof, exhibit a high degree of potency and selectivity for individual metabotropic glutamate receptor (mGluR) subtypes, hi particular there are compounds according to the present invention that are potent and selective for mGluR5 receptor. Accordingly, compounds of the present invention are expected to be useful in the prevention and/or treatment of conditions associated with excitatory activation of an mGluR5 receptor and for inhibiting neuronal damage caused by excitatory activation of an mGluR5 receptor. Compounds maybe used to produce an inhibitory effect of mGluR5, in mammals, including human.

Thus, it is expected that compounds of the invention are well suited for the prevention and/or treatment of mGluR5 receptor-mediated disorders such as acute and chronic neurological and psychiatric disorders, chronic and acute pain disorders and neuromuscular dysfunctions of the lower urinary tract.

The dose required for the therapeutic or preventive treatment of a particular disorder will necessarily be varied depending on the host treated and the route of administration.

The invention relates to compounds of formula (I) as defined hereinbefore, for use in therapy.

The invention relates to compounds of formula (I) as defined hereinbefore, for use in prevention and/or treatment of mGluR5 receptor-mediated disorders.

The invention relates to compounds of formula (I) as defined hereinbefore, for use in prevention and/or treatment of neurological disorders.

The invention relates to compounds of formula (I) as defined hereinbefore, for use in prevention and/or treatment of psychiatric disorders. The invention relates to compounds of formula (I) as defined hereinbefore, for use in prevention and/or treatment of chronic and acute pain disorders.

The invention relates to compounds of formula (I) as defined hereinbefore, for use in prevention and/or treatment of neuromuscular dysfunctions of the lower urinary tract.

The invention relates to compounds of formula (I) as defined hereinbefore, for use in prevention and/or treatment of pain related to migraine, inflammatory pain, neuropathic pain disorders such as diabetic neuropathies, arthritis and rheumatitiod diseases, low back pain, post-operative pain and pain associated with various conditions including angina, in renal or billiary colic, menstruation, migraine and gout.

The invention relates to compounds of formula (I) as defined hereinbefore, for use in prevention and/or treatment of Alzheimer's disease senile dementia, AIDS-induced dementia Parkinson's disease, amyotrophic lateral sclerosis, Huntington's Chorea, migraine, epilepsy, schizophrenia, depression, anxiety, acute anxiety, obsessive compulsive disorder, ophthalmological disorders such as retinopathies, diabetic retinopathies, glaucoma, auditory neuropathic disorders such as tinnitus, chemotherapy induced neuropathies, post-herpetic neuralgia and trigeminal neuralgia, tolerance, dependency, Fragile X, autism, mental retardation, schizophrenia and Down's Syndrome.

The invention relates to compounds of formula (I) as defined hereinbefore, for use in prevention and/or treatment of stroke, head trauma, anoxic and ischemic injuries, hypoglycemia, cardiovascular diseases and epilepsy.

The compounds are also well suited for the treatment of neuromuscular dysfunction of the lower urinary tract, such as urinary urgency, overactive bladder, greater urinary frequency, reduced urinary compliance, cystitis, incontinence, enuresis and dysuria.

The present invention relates also to the use of a compound of formula (I) as defined hereinbefore, in the manufacture of a medicament for the prevention and/or treatment of mGluR5 receptor-mediated disorders and any disorder listed above. The invention also provides a method of treatment and/or prevention of mGluR5 receptor mediated disorders and any disorder listed above, in a patient suffering from, or at risk of, said condition, which comprises administering to the patient an effective amount of a compound of formula (I), as hereinbefore defined.

In the context of the present specification, the term "therapy" includes treatment as well as prevention, unless there are specific indications to the contrary. The terms "therapeutic" and "therapeutically" should be construed accordingly.

In this specification, unless stated otherwise, the term "antagonist" means a compound that by any means, partly or completely blocks the transduction pathway leading to the production of a response by the ligand. The term "disorder", unless stated otherwise, means any condition and disease associated with metabotropic glutamate receptor activity. Pharmacology

The pharmacological properties of the compounds of the invention were analyzed by determining binding affinity of the compounds to a binding site on mGluR5 receptors and by fluorimetric assays of intracellular calcium concentration to determine functional activity.

Compounds of the invention showed affinity for both rat and human mGluR5 receptors and proved to be functional antagonists, that is to inhibit functional responses elicited by stimulation of mGluR5 receptors. Detailed protocols for testing the compounds of the invention and results for representative compounds are provided below in Pharmacological Examples.

Methods of preparations

Another aspect of the present invention provides processes for preparing compounds of formula (I) or salts thereof.

Throughout the following description of such processes it is to be understood that, where appropriate, suitable protecting groups will be added to, and subsequently removed from, the various reactants and intermediates in a manner that will be readily understood by one skilled in the art of organic synthesis. Conventional procedures for using such protecting groups as well as examples of suitable protecting groups are described, for example, in "Protective Groups in Organic Synthesis," T. W. Green, P.G.M. Wuts, Wiley-Interscience, New York, 1999.

Unless specified otherwise the meaning of Y₁, Y₂, Z, X, R, R¹, R² and n is as defined above for formula (I).

Abbreviations

The abbreviations used herein have the following tabulated meanings. Abbreviations not tabulated below have their meanings as commonly used unless specifically stated otherwise.

Boc- tert-butoxycarbonyl-

EDC N-(3-dimethylaminopropyl)-N'-ethylcarbodiimid hydrochloride

HBTU 2-(l H-(benzotriazol- 1 -yl)- 1 , 1 ,3 ,3 ,-tetramethyluronium- hexafluorophosphate

TEA triethylamine

DMF N,N-dimethylformamide

DIPEA N,N-diisopropylethylamine

DMAP 4-dimethylaminopyridine

DCC N₅N' -dicyclohexylcarbodiimide

LAH lithium aluminum hydride

THF tetrahydrofuran

DCU N₅N' -dicyclohexylcarbamide

General synthesis of 2,5-disubstituted tetrazoles:

Compounds of the present invention can be prepared according to the following methods. Unless stated otherwise, the meaning of substituents is as defined above for formula (I) or apparent to one skilled in the art. Synthesis of compound of formula (V)

π m IV

V a. NH(CH₃)OCH₃*HCl, DIPEA, DMAP, DCC, dichloromethane, 30 minutes at 0 ⁰C, 3 hours at 25 ⁰C, b. LAH, anhydrous THF, 10 minutes at 0 °C, c. p-toluenesulfonhydrazide, ethanol, 30 minutes at 25 °C, d. NaOH, aqueous ethanol, at 0 °C, aqueous solution of compound of formula VH (azide), 30 minutes at O ⁰C, 1 hour at 25 °C, e. ethyl acetate saturated with hydrogen chloride gas,

Compound of formula (III) can be prepared using synthetic chemical methods well known in the art (Martinez, J. et al. J. Med. Chem., 1985, 28, 1874-1879; Joyeau, R. et al. Eur. J. Med. Chem. Chim.Ther., 2000, 35, 257-266). Aldehydes of formula (III) can be prepared by reduction of Weinreb amide in anhydrous THF at 0 °C with LAH for 10- 15 minutes. (Balboni, G. et al. Eur. J. Med. Chem. Chim.Ther., 2000, 35, 979-988). Weinreb amid can be prepared by reacting a Boc-protected amino acid with N₅O- dimethylhydroxylamine hydrochloride in the presence of DIPEA, DCC and DMAP.

Hydrazone of formula (IV) can be prepared by reacting an aldehyde of formula (III) with p-toluenesulfonhydrazide in ethanol (Chandrasekhar, S. et al., Tetrahedron Lett., 2000, 41, 10131-10134).

2,5-Disubstituted tetrazoles of formula (V) can be prepared by reacting a phenylsulfonylhydrazones of formula (IV) with an appropriate aryldiazonium salt, compound of formula (VII) according to the process well known in the art (Ito, S. et al., Bull. Chem. Soc. Jpn., 1976, 49, 1920-1923; Shavali, A.S. J. Heterocyclic Chem., 1979, 16, 123-128).

An aqueous solution of compound of formula (VII) can be prepared from the hydrochloric acid solution of a suitable substituted aniline of formula (VI) and sodium nitrite at 0 °C.

VI VII

/ NaNOz, hydrochloric acid, water, at 0 °C

Compound of formula (V) can be prepared by reacting a solution of hydrazon of formula (IV) with a solution of diazonium salt of formula (VII) in a mixture of sodium hydroxide and ethanol at 0-5 ⁰C. Compound of formula (V) can be obtained by acidic hydrolysis with a solvent such as ethyl acetate or dioxane saturated with hydrogen chloride gas.

Synthesis of compound of formula (I)

The present invention provides processes for the synthesis of compounds of formula (I),

I wherein X is oxygen and Y₁, Y₂, Z, X, R, R , 1 , r R>2 and n are the same as defined above for formula (I), by reacting a compound of formula (V)

V with an activated acid of formula RCOOH, wherein R is as defined in claim 1. Acylation of compound of formula (V) can be accomplished with an acid (RCOOH) as reagent, which is activated with EDC in the presence of a base such as sodium hydrogen carbonate or TEA for 1 hour at 25 ⁰C.

When R = NR R , the acylation can be carried out with an appropriate amino- carbamoyl-chloride or appropriate isocyanides.

Compound of formula (I),

wherein X is two hydrogen atoms and Y₁, Y₂, Z, X, R, R¹, R² and n are the same as defined above for formula (I), can also be synthesized by reacting a compound of formula (V)

with an aldehyde of formula RCHO, wherein R is as defined in claim 1. Reductive alkylation of compound of formula (V) can be accomplished with an aldehyde (RCHO) and sodium triacetoxy-borohydride (Abdel-Magid, A.F. et al. Tetrahedron Lett. 1990, 31, 5595-5598 ).

Compounds of the present invention can also be synthesized by parallel synthesis using the following conditions:

Acylation of secondary amines of formula (V) (piperidine, pyrrolidine) — deliberated from salt form - can be carried out using aliphatic, aromatic and heteroaromatic carboxylic acids (RCOOH) with multiple surplus and EDC activator in dichloromethane or dichloromethane/DMF. Purification of the product can be carried out by fluid/fluid extraction (water/dichloromethane). Basic extraction can be used for purification of carboxylic acids and acidic extraction can be used for elimination of EDC and secondary amine.

The final product, compound (I), can be obtained in appropriate purity therefore after concentration of the solution biological experiments can be carried out without further purification.

Compounds of the present invention were characterized by high performance liquid chromatography coupled to mass selective detector (LC/MS) using HP 1100 Binary Gradient chromatography system with Microplate Sampler (Agilent, Waldbronn), controlled by ChemStation software. Detection was carried out by a Hewlett-Packard-type diode array detector, at λ = 240 nm wavelength. Discovery C16-Amide column, 5 cm x 4.6 mm was used, with flow rate = 1 ml/min. AU experiments were performed using Hewlett-Packard MSD

(Agilent, Waldbronn) single quadruple spectrometer equipped with electrospray ionisation source to determine the structure. The compounds were characterized by the k'-values (capacity ratio) and by the (M+H)⁺- values (M: molecule mass). Optical purities of the enantiomers were controlled by HPLC, using DAICEL Chiracel ODH chiral column. Eluent: a mixture of n-hexane/2-propanol/methanol (90:5:5 v/v) containing 0.05 % diethylamine. Flow rate: 1 ml/min, detection: at 220 nm. ¹H NMR spectra were recorded on a Varian Unity Inova 300 or on a Varian Unity Inova 500 spectrometer. Chemical shifts are reported in parts per million relative to TMS as internal standard.

The syntheses of compounds and pharmaceutical compositions according to the invention are illustrated by the following not limiting Examples.

Examples

Starting materials are either commercially available or can be synthesized by different known methods described in the literature.

Example 1

Cyclobutyl-{2-[2-(3-chloro-phenyl)-2i?-tetrazol-5-yl]-piperidine-l-yl}-methanone Compound 25, Table II

2-[2-(3-Chlorophenyl)-2i7-tetrazol-5-yl]-ρiperidine hydrochloride (0.24 g, 0.8 mmol) (intermediate E) was suspended in dichloromethane (4 ml), TEA (0.14 ml, 1 mmol), cyclobutanecarboxylic acid (0.15 ml, 1.3 mmol) and EDC (0.25 g, 1.3 mmol) were added to the mixture. After adding a further amount of TEA (0.14 ml, 1 mmol) the reaction mixture was stirred at 25 ⁰C for 20 hours. The solvent was evaporated, the residue was dissolved in ethyl acetate (20 ml), washed twice with 1 N aqueous hydrochloric acid (5-5 ml), then with water, with sodium hydrogen carbonate solution and with water again. The solution was dried and concentrated to yield 0.255 g (93 %) of the title compound as an oily residue.

Intermediates (A, B, C, D, E)

2-βfethoxy-methyl-carbamoyl)-piperidine-l-carboxylic acid tert-butyl ester (Intermediate A)

To a stirred solution of Boc-DL-pipecolinic acid (5.04 g; 22 mmol) in dichloromethane (80 ml) DIPEA (4.6 ml, 26.4 mmol) and N,O-dimethyl-hydroxylamine (2.6 g, 26.4 mmol) were added. The reaction mixture was cooled to 0 ⁰C, and after adding DMAP

(1.2 g, 10 mmol) and DCC (5.0 g, 24 mmol) the mixture was stirred at 0 °C for 30 minutes, then at 25 °C for 20 hours. The precipitated DCU was filtered off and the filtrate was washed twice with 1 N aqueous hydrochloric acid (30-30 ml), then with water and sodium hydrogen carbonate solution (5%). The organic phase was dried and concentrated. The crude product was purified by column chromatography (Kieselgel 60, eluent: n-hexane:ethyl acetate = 2:1) to yield 5.04 g (84 %) of the title compound as an oily residue, which solidified during the storage at 4 °C. Melting point: 66-68 ⁰C.

2-Formyl-piperidine-l-carboxylic acid tert-butyl ester (Intermediate B)

2-(Methoxy-methyl-carbamoyl)-piperidine-l-carboxylic acid tert-butyl ester

(Intermediate A) (5.0 g, 18.5 mmol) was dissolved in anhydrous THF (45 ml) and under nitrogen LAH (0.7 g, 18.5 mmol) was added to the stirred solution at 0 °C in 10 minutes. The reaction mixture was stirred at 0 ⁰C for 30 minutes, then ethyl acetate (25 ml) and water (25 ml) were added. The phases were separated, the aqueous phase was extracted twice with ethyl acetate (25 ml) and the combined organic layers were washed once with 1 N aqueous sulphuric acid and twice with brine. The solution was dried and concentrated to yield 3.7 g (94 %) of the title compound as an oil.

2-[(4-Methyl-phenyl-sulfonyl)-hydrazonomethyl]-piperidine-l-carboxylic acid tert-butyl ester (Intermediate C)

To a stirred solution of p-toluenesulfonhydrazide (3.5 g, 19 mmol) in ethanol (40 ml) a solution of 2-formyl-piperidine-l-carboxylic acid tert-butyl ester (Intermediate B) (3.7 g, 17.4 mmol) in ethanol (30 ml) was added. The reaction mixture was stirred at room temperature for 20 minutes and concentrated. The residue was dissolved in ethyl acetate (70 ml) and the solution was washed once with 0.5 N hydrochloric acid (20 ml) and twice with water. The solution was dried, concentrated and the residue was solidified with n-hexane to yield 5.83 g (88 %) of the title compound.

Melting point: 113 - 115 °C;

MS: ml Q= 404.4 (M+Na)⁺-

2-[2-(3-Chloro~phenyl)-2H-tetrazol-5-yl]-piperidine-l-carboxylic acid tert-butyl ester

(Intermediate D)

3-Chloroaniline (1.5 ml, 14 mmol) was suspended in 6 N aqueous hydrochloric acid (9 ml), the stirred suspension was cooled to 0 °C and a solution of sodium nitrite (1.1 g, 16 mmol) in water (7 ml) was added at 0-5 ⁰C, then the mixture was stirred at this temperature for 15 minutes.

In the same time 2-[(4-methyl-phenyl-sulfonyl)-hydrazonomethyl]-piperidine-l- carboxylic acid tert-butyl ester (Intermediate C) (4.3 g, 11.4 mmol) was dissolved in a mixture of sodium hydroxide (1.8 g, 46 mmol), water (15 ml) and ethanol (55 ml), the stirred solution was cooled to 0 °C and the above reaction mixture was added at 0 °C in small portions during 30-35 minutes. The so obtained reaction mixture was stirred at 0 °C for 20 minutes, then at 25 °C for one hour. After diluting with ethyl-acetate (200 ml) the phases were separated and the aqueous phase was extracted with ethyl-acetate (40 ml), the combined organic layers were washed twice with 1 N aqueous hydrochloric acid (40 ml) and brine. After drying and concentration, the oily residue of the crude product was purified by column chromatography (Kieselgel 60, eluent: n-hexane:ethyl-acetate=9:l) to yield 2.5 g (60 %) of the title compound.

MS: m/e= 386.4 (M+Na)⁺-

2-[2~(3-Chlorophenyl)-2H-tetrazol-5-yl]-piperidine hydrochloride (Intermediate E)

Compound 10 in Table I

To a solution of 2-[2-(3-chloro-phenyl)-2/f-tetrazol-5-yl]-piperidine-l-carboxylic acid tert-butyl ester (Intermediate D) (2.54 g, 7 mmol) in ethyl acetate (5 ml) ethyl acetate saturated with hydrogen chloride gas (30 ml, 2.5 mol/1) was added, and the mixture was stirred for 3 hours. The precipitated crystals were filtered and washed with ether to yield 1.778 g (85 %) of the title compound. Melting point: 212-213 ⁰C; MS: m/e=264.3 (M+H)⁺

Table L:

Example 2 2-[2-(3-Chloro-phenyl)-2Jϊ-tetrazol-5-yl]-piperidine-l-carboxylic acid dimethylamide Compound 1, Table II

2-[2-(3-Chlorophenyl)-2i7-tetrazol-5-yl]-ρiperidine hydrochloride (Intermediate E in Example 1) (0.21 g, 0.7 mmol) was suspended in dichloromethane (6 ml), TEA (0.14 ml, 1 mmol) and NjN-dimethyl-carbamoyl-chloride (0.1 ml, 1 mmol) were added to the stirred reaction mixture. After stirring at 25 °C for 72 hours the reaction mixture was diluted with dichloromethane, washed once with 1 N aqueous hydrochloric acid and twice with water. The solution was dried and concentrated, and the crude product was purified by column chromatography (Kieselgel 60, eluent: n-hexane: ethyl acetate=2:l) to yield 0.227 g (97 %) of the title compound. Example 3

3-[2-(3-Chloro-phenyl)-2£T-tetrazol-5-yl]-piperidine-l-carboxylic acid dimethylamide Compound 26, Table II

3-[2-(3-Chloro-phenyl)-2H-tetrazol-5-yl]~piperidine hydrochloride (Intermediate E) (0.18 g, 0.6 mmol) was suspended in dichloromethane (5 ml), TEA (0.14 ml, 1 mmol) and NjN-dimethyl-carbamoyl-chloride (0.1 ml, 1 mmol) were added to the stirred reaction mixture. After stirring at 25 °C for 72 hours the reaction mixture was diluted with dichloromethane (15 ml), washed once with 1 N aqueous hydrochloric acid and twice with water. The solution was dried and concentrated and the crude product was purified by column chromatography (Kieselgel 60, eluent: n-hexane: ethyl acetate=2:l) to yield 0.133 g (67 %) of the title compound.

Intermediates (A, B, C, D, E)

^-(Methoxy-meihyl-carbamoyiypiperidine-l-cai'boxylic acid tert-butyl ester (Intermediate A)

The title compound was prepared from Boc-nipecotic acid according to the method described in Example 1 for Intermediate A. The compound was purified by column chromatography to yield (96 %) an oily product.

MS: m/e=295.2 (M+Na)⁺

3-Formyl-piperidine-l-carboxylic acid tert-butyl ester (Intermediate B)

The title compound was prepared from 3-(methoxy-methyl-carbamoyl)-piperidine- 1-carboxylic acid tert-butyl ester (Intermediate A) according to the method described in Example 1 for Intermediate B. The product was obtained as a thin oily residue and was used without further purification.

3-[(4-Methyl-phenyl-sulfonyl)-hydrazonomethyl]-piperidine-l-carboxylic acid tert-butyl ester (Intermediate C) The title compound was prepared from 3-formyl-piperidine-l-carboxylic acid tert-butyl ester (Intermediate B) according to the method described in Example 1 for Intermediate C. Yield: 96%;

Melting point: 105-107 °C; MS : m/e = 404.4 (M+ Na)+.

S-P-β-Chloro-phenyty-lH-tetrazolS-ylJ-piperidine-l-carboxylic acid tert-butyl ester (Intermediate D)

The title compound was prepared from 3-[(4-methyl-phenyl-sulfonyl)- hydrazonomethyl]-piperidine-l-carboxylic acid tert-butyl ester (Intermediate C) and 3- chloroaniline according to the method described in Example 1 for Intermediate D. The compound was purified by column chromatography to yield (38 %) an oily product. MS: m/e= 386.4 (M+Na)⁺-

3-[2-(3-Chlorophenyl)-2H-tetrazol-5-yl]-piperidine hydrochloride (Intermediate E) Compound 20, Table I

The title compound was prepared from 3-[2-(3-chloro-phenyl)-2H-tetrazol-5-yl]- piperidine-1-carboxylic acid tert-butyl ester (Intermediate D) according to the method described in Example 1 for Intermediate E.

Yield: 96%;

Melting point: 205-206 °C;

MS: m/e= 264.7 (M+H)⁺.

Example 4

Cyclobutyl-{2R-[2-(3-chloro-phenyI)-2H-tetrazol-5-yl]-piperidine-l-yI}-methanone

Compound 10, Table II

2R-[2-(3-Chlorophenyl)-2H-tetrazol-5-yl]-piρeridine hydrochloride (0.24 g, 0.8 mmol) (E) was suspended in dichloromethane (4 ml), TEA (0.14 ml, 1 mmol), cyclobutanecarboxylic acid (0.15 ml, 1.3 mmol) and EDC (0.25 g, 1.3 mmol) were added to the stirred suspension. After adding a further amount of TEA (0.14 ml, 1 mmol) the reaction mixture was stirred at 25 ⁰C for 20 hours. The solvent was evaporated and the residue was dissolved in ethyl acetate (20 ml), washed twice with 1 N aqueous hydrochloric acid (5 ml), water, aqueous sodium hydrogen carbonate solution (5 %) and water. The organic layer was dried and concentrated to yield 0.22g (90%) of the title compound. Optical purity: 94%.

Intermediates (A, B, C, D, E) 2R-(Methoxy-methyl-carbamoyl)-piperidine-l-carboxylic acid tert-butyl ester (Intermediate A)

The title compound was prepared from D-Boc-pipecolinic acid according to the method described in Example 1 for Intermediate A. The compound was purified by column chromatography to yield (92 %) an oily product.

2R-Formyl-piperidine-l-carboxylic acid tert-butyl ester (Intermediate B)

The title compound was prepared from 2R-(methoxy-methyl-carbamoyl)-ρiperidine- 1-carboxylic acid tert-butyl ester (Intermediate A) according to the method described in Example 1 for Intermediate B. Yield: 87 %.

2R-[(4-Methyl-phenyl-sulfonyl)-hydrazonomethyl]-piperidine-l-carboxylic acid tert-butyl ester (Intermediate C)

The title compound was prepared from 2R-formyl-piperidine- 1-carboxylic acid tert- butyl ester (Intermediate B) according to the method described in Example 1 for intermediate C. The title product was isolated as white crystals. Yield: 83 %;

MS: m/e= 404.4 (M+Na)⁺. 2R-[2-(3-Chloro-phenyl)-2H-tetrazol-5-yl]-piperidine-l-carboxylic acid tert-butyl ester (Intermediate D)

The title compound was prepared from 2R-[(4-methyl-phenyl-sulfonyl)- hydrazonomethyl]-piperidine-l-carboxylic acid tert-butyl ester (Intermediate C) according to the method described in Example 1 for Intermediate D. Yield: 52 %; MS: ml Q= 386.3 (M+Na)⁺.

2R-[2-(3-chlorophenyl)-2H-tetrazol-5-yl]-piperidine hydrochloride (Intermediate E)

The title compound was prepared from 2R-[2-(3-chloro-phenyl)-2H-tetrazol-5-yl]- piperidine-1-carboxylic acid tert-butyl ester (Intermediate D) according to the method described in Example 1 for Intermediate E. Yield: 84 %;

MS: m/e= 264.3 (MH-H)⁺.

Example 5 {2R-[2-(3-Chloro-phenyl)-2H-tetrazol-5-yl]-pyrroUdin-l-yl}-l-(5-methyl-thiophen-2-yl)- methanone Compound 12, Table II

To a stirred solution of 2R-(3-chloro-phenyl)-5-pyrrolidin-2-yl-2i7-tetrazole hydrochloride (0.23 g, 0.8 mmol) (Intermediate E), TEA (0.22 ml, 1.6 mmol) and 5-methyl-2- tiophenecarboxylic acid (0.16 g, 1.1 mmol) a solution of EDC (0.21 g, 1.1 mmol) in dichloromethane (4 ml) was added and the reaction mixture was stirred at 25 ⁰C for 3 hours. The solvent was evaporated and the residue was dissolved in ethyl acetate (20 ml), washed twice with 1 N aqueous hydrochloric acid (5 ml), water, aqueous sodium hydrogen carbonate solution (5 %) and water. The organic layer was dried and concentrated. The crude product was purified by column chromatography (Kieselgel 60, eluent: n-hexane:ethyl acetate=2:l) to yield 0.28 g (94 %) of the title compound. Melting point: 85-86 °C. Optical purity: 98%. Intermediates (A, B, C, D, E)

2R-(Methoxy-methyl-carbamoyl)-pyrrolidine-l-carboxylic acid tert-butyl ester (Intermediate A)

The title compound was prepared from Boc-D-proline according to the method described in Example 1 for Intermediate A.

Yield: 73%;

MS: m/e= 281.4 (M+ Na)⁺.

2R-Formyl-pyrrolidine-l-carboxylic acid tert-butyl ester (Intermediate B)

The title compound was prepared from 2R-(methoxy-methyl-carbamoyl)- pyrrolidine-1-carboxylic acid tert-butyl ester (Intermediate A) according to the method described in Example 1 for Intermediate B. Yield: 99%.

2R-[(4-Methyl-phenyl-sulfonyl)-hydrazonomethyl]-pyrrolidine-l-carboxylic acid tert-butyl ester (Intermediate C)

The title compound was prepared from 2R-formyl-pyrrolidine-l-carboxylic acid tert-butyl ester (Intermediate B) according to the method described in Example 1 for Intermediate C. The title product was isolated as white crystals.

Yield: 85%; Melting point: 170-174 °C;

MS: m/e= 390.4 (M+ Na)⁺.

2R-[2-(3~Chloro-phenyl)-2H-tetrazol-5-yl]-pyrrolidine-I-carboxylic acid tert-butyl ester (Intermediate D)

The title compound was prepared from 2R-[(4-methyl-phenyl-sulfonyl)- hydrazonomethyl]-pyrrolidine-l-carboxylic acid tert-butyl ester (Intermediate C) according to the method described in Example 1 for Intermediate D.

Yield: 45 %; MS: m/e= 372.8 (M+Na)⁺. 2R-[2-β-Chlorophenyl)-2H-tetrazol-5-yl]-pyrrolidine hydrochloride (Intermediate E)

The title compound was prepared from 2R-[2-(3-chloro-phenyl)-2H-tetrazol-5-yl]- pyrrolidine- 1-carboxylic acid tert-butyl ester (Intermediate D) according to the method described in Example 1 for Intermediate E. Yield: 80 %; MS: m/e= 250.3 (M+H)⁺.

Example 6

Cyclobutyl-[2-(2-m-tolyl-2H^r-tetrazol-5-yl)-piperidin-l-yl]-methanone Compound 5, Table II

2-(2-m-Tolyl-2H-tetrazol-5-yl)-piρeridine hydrochloride (0.25 g, 0.9 mmol)

(compound 11, Table L) was suspended in dichloromethane (5 ml), then TEA (0.14 ml, 1 mmol), cyclobutanecarboxylic acid (0.15 ml, 1.3 mmol) and EDC (0.25 g, 1.3 mmol) were added to the stirred suspension. After adding a further amount of TEA (0.14 ml, 1 mmol) the reaction mixture was stirred at 25 °C for 3 hours, then diluted with dichloromethane (20 ml) and washed with 1 N aqueous hydrochloric acid (5 ml), water, sodium hydrogen carbonate solution (5 %) and water (10 ml). After drying and concentration the obtained crude product was purified by column chromatography (Kieselgel 60, eluent: n-hexane: ethyl acetate=2:l) to yield 0.26 g (90 %) of the title compound.

Intermediates (D, E)

2-(2-m-Tolyl-2H-tetrazol-5-yl)-piperidine-l-carboxylic acid tert-butyl ester (Intermediate D)

The title compound was prepared from 2-[(4-methyl-phenyl-sulfonyi)~ hydrazonomethyl]-piperidine- 1-carboxylic acid tert-butyl ester (Intermediate C in Example 1) and m-toluidine according to the method described in Example 1 for Intermediate D. 2-(2-m-Tolyl-2H-tetrazol-5-yl)-piperidine hydrochloride (Intermediate E)

The title compound was prepared from 2-(2-m-tolyl-2H-tetrazol-5-yi)-piperidine-l- carboxylic acid tert-butyl ester (Intermediate D) according to the method described in Example 1 for Intermediate E.

Example 7

(5-Bromo-furan-2-yl)-{4-[2-(3-chloro-phenyl)-2J3-tetrazol-5-yl]-thiazolidin-3-yl}- methanone Compound 21, Table II

To a stirred solution of 2-(3-chloro-phenyl)-5-thiazolidin-4-yl-2H^"-tetrazole hydrochloride (0.31 g, 1.0 mmol) (Intermediate E) in DMF (3 ml) TEA (0.14 ml, 1.0 mmol), 5-bromo-2-furancarboxylic acid (0.29 g, 1.5mmol) and HBTU (0.46g, 1.2 mmol) were added. The reaction mixture was stirred at room temperature for 2 days. The solvent was evaporated and the residue was dissolved in ethyl acetate (20 ml), washed with 1 N aqueous hydrochloric acid (5 ml), water, sodium hydrogen carbonate solution (5 %) and water. After drying and concentration the obtained crude product was purified by column chromatography (Kieselgel 60, eluent: chloroform:methanol=5:0.15) to yield 0.26 g (59 %) of the title compound.

Intermediates (A, B, C, D, E)

4-(Methoxy-methyl-carbamoyl)-thiazolidine-3-carboxylic acid tert-butyl ester (Intermediate A)

The title compound was prepared from DL-Boc-thiaproline according to the method described in Example 1 for Intermediate A. Yield: 88 %.

^Formyl-thiazolidineS-carboxylic acid tert-butyl ester (Intermediate B)

The title compound was prepared from 4-(methoxy-methyl-carbamoyl)-thiazolidine- 3-carboxylic acid tert-butyl ester (Intermediate A) according to the method described in Example 1 for Intermediate B. Yield: 89 %.

4-[(4-Methyl-phenyl'Sulfonyl)-hydrazonomethyl]-thiazolidine-3-carboxylic acid tert-butyl ester (Intermediate C)

The title compound was prepared from 4-formyl-thiazolidine-3-carboxylic acid tert- butyl ester (Intermediate B) according to the method described in Example 1 for Intermediate C. The title product was isolated as white crystals.

Yield: 51 %; MS: m/e= 408.4 (MH-Na)⁺.

4-[2-(3-Chloro-phenyl)-2H-tetrazol-5-yl]-thiazolidine-3-carboxylic acid tert-butyl ester (Intermediate D)

The title compound was prepared from 4-[(4-methyl-phenyl-sulfonyl)- hydrazonomethyl]-thiazolidine-3-carboxylic acid tert-butyl ester (Intermediate C) according to the method described in Example 1 for Intermediate D.

Yield: 57 %;

MS: m/e= 391.4 (M+Na)⁺.

2-(3-Chloro-phenyl)-5-thiazolidin-4-yl-2H-tetrazole hydrochloride (Intermediate E)

The title compound was prepared from 4-[2-(3-chloro-phenyl)-2H-tetrazol-5-yl]- thiazolidine-3-carboxylic acid tert-butyl ester (Intermediate D) according to the method described in Example 1 for Intermediate E. Yield: 72 %; MS: m/e= 268.3 (M+H)⁺.

Example 8

2-{2-[2-(3-Chloro-phenyl)-2_JH^r-tetrazol-5-yl]-piperidin-l-yl-methyl}-pyridine Compound 23, Table II

To a stirred solution of 2-[2-(3-chlorophenyl)-2H-tetrazol-5-yl]-piperidine hydrochloride (0.3 g, 1 mmol) (Intermediate E in Example 1) in dichloromethane (10 ml) TEA (0.14 ml, 1 mmol), pyridine-2-carboxaldehyde (0.11 ml, 1.2 mmol) and sodium triacetoxyborohydride (0.32 g, 1.5 mmol) were added. The reaction mixture was stirred at room temperature for 1 day, then aqueous potassium carbonate solution (10 ml, 20%) was added. The phases were separated and the aqueous phase was extracted twice with dichloromethane (10 ml). After drying the solvent was evaporated in vacuo. The obtained crude product was purified by column chromatography (Kieselgel 60, eluent: chlorofoπn:methanol=5:0.15) to yield 0.33 g (93%) of the title compound. MS: m/e= 355.9 (M+H)⁺.

Example 9

Description of the preparation of compounds of formula (I) by automated parallel synthesis:

Process ,,A" {acylation of amines of formula (V), Compounds 1-22 in Table I, with aliphatic carboxylic acids):

To an amine hydrochloride of formula (V) (1 mmol) dichloromethane (100 ml) and aqueous sodium carbonate (35 ml, 20%) were added. The mixture was stirred, then the dichloromethane phase was separated, dried over anhydrous sodium sulphate and evaporated in vacuo.

Solutions of carboxylic acids were prepared in a concentration of 0.25 mmol/ml, and solutions of EDC and amines in a concentration of 0.1 mmol/ml. EDC and amines were dissolved in dichloromethane. Carboxylic acids were dissolved in dichloromethane or in a mixture of dichloromethane:DMF (DMF content should not be more than 70% (v/v) depending on the solubility of acid). To a solution of carboxylic acid (1.0 ml, 0.25 mmol) and EDC (2.5 ml, 0.25 mmol) a solution of amine (1.0 ml, 0.10 mmol) was added and the reaction mixture was stirred at room temperature for 72 hours. The reaction mixture was diluted with dichloromethane (4 ml), washed twice with aqueous hydrochloric acid (6 ml, 1% (m/m), twice with aqueous sodium carbonate solution (6 ml, 2 % m/m) and once with ion exchanged water (6 ml). The organic layer was passed through a column filled with 400 mg isolute®sorbent and the resulting dry dichloromethane solution was concentrated to dryness (Addition of reagents and extractions were carried out with Tecan Combitec synthesizer, the samples were concentrated with Savant centrifugal evaporator.) Process ,,B" facylation of amines of formula (V), Compounds 1-22 in Table I, with aromatic and heteroaromatic carboxylic acids):

Solutions of carboxylic acids were prepared in a concentration of 0.25 mmol/ml, and solutions of EDC and amines in a concentration of 0.1 mmol/ml. EDC and amines were dissolved in dichloromethane. Carboxylic acids were dissolved in dichloromethane or in a mixture of dichloromethanerDMF (DMF content should not be more than 60% (v/v) depending on the solubility of the acid). To a solution of carboxylic acid (0.6 ml, 0.15 mmol) and EDC (1.5 ml, 0.15 mmol) a solution of amine (1.0 ml, 0.10 mmol) was added and the reaction mixture was stirred at room temperature for 72 hours. The reaction mixture was diluted with dichloromethane (4 ml), washed twice with aqueous hydrochloric acid (6 ml, 1% m/m), twice with aqueous sodium carbonate solution (6 ml, 2 % m/m) and once with ion exchanged water (6 ml). The organic layer was passed through a column filled with 400 mg isoluteOsorbent and the resulting dry dichloromethane solution was concentrated to dryness (Addition of reagents and extractions were carried out with Tecan Combitec synthesizer, the samples were concentrated with Savant centrifugal evaporator.)

Example 10 Preparation of pharmaceutical compositions: a) Tablets:

0.01-50 % of active ingredient of formula (I), 15-50 % of lactose, 15-50 % of potato starch, 5-15 % of polyvinyl pyrrolidone, 1-5 % of talc, 0.01-3 % of magnesium stearate, 1-3 % of colloid silicon dioxide and 2-7 % of ultraamylopectin were mixed, then granulated by wet granulation and pressed to tablets.

b) Dragέes, filmcoated tablets:

The tablets made according to the method described above were coated by a layer consisting of entero- or gastrosolvent film, or of sugar and talc. The dragees were polished by a mixture of beeswax and carnuba wax. c) Capsules:

0.01-50 % of active ingredient of formula (I), 1-5 % of sodium lauryl sulfate, 15-50 % of starch, 15-50 % of lactose, 1-3 % of colloid silicon dioxide and 0.01-3 % of magnesium stearate were thoroughly mixed, the mixture was passed through a sieve and filled in hard gelatin capsules. d) Suspensions:

Ingredients: 0.01-15 % of active ingredient of formula (I), 0.1-2 % of sodium hydroxide, 0.1-3 % of citric acid, 0.05-0.2 % of nipagin (sodium methyl 4-hydroxybenzoate),

0.005-0.02 % of nipasol, 0.01-0.5 % of carbopol (polyacrilic acid), 0.1-5 % of 96 % ethanol,

0.1-1 % of flavoring agent, 20-70 % of sorbitol (70 % aqueous solution) and 30-50 % of distilled water.

To solution of nipagin and citric acid in 20 ml of distilled water, carbopol was added in small portions under vigorous stirring, and the solution was left to stand for 10-12 h. Then the sodium hydroxide in 1 ml of distilled water, the aqueous solution of sorbitol and finally the ethanolic raspberry flavor were added with stirring. To this carrier the active ingredient was added in small portions and suspended with an immersing homogenizator. Finally the suspension was filled up to the desired final volume with distilled water and the suspension syrup was passed through a colloid milling equipment. e) Suppositories:

For each suppository 0.01-15% of active ingredient of formula (I) and 1-20% of lactose were thoroughly mixed, then 50-95% of adeps pro suppository (for example Witepsol 4) was melted, cooled to 35 °C and the mixture of active ingredient and lactose was mixed in it with homogenizator. The obtained mixture was mould in cooled forms. β Lyophilized powder ampoule compositions:

A 5 % solution of mannitol or lactose was made with bidistilled water for injection use, and the solution was filtered so as to have sterile solution. A 0.01-5 % solution of the active ingredient of formula (I) was also made with bidistilled water for injection use, and this solution was filtered so as to have sterile solution. These two solutions were mixed under aseptic conditions, filled in 1 ml portions into ampoules, the content of the ampoules was lyophilized, and the ampoules were sealed under nitrogen. The contents of the ampoules were dissolved in sterile water or 0.9 % (physiological) sterile aqueous sodium chloride solution before admim^'stration. Pharmacological examples

Methods for testing pharmacological properties of the compounds

MGluR5 receptor binding tests

MGluR5 receptor binding was determined according to Gasparini et.al. (Bioorg. Med. Chem. Lett. 2000, 12:407-409) with modifications. Based on the high homology between the human and rat mGluR5 receptors, rat cerebro-cortical membrane preparation was used to determine the binding characteristics of reference compounds and novel compounds to the rat mGluR5. The Al 8 cell line expressing hmGluR5a (purchased from Euroscreen) was used to determine binding characteristics of the chemical compounds to the human mGluR5a receptor. As radioligand [³H]-M-MPEP (2 nM) was used. The nonspecific binding was determined in the presence of 10 μM M-MPEP.

Assessment of functional activity

Cell cultures for native ratmGluR5 receptors

Functional potency at native rat mGluR5 receptors was estimated using primary neocortical cell cultures derived from 17 day old Charles River rat embryos and primary cerebellar cell cultures derived from 4-day old Wistar rats, respectively (for the details on the preparation of neural cell cultures see Johnson, M.I.; Bunge, R.P. (1992): Primary cell cultures of peripheral and central neurons and glia. In: Protocols for Neural Cell Culture, eds: Fedoroff, S.; Richardson A., The Humana Press Inc., 51-77.) After isolation the cells were plated onto standard 96-well microplates and the cultures were maintained in an atmosphere of 95% air-5% CO₂ at 37 ⁰C. The neocortical and cerebellar cultures were used for the calcium measurements after 5-7 and 3-4 days in vitro, respectively. Cell cultures for recombinant human mGluRδa receptors

Chinese hamster ovary (CHO) cells stably expressing recombinant human mGluR5a (CH0-mGluR5a, purchased from Euroscreen) receptors were cultured in F 12 medium containing 10% FCS, 1% antibiotic antimycotic solution, 400 μg/ml G418, 250 μg/ml zeocin, 5 μg/ml puromycin. Cells were kept at 37 °C in a humidified incubator in an atmosphere of 5% CO₂/95% air and were passaged three times a week. Cells were plated at 2.5-3.5xlO⁴ cell/well on standard 96-well microplates, receptor expression was induced by adding 600 ng/ml doxycycline on the next day. The calcium measurements were carried out 16-24 hours after the addition of the inducing agent.

Fluorimetric measurement of cytosolic calcium concentration

Measurements of cytosolic calcium concentration ( [Ca²⁺Ji ) were carried out on primary neocortical cultures, and on CHO-mGluR5a cells stably expressing human mGluR5a receptors. Cells were grown in standard 96-well microplates and before the measurement were loaded with a fluorescent Ca²⁺-sensitive dye, fluo-4/AM (2 μM): the neural cultures were loaded in their growth medium, CHO-mGluR5a cells were loaded in assay buffer (145 mM NaCl, 5 mM KCl, 2 mM MgCl₂, 2 mM CaCl₂, 10 mM HEPES, 20 mM D-glucose, 2 mM probenecid, pH=7.4). Loading was done by incubating the cells with 100 μl/well dye solution at 37 °C in a humidified incubator in an atmosphere of 5% CO₂/95% air for 40-120 min. To stop dye loading cells were washed twice with assay buffer. After washing, various concentrations of the test compounds (diluted in assay buffer from a DMSO stock solution, final DMSO concentration was <0.1%) or buffer were added to each well depending on the experimental setup.

In the case of neocortical cultures the assay buffer also contained TTX (0.5 μM, to suppress spontaneous oscillations of [Ca²⁺]j). After incubation at 37 ⁰C for 10-20 min. baseline and agonist-evoked changes of [Ca²⁺]i were measured column by column with a plate reader fluorimeter (FlexStation II, Molecular Devices). Excitation and detection of emission was carried out from the bottom of the plate. The whole measurement process was performed at 37 ⁰C and was controlled by custom software. Inhibitory potency of the test compounds was assessed by measuring the reduction in the agonist-evoked [Ca²⁺]i-elevation in the presence of different concentrations of the compounds.

DHPG was used as agonist for both cultures, the concentration was 20 μM for the neocortical cultures. In the case of CH0-mGluR5a cells DHPG was applied at an EC_8O concentration, the ECgo-values were derived from daily determined dose-response curves. Fluorescence data were expressed as ΔF/F (fluorescence change normalized to baseline).

All treatments on a single plate were measured in multiple wells. Data from all wells with the same treatment were averaged and the average values were used for analysis. Inhibitory potency of a compound at a single concentration point was expressed as percent inhibition of the control agonist response. Sigmoidal concentration-inhibition curves were fitted to the data (derived from at least three independent experiments) and ICso-values were determined as the concentration that produces half of the maximal inhibition caused by the compound. Raw fluorescence data were analyzed using Soft Max Pro (Molecular Devices), curve fitting was done with GraphPad Prism.

Results

Compounds of the invention showed affinity for both rat and human mGluR5 receptors and proved to be functional antagonists, that is to inhibit functional responses elicited by stimulation of mGluR5 receptors. Examples of compounds with affinity for rat mGluR5 are given in Table II.

Table IL

1

Claims

1. A compound having the formula (I)

- wherein

Y₁ and Y₂ selected from the group consisting of hydrogen, halogen atom, C_1-4 alkyl, C_1-4 alkoxy or cyano group, X is oxygen or two hydrogen atoms;

Z is -(CH₂)Ii- group or S; n is 1 or 2;

R is selected from the group consisting of optionally substituted C_1-7 alkyl, C_1-4 haloalkyl, C_1-4 hydroxyalkyl, C_1-3OC_1-3 alkyl, C_1-4 cyanoalkyl, C^NR^alkyl, C_M-alkylCOOC_1-4-alkyl, C_1-4-alkylOCOC_1-4-alkyl,

C_1-4-alkylNHCOC_1-4-alkyl, C_2-7 alkenyl, C_2-7 alkynyl, CH₂O-(CH₂)_1-3-OCH₃; an optionally substituted C_3-7 cycloalkyl; phenyl; C_3-7 saturated or unsaturated heterocyclyl or heteroaryl group containing 1 -4 heteroatom(s);

R¹ and R² are independently selected from hydrogen, C_1-7 alkyl or C_1-6 alkanoyl group - and/or enantiomers and/or racemates and/or diastereomers and/or geometric isomers and/or pharmaceutically acceptable salts thereof formed with acids and bases.

2. A compound according to claim 1, wherein Y₁ and Y₂ selected from the group consisting of hydrogen, halogen atom, Ci_-4 alkyl, C_1-4 alkoxy or cyano group; X is oxygen or two hydrogen atoms;

Z is -(CH₂)Ii- group or S; n is 1 or 2;

R is selected from the group consisting of optionally substituted C_1-7 alkyl, C_1-4 haloalkyl, C_1-4 hydroxyalkyl, Ci_-3OC_1-3 alkyl, C_1-4 cyanoalkyl, Co^CNR^alkyl, Ci_-4-alkylCOOC_1-4-alkyl, C_1-4-alkylOCOC_1-4-alkyl,

C_1-4-alkylNHCOCi_-4-alkyl, C_2-7alkenyl, C_2-7 alkynyl, CH₂O-(CH₂)_I-3-OCH₃;

C_3-7 cycloalkyl, which is optionally substituted by one or more substituent(s) selected from the group of C_1-7 alkyl, cyano, acetamido or oxo group, C_3-7 saturated or unsaturated heterocyclyl group, which is optionally substituted by one or more substituent(s) selected from Ci_-7 alkyl or oxo group, wherein the 1-4 heteroatom is independently selected from the group of N, O, S; phenyl group, which is optionally substituted by one or more substituent(s) selected from the group Of C_1-7 alkyl, C_2-7 alkenyl, C_2-7 alkynyl or cyano group, heteroaryl group, which is optionally substituted by one or more substituents selected from halogen atom, Ci_-7 alkyl, acetamido, Ci_-4 alkoxy, cyano, Ci_-4 thioalkyl, or C_1-4 alkanoyl group, wherein the 1-4 heteroatom is independently selected from the group of N, O, S;

R and R are independently selected from hydrogen, C_1-7 alkyl or C_1-6 alkanoyl group - and/or enantiomers and/or racemates and/or diastereomers and/or geometric isomers and/or pharmaceutically acceptable salts thereof formed with acids and bases.

3. A compound according to claim 1, wherein Y₁ and Y₂ selected from the group consisting of hydrogen, halogen atom, C_1-4 alkyl, C_1-4 alkoxy or cyano group;

X is oxygen or two hydrogen atoms;

Z is -(CH₂)n- group or S; n is 1 or 2; R is selected from the group consisting of optionally substituted Ci_-7 alkyl, Ci_-4 haloalkyl, Ci_-4 hydroxyalkyl, Ci_-3OC_1-3 alkyl, C_1-4 cyanoalkyl, Co^CNR^alkyl, C_M-alkylCOOC^-alkyL Ci_-4-alkylOCOC_1-4-alkyl, C_1-4-alkylNHCOC_1-4-alkyl, C_2-7 alkenyl, C_2-7 alkynyl, CH₂O-(CH₂)_1-3-OCH₃;

C_3-7 cycloalkyl, which is optionally substituted by one or more substituent(s) selected from the group consisting of C_1-7 alkyl, cyano, acetamido or oxo group,

C_3-7 saturated or unsaturated heterocyclyl which is optionally substituted by one or more substituent(s) selected from C_1-7 alkyl or oxo group, wherein the 1-4 heteroatom is independently selected from the group of N, O, S; phenyl group, which is optionally substituted by one or more substituent(s) selected from the group Of C_1-7 alkyl, C_2-7 alkenyl, C_2-7 alkynyl or cyano group; a heteroaryl group, which is selected from the group of furyl, thiophenyl, pyrrolyl, pyrazolyl, imidazolyl, pyridinyl, pyrazinyl, thiazolyl, thiadiazolyl, izoxazolyl group and is optionally substituted by one or more substituent(s) selected from halogen, C_1-7 alkyl, acetamido, C_1-4 alkoxy, cyano, C_1-4 thioalkyl, or C_1-4 alkanoyl group;

R and R are independently selected from hydrogen, C_1-7 alkyl or C_1-6 alkylcarbonyl group - and/or enantiomers and/or racemates and/or diastereomers and/or geometric isomers and/or pharmaceutically acceptable salts thereof formed with acids and bases.

4. A compound according to claim 1 selected from the group consisting of:

(5-Bromo-furan-2-yl)-{2-[2-(3-chloro-phenyl)-2H-tetrazol-5-yl]-piρeridin-l-yl}-methanone, Cyclobutyl-[2-(2-m-tolyl-2H-tetrazol-5-yl)-piperidin-l-yl]-methanone,

Cyclobutyl-{2R-[2-(3-chloro-phenyl)-2H-tetrazol-5-yl]-piperidin-l-yl}-methanone,

{2R-[2-(3 -chloro-phenyl)-2H-tetrazol-5-yl] -pyrrolidin- 1 -yl} - 1 -(5-methyl-thiophen-2-yl)- methanone,

Cyclopentyl- {2-[2-(3 -chloro-phenyl)-2H-tetrazol-5-yl] -piperidin- 1 -yl} -methanone, Cyclopentyl-[2-(2-m-tolyl-2H-tetrazol-5-yl)-piperidin-l-yl]-methanone,

{2-[2-(3-chloro-phenyl)-2H-tetrazol-5-yl]-ρyrrolidin- 1 -yl} - 1 -(5-methyl-furan-2-yl)- methanone,

{2-[2-(3 -Chloro-ρhenyl)-2H-tetrazol-5-yl] -piperidin- 1 -yl} - 1 -(5-methyl-thioρhen-2-yl)- methanone, 1 - {2R- [2-(3 -Chloro-ρhenyl)-2H-tetrazol-5-yl] -piperidin- 1 -yl } -hept-7-yn- 1 -one,

(5-Bromo-thioρhen-2-yl)-{2-[2-(3-chloro-phenyl)-2H-tetrazol-5-yl]-ρiperidin-l-yl}-l- methanone, l-{2-[2-(3-Chloro-phenyl)-2H-tetrazol-5-yl]-piperidin-l-yl}-2-methyl-propan-l-one, [2-(2-m-Tolyl-2H-tetrazol-5-yl)-piperidin-l-yl]-l-(5-methyl-thiophen-2-yl)-methanone, {2-[2-(3-Chloro-ρhenyl)-2H-tetrazol-5-yl]-piperidin-l-yl}-l-(4,5-dimethyl-furan-2-yl)- methanone, 3-[2-(3-Chloro-phenyl)-2H-tetrazol-5-yl]-piperidine-l-carboxylic acid dimethylamide, Cycloheptyl-{2-[2-(3-chloro-phenyl)-2H-tetrazol-5-yl]-piperidin-l-yl}-methanone, 2-[2-(3-Chloro-ρhenyl)-2H-tetrazol-5-yl]-piperidine-l -carboxylic acid dimethylamide, {2-[2-(3 -Chloro-phenyl)-2H-tetrazol-5-yl]-piperidin- 1 -yl} - 1 -furan-3 -yl)-methanone, (5-Bromo-thioρhen-2-yl)-[2-(2-m-tolyl-2H-tetrazol-5-yl)-ρyrrolidin-l-yl]-methanone, (5-Bromo-furan-2-yl)-{2-[2-(3-bromo-ρhenyl)-2H-tetrazol-5-yl]-piperidin-l-yl}-methanone, {2-[2-(3-Bromo-phenyl)-2H-tetrazol-5-yl]-piρeridin-l-yl}-l-(5-methyl-furan-2-yl)- methanone,

[2-(2-m-Tolyl-2H-tetrazol-5-yl)-piperidin- 1 -yl] - 1 -(5-methyl-foran-2-yl)-methanone, (5-Bromo-furan-2-yl)-{4-[2-(3-chloro-phenyl)-2H-tetrazol-5-yl]-thiazolidm-3-yl}-methanone, {4-[2-(3-Chloro-phenyl)-2H-tetrazol-5-yl]-thiazolidin-3-yl}-(5-methyl-thiophen-2-yl)- methanone,

2- {2-[2-(3 -Chloro-phenyl)-2H-tetrazol-5-yl] -piperidin- 1 -ylmethyl} -pyridine, and/or salts thereof.

5. A process for the preparation of a compound of formula (I)

I wherein X is oxygen and Y₁, Y₂, Z, X, R, R¹, R² and n are the same as defined in claim 1, comprising reacting a compound of formula (V)

with an activated acid of formula RCOOH, wherein R is as defined in claim 1.

6. A process for the preparation of a compound of formula (I)

wherein X is hydrogen and Y₁, Y₂, Z, X, R, R¹, R² and n are the same as defined in claim 1, comprising reacting a compound of formula (V)

with an aldehyde of formula RCHO, wherein R is as defined in claim 1.

7. A process according to claim 5, wherein the activated acid (RCOOH) is activated with EDC in the presence of a base such as sodium hydrogen carbonate or TEA.

8. A pharmaceutical formulation comprising as an active ingredient a therapeutically effective amount of a compound according to claim 1 in association with one or more pharmaceutically acceptable diluents, excipients and/or inert carriers.

9. A pharmaceutical formulation according to claim 8, for use in the prevention and/or treatment of mGluR5 receptor-mediated disorders.

10. A compound according to claim 1, for use in therapy.

11. A compound according to claim 10, for use in the prevention and/or treatment of mGluR5 receptor-mediated disorders.

12. Use of a compound according to claim 1 in the manufacture of a medicament for the prevention and/or treatment of mGluR5 receptor-mediated disorders.

13. Use according to claim 12, wherein said mGluR5 receptor-mediated disorders are psychiatric disorders.

14. Use according to claim 12, wherein said mGluR5 receptor-mediated disorders are neurological disorders.

15. Use according to claim 12, wherein said mGluR5 receptor-mediated disorders are chronic and acute pain.

16. Use according to claim 12, wherein said mGluR5 receptor-mediated disorders are neuromuscular dysfunctions of the lower urinary tract.

17. A method of prevention and/or treatment of mGluR5 receptor-mediated disorders, comprising administering to a mammal in need of such prevention and/or treatment, a therapeutically effective amount of a compound according to claim 1.

18. A method according to claim 17, wherein said mammal is a human.

19. A method according to claim 17, wherein said mGluR5 receptor-mediated disorders are psychiatric disorders.

20. A method according to claim 17, wherein said mGluR5 receptor-mediated disorders are neurological disorders.

21. A method according to claim 17, wherein said mGluR5 receptor-mediated disorders are chronic and acute pain disorders.

22. A method according to claim 17, wherein said mGluR5 receptor-mediated disorders are neuromuscular dysfunctions of the lower urinary tract.