# Patent

## Title
Ether derivatives

## Abstract

The present invention relates to ether derivatives according to general formula I,




and to their pharmaceutically-acceptable salts, which may be used in treating or preventing cognitive disorders, drug addiction, depression, anxiety, drug dependence, dementias, memory impairment, psychotic disorders comprising schizophrenia, schizoaffective disorders, bipolar disease, mania, psychotic depression, or psychoses comprising paranoia and delusions.

## Background
PRIORITY TO RELATED APPLICATION(S)
This application claims the benefit of European Patent Application No. 06123274.0, filed Oct. 31, 2006, which is hereby incorporated by reference in its entirety.
FIELD OF THE INVENTION
The present invention relates to ether derivatives which are dual modulators of serotonin 5-HT2a and dopamine D3 receptors.
BACKGROUND OF THE INVENTION
Schizophrenia is characterized by complex symptomatology including positive symptoms, (i.e. delusions and hallucinations), and negative symptoms, (i.e. anhedonia, restricted fluency and productivity of thought and speech). In addition, it is now well recognized that cognitive impairment is the third major diagnostic category of schizophrenia, characterized by loss in working memory as well as other deficits. Other symptoms include aggressiveness, depression and anxiety (Stahl, S. M. (2000) Essential Psychopharmacology. Neuroscientific Basis and Practical Applications. Cambridge University Press, second edition, Cambridge, UK). The different categories and the clinical features of the disorder are defined in diagnostic schemes such as DSM-IV (Diagnostic and statistical manual of mental disorders, 4th edition) or ICD-10 (International classification of diseases, 10th edition). Currently, medication used to treat schizophrenia, bipolar mania and other psychoses include antipsychotics. Such antipsychotics include both typical antipsychotics (D2/D3 preferring) and atypical antipsychotics. Atypical antipsychotics exhibit polypharmacology in that they interact at multiple receptors (e.g., D1, D2, D3, D4, 5-HT1A, 5-HT2A, 5-HT2C, H1, M1, M2, M4 etc; Roth, B. L et al. (2004) Magic shotguns versus magic bullets: selectively non-selective drugs for mood disorders and schizophrenia. Nat. Rev. Drug Discov. 3, 353-359). These antipsychotics, although relatively successful (some patients exhibit treatment resistance) at treating the positive symptoms of schizophrenia, are less effective at treating negative symptoms, cognitive deficits, and associated depression and anxiety, all of which lead to reduced patient quality of life and socioeconomic problems (Lieberman J. A., et al. Clinical Antipsychotic Trials of Intervention Effectiveness (CATIE) Investigators. (2005) Effectiveness of antipsychotic drugs in patients with chronic schizophrenia. N. Engl. J. Med. 353, 1209-1223). Furthermore, patient compliance is compromised by prevalent side effects such as weight gain, extrapyramidal symptoms (EPS), and cardiovascular effects (Lieberman J. A. et al. Clinical Antipsychotic Trials of Intervention Effectiveness (CATIE) Investigators. (2005) Effectiveness of antipsychotic drugs in patients with chronic schizophrenia. N. Engl. J. Med. 353, 1209-1223).
Dopamine, a major catecholamine neurotransmitter, is involved in the regulation of a variety of functions which include emotion, cognition, motor functions, and positive reinforcement, (Purves, D. et al. (2004) Neuroscience. Sinauer, third edition, Sunderland, Mass.). The biological activities of dopamine are mediated through G protein-coupled receptors (GPCRs). In humans, five different dopamine receptors D1-D5 have been identified, where the D2-like receptors (D2, D3 and D4) couple to the G-protein GC, (Missale, C. et al. (1998) Dopamine receptors: from structure to function. Physiol. Rev. 78, 189-225). The D3 dopamine receptor is most highly expressed in the nucleus accumbens (Gurevich, E. V., Joyce, J. N. (1999) Distribution of dopamine D3 receptor expressing neurons in the human forebrain: comparison with D2 receptor expressing neurons. Neuropsychopharmacology 20, 60-80) and is proposed to modulate the mesolimbic pathway consisting of neuronal projections from the ventral tegmental area, hippocampus and amygdala to the nucleus accumbens, which projects to the prefrontal and cingulate cortices as well as various thalamic nuclei. The limbic circuit is thought to be important for emotional behavior and thus D3 receptor antagonists are proposed to modulate psychotic symptoms such as hallucinations, delusions and thought disorder (Joyce, J. N. and Millan M. J., (2005) Dopamine D3 receptor antagonists as therapeutic agents. Drug Discovery Today, {Drug-Discov-Today}, 1 July, Vol. 10, No. 13, P. 917-25, Issn: 1359-6446), while these antagonists spare the D2 modulated striatal extrapyramidal system (associated with EPS induction). In addition, it has been reported that drug naive schizophrenic patients show altered levels of D3 receptor expression (Gurevich, E. V. et al. (1997) Mesolimbic dopamine D3 receptors and use of antipsychotics in patients with schizophrenia. A postmortem study. Arch. Gen. Psychiatry 54, 225-232) and dopamine release (Laruelle, M. (2000) Imaging dopamine dysregulation in schizophrenia: implication for treatment. Presented at Workshop Schizophr.: Pathol. Bases and Mech. Antipsychotic Action, Chicago), indicating that a disturbed homeostasis of dopamine plays an important role in the etiology of schizophrenic symptoms.
The neurotransmitter serotonin is implicated in several psychiatric conditions including schizophrenia (Kandel, E. R. et al. (eds.; 2000) Principles of Neural Science, 3rd edition Appleton & Lange, Norwalk, Conn.). The involvement of serotonin in psychotic disorders is suggested by multiple studies which include treatment in humans with the psychotropic drug Lysergic acid (LSD; a serotonin agonist) which can induce schizophrenia-like symptoms such as hallucinations (Leikin, J. B. et al. (1989) Clinical features and management of intoxication due to hallucinogenic drugs. Med. Toxicol. Adverse Drug Exp. 4, 324-350). Furthermore, altered brain distribution of serotonin receptors as well as an altered serotonergic tone, have been detected in schizophrenic patients (Harrison, P. J. (1999) Neurochemical alterations in schizophrenia affecting the putative receptor targets of atypical antipsychotics. Focus on dopamine (D1, D3, D4) and 5-HT2A receptors. Br. J. Psychiatry Suppl. 38, 12-22). In mammals serotonin exerts its biological activities through a family of 14 5-HT GPCRs (Barnes, N. M., Sharp, T. (1999) A review of central 5-HT receptors and their function. Neuropharmacology 38, 1083-1152). The 5-HT2A receptor is most prominently expressed in the prefrontal cortex and at lower levels in the basal ganglia and the hippocampus in human brain (Pompeiano, M. et al. (1994) Distribution of the serotonin 5-HT2 receptor family mRNAs: comparison between 5-HT2A and 5-HT2C receptors. Brain Res. Mol. Brain. Res. 23, 163-178; Pazos, A., Probst, A., Palacios, J. M. (1987) Serotonin receptors in the human brain-IV. Autoradiographic mapping of serotonin-2 receptors. Neuroscience 21, 123-139), and is coupled predominantly to the G-protein Guq (Roth, B. L. et al. (1998) 5-Hydroxytryptamine-2-family receptors (5-hydroxytryptamine2A, 5-hydroxytryptamine2B, 5-hydroxytryptamine2C): where structure meets function. Pharmacol. Ther. 79, 231-257). Genetic linkage studies of a 5-HT2A polymorphism to schizophrenia (Spurlock, G. et al. (1998) A family based association study of T102C polymorphism in 5HT2A and schizophrenia plus identification of new polymorphisms in the promoter. Mol. Psychiatry. 3, 42-49), as well as responsiveness to antipsychotic drugs (Arranz, M. J. et al. (2000) Pharmacogenetic prediction of clozapine response. Lancet 355, 1615-1616), further suggests a role for the 5-HT2A receptor both in the treatment and pathology of psychosis. In addition, dopaminergic neurotransmission appears to be under the afferent regulation of the 5-HT2A receptor (Porras, G. et al. 5-HT2A and 5-HT2C/2B receptor subtypes modulate dopamine release induced in vivo by amphetamine and morphine in both the rat nucleus accumbens and striatum. Neuropsychopharmacology 26, 311-324-2002). Overall 5-HT2A receptor antagonists are proposed to be suitable for the treatment of disorders associated with dysfunctional dopaminergic systems. Moreover, 5-HT2A receptor antagonism has been recognized as beneficial for the treatment of psychosis (reviewed in de Angelis, L. (2002) 5-HT2A antagonists in psychiatric disorders. Curr. Opin. Investig. Drugs 3, 106-112) and indeed is one of the defining features of so-called atypical antipsychotic drugs which are characterized by a relatively high affinity for the 5-HT2A-relative to the D2 receptor (Meltzer, H. Y. et al. (1989) Classification of typical and atypical antipsychotic drugs on the basis of dopamine D-1, D-2 and serotonin2 pKi values. J. Pharmacol. Exp. Ther. 251, 238-246).
We found that the compounds of the present invention are dual modulators of the serotonin 5-HT2a and dopamine D3 receptors.
The compounds of the invention have high affinity for the dopamine D3 and serotonin (5-Hydroxytryptamine; 5-HT) 5-HT2A receptors and are believed to be effective in the treatment of psychotic disorders, as well as other diseases such as depression and anxiety, drug dependence, dementias and memory impairment. Psychotic disorders encompass a variety of diseases, which include schizophrenia, schizoaffective disorders, bipolar disease, mania, psychotic depression, and other psychoses involving paranoia and delusions (Reavill-C −et al. (2000) Pharmacological actions of a novel, high-affinity, and selective human dopamine D3 receptor antagonist, SB-277011-A. JPET 294:1154-1165; Harrison, P. J. (1999) Neurochemical alterations in schizophrenia affecting the putative receptor targets of atypical antipsychotics. Focus on dopamine (D1, D3, D4) and 5-HT2A receptors. Br. J. Psychiatry Suppl. 38, 12-22; de Angelis, L. (2002) 5-HT2A antagonists in psychiatric disorders. Curr. Opin. Investig. Drugs 3, 106-112; Joyce, J. N. and Millan M. J., (2005) Dopamine D3 receptor antagonists as therapeutic agents. Drug Discovery Today, {Drug-Discov-Today}, 1 July, Vol. 10, No. 13, P. 917-25, Issn: 1359-6446); drug dependency and abuse and withdrawal (Vorel, S. R. et al. E. L (2002) Dopamine D3 receptor antagonism inhibits cocaine-seeking and cocaine-enhanced brain reward in rats. J. Neurosci., 22, 9595-9603; Campos, A. C. et al. (2003) The dopamine D3 receptor antagonist SB277011A antagonizes nicotine-enhanced brain-stimulation reward in rat. Soc. Neurosci. Abstr., 322.8; Ashby, C. R., et al. (2003). Acute administration of the selective D3 receptor antagonist SB-277011-A blocks the acquisition and expression of the conditioned place preference response to heroin in male rats. Synapse, 48, 154-156); anxiety, and depression (Reavill-C et al. (2000) Pharmacological actions of a novel, high-affinity, and selective human dopamine D3 receptor antagonist, SB-277011-A. JPET 294:1154-1165; Drescher, K. et al. (2002) In vivo effects of the selective dopamine D3 receptor antagonist A-437203. Am. Soc. Neurosci. 894.6). As such, the compounds of the present invention are proposed to treat psychoses and other diseases, with fewer associated side affects than those exhibited by prior art compounds.
SUMMARY OF THE INVENTION
The present invention relates to a compound according to general formula I:




wherein:

A is selected from the group consisting of: aryl and 5- to 12-membered heteroaryl, wherein said aryl or heteroaryl is optionally substituted by at least one substituent, each said substituent independently selected from the group consisting of:

    
    
        halogen,
        cyano,
        C1-6-alkyl optionally substituted by cyano or C1-6-alkoxy,
        C1-6-alkoxy, and
        —S(O)2—C1-6-alkyl;

R1 is selected from the group consisting of:

        C1-6-alkyl optionally substituted by at least one substituent, each of said substituent being independently selected from the group consisting of: halogen,
        
            C1-6-alkoxy, and aryl optionally substituted by halogen;
        
        
        C3-10-cycloalkyl optionally substituted by one or more Ra;
        5- to 12-membered heterocycloalkyl optionally substituted by one or more Ra;
        aryl optionally substituted by one or more Ra;
        5- to 12-membered heteroaryl optionally substituted by one or more Ra; and
        —NRbRc, wherein Rb is hydrogen or C1-6-alkyl and Rc is hydrogen,
        
            C1-6-alkyl or aryl optionally substituted by one or more Ra;

each Ra is independently selected from the group consisting of:

        
        
        halogen;
        —S(O)2—C1-6-alkyl;
        cyano;
        oxo;
        C1-6-alkyl optionally substituted by aryl which is substituted by halogen;
        C1-6-haloalkyl;
        C1-6-haloalkoxy;
        C1-6-alkoxy optionally substituted by 5- to 6-membered heteroaryl which is optionally substituted by C1-6-alkyl;
        —NH(CO)—C1-6-alkyl;
        5- to 6-membered heterocycloalkyl; and
        5- to 6-membered heteroaryl optionally substituted by C1-6-alkyl or oxo; and

R2 is selected from the group consisting of hydrogen and hydroxyl;

and to a pharmaceutically-acceptable salt of such a compound.

    
    


The invention relates also to a pharmaceutical composition comprising a compound of the aforementioned formula or a pharmaceutically-acceptable salt thereof.
Another aspect of the present invention is a process for the preparation of a compound of the aforementioned formula


DETAILED DESCRIPTION OF THE INVENTION
The present invention relates to a compound according to general formula I:




wherein:

A is selected from the group consisting of: aryl and 5- to 12-membered heteroaryl, wherein said aryl or heteroaryl is optionally substituted by at least one substituent, each said substituent independently selected from the group consisting of:

    
    
        halogen,
        cyano,
        C1-6-alkyl optionally substituted by cyano or C1-6-alkoxy,
        C1-6-alkoxy, and
        —S(O)2—C1-6-alkyl;

R1 is selected from the group consisting of:

        C1-6-alkyl optionally substituted by at least one substituent, each of said substituent being independently selected from the group consisting of: halogen,
        
            C1-6-alkoxy, and aryl optionally substituted by halogen;
        
        
        C3-10-cycloalkyl optionally substituted by one or more Ra;
        5- to 12-membered heterocycloalkyl optionally substituted by one or more Ra;
        aryl optionally substituted by one or more Ra;
        5- to 12-membered heteroaryl optionally substituted by one or more Ra; and —NRbRc, wherein Rb is hydrogen or C1-6-alkyl and Rc is hydrogen,
        
            C1-6-alkyl or aryl optionally substituted by one or more Ra;

each Ra is independently selected from the group consisting of:

        
        
        halogen;
        —S(O)2—C1-6-alkyl;
        cyano;
        oxo;
        C1-6-alkyl optionally substituted by aryl which is substituted by halogen;
        C1-6-haloalkyl;
        C1-6-haloalkoxy;
        C1-6-alkoxy optionally substituted by 5- to 6-membered heteroaryl which is optionally substituted by C1-6-alkyl;
        —NH(CO)—C1-6-alkyl;
        5- to 6-membered heterocycloalkyl; and
        5- to 6-membered heteroaryl optionally substituted by C1-6-alkyl or oxo; and

R2 is selected from the group consisting of hydrogen and hydroxyl;

and to a pharmaceutically-acceptable salt of such a compound.

    
    


Compounds of formula (I) may form acid addition salts with acids, such as conventional pharmaceutically-acceptable acids, for example hydrochloride, hydrobromide, phosphate, acetate, fumarate, maleate, salicylate, sulphate, pyruvate, citrate, lactate, mandelate, tartarate, and methanesulphonate. Preferred are the hydrochloride salts. Also solvates and hydrates of compounds of formula I and their salts form part of the present invention.
Compounds of formula (I) can have one or more asymmetric carbon atoms and can exist in the form of optically pure enantiomers, mixtures of enantiomers such as, for example, racemates, optically pure diastereoisomers, mixtures of diastereoisomers, diastereoisomeric racemates or mixtures of diastereoisomeric racemates. The optically active forms can be obtained for example by resolution of the racemates, by asymmetric synthesis or asymmetric chromatography (chromatography with a chiral adsorbents or eluent). The invention embraces all of these forms.
It will be appreciated, that the compounds of general formula (I) in this invention may be derivatised at functional groups to provide derivatives which are capable of conversion back to the parent compound in vivo. Physiologically acceptable and metabolically labile derivatives, which are capable of producing the parent compounds of general formula I in vivo are also within the scope of this invention.
“Aryl” means a monovalent cyclic aromatic moiety consisting of a mono-, bi- or tricyclic aromatic ring wherein each member of the ring is carbon. Examples of aryl moieties include, but are not limited to, optionally substituted phenyl, naphthyl, phenanthryl, fluorenyl, indenyl, pentalenyl, azulenyl, oxydiphenyl, biphenyl, methylenediphenyl, aminodiphenyl, diphenylsulfidyl, diphenylsulfonyl, and diphenylisopropylidenyl, as well as those specifically illustrated by the examples herein below. Preferred aryl moieties are phenyl and naphthyl with phenyl being more particularly preferred.
The aryl moieties of the invention further can be substituted by one, two or three substituents such as those substituents specifically illustrated in the examples herein below.
“C1-6-alkyl” denotes a straight- or branched-carbon chain group containing from 1 to 6 carbon atoms, for example, methyl, ethyl, propyl, isopropyl, isobutyl, sec-butyl, tert-butyl, pentyl, n-hexyl as well as those specifically illustrated by the examples herein below.
“C1-6-haloalkyl” denotes a C1-6-alkyl group as defined above which is substituted by one or more halogen(s). Examples of C1-6-haloalkyl include but are not limited to methyl, ethyl, propyl, isopropyl, isobutyl, sec-butyl, tert-butyl, pentyl or n-hexyl substituted by one or more Cl, F, Br or I atom(s) as well as those groups specifically illustrated by the examples herein below. Preferred C1-C7-haloalkyl groups are difluoro- or trifluoro-methyl or ethyl.
“C1-6-alkoxy” denotes a group wherein the alkyl group is as defined above and the alkyl group is connected to the remainder of the molecule via an oxygen atom.
“C1-6-haloalkoxy” denotes a C1-6-alkoxy group as defined above which is substituted by one or more halogen. Examples of C1-6-haloalkoxy include but are not limited to methoxy or ethoxy, substituted by one or more Cl, F, Br or I atom(s) as well as those groups specifically illustrated by the examples herein below. Preferred C1-C7 haloalkoxy groups are difluoro- or trifluoro-methoxy or ethoxy.
“Halogen” denotes chlorine, iodine, fluorine and bromine.
“C3-10-cycloalkyl” denotes a monovalent saturated moiety, consisting of one, two or three carbon rings having 3 to 10 carbon atoms as ring members and includes but is not limited to cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl and polyspiro groups such as bicyclo[3.2.1]octane or adamantane as well as those groups specifically illustrated by the examples herein below.
The term “heteroatom” when used to describe atoms within a “heteroaryl” or “heterocycloalkyl” group (as defined below) refers to an atom selected from the group consisting of nitrogen, oxygen, and sulfur. In a heteroaryl or heterocycloalkyl with more than one heteroatom, the heteroatoms can be the same or different.
“Heteroaryl” means a monocyclic or bicyclic radical having at least one aromatic ring containing one, two, three or four ring heteroatoms, the remaining ring atoms being carbon, with the understanding that the attachment point of the radical to the remainder of the molecule is on the aromatic ring moiety containing the heteroatom(s). The heteroaryl ring may be optionally substituted as defined herein. Heteroaryls having 5 to 12 ring atoms and are referred to herein as “5- to 12-membered heteroaryl”s. Examples of such heteroaryl moieties include, but are not limited to, optionally substituted imidazolyl, oxazolyl, isoxazolyl, thiazolyl, isothiazolyl, oxadiazolyl, thiadiazolyl, pyrazinyl, thienyl, benzothienyl, furanyl, pyridyl, pyrrolyl, pyrazolyl, pyrimidyl, quinolinyl, isoquinolinyl, benzofurylbenzimidazolyl, benzooxazolyl, benzooxadiazolyl, benzothiazolyl, benzothiadiazolyl, benzopyranyl, indolyl, isoindolyl, triazolyl, triazinyl, quinoxalinyl, purinyl, quinazolinyl, quinolizinyl, naphthyridinyl, pteridinyl, carbazolyl, azepinyl, diazepinyl, acridinyl and the like, as well as those specifically illustrated by the examples herein below. Preferred heteroaryls have 5 or 6 ring atoms and are referred to herein as “5- to 6-membered heteroaryl”s. Examples of such 5- to 6-membered heteroaryls are [1,2,4]oxadiazolyl, indolyl, thiophenyl, pyridinyl as well as those specifically illustrated by the examples herein below. Also preferred are heteroaryls which have 5 to 10 ring atoms and are referred to herein as “5- to 10-membered heteroaryl”s. Examples of such 5- to 10-membered heteroaryls include [1,2,4]oxadiazolyl, thiophenyl, pyridinyl, quinolinyl as well as those specifically illustrated by the examples herein below.
In embodiments in which the heteroaryl moiety consists of a bicyclic ring, preferably one of the rings is a six-membered aromatic ring where the members are each carbon and the other ring is a 5- to 6-membered ring containing two oxygen atoms. Examples of such heteroaryl moieties include, but are not limited to, 2,3-dihydro-benzo[1,4]dioxinyl, 2,3-dihydro-benzofuranyl, benzodioxolyl, benzopyranyl, benzoxazinyl, benzoxazinonyl, benzopiperidinyl, benzopiperazinyl, benzopyrrolidinyl, benzomorpholinyl, as well as those specifically illustrated by the examples herein below.
“Heterocycloalkyl” means a monovalent saturated or partially unsaturated radical, consisting of one to three rings, incorporating one, two, or three or four heteroatoms, the remaining ring atoms being carbon, with the understanding that the attachment point of the radical to the remainder of the molecule is on the heterocyclic, saturated or partially saturated moiety. Heterocycloalkyls having 5 to 12 ring atoms and are referred to herein as “5- to 12-membered heterocycloalkyls. Preferably, the rings are three- to seven-membered. The heterocycloalkyl ring may be optionally substituted as defined herein. Examples of heterocycloalkyl radicals include, but are not limited to, optionally substituted piperidinyl, piperazinyl, homopiperazinyl, azepinyl, pyrrolidinyl, pyrazolidinyl, imidazolinyl, imidazolidinyl, oxazolidinyl, isoxazolidinyl, morpholinyl, thiazolidinyl, isothiazolidinyl, quinuclidinyl, thiadiazolylidinyl, benzothiazolidinyl, benzoazolylidinyl, dihydrofuryl, tetrahydrofuryl, dihydropyranyl, tetrahydropyranyl, thiamorpholinyl, thiamorpholinylsulfoxide, thiamorpholinylsulfone, dihydroquinolinyl, dihydrisoquinolinyl, tetrahydroquinolinyl, tetrahydrisoquinolinyl, as well as those groups specifically illustrated by the examples herein below. Preferred 5- to 12-membered heterocycloalkyls are those having 5 to 10 ring atoms. Such heterocycloalkyls are termed “5- to 10-membered heterocycloalkyl”s. Examples of such heterocycloalkyls are tetrahydrofuranyl and tetrahydropyranyl. Also preferred are heterocycloalkyls having 5 to 6 ring atoms. Such heterocycloalkyls are termed “5- to 6-membered heterocycloalkyls”.
“Oxo” denotes a ═O group.
“Cyano” denotes a —CN group.
“Pharmaceutically-acceptable”, when used to describe a salt, acid, excipient, or other compound, means that the compound is useful in preparing a pharmaceutical composition that is generally safe, non-toxic, and neither biologically nor otherwise undesirable and includes compounds which are acceptable for veterinary as well as human pharmaceutical use.
A “pharmaceutically-acceptable salt” of a compound means a salt that is pharmaceutically-acceptable, as defined herein, and that possesses the desired pharmacological activity of the parent compound. Such salts include acid addition salts formed with inorganic acids such as hydrochloric acid, hydrobromic acid, sulfuric acid, nitric acid, phosphoric acid, and the like; or formed with organic acids such as acetic acid, benzenesulfonic acid, benzoic, camphorsulfonic acid, citric acid, ethanesulfonic acid, fumaric acid, glucoheptonic acid, gluconic acid, glutamic acid, glycolic acid, hydroxynaphtoic acid, 2-hydroxyethanesulfonic acid, lactic acid, maleic acid, malic acid, malonic acid, mandelic acid, methanesulfonic acid, muconic acid, 2-naphthalenesulfonic acid, propionic acid, salicylic acid, succinic acid, tartaric acid, p-toluenesulfonic acid, trimethylacetic acid, as well as those groups specifically illustrated by the examples herein below.
In a preferred embodiment of the present invention, the compound is a compound of formula I, or a pharmaceutically-acceptable salt thereof, in which A is selected from the group consisting of:
aryl, optionally substituted by at least one substituent, each substituent being independently selected from the group consisting of: halogen, cyano and C1-6-alkyl substituted by cyano; and
5- to 6-membered heteroaryl, for example pyridinyl.
In a certain embodiment of the invention, the compound is a compound of formula I, or a pharmaceutically-acceptable salt thereof, in which R1 is C1-6-alkyl optionally substituted by at least one substituent, each substituent being independently selected from the group consisting of: halogen and C1-6-alkoxy. Examples of such compounds include:

    N-trans(4-{2-[4-(4-Fluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-3-methoxy-propionamide;
    N-trans(4-{2-[4-(4-Fluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-acetamide;
    N-trans(4-{2-[4-(2-Chloro-4-fluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-3-methoxy-propionamide;
    N-trans(4-{2-[4-(2-Chloro-4-fluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-propionamide;
    N-trans(4-{2-[4-(2-Chloro-4-fluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-acetamide;
    N-trans(4-{2-[4-(2,4-Difluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-acetamide;
    N-trans(4-{2-[4-(2-Cyano-4-fluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-3-methoxy-propionamide;
    N-trans(4-{2-[4-(2-Cyano-4-fluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-acetamide;
    N-trans(4-{2-[4-(2-Cyano-4-fluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-2,2,2-trifluoro-acetamide; trans N-(4-{2-[4-(2,3-Dichloro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-3-methoxy-propionamide;
    N-trans(4-{2-[4-(2,3-Dichloro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-acetamide;
    N-trans(4-{2-[4-(2,6-Dichloro-4-fluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-3-methoxy-propionamide;
    N-trans(4-{2-[4-(2,6-Dichloro-4-fluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-acetamide;
    N-trans(4-{2-[4-(2,4,5-Trifluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-acetamide;
    N-trans(4-{2-[4-(2-Cyano-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-acetamide;
    N-trans(4-{2-[4-(4-Chloro-2-cyano-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-acetamide;
    N-trans(4-{2-[4-(3-Chloro-2-cyano-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-acetamide;
    N-trans(4-{2-[4-(3-Chloro-4-fluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-acetamide;
    N-trans(4-{2-[4-(2,3,4-Trifluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-acetamide;
    N-(trans-4-{2-[4-(Pyridin-3-yloxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-acetamide; and

pharmaceutically-acceptable salts of such compounds.



In another embodiment of the invention, the compound is a compound of formula I, or a pharmaceutically-acceptable salt thereof, in which R1 is C3-10-cycloalkyl optionally substituted by at least one Ra, wherein each Ra is independently a C1-6-alkyl. Examples of such compounds include:

    Cyclopropanecarboxylic acid trans(4-{2-[4-(4-fluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-amide;
    Cyclopropanecarboxylic acid trans(4-{2-[4-(2-chloro-4-fluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-amide;
    Cyclobutanecarboxylic acid trans(4-{2-[4-(2-cyano-4-fluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-amide;
    Cyclopropanecarboxylic acid trans(4-{2-[4-(2-cyano-4-fluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-amide;
    2-Methyl-cyclopropanecarboxylic acid trans(4-{2-[4-(2-cyano-4-fluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-amide;
    Cyclobutanecarboxylic acid trans(4-{2-[4-(2,3-dichloro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-amide;
    Cyclobutanecarboxylic acid trans(4-{2-[4-(2,6-dichloro-4-fluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-amide;
    Cyclobutanecarboxylic acid trans(4-{2-[4-(2,4,6-trifluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-amide;
    Cyclobutanecarboxylic acid trans(4-{2-[4-(2,4,5-trifluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-amide;
    2-Methyl-cyclopropanecarboxylic acid trans(4-{2-[4-(2,4,5-trifluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-amide;
    Cyclopropanecarboxylic acid trans(4-{2-[4-(4-cyano-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-amide; and

pharmaceutically-acceptable salts of such compounds.



In another embodiment of the invention, the compound is a compound of formula I, or a pharmaceutically-acceptable salt thereof, in which R1 is a 5- to 12-membered heterocycloalkyl. Examples of such compounds include:

    Tetrahydro-pyran-4-carboxylic acid trans(4-{2-[4-(4-fluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-amide;
    Tetrahydro-pyran-4-carboxylic acid trans(4-{2-[4-(2-chloro-4-fluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-amide;
    Tetrahydro-pyran-4-carboxylic acid trans(4-{2-[4-(2,4-difluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-amide;
    Tetrahydro-pyran-4-carboxylic acid trans(4-{2-[4-(2-cyano-4-fluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-amide;
    Tetrahydro-pyran-4-carboxylic acid trans(4-{2-[4-(2,3-dichloro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-amide;
    Tetrahydro-furan-2-carboxylic acid trans(4-{2-[4-(2,6-dichloro-4-fluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-amide;
    Tetrahydro-pyran-4-carboxylic acid trans(4-{2-[4-(2,6-dichloro-4-fluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-amide;
    Tetrahydro-furan-2-carboxylic acid trans(4-{2-[4-(2,4,6-trifluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-amide;
    Tetrahydro-pyran-4-carboxylic acid trans(4-{2-[4-(2,4,5-trifluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-amide;
    Tetrahydro-pyran-4-carboxylic acid trans(4-{2-[4-(4-chloro-2-cyano-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-amide; and

pharmaceutically-acceptable salts of such compounds.



In another embodiment of the invention, the compound is a compound of formula I, or a pharmaceutically-acceptable salt thereof, in which R1 is aryl optionally substituted by at least one Ra, wherein each Ra is independently selected from the group consisting of: halogen, C1-6-alkoxy, —S(O)2—C1-6-alkyl, and 5- to 6-membered heteroaryl optionally substituted by C1-6-alkyl. Examples of such compounds include:

    4-Chloro-N-trans(4-{2-[4-(4-fluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-benzamide;
    N-trans(4-{2-[4-(4-Fluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-3-(5-methyl-[1,2,4]oxadiazol-3-yl)-benzamide;
    N-trans(4-{2-[4-(4-Fluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-4-methanesulfonyl-benzamide;
    N-trans(4-{2-[4-(2-Chloro-4-fluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-4-methanesulfonyl-benzamide;
    4-Chloro-N-trans(4-{2-[4-(2-chloro-4-fluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-benzamide;
    N-trans(4-{2-[4-(2-Chloro-4-fluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-3-(5-methyl-[1,2,4]oxadiazol-3-yl)-benzamide;
    4-Chloro-N-trans(4-{2-[4-(2-cyano-4-fluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-benzamide;
    N-trans(4-{2-[4-(2-Cyano-4-fluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-4-methoxy-benzamide;
    4-Methoxy-N-trans(4-{2-[4-(2,4,6-trifluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-benzamide;
    4-Chloro-N-trans(4-{2-[4-(2,4,6-trifluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-benzamide;
    4-Methoxy-N-trans(4-{2-[4-(2,4,5-trifluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-benzamide;
    4-Chloro-N-trans(4-{2-[4-(2,4,5-trifluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-benzamide;
    N-trans(4-{2-[4-(2-Cyano-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-4-ethoxy-benzamide;

and pharmaceutically-acceptable salts of such compounds.



In another embodiment of the invention, the compound is a compound of formula I, or a pharmaceutically-acceptable salt thereof, in which R1 is a 5- to 12-membered heteroaryl. Examples of such compounds include:

    1H-Indole-2-carboxylic acid trans(4-{2-[4-(4-fluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-amide;
    Quinoline-4-carboxylic acid trans(4-{2[4-(2-chloro-4-fluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-amide;
    Quinoline-6-carboxylic acid trans(4-{2-[4-(2,4-difluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-amide;
    Quinoline-4-carboxylic acid trans(4-{2-[4-(2,4-difluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-amide;
    Thiophene-2-carboxylic acid trans(4-{2-[4-(2-cyano-4-fluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-amide;
    Thiophene-2-carboxylic acid trans(4-{2-[4-(2,3-dichloro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-amide;
    Thiophene-2-carboxylic acid trans(4-{2-[4-(2,6-dichloro-4-fluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-amide;
    Thiophene-2-carboxylic acid trans(4-{2-[4-(2,4,5-trifluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-amide;
    Thiophene-2-carboxylic acid trans(4-{2-[4-(4-cyano-2-fluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-amide;
    Quinoline-4-carboxylic acid trans(4-{2-[4-(2-cyano-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-amide;
    Quinoline-4-carboxylic acid trans(4-{2-[4-(2-chloro-4-fluoro-phenoxy)-3-hydroxy-piperidin-1-yl]-ethyl}-cyclohexyl)-amide;
    Quinoline-4-carboxylic acid trans(4-{2-[(3R,4R)-4-(2-chloro-4-fluoro-phenoxy)-3-hydroxy-piperidin-1-yl]-ethyl}-cyclohexyl)-amide;
    Quinoline-4-carboxylic acid trans(4-{2-[(3S,4S)-4-(2-chloro-4-fluoro-phenoxy)-3-hydroxy-piperidin-1-yl]-ethyl}-cyclohexyl)-amide;
    Quinoline-4-carboxylic acid trans(4-{2-[4-(4-fluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-amide;
    Quinoline-4-carboxylic acid trans(4-{2-[4-(2,3-dichloro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-amide;
    Quinoline-4-carboxylic acid trans(4-{2-[4-(3,4-dichloro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-amide;
    Quinoline-4-carboxylic acid trans(4-{2-[4-(pyridin-4-yloxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-amide; and

pharmaceutically-acceptable salts of such compounds.



In another embodiment of the invention, the compound is a compound of formula I, or a pharmaceutically-acceptable salt thereof, in which R1 is —NRbRc wherein Rb is hydrogen and Rc is independently selected from the group consisting of hydrogen and aryl optionally substituted by at least one Ra, wherein each Ra is independently selected from the group consisting of halogen and C1-6-alkyl. Examples of such compounds include:

    1-(4-Chloro-phenyl)-3-trans(4-{2-[4-(4-fluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-urea;
    1-trans(4-{2-[4-(4-Fluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-3-p-tolyl-urea;
    1-trans(4-{2-[4-(2-Chloro-4-fluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-3-p-tolyl-urea;
    1-trans(4-{2-[4-(2-Chloro-4-fluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-3-(4-chloro-phenyl)-urea; and

pharmaceutically-acceptable salts of such compounds.



A further aspect of the present invention is a process for the preparation of a compound of the present invention.
In an embodiment of the present invention, such a process involves reacting a compound of the formula II:




with an acid of the formula III:

HOOCR1  (III)

in the presence of a coupling reagent such as O-(benzotriazol-1-yl)-N,N,N′,N′-tetramethyluronium tetrafluoroborate (TBTU) in a suitable solvent like, e.g. dimethylformamide (DMF) or dioxane in the presence of a base (e.g. triethylamine or diisopropylethylamine) to obtain a compound of the formula (I).

In the above formulas, R1 is selected from the group consisting of:

    
    
        C1-6-alkyl optionally substituted by at least one substituent, each of said substituent being independently selected from the group consisting of: halogen, C1-6-alkoxy, and aryl optionally substituted by halogen;
        C3-10-cycloalkyl optionally substituted by one or more Ra;
        5- to 12-membered heterocycloalkyl optionally substituted by one or more Ra;
        aryl optionally substituted by one or more Ra; and
        5- to 12-membered heteroaryl optionally substituted by one or more Ra.

A, Ra, and R2 are as defined herein above.

    
    


In another embodiment of the present invention, the process involves reacting a compound of formula II




wherein A, Ra, and R2 are as defined above and R1 is —NRbRc, wherein Rb is hydrogen or C1-6-alkyl and wherein Rc is aryl optionally substituted by one or more Ra, with an isocyanate or a reactive intermediate such as para nitro carbamate in a suitable solvent like, e.g. dimethylformamide (DMF) or acetonitrile in the presence of a base (e.g. triethylamine or diisopropylethylamine) to obtain a compound of the formula (I).

If desired, the compound as obtained by either of the above processes may be converted into a pharmaceutically-acceptable acid addition salt.
The preparation of compounds of formula (I) of the present invention may be carried out in sequential or convergent synthetic routes. Syntheses of the invention are shown in the following schemes. The skills required for carrying out the reaction and purification of the resulting products are known to those skilled in the art. The substituents and indices used in the following description of the processes have the significance given herein before unless indicated to the contrary.
In more detail, the compounds of formula (I) can be manufactured by the methods given below, by the methods given in the examples or by analogous methods. Appropriate reaction conditions for the individual reaction steps are known to a person skilled in the art. Starting materials are either commercially available or can be prepared by methods analogous to the methods given herein below, by methods described in references cited in the description or in the examples, or by methods known in the art.
In the following schemes and unless stated otherwise, A, R1, R2, Rb, and Rc are as described hereinabove.




The piperidin-4-yloxy-aryl or heteroaryl compound can be prepared according to scheme 1. The syntheses of ethers are widely described in literature and the procedures are known to those in the art (for reaction conditions described in literature affecting such reactions see for example: Comprehensive Organic Transformations: A Guide to Functional Group Preparations, 2nd Edition, Richard C. Larock. John Wiley & Sons, New York, 1999). The transformation can be effected by employing reaction conditions which are commonly utilised in the so called “Mitsunobu reaction” which is known to those in the art and widely described (Hughes, David L. The Mitsunobu reaction. Organic Reactions, John Wiley & Sons, New York, 1992, 42, 335-656). It has been found convenient to couple the commercially available 4-hydroxy-piperidine-1-carboxylic acid tert-butyl ester with aryl or heteroaryl alcohols of formula B (either commercially available or accessible by methods described in references or by methods known in the art; as appropriate) under conditions employing a phosphine, for example a trialkylphosphine such as tributylphosphine ((n-Bu)3, P) or a triarylphosphine such as triphenylphosphine (PPh3) and the like, and a diazo-compound, for example diethyl-azodicarboxylate (DEAD), diisopropyl-azodicarboxylate (DIAD) (optionally polymer bound), tetramethyl azodicarboxamide and the like, in a solvent commonly used in such transformations like tetrahydrofuran (THF), toluene, dichloromethane and the like. There is no particular restriction on the nature of the solvent to be employed, provided that it has no adverse effect on the reaction or the reagents involved and that it can dissolve the reagents, at least to some extent. The reaction can take place over a wide range of temperatures, and the precise reaction temperature is not critical to the invention. It has been found convenient to carry out the reaction at ambient temperature. The time required for the reaction may also vary widely, depending on many factors, notably the reaction temperature and the nature of the reagents. However, a period of from few hours to one day will usually suffice to yield the compounds of formula C. The protecting group can be removed under conditions known for those skilled in the art (e.g. treatment with an acid such as trifluoroacetic acid in a suitable solvent such as dichloromethane) as described on scheme 1.




Aryl or heteroaryl piperidin-4-yloxy compounds with R2═OH can be prepared according to scheme 2 with opening of rac-cis-7-oxa-3-aza-bicyclo[4.1.0]heptane-3-carboxylic acid tert-butyl ester using the aryl or heteroaryl hydroxy derivative A-OH in the presence of sodium hydroxide heating in a solvent like dioxane. Removal of the protecting group in conditions as the ones described on scheme 1 provides compounds of formula D were R2═OH




Also aryl or heteroaryl piperidin-4-yloxy compounds of structure D containing an electron withdrawing group such as nitrile in ortho or para position can be prepared according to scheme 3 by an nucleophilic aromatic substitution of the corresponding fluoroaryl compound (A-F) with 4-hydroxy-piperidine-1-carboxylic acid tert-butyl ester after deprotonation with a base such as NaH in a polar solvent such as DMF. Removal of the protective group in conditions as the ones described in scheme 1 provides compounds of formula D.




(Heteroaryl or phenoxy-piperidin-1-yl)trans-ethyl-cyclohexyl-amides or trans-1,4-cyclohexyl ethyl derivates of formula (I) can be prepared as depicted in scheme 4 starting from 4-nitro-phenylacetic acid. 4-nitro-phenylacetic acid is hydrogenated using Raney nickel as a catalyst. The hydrogenation with nickel leads preferentially to the desired trans-isomer (according to Wustrow et. al. J of Med. Chem., 1998, 41, 760-771). The ethyl ester can be prepared according to methods known to those skilled in the art and described in the mentioned literature (e.g by treatment with ethanol on the presence of an acid such as HCl) and the desired pure diastereoisomer can be resolved from the cis/trans mixture by crystallization as the HCl salt. trans-Amino ester chloride G is obtained. Reaction with tert-butyl dicarbonate ((BOc)2O) in the presence of a base like triethylamine and a catalyst like dimethylaminopyridine (DMAP) and reduction with diisobutylaluminium hydride (DIBAL-H) in an appropriate solvent such as e.g. toluene at −78° C. gives the aldehyde H which can be used without purification on the next step. Reductive amination of aldehyde H with aryl or heteroaryl piperidin-4-yloxy compounds of formula D (which is either commercially available or can be made by methods described in references, by methods described in this patent or by methods known in the art) in the presence of a solvent like 1,2-dichloroethane and a reducing agent such as sodium triacetoxy borohydride (Na(OAc)3BH) yields intermediate J. Removal of the tert-butyl acetate protective group under acidic conditions, for example, using trifluoroacetic acid (TFA), in a suitable solvent, such as tetrahydrofuran (THF), yields the trans-amino cyclohexyl ethyl intermediate K (usually the TFA salt). The coupling of the amine intermediate K with carboxylic acids (either commercially available or accessible by methods described in references or by methods known in the art) is widely described in the literature (e.g. Comprehensive Organic Transformations: A Guide to Functional Group Preparations, 2nd Edition, Richard C. Larock. John Wiley & Sons, New York, N.Y. 1999) and can be accomplished by employing coupling reagents such as, e.g. N,N-carbonyldiimidazole (CDI) or O-(benzotriazol-1-yl)-N,N,N′,N′-tetramethyluronium tetrafluoroborate (TBTU) in a suitable solvent like e.g. dimethylformamide (DMF) or dioxane in the presence of a base (e.g. triethylamine or diisopropylethylamine) to yield compounds of formula (I). In other cases an acid chloride (RCOCl wherein R is an organic radical group) can also be used in the presence of a base (e.g. triethylamine (Et3N) or diisopropylethylamine (DIPEA)) in a solvent like dichloromethane.




In other embodiments the intermediate K can also react with an isocyanate (RbCON) (when Rc is hydrogen) or a reactive intermediate (when Rc is other than hydrogen) such as an appropriate acid chloride or a para nitro carbamate prepared by methods known in the art on the presence of a suitable solvent like, e.g. acetonitrile or dichloromethane in the presence of a base (e.g. triethylamine or diisopropylethylamine) to obtain a compound of the formula (Ia) as described on scheme 5 above.




In some embodiments the aryl or heteroaryl piperidin-4-yloxy compounds of formula D can be coupled in a reductive amination step with a more elaborated aldehyde N according to scheme 6. In some cases the quinoline-4-carboxylic acid [4-(2-oxo-ethyl)-cyclohexyl]-amide was used. The preparation of quinoline-4-carboxylic acid [4-(2-oxo-ethyl)-cyclohexyl]-amide N is described on scheme 6 starting from 4-nitro-phenylacetic acid F that is hydrogenated as already described on scheme 3 using Raney nickel and preparing the trans-amino ethyl ester chloride G as already also described on scheme 3. In this case instead of reacting G with tert-butyl dicarbonate, the amine hydrochloride can be reacted with quinoline-4-carbonyl chloride in the presence of a base such as triethylamine in a solvent such as dichloromethane to obtain trans-{4-[(quinoline-4-carbonyl)-amino]-cyclohexyl}-acetic acid ethyl ester. Hydrolysis of the ester function under acidic or basic conditions such as lithium hydroxide in a solvent mixture such as tetrahydrofuran (THF):water gives the corresponding carboxylic acid L. The preparation of acid derivatives in order to make reductions is known in literature (e.g. T. Fukuyama et. al., Synthesis 2000, 8, 1121-1123). In this case reaction of the carboxylic acid with sodium ethylthiolate prepared previously from ethanothiol and a base such as butyllithium (BuLi) in a solvent such as dimethoxyethane yields trans-{4-[(quinoline-4-carbonyl)-amino]-cyclohexyl}-thioacetic acid S-ethyl ester M that can be reduced with palladium on charcoal (Pd/C) and triethylsilane (Et3SiH) in a solvent mixture like acetone/methylenehloride (1:1) to obtain the desired trans-quinoline-4-carboxylic acid [4-(2-oxo-ethyl)-cyclohexyl]-amide N that can be used in a reductive amination using a reducing agent such as sodium triacetoxy borohydride (Na(OAc)3BH) in a solvent such as dichloromethane to obtain directly trans-quinoline-4-carboxylic acid (4-{2-[(heteroaryl or phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-amide (Ib).




Acetic acid amide derivatives of structure (Ic) can be conveniently prepared according to scheme 7 starting from compound G. The reaction sequence involves in a first step the treatment of compound G with acetyl chloride (AcCl) in presence of a base such as triethylamine (Et3N) in a solvent such as CH2Cl2 to obtain a compound of formula O. Reduction with a reagent such as LiAlH4 in a solvent such as CH2Cl2 at 0° C. provides a compound of formula P. Among several oxidation conditions known in the literature, the Swern oxidation (A. Mancuso, D. Swern, Synthesis 1981, 165-185) of alcohol P provides intermediate Q. Reaction of aldehyde Q with an appropriate substituted piperidine in the presence of a reducing agent such as sodium triacetoxy borohydride (Na(AcO)3BH) in a solvent such as 1,2-dichloroethane provides compounds of formula (Ic).
The compounds of formula I and pharmaceutically-acceptable salts thereof can be used as medicaments, e.g. in the form of pharmaceutical preparations. The pharmaceutical preparations can be administered orally, e.g. in the form of tablets, coated tablets, dragées, hard and soft gelatine capsules, solutions, emulsions or suspensions. However, the administration can also be effected rectally, e.g. in the form of suppositories, or parenterally, e.g. in the form of injection solutions.
The compounds of formula I and pharmaceutically acceptable salts thereof can be processed with pharmaceutically inert, inorganic or organic carriers for the production of pharmaceutical preparations. Lactose, corn starch or derivatives thereof, talc, stearic acid or its salts and the like can be used, for example, as such carriers for tablets, coated tablets, dragées and hard gelatine capsules. Suitable carriers for soft gelatine capsules are, for example, vegetable oils, waxes, fats, semi-solid and liquid polyols and the like; depending on the nature of the active substance no carriers are, however, usually required in the case of soft gelatine capsules. Suitable carriers for the production of solutions and syrups are, for example, water, polyols, sucrose, invert sugar, glucose and the like. Adjuvants, such as alcohols, polyols, glycerol, vegetable oils and the like, can be used for aqueous injection solutions of water-soluble salts of compounds of formula I, but as a rule are not necessary. Suitable carriers for suppositories are, for example, natural or hardened oils, waxes, fats, semi-liquid or liquid polyols and the like.
In addition, the pharmaceutical preparations can contain preservatives, solubilizers, stabilizers, wetting agents, emulsifiers, sweeteners, colorants, flavorants, salts for varying the osmotic pressure, buffers, masking agents or antioxidants. They can also contain still other therapeutically valuable substances.
Pharmaceutical compositions containing a compound of formula I, or a pharmaceutically-acceptable salt thereof, and a therapeutically inert excipient are also an object of the present invention, as is a process for the production of such a composition which comprises bringing one or more compounds of formula I, or pharmaceutically-acceptable salts thereof, and, if desired, one or more other therapeutically valuable substances into a galenical dosage form together with one or more therapeutically inert carriers such as those described above.
The compound of the present invention may be used in a method for treating or preventing cognitive disorders, drug addiction, depression, anxiety, drug dependence, dementias, memory impairment, psychotic disorders comprising schizophrenia, schizoaffective disorders, bipolar disease, mania, psychotic depression, or psychoses comprising paranoia and delusions. In such a method, the compound is administered to a patient in a therapeutically-effective amount. A “therapeutically-effective amount”, as used herein, means the amount of the subject compound or combination that will elicit the biological or medical response of a tissue, system, animal or human that is being sought by the researcher, veterinarian, medical doctor or other clinician. The amount can vary within wide limits and will, of course, be fitted to the individual requirements in each particular case. In general, the effective dosage for oral or parenteral administration of the compound is between 0.01-20 mg/kg/day, with a dosage of 0.1-10 mg/kg/day being preferred for all of the indications described. The daily dosage for an adult human being weighing 70 kg accordingly lies between 0.7-1400 mg per day, preferably between 7 and 700 mg per day.
EXAMPLES
The following examples are provided to further elucidate the invention.
Example 1
1H-Indole-2-carboxylic acid trans-(4-{2-[4-(4-fluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-amide
Intermediate C
1.1 4-(4-Fluoro-phenoxy)-piperidine 1-carboxylic acid tert-butyl ester
To a solution of triphenyl phosphine (7.7 g, 29 mmol), in tetrahydrofuran (40 mL), diethylazodicarboxylate (5.12 g, 29 mmol) was added and the solution was stirred for 20 minutes. 4-Fluorophenol (3 g, 27 mmol) was added and the mixture was stirred for another 20 minutes at 0° C. N—Boc-4-hydroxypiperidine (5.9 g, 29 mmol) was added dissolved in tetrahydrofuran (20 mL) and the mixture was stirred at room temperature overnight. Water was added and the solution was extracted three times with dichloromethane. The combined organic layers were washed with water and brine, dried over magnesium sulfate, filtered and evaporated. The crude product was purified by flash-chromatography on silica gel with hexane:ethyl acetate (1:0 to 1:1) to give 4.8 g (60%) of the product as a white solid. MS (m/e): 296.3 (M−H+).
Intermediate D
1.2 4-(4-Fluoro-phenoxy)-piperidine
2 g (7 mmol) of 4-(4-fluoro-phenoxy)-piperidine 1-carboxylic acid tert-butyl ester was solvated in dichloromethane (12 mL) and trifluoroacetic acid was added at 0° C. (6.17 mL, 54 mmol). The mixture was stirred at room temperature overnight. NaHCO3 was slowly added until pH 9 and the mixture extracted 3 times with dichloromethane and ethyl acetate. The solvent was evaporated to yield 1.81 g (58.5 mmol, 85%) of a white solid that was used without purification on the next steps. MS (m/e): 196.3 (M+H+).
1.3 trans-(4-{2-[4-(4-Fluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-carbamic acid tert-butyl ester
Intermediate G
trans-(4-Amino-cyclohexyl)-acetic acid ethyl ester
Step 1.
(4-Nitro-phenyl)-acetic acid (50 g, 276 mmol) was added to a stirred solution of 22.08 g of 50% sodium hydroxide solution in 450 mL deionizated water. The clear yellow solution was transferred into a high-pressure autoclave that it charged with 30 g (511 mmol) of water-wet sponge nickel catalyst. The autoclave was sealed, flushed with nitrogen and then pressurized to 115 bar with hydrogen. The reaction mixture was stirred and heated to 125° C. for 48 h. At that time the autoclave was cooled, vented and charged under nitrogen with another 30 g (511 mmol) of the sponge nickel catalyst. The autoclave was flushed again with nitrogen and then pressurized to 115 bar and the vessel was heated to 130° C. while stirring (a maximum pressure of 130 bars was observed). Hydrogenation was continued for 5 days to 130° C. The autoclave was then cooled, vented and flushed with nitrogen and the contents are removed and filtered through filter aid to remove catalyst. After removal of the solvent 74 g of crude material was obtained. The intermediated was used directly in the next step without purification. MS (m/e): 158.3 (M+H+).
Step 2
A solution of trans-(4-amino-cyclohexyl)-acetic acid (74 g, 476 mmol) was adjusted to pH 5 with 25% HCl. The mixture was evaporated to dryness and dried under vacuum overnight. The residue was suspended in 146 mL of a 6.5 N ethanolic HCl solution and 0.6 L of ethanol was added to the mixture. After 4 hours refluxing, the mixture was cooled and filtered and the filtrate was concentrated to dryness under vacuum. The residue was dissolved in ethanol, treated with ether and cooled overnight in the refrigerator to give trans-(4-amino-cyclohexyl)-acetic acid ethyl ester hydrochloride (19.7 g, 32% on the two steps) as a white solid which was filtered and dried under vacuum. MS (m/e): 186.1 (M+H+).
Intermediate H
Step 1
trans-(4-tert-Butoxycarbonylamino-cyclohexyl)-acetic acid ethyl ester
To a solution of trans-(4-amino-cyclohexyl)-acetic acid ethyl ester (1.28 g, 7 mmol), in dichloromethane (15 mL), di-tert-butyl-dicarbonate (2.26 g, 10 mmol), triethylamine (0.699 mL, 7 mmol) and 4-dimethylaminopyridine (0.042 mL, 0.35 mmol) were added. The mixture was stirred for 8 h until TLC indicated completion of the reaction. Water was added and the solution was extracted three times with dichloromethane. The combined organic layers were washed with water and brine, dried over magnesium sulfate, filtered and evaporated. The crude product was purified by flash-chromatography on silica gel with hexane:ethyl acetate (4:2 to 3:2) to give 1.2 g (60%) of the product as a white solid. MS (m/e): 284.4 (M−H+).
Step 2
trans-[4-(2-Oxo-ethyl)-cyclohexyl]-carbamic acid tert-butyl ester
To a solution of trans-(4-tert-butoxycarbonylamino-cyclohexyl)-acetic acid ethyl ester (1.04 g, 4 mmol), in toluene (10 mL) at −78° C. a 1.2 M solution of diisobutylaluminium hydride (DIBAL-H) (5.1 mL, 6 mmol) in toluene was added. The mixture was stirred at −78° C. until TLC after 0.5 h indicated completion of the reaction. Water was added and the solution was extracted three times with dichloromethane. The combined organic layers were washed with water and brine, dried over magnesium sulfate, filtered and evaporated. The crude product was used without purification on the next step. MS (m/e): 242.3 (M+H+).
Intermediate J
trans-(4-{2-[4-(4-Fluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-carbamic acid tert-butyl ester
A mixture of 4-(4-fluorophenoxy)piperidine (0.150 g, 0.485 mmol), trans-[4-(2-oxo-ethyl)-cyclohexyl]-carbamic acid tert-butyl ester (0.117 g, 0.48 mmol), in 1, 2 dichloroethane (3 mL) and methanol (0.500 mL) was stirred for 4 hours at room temperature. Sodium triacetoxyborohydride (0.175 g, 0.829 mmol) was added and the resulting solution was stirred for 12 hours until the TLC indicated completion of the reaction. The mixture was filtrated and concentrated to dryness and purified with column chromatography on silica gel using CH2Cl2-CH2Cl2/CH3OH (1-9:1). The product fractions were concentrated to give 0.176 g (0.45 mmol, 92.5% yield) of a light yellow solid. MS (m/e): 393.4 (M+H+).
Intermediate K
1.4 trans-4-{2-[4-(4-Fluoro-Phenoxy)-piperidin-1-yl]-ethyl}-cyclohexylamine trifluoroacetate
0.155 g (0.368 mmol) of trans-(4-{2-[4-(4-fluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-carbamic acid tert-butyl ester was solved in dichloromethane (2 mL) and trifluoroacetic acid was added at 0° C. (0.230 mL, 3 mmol) and the mixture was stirred at room temperature overnight. NaHCO3 was slowly added until pH 9 and the mixture extracted 3 times with dichloromethane and ethyl acetate. The solvent was evaporated to yield 0.160 g (0.368 mmol, 100%) of a white solid that was used without purification on the next steps. MS (m/e): 321.4 (M+H+).
1.5 1H-Indole-2-carboxylic acid trans-(4-{2-[4-(4-fluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-amide
The title compound was prepared as follows.
1H-Indole-2-carboxylic acid (0.006 g, 0.037 mmol), 2-(1H-benzotriazol-1-yl)-1,1,3,3-tetramethyl uronium tetrafluoroborate (0.011 g, 0.034 mmol) and (0.02 mL, 0.102 mmol) of N-ethyldiisopropylamine were stirred in 0.5 mL of dimethylformamide (DMF) for 0.5 h at room temperature and trans-4-{2-[4-(4-fluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexylamine trifluoro-acetic acid salt (0.015 g, 0.034 mmol) was added. The mixture was stirred for 12 hours at room temperature. The mixture was concentrated to dryness and the residue was taken up on methanol and purified with preparative HPLC on reversed phase eluting with acetonitrile/water. The combined product containing fractions were evaporated under reduced pressure to yield 0.009 g of an off-white solid (0.019 mmol, 52.4%). MS (m/e): 464.2 (M+H+).
Examples 2 to 7
According to the procedure described in Section 1.5 above, further derivatives have been synthesized from the respective trans-4-{2-[4-(4-fluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexylamine and various acids. They comprise examples 2 to 7.


















MW


Ex. No
Systematic name
MW
Starting materials
found (M + H)+



















1
1H-Indole-2-
463.5
trans-4-{2-[4-(4-Fluoro-
464.2



carboxylic acid trans-

phenoxy)-piperidin-1-



(4-{2-[4-(4-fluoro-

yl]-ethyl}-



phenoxy)-piperidin-1-

cyclohexylamine and



yl]-ethyl}-

1H-Indole-2-carboxylic



cyclohexyl)-amide

acid


2
Tetrahydro-pyran-4-
432.6
trans-4-{2-[4-(4-Fluoro-
433.4



carboxylic acid (trans-

phenoxy)-piperidin-1-



4-{2-[4-(4-fluoro-

yl]-ethyl}-



phenoxy)-piperidin-1-

cyclohexylamine and



yl]-ethyl}-

tetrahydro-pyran-4-



cyclohexyl)-amide

carboxylic acid


3
N-(trans-4-{2-[4-(4-
406.53
trans-4-{2-[4-(4-Fluoro-
407.4



Fluoro-phenoxy)-

phenoxy)-piperidin-1-



piperidin-1-yl]-ethyl}-

yl]-ethyl}-



cyclohexyl)-3-

cyclohexylamine and



methoxy-

3-methoxy-propionic



propionamide

acid


4
4-Chloro-N-trans (4-
459.0
trans-4-{2-[4-(4-Fluoro-
459.4



{2-[4-(4-fluoro-

phenoxy)-piperidin-1-



phenoxy)-piperidin-1-

yl]-ethyl}-



yl]-ethyl}-

cyclohexylamine and 4-



cyclohexyl)-

chloro benzoic acid



benzamide


5
N-trans (4-{2-[4-(4-
506.6
trans-4-{2-[4-(4-Fluoro-
507.2



Fluoro-phenoxy)-

phenoxy)-piperidin-1-



piperidin-1-yl]-ethyl}-

yl]-ethyl}-



cyclohexyl)-3-(5-

cyclohexylamine and



methyl-

3-(5-methyl-1,2,4-



[1,2,4]oxadiazol-3-yl)-

oxadiazol-3-yl)-benzoic



benzamide

acid


6
Cyclopropanecarboxylic
388.5
trans 4-{2-[4-(4-Fluoro-
389.3



acid (trans-4-{2-[4-

phenoxy)-piperidin-1-



(4-fluoro-phenoxy)-

yl]-ethyl}-



piperidin-1-yl]-ethyl}-

cyclohexylamine and



cyclohexyl)-amide

Cyclopropanecarboxylic





acid


7
N-(4-{2-[4-(4-Fluoro-
502.6
Trans 4-{2-[4-(4-
503.1



phenoxy)-piperidin-1-

Fluoro-phenoxy)-



yl]-ethyl}-

piperidin-1-yl]-ethyl}-



cyclohexyl)-4-

cyclohexylamine and



methanesulfonyl-

4-methanesulfonyl-



benzamide

benzoic acid









Example 8
Trans N-(4-{2-[4-(4-Fluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-acetamide
The title compound was prepared as follows.
Trans-4-{2-[4-(4-Fluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexylamine (intermediate K, example 1.4) (0.120 g, 0.276 mmol) was suspended in dichloromethane (2.4 mL) and triethylamine was added (0.964 mL, 0.690 mmol) followed by acetylchloride (0.021 mL, 0.303 mmol) and the mixture was stirred for 2 hours at room temperature until thin layer chromatography (TLC) indicated the end of the reaction. The solvent was removed and dimethylformamide (DMF) (0.8 mL) was added and the solution was purified with preparative HPLC on reversed phase eluting with acetonitrile/water (0.05% Et3N). The combined product fractions were evaporated under reduced pressure to yield 0.016 g of an off-white solid (0.045 mmol, 16.3%). MS (m/e): 363.3 (M+H+)
Example 9
Trans-1-(4-Chloro-phenyl)-3-(4-{2-[4-(4-fluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-urea
The title compound was prepared as follows.
Trans-4-{2-[4-(4-Fluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexylamine, trifluoroacetic acid salt (intermediate K, example 1.4) (0.030 g, 0.07 mmol) was suspended in acetonitrile (0.600 mL) and 4-chlorophenyl isocyanate was added (0.012 g, 0077 mmol) and the mixture was stirred for 2 hours at room temperature until thin layer chromatography (TLC) indicated the end of the reaction. The solvent was removed and the crude was purified with chromatography eluting with dichloromethane/methanol (1/0 to 9/1). The combined product fractions were evaporated under reduced pressure to yield 0.020 g of a white solid (0.042 mmol, 60%). MS (m/e): 474.1 (M+H+)
Example 10
Trans-1-(4-{2-[4-(4-Fluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-3-p-tolyl-urea
According to the procedure described for the synthesis of example 9, 1-Trans(4-{2-[4-(4-Fluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-3-p-tolyl-urea was synthesized from Trans-{1-[2-(4-Amino-cyclohexyl)-ethyl]-piperidin-4-yl}-(4-fluoro-phenyl)-methanone and p-tolyl isocyanate.


















MW


Ex.



found


No
Systematic name
MW
Starting materials
(M + H)+



















9
1-(4-Chloro-phenyl)-3-
474.02
Trans-4-{2-[4-(4-
474.1



trans (4-{2-[4-(4-

Fluoro-phenoxy)-



fluoro-phenoxy)-

piperidin-1-yl]-ethyl}-



piperidin-1-yl]-ethyl}-

cyclohexylamine and



cyclohexyl)-urea

4-chlorophenyl





isocyanate


10
1-Trans (4-{2-[4-(4-
453.6
Trans-4-{2-[4-(4-
454.5



Fluoro-phenoxy)-

Fluoro-phenoxy)-



piperidin-1-yl]-ethyl}-

piperidin-1-yl]-ethyl}-



cyclohexyl)-3-p-tolyl-

cyclohexylamine and



urea

p-tolyl-isocyanate









Example 11
Quinoline-4-carboxylic acid trans(4-{2[4-(2-chloro-4-fluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-amide
Intermediate J
11.3 Trans(4-{2-[4-(2-Chloro-4-fluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-carbamic acid tert-butyl ester
According to the synthesis of intermediate J, example 1, the title compound was prepared from 4-(2,3-Dichloro-phenoxy)-piperidine (intermediate D, example 1.2) (0.600 g, 1.7 mmol), Trans-[4-(2-Oxo-ethyl)-cyclohexyl]-carbamic acid tert-butyl ester (0.506 g, 2 mmol) (intermediate H, example 1) and sodium triacetoxyborohydride (0.666 g, 3 mmol) in 1,2-dichloroethane (8 mL). The mixture was filtrated and concentrated to dryness and purified with column chromatography on silica gel using CH2Cl2-CH2Cl2/CH3OH (1-9:1). The product fractions were concentrated to give 0.696 g (1.53 mmol, 87.5% yield) of a light yellow solid. MS (m/e): 467.3 (M+H+).
Intermediate K
11.4 Trans 4-{2-[4-(2-Chloro-4-fluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexylamine; trifluoro-acetic acid salt
According to the synthesis of intermediate K, example 1.4, the title compound was prepared from 0.695 g (1.48 mmol) of Trans(4-{2-[4-(2-Chloro-4-fluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-carbamic acid tert-butyl ester in dichloromethane (8 mL) and trifluoroacetic acid (1.05 mL, 14 mmol) to yield 0.603 g (1.3 mmol, 84.1%) of the title compound as a white solid that was used without purification on the next steps. MS (m/e): 355.3 (M+H+).
11.5 Quinoline-4-carboxylic acid trans(4-{2[4-(2-chloro-4-fluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-amide
The title compound was prepared as follows.
Quinoline-4-carboxylic acid (0.020 g, 0.115 mmol), 2-(1H-benzotriazol-1-yl)-1,1,3,3-tetramethyl uronium tetrafluoroborate (0.035 g, 0.106 mmol) and (0.05 mL, 0.318 mmol) of N-ethyldiisopropylamine were stirred in 0.5 mL of dimethylformamide (DMF) for 0.5 h at room temperature and Trans-4-{2-[4-(4-Fluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexylamine; trifluoro-acetic acid salt (0.050 g, 0.106 mmol) was added. The mixture was stirred for 12 hours at room temperature. The mixture was concentrated to dryness and the residue was taken up on methanol and purified with preparative HPLC on reversed phase eluting with acetonitrile/water. The combined product fractions were evaporated under reduced pressure to yield 0.054 g of a off-white solid (0.101 mmol, 54.9%). MS (m/e): 510.2 (M+H+).
Examples 12 to 18
According to the procedure described for the synthesis of example 11.5, further derivatives have been synthesized from Trans-4-{2-[4-(2-Chloro-4-fluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexylamine; trifluoro-acetic acid salt and various acids. They comprise examples 12 to 18


















MW


Ex. No
Systematic name
MW
Starting materials
found (M + H)+



















11
Quinoline-4-
510.2
Trans4-{2-[4-(2-
510.4



carboxylic acid

Chloro-4-fluoro-



trans(4-{2[4-(2-

phenoxy)-piperidin-1-



chloro-4-fluoro-

yl]-ethyl}-



phenoxy)-piperidin-1-

cyclohexylamine and



yl]-ethyl}-

Quinoline-4-carboxylic



cyclohexyl)-amide

acid


12
N-trans(4-{2-[4-(2-
537.09
Trans 4-{2-[4-(2-
538.2



Chloro-4-fluoro-

Chloro-4-fluoro-



phenoxy)-piperidin-1-

phenoxy)-piperidin-1-



yl]-ethyl}-

yl]-ethyl}-



cyclohexyl)-4-

cyclohexylamine and



methanesulfonyl-

4-methanesulfonyl-



benzamide

benzoic acid


13
N-trans (4-{2-[4-(2-
440.9
Trans 4-{2-[4-(2-
441.0



Chloro-4-fluoro-

Chloro-4-fluoro-



phenoxy)-piperidin-1-

phenoxy)-piperidin-1-



yl]-ethyl}-

yl]-ethyl}-



cyclohexyl)-3-

cyclohexylamine and



methoxy-

3-Methoxy-propionic



propionamide

acid


14
4-Chloro-N-trans (4-
493.45
Trans 4-{2-[4-(2-
493.1



{2-[4-(2-chloro-4-

Chloro-4-fluoro-



fluoro-phenoxy)-

phenoxy)-piperidin-1-



piperidin-1-yl]-ethyl}-

yl]-ethyl}-



cyclohexyl)-

cyclohexylamine and



benzamide

4-Chloro benzoic acid


15
Tetrahydro-pyran-4-
467.02
Trans 4-{2-[4-(2-
467.0



carboxylic acid trans

Chloro-4-fluoro-



(4-{2-[4-(2-chloro-4-

phenoxy)-piperidin-1-



fluoro-phenoxy)-

yl]-ethyl}-



piperidin-1-yl]-ethyl}-

cyclohexylamine and



cyclohexyl)-amide

Tetrahydro-pyran-4-





carboxylic acid


16
N-trans (4-{2-[4-(2-
541.06
Trans 4-{2-[4-(2-
541.1



Chloro-4-fluoro-

Chloro-4-fluoro-



phenoxy)-piperidin-1-

phenoxy)-piperidin-1-



yl]-ethyl}-

yl]-ethyl}-



cyclohexyl)-3-(5-

cyclohexylamine and



methyl-

3-(5-methyl-



[1,2,4]oxadiazol-3-yl)-

[1,2,4]oxadiazol-3-yl)-



benzamide

benzoic acid


17
Cyclopropanecarboxylic
422.9
Trans 4-{2-[4-(2-
423.3



acid trans (4-{2-[4-

Chloro-4-fluoro-



(2-chloro-4-fluoro-

phenoxy)-piperidin-1-



phenoxy)-piperidin-1-

yl]-ethyl}-



yl]-ethyl}-

cyclohexylamine and



cyclohexyl)-amide

Cyclopropanecarboxylic





acid


18
N-trans (4-{2-[4-(2-
410.9
Trans 4-{2-[4-(2-
411.0



Chloro-4-fluoro-

Chloro-4-fluoro-



phenoxy)-piperidin-1-

phenoxy)-piperidin-1-



yl]-ethyl}-

yl]-ethyl}-



cyclohexyl)-

cyclohexylamine and



propionamide

propionic acid









Example 19
N-trans(4-{2-[4-(2-Chloro-4-fluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-acetamide
According to the synthesis of N-Trans(4-{2-[4-(4-Fluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-acetamide (example 8), the title compound was prepared from Trans 4-{2-[4-(2-Chloro-4-fluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexylamine and acetylchloride MS (m/e): 397.0 (M+H+).
Example 20
Trans 1-(4-{2-[4-(2-Chloro-4-fluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-3-(4-chloro-phenyl)-urea
According to the synthesis of Trans 1-(4-Chloro-phenyl)-3-(4-{2-[4-(4-fluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-urea (example 9) the title compound was prepared from Trans 1-(4-{2-[4-(2-Chloro-4-fluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexylamine and 4-chlorophenyl isocyanate. MS (m/e): 508.3 (M+H+).
Example 21
1-trans(4-{2-[4-(2-Chloro-4-fluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-3-p-tolyl-urea
According to the procedure described for the synthesis of example 20, the title compound was synthesized from Trans-1-(4-{2-[4-(2-Chloro-4-fluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexylamine and p-tolyl-isocyanate.


















MW


Ex.



found


No
Systematic name
MW
Starting materials
(M + H)+



















20
1-trans (4-{2-[4-(2-
508.4
Trans 4-{2-[4-(2-
508.3



Chloro-4-fluoro-

Chloro-4-fluoro-



phenoxy)-piperidin-1-

phenoxy)-piperidin-1-



yl]-ethyl}-cyclohexyl)-

yl]-ethyl}-



3-(4-chloro-phenyl)-

cyclohexylamine and



urea

4-chlorophenyl





isocyanate


21
1-trans (4-{2-[4-(2-
488.05
Trans-4-{2-[4-(4-
488.2



Chloro-4-fluoro-

Fluoro-phenoxy)-



phenoxy)-piperidin-1-

piperidin-1-yl]-ethyl}-



yl]-ethyl}-cyclohexyl)-

cyclohexylamine and



3-p-tolyl-urea

p-tolyl-isocyanate









Example 22
Tetrahydro-pyran-4-carboxylic acid trans(4-{2-[4-(2,4-difluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-amide
Intermediate J
22.3 Trans(4-{2-[4-(2,4-Difluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-carbamic acid tert-butyl ester
According to the synthesis of Trans-(4-{2-[4-(4-Fluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-carbamic acid tert-butyl ester (intermediate J, example 1.3) the title compound was prepared from (2,4-Difluoro-phenoxy)-piperidine and Trans-[4-(2-Oxo-ethyl)-cyclohexyl]-carbamic acid tert-butyl ester with sodium triacetoxyborohydride in 1,2-dichloroetane. MS (m/e): 439.4 (M+H+).
Intermediate K
22.4 Trans 4-{2-[4-(2,4-Difluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexylamine; compound with trifluoro-acetic acid
According to the synthesis of Trans 4-{2-[4-(4-Difluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexylamine (example 1.4) the title compound was prepared from Trans(4-{2-[4-(2,4-Difluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-carbamic acid tert-butyl ester and trifluoroacetic acid. MS (m/e): 339.3 (M+H+).
22.5 Tetrahydro-pyran-4-carboxylic acid trans(4-{2-[4-(2,4-difluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-amide
According to the synthesis of 1H-Indole-2-carboxylic acid trans-(4-{2-[4-(4-fluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-amide (example 1) the title compound was prepared from Trans(4-{2-[4-(2,4-Difluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexylamine; trifluoro-acetic acid salt and Tetrahydro-pyran-4-carboxylic acid using 2-(1H-benzotriazol-1-yl)-1,1,3,3-tetramethyl uronium tetrafluoroborate and N-ethyldiisopropylamine in dimethylformamide (DMF). The residue was taken up on methanol and purified with preparative HPLC on reversed phase eluting with acetonitrile/water. MS (m/e): 451.3. (M+H+).
Example 23
Quinoline-6-carboxylic acid trans(4-{2-[4-(2,4-difluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-amide
According to the procedure described in Example 22.5, the title compound was synthesized from Trans(4-{2-[4-(2,4-Difluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexylamine; trifluoro-acetic acid salt and quinoline-6-carboxylic acid.
Example 24
Quinoline-4-carboxylic acid trans(4-{2-[4-(2,4-difluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-amide
According to the procedure described in Example 22.5, the title compound was synthesized from Trans(4-{2-[4-(2,4-Difluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexylamine; trifluoro-acetic acid salt and quinoline-4-carboxylic acid.














Ex.



MW found


No
Systematic name
MW
Starting materials
(M + H)+



















22
Tetrahydro-pyran-4-
450.5
Trans (4-{2-[4-(2,4-
451.3



carboxylic acid trans

Difluoro-phenoxy)-



(4-{2-[4-(2,4-difluoro-

piperidin-1-yl]-ethyl}-



phenoxy)-piperidin-1-

cyclohexylamine;



yl]-ethyl}-

trifluoroacetic acid salt



cyclohexyl)-amide

and Tetrahydro-pyran-





4-carboxylic acid


23
Quinoline-6-
493.6
Trans (4-{2-[4-(2,4-
494.5



carboxylic acid trans

Difluoro-phenoxy)-



(4-{2-[4-(2,4-difluoro-

piperidin-1-yl]-ethyl}-



phenoxy)-piperidin-1-

cyclohexylamine;



yl]-ethyl}-

trifluoroacetic acid salt



cyclohexyl)-amide

and Quinoline-6-





carboxylic acid


24
Quinoline-4-
493.5
Trans (4-{2-[4-(2,4-
494.4



carboxylic acid trans

Difluoro-phenoxy)-



(4-{2-[4-(2,4-difluoro-

piperidin-1-yl]-ethyl}-



phenoxy)-piperidin-1-

cyclohexylamine;



yl]-ethyl}-

trifluoroacetic acid salt



cyclohexyl)-amide

and Quinoline-4-





carboxylic acid









Example 25
N-Trans(4-{2-[4-(2,4-Difluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-acetamide
According to the synthesis of N-Trans(4-{2-[4-(4-Fluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-acetamide (example 8), the title compound was prepared from Trans(4-{2-[4-(2,4-Difluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexylamine; trifluoroacetic acid salt and acetylchloride MS (m/e): 381.3 (M+H+).
Example 26
Cyclobutanecarboxylic acid trans(4-{2-[4-(2-cyano-4-fluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-amide
Intermediate C
26.1 4-(2-Cyano-4-fluoro-phenoxy)-piperidine-1-carboxylic acid tert-butyl ester
The title compound was prepared a follows.
2-5-Difluorobenzonitrile (1.00 g, 7.2 mmol) was added at room temperature to a stirred mixture under argon of sodium hydride (55%, 207 mg, 9 mmol) in dimethylformamide (DMF) (10 ml). 4-Hydroxypiperidine-1-carboxylic acid tert-butyl ester (3.32 g, 17 mmol) was added in portions. The resulting mixture was stirred several hours at 50° C. before partitioning it between H2O and ethyl acetate (EtOAc). The organic layer was washed with sat. aq. NH4Cl sol. and brine and dried over MgSO4. Evaporation of the solvent yielded 2.24 g (97.2%, 7 mmol) of a light brown solid. MS (m/z): 321.1 (M+H+).
Intermediate D
26.2 5-Fluoro-2-(piperidin-4-yloxy)-benzonitrile; hydrochloride
The title compound was prepared as follows.
A solution 4-(2-Cyano-4-fluoro-phenoxy)-piperidine-1-carboxylic acid tert-butyl ester (2.2 g, 0.7 mmol) in CH2Cl2 (20 ml) was treated with sat. HCl sol. in diethyl ether (Et2O) (10 ml). After 3 hours, the formed solid was collected by filtration and washed with Et2O to yield 1.7 g (95%, 0.68 mmol) of a light brown solid. MS (m/z): 221.3 (M+H+)
26.3 Trans(4-{2-[4-(2-Cyano-4-fluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-carbamic acid tert-butyl ester
The title compound was prepared analogously to example 1 (1.3) starting from 5-Fluoro-2-(piperidin-4-yloxy)-benzonitrile; hydrochloride and Trans-[4-(2-Oxo-ethyl)-cyclohexyl]-carbamic acid tert-butyl ester with sodium triacetoxyborohydride in 1,2-dichloroetane. MS (m/e): 446.3 (M+H+)
26.4 Trans 2-{1-[2-(4-Amino-cyclohexyl)-ethyl]-piperidin-4-yloxy}-5-fluoro-benzonitrile; compound with trifluoro-acetic acid
The title compound was prepared analogously to example 1 (1.4) starting from Trans(4-{2-[4-(2-Cyano-4-fluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-carbamic acid tert-butyl ester and trifluoroacetic acid MS (m/e): 346.2 (M+H+).
26.5 Cyclobutanecarboxylic acid (4-{2-[4-(2-cyano-4-fluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-amide
The title compound was prepared analogously to example 1 (1.5) from Trans 2-{1-[2-(4-Amino-cyclohexyl)-ethyl]-piperidin-4-yloxy}-5-fluoro-benzonitrile; trifluoro-acetic acid salt and cyclobutanecarboxylic acid using 2-(1H-benzotriazol-1-yl)-1,1,3,3-tetramethyl uronium tetrafluoroborate and N-ethyldiisopropylamine in dimethylformamide (DMF). The residue was taken up on methanol and purified with preparative HPLC on reversed phase eluting with acetonitrile/water. MS (m/e): 428.0. (M+H+).
Examples 27 to 33
Using the procedure described in example 26.5, further derivatives have been synthesized from Trans 2-{1-[2-(4-Amino-cyclohexyl)-ethyl]-piperidin-4-yloxy}-5-fluoro-benzonitrile and various acids. They comprise examples 27 to 33.


















MW






found


Ex.



(M +


No
Systematic name
MW
Starting materials
H)+



















26
Cyclobutanecarboxylic
427.5
Trans 2-{1-[2-(4-
428.0



acid trans (4-{2-[4-(2-

Amino-cyclohexyl)-



cyano-4-fluoro-

ethyl]-piperidin-4-



phenoxy)-piperidin-1-

yloxy}-5-fluoro-



yl]-ethyl}-

benzonitrile and



cyclohexyl)-amide

Cyclobutanecarboxylic





acid


27
Tetrahydro-pyran-4-
457.5
Trans 2-{1-[2-(4-
458.3



carboxylic acid trans

Amino-cyclohexyl)-



(4-{2-[4-(2-cyano-4-

ethyl]-piperidin-4-



fluoro-phenoxy)-

yloxy}-5-fluoro-



piperidin-1-yl]-ethyl}-

benzonitrile and



cyclohexyl)-amide

Tetrahydro-pyran-4-





carboxylic acid


28
4-Chloro-N-trans (4-
484.0
Trans 2-{1-[2-(4-
484.3



{2-[4-(2-cyano-4-

Amino-cyclohexyl)-



fluoro-phenoxy)-

ethyl]-piperidin-4-



piperidin-1-yl]-ethyl}-

yloxy}-5-fluoro-



cyclohexyl)-

benzonitrile and 4-



benzamide

Chloro benzoic acid


29
N-Trans (4-{2-[4-(2-
479.6
Trans 2-{1-[2-(4-
480.3



Cyano-4-fluoro-

Amino-cyclohexyl)-



phenoxy)-piperidin-1-

ethyl]-piperidin-4-



yl]-ethyl}-

yloxy}-5-fluoro-



cyclohexyl)-4-

benzonitrile and 4-



methoxy-benzamide

Methoxy-benzoic acid


30
N-Trans (4-{2-[4-(2-
413.5
Trans 2-{1-[2-(4-
414.3



Cyano-4-fluoro-

Amino-cyclohexyl)-



phenoxy)-piperidin-1-

ethyl]-piperidin-4-



yl]-ethyl}-

yloxy}-5-fluoro-



cyclohexyl)-3-

benzonitrile and 3-



methoxy-

Methoxy-propionic acid



propionamide


31
Cyclopropanecarboxylic
431.5
Trans 2-{1-[2-(4-
432.2



acid trans (4-{2-[4-

Amino-cyclohexyl)-



(2-cyano-4-fluoro-

ethyl]-piperidin-4-



phenoxy)-piperidin-1-

yloxy}-5-fluoro-



yl]-ethyl}-

benzonitrile and



cyclohexyl)-amide

Cyclopropanecarboxylic





acid


32
2-Methyl-
427.5
Trans 2-{1-[2-(4-
428.4



cyclopropanecarboxylic

Amino-cyclohexyl)-



acid trans (4-{2-[4-

ethyl]-piperidin-4-



(2-cyano-4-fluoro-

yloxy}-5-fluoro-



phenoxy)-piperidin-1-

benzonitrile and 2-



yl]-ethyl}-

Methyl-



cyclohexyl)-amide

cyclopropanecarboxylic


33
Thiophene-2-
455.6
Trans 2-{1-[2-(4-
456.3



carboxylic acid trans

Amino-cyclohexyl)-



(4-{2-[4-(2-cyano-4-

ethyl]-piperidin-4-



fluoro-phenoxy)-

yloxy}-5-fluoro-



piperidin-1-yl]-ethyl}-

benzonitrile and



cyclohexyl)-amide

Thiophene-2-carboxylic





acid









Example 34
Trans N-(4-{2-[4-(2-Cyano-4-fluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-acetamide
According to the synthesis of N-Trans(4-{2-[4-(4-Fluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-acetamide (example 8), the title compound was prepared from Trans 2-{1-[2-(4-Amino-cyclohexyl)-ethyl]-piperidin-4-yloxy}-5-fluoro-benzonitrile; trifluoroacetic acid salt and acetylchloride MS (m/e): 381.3 (M+H+).
Example 35
Trans N-(4-{2-[4-(2-Cyano-4-fluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-2,2,2-trifluoro-acetamide
The title compound was obtained as a by-product from the reaction of Trans(4-{2-[4-(2-cyano-4-fluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-amine; trifluoroacetic acid salt and acetylchloride (example 34) MS (m/e): 442.3 (M+H+).
Example 36
Cyclobutanecarboxylic acid trans(4-{2-[4-(2,3-dichloro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-amide
According to the synthesis of 1H-Indole-2-carboxylic acid trans-(4-{2-[4-(4-fluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-amide (example 1) the title compound was prepared from Trans(4-{2-[4-(2,3-dichloro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-amine and Cyclobutanecarboxylic acid using 2-(1H-benzotriazol-1-yl)-1,1,3,3-tetramethyl uronium tetrafluoroborate and N-ethyldiisopropylamine in dimethylformamide (DMF). The residue was taken up on methanol and purified with preparative HPLC on reversed phase eluting with acetonitrile/water. MS (m/e): 453.0. (M+H+).
Examples 37 to 39
Using the same procedure as in Example 36, further derivatives have been synthesized from Trans(4-{2-[4-(2,3-dichloro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-amine and various acids. They comprise examples 37 to 39.


















MW


Ex.



found


No
Systematic name
MW
Starting materials
(M + H)+



















36
Cyclobutanecarboxylic
453.4
Trans (4-{2-[4-(2,3-
453.0



acid trans (4-{2-[4-

dichloro-phenoxy)-



(2,3-dichloro-

piperidin-1-yl]-ethyl}-



phenoxy)-piperidin-1-

cyclohexyl)-amine and



yl]-ethyl}-cyclohexyl)-

Cyclobutanecarboxylic



amide

acid


37
Trans N-(4-{2-[4-(2,3-
457.4
Trans (4-{2-[4-(2,3-
457.2



Dichloro-phenoxy)-

dichloro-phenoxy)-



piperidin-1-yl]-ethyl}-

piperidin-1-yl]-ethyl}-



cyclohexyl)-3-

cyclohexyl)-amine and



methoxy-propionamide

3-methoxy-propionic





acid


38
Thiophene-2-
481.4
Trans (4-{2-[4-(2,3-
481.1



carboxylic acid trans

dichloro-phenoxy)-



(4-{2-[4-(2,3-dichloro-

piperidin-1-yl]-ethyl}-



phenoxy)-piperidin-1-

cyclohexyl)-amine and



yl]-ethyl}-cyclohexyl)-

Thiophene-2-carboxylic



amide

acid


39
Tetrahydro-pyran-4-
483.4
Trans (4-{2-[4-(2,3-
483.3



carboxylic acid trans

dichloro-phenoxy)-



(4-{2-[4-(2,3-dichloro-

piperidin-1-yl]-ethyl}-



phenoxy)-piperidin-1-

cyclohexyl)-amine and



yl]-ethyl}-cyclohexyl)-

Tetrahydro-pyran-4-



amide

carboxylic acid









Example 40
N-Trans(4-{2-[4-(2,3-Dichloro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-acetamide
According to the synthesis of N-Trans(4-{2-[4-(4-Fluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-acetamide (example 8), the title compound was prepared from the reaction of Trans(4-{2-[4-(2,3-dichloro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-amine and acetylchloride. MS (m/e): 415.3 (M+H+).
Example 41
Cyclobutanecarboxylic acid trans(4-{2-[4-(2,6-dichloro-4-fluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-amide
According to the synthesis of example 1 the title compound was prepared from Trans(4-{2-[4-(2,6-dichloro-4-fluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-amine and cyclobutanecarboxylic acid. Preparative HPLC on reversed phase eluting with acetonitrile/water yielded the title compound. MS (m/e): 471.0 (M+H+).
Examples 42 to 45
Using the same procedure as in example 45 further derivatives have been synthesized from Trans(4-{2-[4-(2,6-dichloro-4-fluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-amine and various acids. They comprise examples 42 to 45.


















MW


Ex.



found


No
Systematic name
MW
Starting materials
(M + H)+



















41
Cyclobutanecarboxylic
471.4
Trans (4-{2-[4-(2,6-
471.0



acid trans (4-{2-[4-

dichloro-4-fluoro-



(2,3-dichloro-

phenoxy)-piperidin-1-



phenoxy)-piperidin-1-

yl]-ethyl}-cyclohexyl)-



yl]-ethyl}-cyclohexyl)-

amine and



amide

Cyclobutanecarboxylic





acid.


42
Tetrahydro-furan-2-
487.4
Trans (4-{2-[4-(2,6-
487.2



carboxylic acid trans

dichloro-4-fluoro-



(4-{2-[4-(2,6-dichloro-

phenoxy)-piperidin-1-



4-fluoro-phenoxy)-

yl]-ethyl}-cyclohexyl)-



piperidin-1-yl]-ethyl}-

amine and Tetrahydro-



cyclohexyl)-amide

furan-2-carboxylic acid


43
Tetrahydro-pyran-4-
501.4
Trans (4-{2-[4-(2,6-
501.4



carboxylic acid trans

dichloro-4-fluoro-



(4-{2-[4-(2,6-dichloro-

phenoxy)-piperidin-1-



4-fluoro-phenoxy)-

yl]-ethyl}-cyclohexyl)-



piperidin-1-yl]-ethyl}-

amine and Tetrahydro-



cyclohexyl)-amide

pyran-4-carboxylic acid


44
N-trans (4-{2-[4-(2,6-
475.4
Trans (4-{2-[4-(2,6-
475.1



Dichloro-4-fluoro-

dichloro-4-fluoro-



phenoxy)-piperidin-1-

phenoxy)-piperidin-1-



yl]-ethyl}-cyclohexyl)-

yl]-ethyl}-cyclohexyl)-



3-methoxy-

amine and 3-methoxy-



propionamide

propionic acid


45
Thiophene-2-
499.4
Trans (4-{2-[4-(2,6-
499.4



carboxylic acid trans

dichloro-4-fluoro-



(4-{2-[4-(2,6-dichloro-

phenoxy)-piperidin-1-



4-fluoro-phenoxy)-

yl]-ethyl}-cyclohexyl)-



piperidin-1-yl]-ethyl}-

amine and Thiophene-



cyclohexyl)-amide

2-carboxylic acid









Example 46
N-Trans(4-{2-[4-(2,6-Dichloro-4-fluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-acetamide
According to the synthesis of N-Trans(4-{2-[4-(4-Fluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-acetamide (example 8), the title compound was prepared from Trans(4-{2-[4-(2,6-dichloro-4-fluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-amine and acetylchloride. MS (m/e): 432.3 (M+H+).
Example 47
Cyclobutanecarboxylic acid trans(4-{2-[4-(2,4,6-trifluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-amide
According to the synthesis of example 19 the title compound was prepared from Trans(4-{2-[4-(2,4,6-trifluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-amine and Cyclobutanecarboxylic acid. Preparative HPLC on reversed phase eluting with acetonitrile/water yielded the title compound. MS (m/e): 439.0 (M+H+).
Examples 48 to 50
Using the same procedure as in Example 47, further derivatives have been synthesized from. Trans(4-{2-[4-(2,4,6-trifluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-amine and various acids. They comprise examples 48 to 50.


















MW


Ex.



found


No
Systematic name
MW
Starting materials
(M + H)+



















47
Cyclobutanecarboxylic
438.5
Trans (4-{2-[4-(2,4,6-
439.0



acid trans (4-{2-[4-

trifluoro-phenoxy)-



(2,3-dichloro-

piperidin-1-yl]-ethyl}-



phenoxy)-piperidin-1-

cyclohexyl)-amine and



yl]-ethyl}-cyclohexyl)-

Cyclobutanecarboxylic



amide

acid


48
Tetrahydro-furan-2-
454.5
Trans (4-{2-[4-(2,4,6-
455.4



carboxylic acid trans

trifluoro-phenoxy)-



(4-{2-[4-(2,4,6-

piperidin-1-yl]-ethyl}-



trifluoro-phenoxy)-

cyclohexyl)-amine and



piperidin-1-yl]-ethyl}-

Tetrahydro-furan-2-



cyclohexyl)-amide

carboxylic acid


49
4-Methoxy-N-trans (4-
490.5
Trans (4-{2-[4-(2,4,6-
491.2



{2-[4-(2,4,6-trifluoro-

trifluoro-phenoxy)-



phenoxy)-piperidin-1-

piperidin-1-yl]-ethyl}-



yl]-ethyl}-cyclohexyl)-

cyclohexyl)-amine and



benzamide

4-Methoxy benzoic





acid


50
4-Chloro-N-trans (4-
494.9
Trans (4-{2-[4-(2,4,6-
495.2



{2-[4-(2,4,6-trifluoro-

trifluoro-phenoxy)-



phenoxy)-piperidin-1-

piperidin-1-yl]-ethyl}-



yl]-ethyl}-cyclohexyl)-

cyclohexyl)-amine and



benzamide

4-Chloro benzoic acid









Example 51
Tetrahydro-pyran-4-carboxylic acid trans(4-{2-[4-(2,4,5-trifluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-amide
According to the synthesis of example 19 the title compound was prepared from Trans(4-{2-[4-(2,4,5-trifluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-amine and tetrahydro-pyran-4-carboxylic acid. Preparative HPLC on reversed phase eluting with acetonitrile/water yielded the title compound. MS (m/e): 469.5 (M+H+).
Examples 52 to 56
Using the same procedure as in example 51, further derivatives have been synthesized using Trans(4-{2-[4-(2,4,5-trifluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-amine and various acids. They comprise examples 52 to 56.


















MW






found


Ex.



(M +


No
Systematic name
MW
Starting materials
H)+



















51
Tetrahydro-pyran-4-
468.5
Trans (4-{2-[4-(2,4,5-
469.5



carboxylic acid trans

trifluoro-phenoxy)-



(4-{2-[4-(2,4,5-

piperidin-1-yl]-ethyl}-



trifluoro-phenoxy)-

cyclohexyl)-amine and



piperidin-1-yl]-ethyl}-

Tetrahydro-pyran-4-



cyclohexyl)-amide

carboxylic acid


52
Cyclobutanecarboxylic
438.5
Trans (4-{2-[4-(2,4,5-
439.0



acid trans (4-{2-[4-

trifluoro-phenoxy)-



(2,4,5-trifluoro-

piperidin-1-yl]-ethyl}-



phenoxy)-piperidin-1-

cyclohexyl)-amine and



yl]-ethyl}-

Cyclobutanecarboxylic



cyclohexyl)-amide

acid


53
2-Methyl-
438.5
Trans (4-{2-[4-(2,4,5-
439.5



cyclopropanecarboxylic

trifluoro-phenoxy)-



acid trans (4-{2-[4-

piperidin-1-yl]-ethyl}-



(2,4,5-trifluoro-

cyclohexyl)-amine and



phenoxy)-piperidin-1-

2-Methyl-



yl]-ethyl}-

cyclopropanecarboxylic



cyclohexyl)-amide

acid


54
4-Methoxy-N-trans
490.5
Trans (4-{2-[4-(2,4,5-
491.2



(4-{2-[4-(2,4,5-

trifluoro-phenoxy)-



trifluoro-phenoxy)-

piperidin-1-yl]-ethyl}-



piperidin-1-yl]-ethyl}-

cyclohexyl)-amine and



cyclohexyl)-

4-Methoxy benzoic acid



benzamide


55
4-Chloro-N-trans (4-
494.9
Trans (4-{2-[4-(2,4,5-
495.2



{2-[4-(2,4,5-trifluoro-

trifluoro-phenoxy)-



phenoxy)-piperidin-1-

piperidin-1-yl]-ethyl}-



yl]-ethyl}-

cyclohexyl)-amine and



cyclohexyl)-

4-Chloro benzoic acid



benzamide


56
Thiophene-2-
466.5
Trans (4-{2-[4-(2,4,5-
467.2



carboxylic acid trans

trifluoro-phenoxy)-



(4-{2-[4-(2,4,5-

piperidin-1-yl]-ethyl}-



trifluoro-phenoxy)-

cyclohexyl)-amine and



piperidin-1-yl]-ethyl}-

Thiophene-2-carboxylic



cyclohexyl)-amide

acid









Example 57
N-trans(4-{2-[4-(2,4,5-Trifluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-acetamide
According to the synthesis of N-Trans(4-{2-[4-(4-Fluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-acetamide (example 8), the title compound was prepared from Trans(4-{2-[4-(2,4,5-trifluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-amine and acetylchloride. MS (m/e): 399.3 (M+H+).
Example 58
Thiophene-2-carboxylic acid trans(4-{2-[4-(4-cyano-2-fluoro-Phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-amide
According to the synthesis of example 1, the title compound was prepared from Trans 4-{1-[2-(4-Amino-cyclohexyl)-ethyl]-piperidin-4-yloxy}-3-fluoro-benzonitrile and Thiophene-2-carboxylic acid. Preparative HPLC on reversed phase eluting with acetonitrile/water yielded the title compound. MS (m/e): 456.3 (M+H+).
Example 59
N-trans(4-{2-[4-(2-Cyano-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-acetamide
59.1 4-(2-Cyano-phenoxy)-piperidine-1-carboxylic acid tert-butyl ester
The title compound was prepared as follows.
2-Fluorobenzonitrile (2.00 g, 17 mmol) was added at room temperature to a stirred mixture under argon of NaH (60%, 793 mg, 20 mmol) in dimethylformamide (DMF) (20 ml). 4-Hydroxypiperidine-1-carboxylic acid tert-butyl ester (3.32 g, 17 mmol) was added in portions. The resulting mixture was stirred several hours at 50° C. before partitioning it between H2O and ethyl acetate (EtOAc). The organic layer was washed with sat. aq. NH4Cl sol. and brine and dried over MgSO4. Evaporation of the solvent yielded 5.65 g (quant., 0.17 mmol) of a yellow oil. MS (m/z): 303.1 (M+H+).
59.2 2-(Piperidin-4-yloxy)-benzonitrile hydrochloride
The title compound was prepared as follows.
A solution of 4-(2-cyano-phenoxy)-piperidine-1-carboxylic acid tert-butyl ester (5.14 g, 17 mmol) in CH2Cl2 (40 ml) was treated with sat. HCl sol. in diethyl ether (Et2O) (20 ml). After 2 hours the formed solid was collected by filtration and washed with Et2O to yield 3.38 g (83%, 14 mmol) of a white powder. MS (m/z): 202.2 (M++).
59.3 Trans-4-{2-[4-(2-Cyano-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-carbamic acid tert-butyl ester
The title compound was prepared as follows.
A solution of 2-(piperidin-4-yloxy)-benzonitrile hydrochloride (255 mg, 1.07 mmol) and [trans-4-(2-oxo-ethyl)-cyclohexyl]-carbamic acid tert-butyl ester (284 mg, 1.18 mmol) in 1,2-dichloroethane (5 ml) was stirred over night at room temperature. Sodium triacetoxyborohydride (Na(AcO)3BH) (340 mg, 1.60 mmol) was added and stirring continued for 24 hours. The mixture was partitioned between H2O and EtOAc. The organic layer was washed with sat. aq. NaHCO3 sol. and brine. After drying (MgSO4) the solvent was evaporated and the product was purified by chromatography (CH2Cl2 to CH2Cl2/CH3OH 9:1) to yield 315 mg (69%, 0.74 mmol) of an off-white solid. MS (m/z): 428.4 (M+H+).
59.4 2-{1-[2-(trans-4-Amino-cyclohexyl)-ethyl]-piperidin-4-yloxy}-benzonitrile hydrochloride
The title compound was prepared as follows.
A solution of Trans-4-{2-[4-(2-cyano-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-carbamic acid tert-butyl ester (305 mg, 0.71 mmol) in CH2Cl2 (3 ml) was treated with sat. HCl sol. in Et2O (2 ml). After 2 hours the formed solid was collected by filtration and washed with Et2O to yield 249 mg (96%, 0.68 mmol) of a white powder. MS (m/z): 328.2 (M+H+)
59.5 N-(trans-4-{2-[4-(2-Cyano-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-acetamide
The title compound was prepared as follows.
To a solution of acetic acid (AcOH) (21 mg, 0.34 mmol) in DMF (3 ml) were subsequently added tetramethyluronium tetrafluoroborate (TBTU) (111 mg, 0.34 mmol) and triethylamine (Et3N) (100 mg, 0.98 mmol). After stirring for 90 minutes at room temperature 2-{1-[2-(trans-4-amino-cyclohexyl)-ethyl]-piperidin-4-yloxy}-benzonitrile hydrochloride (120 mg, 0.33 mmol) was added. Stirring was continued over night, then the solvent was evaporated and the residue partitioned between H2O and EtOAc. The organic layer was washed with sat. aq. NaHCO3 sol. and brine and dried over MgSO4. Solvent evaporation afforded 102 mg (84%, 0.28 mmol) of an off-white solid. MS (m/z): 370.2 (M+H+).
Examples 60 and 61
Using the procedure of example 59, further derivatives have been synthesized using 2-{1-[2-(trans-4-amino-cyclohexyl)-ethyl]-piperidin-4-yloxy}-benzonitrile hydrochloride and various acids. They comprise examples 60 and 61.


















MW


Ex.



found


No
Systematic name
MW
Starting materials
(M + H)+







59
N-(trans-4-{2-[4-(2-
369.5
2-{1-[2-(trans-4-
370.2



Cyano-phenoxy)-

amino-cyclohexyl)-



piperidin-1-yl]-ethyl}-

ethyl]-piperidin-4-



cyclohexyl)-acetamide

yloxy}-benzonitrile





hydrochloride and





acetic acid


60
Quinoline-4-carboxylic
482.6
2-{1-[2-(trans-4-
483.3



acid (trans-4-{2-[4-(2-

amino-cyclohexyl)-



cyano-phenoxy)-

ethyl]-piperidin-4-



piperidin-1-yl]-ethyl}-

yloxy}-benzonitrile



cyclohexyl)-amide

hydrochloride and





quinoline-4-carboxylic





acid


61
N-(trans-4-{2-[4-(2-
475.63
2-{1-[2-(trans-4-
476.1



Cyano-phenoxy)-

amino-cyclohexyl)-



piperidin-1-yl]-ethyl}-

ethyl]-piperidin-4-



cyclohexyl)-4-ethoxy-

yloxy}-benzonitrile



benzamide

hydrochloride and 4-





ethoxy-benzoic acid









Example 62
N-trans-(4-{2-[4-(4-Chloro-2-cyano-Phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-acetamide
62.1 2-{1-[2-(trans-4-Amino-cyclohexyl)-ethyl]-piperidin-4-yloxy}-5-chloro-benzonitrile hydrochloride
The title compound was prepared analogously to example 59.4 starting from 5-chloro-2-fluorobenzonitrile. MS (m/z): 362.3 (M+H+).
62.1 N-(trans-4-{2-[4-(4-Chloro-2-cyano-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-acetamide
The title compound was prepared analogously to example 59.5 from 2-{1-[2-(trans-4-amino-cyclohexyl)-ethyl]-piperidin-4-yloxy}-5-chloro-benzonitrile hydrochloride and acetic acid. MS (m/z): 404.5 (M+H+).
Examples 63 and 64
Using the procedure of example 62, further derivatives have been synthesized using 2-{1-[2-(trans-4-amino-cyclohexyl)-ethyl]-piperidin-4-yloxy}-5-chloro-benzonitrile hydrochloride and various acids. They comprise examples 63 to 64.


















MW


Ex.



found


No
Systematic name
MW
Starting materials
(M + H)+







62
N-(trans-4-{2-[4-(4-

2-{1-[2-(trans-4-amino-
404.5



Chloro-2-cyano-

cyclohexyl)-ethyl]-



phenoxy)-piperidin-1-

piperidin-4-yloxy}-5-



yl]-ethyl}-

chloro-benzonitrile



cyclohexyl)-acetamide

hydrochloride and acetic





acid


63
Cyclopropane-

2-{1-[2-(trans-4-amino-
430.5



carboxylic

cyclohexyl)-ethyl]-



acid trans (4-{2-[4-

piperidin-4-yloxy}-5-



(4-chloro-2-cyano-

chloro-benzonitrile



phenoxy)-piperidin-1-

hydrochloride and



yl]-ethyl}-

Cyclopropanecarboxylic



cyclohexyl)-amide

acid


64
Tetrahydro-pyran-4-

2-{1-[2-(trans-4-amino-
474.3



carboxylic acid trans

cyclohexyl)-ethyl]-



(4-{2-[4-(4-chloro-2-

piperidin-4-yloxy}-5-



cyano-phenoxy)-

chloro-benzonitrile



piperidin-1-yl]-ethyl}-

hydrochloride and



cyclohexyl)-amide

Tetrahydro-pyran-4-





carboxylic acid









Example 65
N-trans 4-{2-[4-(3-Chloro-2-cyano-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-acetamide
Intermediate O
(trans-4-Acetylamino-cyclohexyl)-acetic acid ethyl ester
The title compound was prepared as follows.
(trans-4-Amino-cyclohexyl)-acetic acid ethyl ester (10.0 g, 45 mmol) was dissolved in CH2Cl2 (150 ml) and Et3N and acetyl chloride (3.89 g, 50 mmol) were added. The reaction mixture was stirred for 3 hours at room temperature before washing with H2O and brine. After drying (Na2SO4) the solvent was evaporated to yield 8.42 g (82%, 37 mmol) of a white solid. MS (m/z): 228.3 ([M+H]+).
Intermediate P
N-[trans-4-(2-Hydroxy-ethyl)-cyclohexyl]-acetamide
The title compound was prepared as follows.
LiAlH4 (2.10 g, 55 mmol) and tetrahydrofuran (THF) (150 ml) were placed in a dry balloon. After cooling this mixture to 0° C., a solution of (trans-4-acetylamino-cyclohexyl)-acetic acid ethyl ester (8.42 g, 37 mmol) in little THF was added dropwise. The reaction was stirred for 1 hour before careful neutralization with H2O (5.6 ml), 1 N NaOH (3×5.6 ml) and more H2O (5.6 ml). The resulting mixture was stirred over night before filtering off the solids. Evaporation of the solvent and drying under high vacuum afforded 5.25 g (76%, 28 mmol) of a light brown solid. MS (m/z): 186.4 ([M+H+]).
Intermediate Q
N-[trans-4-(2-Oxo-ethyl)-cyclohexyl]-acetamide
The title compound was prepared as follows.
Dimethyl sulfoxide (DMSO) (3.68 g, 47 mmol) in CH2Cl2 (20 ml) was added at −78° C. to a stirred solution of oxalylchloride (2.9 g, 23 mmol) in CH2Cl2 (100 ml). After 1 hour stirring at −78° C. a solution of N-[trans-4-(2-hydroxy-ethyl)-cyclohexyl]-acetamide (2.18 g, 12 mmol) in CH2Cl2 (80 ml) was added followed after 2 hours by triethylamine (Et3N) (7.14 g, 71 mmol). The mixture was allowed to reach room temperature and was then diluted with H2O and extracted with CH2Cl2. The combined organic layers were dried (Na2SO4) and the solvent was evaporated to afford the crude product. Chromatography (CH2Cl2/CH3OH 95:5) yielded 1.75 g (81%, 9.5 mmol) of a light brown solid. MS (m/z): 184.3 ([M+H]+).
65.1 2-Chloro-6-(piperidin-4-yloxy)-benzonitrile hydrochloride
2-Chloro-6-(piperidin-4-yloxy)-benzonitrile hydrochloride was prepared in a manner analogous to that described in example 59.2 from 2-chloro-6-fluoro-benzonitrile and 4-hydroxy-piperidine-1-carboxylic acid tert-butyl ester. White solid. MS (m/z): 237.0 ([M+H]+).
65.2 N-trans(4-{2-[4-(3-Chloro-2-cyano-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-acetamide
The title compound was prepared as follows.
N-[trans-4-(2-Oxo-ethyl)-cyclohexyl]-acetamide (intermediate Q, 111 mg, 0.60 mmol) was added to a mixture of 2-chloro-6-(piperidin-4-yloxy)-benzonitrile hydrochloride (131 mg, 0.48 mmol) in 1,2-dichloroethane (5 ml). After stirring for 8 hours at room temperature, sodium triacetoxyborohydride (Na(AcO)3BH) (152 mg, 0.72 mmol) was added. The reaction mixture was stirred for a further 7 hours before treatment with aq. sat. NaHCO3 sol. Extraction with CH2Cl2, drying over Na2SO4, evaporation of the solvent and chromatography (amino modified silica gel, heptane to ethyl acetate) afforded 114 mg (59%, 0.28 mmol) of product as a white solid. MS (m/z): 404.5 ([M+H]+).
Example 66
N-trans(4-{2-[4-(3-Chloro-4-fluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-acetamide
66.1 4-(3-Chloro-4-fluoro-phenoxy)-piperidine-1-carboxylic acid tert-butyl ester
The title compound was prepared as follows.
Diethyl-azodicarboxylate (DEAD) (214 mg, 1.2 mmol) was added dropwise to a cooled (0° C.) mixture of 4-hydroxy-piperidine-1-carboxylic acid tert-butyl ester (206 mg, 1.0 mmol), 3-chloro-4-fluorophenol (150 mg, 1.0 mmol) and triphenyl phosphine (PPh3) (332 mg, 1.3 mmol) in tetrahydrofuran (THF) (5 ml). The yellow mixture was stirred overnight at room temperature. The solvent was evaporated and the residue purified by chromatography (heptane:ethyl acetate 4:1) to yield 205 mg (61%, 0.62 mmol) of product. Yellowish viscous oil. MS (m/z): 330.3 ([M+H]+).
66.2 N-trans(4-{2-[4-(3-Chloro-4-fluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-acetamide
The title compound was prepared analogously to example 65.2 starting from 4-(3-chloro-4-fluoro-phenoxy)-piperidine-1-carboxylic acid tert-butyl ester. White solid. MS (m/z): 397.1 ([M+H]+).
Example 67
N-trans(4-{2-[4-(2,3,4-Trifluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-acetamide
The title compound was prepared analogously to example 66 starting from 2,3,4-trifluorophenol. White solid. MS (m/z): 399.3 ([M+H]+).
Example 68
Quinoline-4-carboxylic acid (4-{2-[trans 4-(2-chloro-4-fluoro-phenoxy)-3-hydroxy-piperidin-1-yl]-ethyl}-cyclohexyl)-amide
Intermediate C
68.1 Trans 4-(2-Chloro-4-fluoro-phenoxy)-3-hydroxy-piperidine-1-carboxylic acid tert-butyl ester
The title compound was prepared as follows.
Rac-cis-7-Oxa-3-aza-bicyclo[4.1.0]heptane-3-carboxylic acid tert-butyl ester (1 g, 5 mmol) was solvated in dioxane (5 mL), 2-Chloro-4-Fluorophenol was added (1.471 g, 10 mmol) and sodium hydroxide (0.401 g, 10 mmol). After 20 hours refluxing, the mixture was cooled, ammonium chloride was added and the mixture extracted three times with ethyl acetate. The combined organic phases were dried with magnesium sulfate and concentrated under vacuum. After a flash chromatography with heptane/ethyl acetate 1:1 to 1:2 heptane/ethyl acetate a solid the title compound was obtained as solid (0.778 g, 45% yield). MS (m/e): 404.5 (M+AcO−).
Intermediate D
68.2 Trans 4-(2-Chloro-4-fluoro-phenoxy)-piperidin-3-ol; trifluoroacetic acid salt
The title compound was prepared as follows.
0.126 g (0.36 mmol) of trans 4-(2-chloro-4-fluoro-phenoxy)-3-hydroxy-piperidine-1-carboxylic acid tert-butyl ester was solvated in dichloromethane (1.5 mL) and trifluoroacetic acid was added at 0° C. (0.25 mL, 3 mmol). The mixture was stirred at room temperature overnight. NaHCO3 was slowly added until pH 9 and the mixture extracted 3 times with dichloromethane and ethyl acetate. The solvent was evaporated to yield 0.093 g (0.26 mmol, 71%) of a white solid that was used without purification on the next steps. MS (m/e): 246.2 (M+H+).
Intermediate J
68.3 Trans(4-{2-[(4-(2-Chloro-4-fluoro-phenoxy)-3-hydroxy-piperidin-1-yl]-ethyl}-cyclohexyl)-carbamic acid tert-butyl ester
According to the synthesis of example 1, the title compound was prepared from Trans 4-(2-Chloro-4-fluoro-phenoxy)-piperidin-3-ol; trifluoroacetic acid salt, Trans-[4-(2-Oxo-ethyl)-cyclohexyl]-carbamic acid tert-butyl ester and sodium triacetoxyborohydride. (MS (m/e): 471.4 (M+H+).
Intermediate K
68.4 Trans 4-{2-[4-(2-chloro-4-fluoro-phenoxy)-3-hydroxy-piperidin-1-yl]-ethyl}-cyclohexyl)-amine
According to the synthesis of intermediate K, example 1, the title compound was prepared from Trans(4-{2-[(4-(2-Chloro-4-fluoro-phenoxy)-3-hydroxy-piperidin-1-yl]-ethyl}-cyclohexyl)-carbamic acid tert-butyl ester in dichloromethane and trifluoroacetic acid. MS (m/e): 371.3 (M+H+)
68.5 Quinoline-4-carboxylic acid (4-{2-[trans 4-(2-chloro-4-fluoro-phenoxy)-3-hydroxy-piperidin-1-yl]-ethyl}-cyclohexyl)-amide
The title compound was prepared analogously to example 1 from Trans 4-{2-[4-(2-chloro-4-fluoro-phenoxy)-3-hydroxy-piperidin-1-yl]-ethyl}-cyclohexyl)-amine and quinoline-4-carboxylic acid with 2-(1H-benzotriazol-1-yl)-1,1,3,3-tetramethyl uronium tetrafluoroborate (0.035 g, 0.106 mmol) and N-ethyldiisopropylamine in DMF. MS (m/e): 527.3 (M+H+).
Example 69
Quinoline-4-carboxylic acid trans(4-{2-[(3R,4R)-4-(2-chloro-4-fluoro-phenoxy)-3-hydroxy-piperidin-1-yl]-ethyl}-cyclohexyl)-amide
69.1 (3R,4R)-4-(2-Chloro-4-fluoro-phenoxy)-3-hydroxy-piperidine-1-carboxylic acid tert-butyl ester
The title compound was prepared as follows.
0.700 g of Trans 4-(2-Chloro-4-fluoro-phenoxy)-3-hydroxy-piperidine-1-carboxylic acid tert-butyl ester (example 68.1) was separated in Chiralpak AD using 10% ethanol/heptane to obtain 0.323 g of (3R,4R)-4-(2-Chloro-4-fluoro-phenoxy)-3-hydroxy-piperidine-1-carboxylic acid tert-butyl ester. MS 405.4 (M+AcO−).
Quinoline-4-carboxylic acid trans(4-{2-[(3R,4R)-4-(2-chloro-4-fluoro-phenoxy)-3-hydroxy-piperidin-1-yl]-ethyl}-cyclohexyl)-amide
The title compound was prepared analogously to example 69 from (3R,4R)-4-(2-Chloro-4-fluoro-phenoxy)-3-hydroxy-piperidin-1-yl]-ethyl}-cyclohexyl)-amine and Quinoline-4-carboxylic acid with 2-(1H-benzotriazol-1-yl)-1,1,3,3-tetramethyl uronium tetrafluoroborate (0.035 g, 0.106 mmol) and N-ethyldiisopropylamine in DMF. MS (m/e): 526.3 (M+H+).
Example 70
Quinoline-4-carboxylic acid trans(4-{2-[(3S,4S)-4-(2-chloro-4-fluoro-phenoxy)-3-hydroxy-piperidin-1-yl]-ethyl}-cyclohexyl)-amide
70.1 (3S,4S)-4-(2-Chloro-4-fluoro-phenoxy)-3-hydroxy-piperidine-1-carboxylic acid tert-butyl ester
The title compound was prepared as follows.
0.700 g of Trans 4-(2-Chloro-4-fluoro-phenoxy)-3-hydroxy-piperidine-1-carboxylic acid tert-butyl ester (example 69.1) was separated in Chiralpak AD using 10% ethanol/heptane to obtain 0.322 g of (3S,4S)-4-(2-Chloro-4-fluoro-phenoxy)-3-hydroxy-piperidine-1-carboxylic acid tert-butyl ester. MS 405.4 (M+AcO−).
Quinoline-4-carboxylic acid trans(4-{2-[(3S,4S)-4-(2-chloro-4-fluoro-phenoxy)-3-hydroxy-piperidin-1-yl]-ethyl}-cyclohexyl)-amide
The title compound was prepared analogously to example 69 from (3S,4S)-4-(2-Chloro-4-fluoro-phenoxy)-3-hydroxy-piperidin-1-yl]-ethyl}-cyclohexyl)-amine and quinoline-4-carboxylic acid with 2-(1H-benzotriazol-1-yl)-1,1,3,3-tetramethyl uronium tetrafluoroborate (0.035 g, 0.106 mmol) and N-ethyldiisopropylamine in dimethylformamide (DMF). MS (m/e): 526.3 (M+H+)
Example 71
Quinoline-4-carboxylic acid trans(4-{2-[4-(4-fluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-amide
Intermediate G
Trans-(4-Amino-cyclohexyl)-acetic acid ethyl ester
The Title Compound was Prepared as Follows.
Step 1
(4-Nitro-phenyl)-acetic acid (0.005 g, 276 mmol) was added to a stirred solution of 22.08 g of 50% sodium hydroxide solution in 450 mL deionizated water. The clear yellow solution was transferred into a high-pressure autoclave that it charged with 30 g (511 mmol) of water-wet sponge nickel catalyst. The autoclave was sealed, flushed with nitrogen and then pressurized to 115 bar with hydrogen. The reaction mixture was stirred and heated to 125° C. for 48 hours. At that time the autoclave was cooled, vented and charged under nitrogen with another 30 g (511 mmol) of the sponge nickel catalyst. The autoclave was flushed again with nitrogen and then pressurized to 115 bar and the vessel was heated to 130° C. while stirring (a maximum pressure of 130 bars was observed). Hydrogenation was continued for 5 days to 130° C. The autoclave was then cooled, vented and flushed with nitrogen and the contents are removed and filtered through filter aid to remove catalyst. After removal of the solvent, a crude was obtained. The intermediate was used directly in the next step without purification. MS (m/e): 158.3 (M+H+)
Step 2
A solution of the Trans-(4-amino-cyclohexyl)-acetic acid obtained (74 g, 476 mmol) was adjusted to pH 5 with 25% HCl. The mixture was evaporated to dryness and dried under vacuum overnight. The residue was suspended in 146 mL of a 6.5N ethanolic HCl solution and 0.6 L of ethanol was added to the mixture. After 4 hours refluxing, the mixture was cooled, filtered and the filtrate was concentrated to dryness under vacuum. The residue was dissolved in ethanol, treated with ether and cooled overnight in the refrigerator to give the trans-(4-Amino-cyclohexyl)-acetic acid ethyl ester hydrochloride (19.7 g, 32% on the two steps) as a white solid which was filtered and dried under vacuum. MS (m/e): 186.1 (M+H+)
Intermediate L
Trans-{4-[(Quinoline-4-carbonyl)-amino]-cyclohexyl}-acetic acid
The Title Compound was Prepared as Follows.
Step 1
{Trans-4-[(Quinoline-4-carbonyl)-amino]-cyclohexyl}-acetic acid ethyl ester hydrochloride salt
A mixture of Trans-(4-Amino-cyclohexyl)-acetic acid ethyl ester hydrochloride (3.63 g, 17 mmol) was solved in dichloromethane (115 mL) and quinoline-4-carbonyl chloride hydrochloride was added (4.184 g, 18 mmol) followed by the slow addition of triethylamine (11.3 mL, 81 mmol) at 0° C. The mixture was stirred at room temperature overnight and the salts obtained are removed by filtration and the filtrate was extracted. The organic layer was washed with NaHCO3 and brine. The organic phases are dried and concentrated to obtain 3.8 g of a crude. After a flash chromatography with heptane/ethyl acetate 4:1 a solid was obtained that was recrystallized with ethyl acetate and n-heptane to obtain the title compound as a pink solid (2.72 g, 42% yield). MS (m/e): 341.3 (M+H+).
Step 2
Trans-{4-[(Quinoline-4-carbonyl)-amino]-cyclohexyl}-acetic acid
4-[(Quinoline-4-carbonyl)-amino]-cyclohexyl}-acetic acid ethyl ester hydrochloride salt (2.7 g, 8 mmol) was reacted with lithium hydroxide monohydrate (3.33 g, 79 mmol) in a mixture of water (65 mL) and tetrahydrofuran (THF) (130 mL) and the mixture was heated at reflux for 5 hours. A 2⁄3 of the mixture was evaporated and HCl 37% was added until pH 7. The mixture was then evaporated to dryness and 30 mL of water was added and the suspension was filtered to obtain a solid that was recrystallized on toluene (2.2 g, 88.6% yield). MS (m/e): 313.1 (M+H+).
Intermediate M
Trans-{4-[(Quinoline-4-carbonyl)-amino]-cyclohexyl}-thioacetic acid S— ethyl ester
2.19 g of Trans-{4-[(Quinoline-4-carbonyl)-amino]-cyclohexyl}-acetic acid (7 mmol) was added in 1300 mL of dichloromethane. Then 1.8 mL of oxalyl chloride was added (21 mmol). The suspension was heated to reflux for 3 hours and then the cloudy mixture was concentrated under vacuum. The residue was taken up in 500 mL of dichloromethane as a suspension and (1.28 g, 21 mmol) sodium ethylthiolate freshly prepared from 1.45 mL of ethanothiol and 12.07 mL of butyl lithium (1.6 M in toluene) at 0° C. and by stirring in dimethoxyethane (20 mL) for 1 hour at room temperature. The reaction mixture was stirred overnight. NaHCO3 was added and the organic phase was extracted three times with dichloromethane. The organic phases were dried and concentrated and the residue was chromatographed with heptane/ethyl acetate 1:1 to yield the title compound as a solid (1.97 g, 78.9% yield). MS (m/e): 357.3 (M+H+).
Intermediate N
Quinoline-4-carboxylic acid trans-[4-(2-oxo-ethyl)-cyclohexyl]-amide
The title compound was prepared as follows.
Trans-{4-[(Quinoline-4-carbonyl)-amino]-cyclohexyl}-thioacetic acid S— ethyl ester (1.87 g, 5 mmol) was solved in acetone/methylene chloride (40/40 mL), 0.8 g of molecular sieves were added to the mixture and the solution was stirred for 0.5 h. Then 0.558 g (1 mmol) of palladium on active charcoal 10% was added followed by 1.25 mL (8 mmol) of triethyl-silane. The reaction was stirred for 1.5 hours at room temperature and additional 0.558 g (1 mmol) of palladium on active charcoal 10% and 1.25 mL (8 mmol) of triethyl-silane were added and the stirring was continued for another hour. The mixture was filtrated through celite and the mother liquid was concentrated to obtain after chromatography using heptane/acetate 1:1 1.1 (37.1 mmol, 70.8% yield) of the final compound. MS (m/e): 297.3 (M+H+)
Quinoline-4-carboxylic acid trans(4-{2-[4-(4-fluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-amide
The title compound was prepared as follows.
4-(4-Fluoro-phenoxy)-piperidine (intermediate D, example 1) (0.015 g, 0.076 mmol) was solvated in 1,2-dichloromethane (0.300 mL) and quinoline-4-carboxylic acid trans-[4-(2-oxo-ethyl)-cyclohexyl]-amide (0.025 g, 0.084 mmol) was added. Methanol (0.100 mL) was added to improve solubility and the mixture was stirred overnight. Sodium triacetoxyborohydride (0.029, 0.137 mmol) was added to the clear solution that was stirred 10 hours at room temperature. The mixture was concentrated to dryness and the residue was taken up on methanol and purified with preparative HPLC on reversed phase eluting with acetonitrile/water. The combined product fractions were evaporated under reduced pressure to yield 0.034 g of a white solid (0.07 mmol, 93%). MS (m/e): 476.2 (M+H+)
Example 72
Quinoline-4-carboxylic acid trans(4-{2-[4-(2,3-dichloro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-amide
The title compound was prepared analogously to example 71 using quinoline-4-carboxylic acid trans-[4-(2-oxo-ethyl)-cyclohexyl]-amide and 4-(2,3-dichloro-phenoxy)-piperidine as starting materials.
Example 73
Quinoline-4-carboxylic acid trans(4-{2-[4-(3,4-dichloro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-amide
The title compound was prepared analogously to example 71 using quinoline-4-carboxylic acid trans-[4-(2-oxo-ethyl)-cyclohexyl]-amide and 4-(3,4-dichloro-phenoxy)-piperidine as starting materials.














Ex.



MW found


No
Systematic name
MW
Starting materials
(M + H)+



















71
Quinoline-4-
475.6
Quinoline-4-
476.2



carboxylic acid

carboxylic acid



trans (4-{2-[4-(4-

trans-[4-(2-oxo-



fluoro-phenoxy)-

ethyl)-cyclohexyl]-



piperidin-1-yl]-

amide and



ethyl}-cyclohexyl)-

4-(4-Fluoro-



amide

phenoxy)-





piperidine


72
Quinoline-4-
526.5
Quinoline-4-
526.5



carboxylic acid

carboxylic acid



trans (4-{2-[4-(2,3-

trans-[4-(2-oxo-



dichloro-phenoxy)-

ethyl)-cyclohexyl]-



piperidin-1-yl]-

amide and



ethyl}-cyclohexyl)-

4-(2,3-dichloro-



amide

phenoxy)-





piperidine


73
Quinoline-4-
505.06
Quinoline-4-
505.3



carboxylic acid

carboxylic acid



trans (4-{2-[4-(3,4-

trans-[4-(2-oxo-



dichloro-phenoxy)-

ethyl)-cyclohexyl]-



piperidin-1-yl]-

amide and



ethyl}-cyclohexyl)-

4-(3,4-dichloro-



amide

phenoxy)-





piperidine









Example 74
Quinoline-4-carboxylic acid (trans-4-{2-[4-(Pyridin-4-yloxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-amide
The title compound was prepared analogously to example 59 starting from 4-(piperidin-4-yloxy)-pyridine (CAS#224178-65-8) and performing the amide coupling reaction with quinoline-4-carboxylic acid. Orange crystals. MS (m/z): 459.3 ([M+H]+).
Example 75
N-(trans-4-{2-[4-(Pyridin-3-yloxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-acetamide
The title compound was prepared analogously to example 59 starting from 3-(piperidin-4-yloxy)-pyridine (CAS#310881-48-2) and performing the amide coupling reaction with acetic acid. Off-white solid. MS (m/z): 346.2 ([M+H]+).
Example 76
Film coated tablets containing the following ingredients can be manufactured in a conventional manner:















Ingredients
Per tablet









Kernel:





Compound of formula (I)
10.0 mg 
200.0 mg 



Microcrystalline cellulose
23.5 mg 
43.5 mg 



Lactose hydrous
60.0 mg 
70.0 mg 



Povidone K30
12.5 mg 
15.0 mg 



Sodium starch glycolate
12.5 mg 
17.0 mg 



Magnesium stearate
1.5 mg
4.5 mg



(Kernel Weight)
120.0 mg 
350.0 mg 



Film Coat:



Hydroxypropyl methyl cellulose
3.5 mg
7.0 mg



Polyethylene glycol 6000
0.8 mg
1.6 mg



Talc
1.3 mg
2.6 mg



Iron oxide (yellow)
0.8 mg
1.6 mg



Titanium dioxide
0.8 mg
1.6 mg










The active ingredient is sieved and mixed with microcrystalline cellulose and the mixture is granulated with a solution of polyvinylpyrrolidone in water. The granulate is mixed with sodium starch glycolate and magnesium stearate and compressed to yield kernels of 120 or 350 mg respectively. The kernels are lacquered with an aqueous solution/suspension of the above mentioned film coat.
Example 77
Capsules containing the following ingredients can be manufactured in a conventional manner:














Ingredients
Per capsule









Compound of formula (I)
25.0 mg



Lactose
150.0 mg 



Maize starch
20.0 mg



Talc
 5.0 mg










The components are sieved and mixed and filled into capsules of size 2.

Example 78
Injection solutions can have the following composition:

















Compound of formula (I)
3.0
mg



Gelatine
150.0
mg



Phenol
4.7
mg










Sodium carbonate
to obtain a




final pH of 7











Water for injection solutions
ad 1.0
ml










Example 79
Soft gelatin capsules containing the following ingredients can be manufactured in a conventional manner:

















Capsule contents





Compound of formula (I)
5.0
mg



Yellow wax
8.0
mg



Hydrogenated Soya bean oil
8.0
mg



Partially hydrogenated plant oils
34.0
mg



Soya bean oil
110.0
mg



Weight of capsule contents
165.0
mg



Gelatin capsule



Gelatin
75.0
mg



Glycerol 85%
32.0
mg



Karion 83
8.0
mg (dry matter)



Titanium dioxide
0.4
mg



Iron oxide yellow
1.1
mg










The active ingredient is dissolved in a warm melting of the other ingredients and the mixture is filled into soft gelatin capsules of appropriate size. The filled soft gelatin capsules are treated according to the usual procedures.
Example 80
Sachets containing the following ingredients can be manufactured in a conventional manner:
















Compound of formula (I)
50.0 mg



Lactose, fine powder
1015.0 mg 



Microcrystalline cellulose (AVICEL PH 102)
1400.0 mg 



Sodium carboxymethyl cellulose
14.0 mg



Polyvinylpyrrolidone K 30
10.0 mg



Magnesium stearate
10.0 mg



Flavoring additives
 1.0 mg










The active ingredient is mixed with lactose, microcrystalline cellulose and sodium carboxymethyl cellulose and granulated with a mixture of polyvinylpyrrolidone in water. The granulate is mixed with magnesium stearate and the flavoring additives and filled into sachets.
Example 81
The ability of compounds of the present invention to bind to the 5-HT2A, D3 and D2 receptors was determined using radioligand binding to cloned receptors selectively expressed in HEK-293 EBNA cells.
Membrane Preparation for Human D2, Human D3 and Human 5-HT2A Receptors
HEK-293 EBNA cells were transiently transfected with expression plasmids encoding for the human D2 or D3 dopamine- or for the human 5-HT2A serotonin receptor, respectively. The cells were harvested 48 hours post-transfection, washed three times with cold phosphate buffered saline (PBS) and stored at −80° C. prior to use. The pellet was suspended in cold 50 mM Tris-HCl buffer containing 10 mM EDTA (pH 7.4) and homogenized with a Polytron (Kinematica AG, Basel, Switzerland) for 20-30 seconds at 12.000 rpm. After centrifugation at 48.000×g for 30 minutes at 4° C., the pellet was resuspended in cold 10 mM Tris-HCl buffer containing 0.1 mM EDTA (pH 7.4), homogenized, and centrifuged as above. This pellet was further resuspended in a smaller volume of ice cold 10 mM Tris-HCl buffer containing 0.1 mM EDTA (pH 7.4) and homogenized with a Polytron for 20-30 sec at 12.000 rpm. The protein content of this homogenate was determined with the Bio-Rad (Bradford) Protein Assay (Biorad Laboratories GmbH, München, Germany) according to the instructions of the manufacturer using gamma globulin as the standard. This homogenate was stored at −80° C. in aliquots and thawed immediately prior to use.
Radioligand Binding Assay Conditions
Aliquots of membrane preparations were thawed at room temperature, resuspended in assay buffer (D2, D3: 50 mM Tris-HCl, 120 mM NaCl, 5 mM MgCl2, 1 mM EDTA, 5 mM KCl, 1.5 mM CaCl2, pH=7.4; 5-HT2A: 50 mM Tris-HCl, 10 mM MgCl2, 1 mM EGTA, pH=7.4), homogenized with a Polytron for 20-30 seconds at 12.000 rpm and adjusted to a final concentration of approximately 7.5 μg protein/well (D2, D3) and 15 μg protein/well (5-HT2A), respectively.
The binding affinity (Ki) of the compounds was determined using radioligand binding. Membranes were incubated in a total volume of 200 μl with a fixed concentration of radioligand (final concentration approximately 0.7 nM [3H]-spiperone for D2, 0.5 nM [3H]-spiperone for D3, and 1.1 nM [3H]-ketanserin for 5-HT2A) and ten concentrations of test compound ranging between 10 μM-0.1 nM for 1 h at RT. At the end of the incubation, the reaction mixtures were filtered on to unifilter 96-well white microplates with bonded GF/C filters (Packard BioScience, Zudrich, Switzerland; preincubated for 1 h in 0.1% polyethylenimine (PEI) in assay buffer) with a Filtermate 196 harvester (Packard BioScience) and washed 3 times with cold assay buffer. The nonspecific binding was determined with equally composed reaction mixtures in the presence of 10 μM unlabelled spiperone. Per well 45 μl of Microscint 40 (Perkin Elmer, Schwerzenbach, Switzerland) was added, plates for sealed, shaken for 20 min and counted for 3 minutes on a Topcount Microplate Scintillation Counter (Can berra Packard SA, Zu-rich, Switzerland) with quenching correction.
Data Calculation
The CPM value for each duplicate of a concentration of competing compound was averaged (y1), then the % specific binding was calculated according to the equation (((y1−non-specific)/(total binding-non-specific))×100). Graphs were plotted with the % specific binding using XLfit, a curve fitting program that iteratively plots the data using Levenburg Marquardt algorithm. The single site competition analysis equation used was y=A+((B−A)/(1+((x/C)D))), where y is the % specific binding, A is the minimum y, B is the maximum y, C is the IC50, x is the log10 of the concentration of the competing compound and D is the slope of the curve (the Hill Coefficient). From these curves the IC50 (inhibition concentration at which 50% specific binding of the radioligand was displaced) and Hill coefficient were determined. The affinity constant (Ki) was calculated using the Cheng-Prusoff equation Ki=(IC50/1+([L]/Kd), where [L] is the concentration of radioligand and Kd is the dissociation constant of the radioligand at the receptor as determined by the saturation isotherm.
The compounds of the present invention are selective dual modulators of the serotonin 5-HT2a and dopamine D3 receptors as this is shown with the activity table hereinafter which gives the Ki values in nM for the serotonin 5-HT2a, dopamine D3 and dopamine D2 receptors for some examples of the compounds of the present invention:









ACTIVITY TABLE









Example












3
11
18
51





Ki(nM)
48/22/1474
17/2/321
5/2/604
29/36/638


D3/5HT2A/D2












Example












8
13
19
62





Ki(nM)
50/31/843
14/3/790
12/3/683
100/43/3323


D3/5HT2A/D2












Example












9
15
21
72





Ki(nM)
14/13/574
17/2/556
3/2/697
5/9/319


D3/5HT2A/D2












Example












10
16
24
74





Ki(nM)
16/22/592
11/5/553
8/3/453
208/60/3004


D3/5HT2A/D2

## Claims

1. A compound according to general formula I:




wherein:
A is optionally substituted by at least one substituent, each said substituent independently selected from the group consisting of:
halogen,
cyano,
C1-6-alkyl optionally substituted by cyano or C1-6-alkoxy,
C1-6-alkoxy, and
—S(O)2—C1-6-alkyl;

R1 is selected from the group consisting of:
C1-6-alkyl optionally substituted by at least one substituent, each of said substituent being independently selected from the group consisting of: halogen, C1-6-alkoxy, and aryl optionally substituted by halogen;
C3-10-cycloalkyl optionally substituted by one or more Ra;
5- to 12-membered heterocycloalkyl optionally substituted by one or more Ra;
aryl optionally substituted by one or more Ra;
5- to 12-membered heteroaryl optionally substituted by one or more Ra; and
—NRbRc, wherein Rb is hydrogen or C1-6-alkyl and Rc is hydrogen,
C1-6-alkyl or aryl optionally substituted by one or more Ra;

each Ra is independently selected from the group consisting of:
halogen;
—S(O)2—C1-6-alkyl;
cyano;
oxo;
C1-6-alkyl optionally substituted by aryl which is substituted by halogen;
C1-6-haloalkyl;
C1-6-haloalkoxy;
C1-6-alkoxy optionally substituted by 5- to 6-membered heteroaryl which is optionally substituted by C1-6-alkyl;
—NH(CO)—C1-6-alkyl;
5- to 6-membered heterocycloalkyl; and
5- to 6-membered heteroaryl optionally substituted by C1-6-alkyl or oxo; and

R2 is selected from the group consisting of hydrogen and hydroxyl;
or a pharmaceutically-acceptable salt thereof.

2. A compound according to claim 1, wherein A is
aryl optionally substituted by at least one substituent, said substituent independently selected from the group consisting of: halogen, cyano and C1-6-alkyl substituted by cyano.

3. A compound according to claim 1, wherein R1 is C1-6-alkyl optionally substituted by at least one substituent, each of said substituent being independently selected from the group consisting of: halogen and C1-6-alkoxy.

4. A compound according to claim 3, said compound being selected from the group consisting of:
N-trans(4-{2-[4-(4-Fluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-3-methoxy-propionamide;
N-trans(4-{2-[4-(4-Fluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-acetamide;
N-(4-{2-[4-(2-Chloro-4-fluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-3-methoxy-propionamide;
N-trans(4-{2-[4-(2-Chloro-4-fluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-propionamide;
N-trans(4-{2-[4-(2-Chloro-4-fluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-acetamide;
N-trans(4-{2-[4-(2,4-Difluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-acetamide;
N-Trans(4-{2-[4-(2-Cyano-4-fluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-3-methoxy-propionamide;
N-trans(4-{2-[4-(2-Cyano-4-fluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-acetamide;
N-trans(4-{2-[4-(2-Cyano-4-fluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-2,2,2-trifluoro-acetamide;
Trans N-(4-{2-[4-(2,3-Dichloro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-3-methoxy-propionamide;
N-Trans(4-{2-[4-(2,3-Dichloro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-acetamide;
N-trans(4-{2-[4-(2,6-Dichloro-4-fluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-3-methoxy-propionamide;
N-Trans(4-{2-[4-(2,6-Dichloro-4-fluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-acetamide;
N-trans(4-{2-[4-(2,4,5-Trifluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-acetamide;
N-trans(4-{2-[4-(2-Cyano-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-acetamide;
N-trans(4-{2-[4-(4-Chloro-2-cyano-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-acetamide;
N-trans(4-{2-[4-(3-Chloro-2-cyano-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-acetamide;
N-trans(4-{2-[4-(3-Chloro-4-fluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-acetamide; and
N-trans(4-{2-[4-(2,3,4-Trifluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-acetamide;
or a pharmaceutically-acceptable salt thereof.

5. A compound according to claim 1, wherein R1 is C3-10-cycloalkyl optionally substituted by at least one Ra, wherein each Ra is independently a C1-6-alkyl.

6. A compound according to claim 5, said compound being selected from the group consisting of:
Cyclopropanecarboxylic acid trans(4-{2-[4-(4-fluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-amide;
Cyclopropanecarboxylic acid trans(4-{2-[4-(2-chloro-4-fluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-amide;
Cyclobutanecarboxylic acid trans(4-{2-[4-(2-cyano-4-fluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-amide;
Cyclopropanecarboxylic acid trans(4-{2-[4-(2-cyano-4-fluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-amide;
2-Methyl-cyclopropanecarboxylic acid trans(4-{2-[4-(2-cyano-4-fluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-amide;
Cyclobutanecarboxylic acid trans(4-{2-[4-(2,3-dichloro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-amide;
Cyclobutanecarboxylic acid trans(4-{2-[4-(2,6-dichloro-4-fluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-amide;
Cyclobutanecarboxylic acid trans(4-{2-[4-(2,4,6-trifluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-amide;
Cyclobutanecarboxylic acid trans(4-{2-[4-(2,4,5-trifluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-amide;
2-Methyl-cyclopropanecarboxylic acid trans(4-{2-[4-(2,4,5-trifluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-amide; and
Cyclopropanecarboxylic acid trans(4-{2-[4-(4-chloro-2-cyano-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-amide; and
or a pharmaceutically-acceptable salt thereof.

7. A compound according to claim 1, wherein R1 is 5- to 12-membered heterocycloalkyl.

8. A compound according to claim 7, said compound being selected from the group consisting of:
Tetrahydro-pyran-4-carboxylic acid trans(4-{2-[4-(4-fluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-amide;
Tetrahydro-pyran-4-carboxylic acid trans(4-{2-[4-(2-chloro-4-fluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-amide;
Tetrahydro-pyran-4-carboxylic acid trans(4-{2-[4-(2,4-difluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-amide;
Tetrahydro-pyran-4-carboxylic acid trans(4-{2-[4-(2-cyano-4-fluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-amide;
Tetrahydro-pyran-4-carboxylic acid trans(4-{2-[4-(2,3-dichloro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-amide;
Tetrahydro-furan-2-carboxylic acid trans(4-{2-[4-(2,6-dichloro-4-fluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-amide;
Tetrahydro-pyran-4-carboxylic acid trans(4-{2-[4-(2,6-dichloro-4-fluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-amide;
Tetrahydro-furan-2-carboxylic acid trans(4-{2-[4-(2,4,6-trifluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-amide;
Tetrahydro-pyran-4-carboxylic acid trans(4-{2-[4-(2,4,5-trifluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-amide; and
Tetrahydro-pyran-4-carboxylic acid trans(4-{2-[4-(4-chloro-2-cyano-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-amide;
or a pharmaceutically-acceptable salt thereof.

9. A compound according to claim 1, wherein R1 is aryl optionally substituted by at least one Ra, wherein each Ra is independently selected from the group consisting of: halogen, C1-6-alkoxy, —S(O)2—C1-6-alkyl, and 5- to 6-membered heteroaryl optionally substituted by C1-6-alkyl.

10. A compound according to claim 9, said compound being selected from the group consisting of:
4-Chloro-N-trans(4-{2-[4-(4-fluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-benzamide;
N-trans(4-{2-[4-(4-Fluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-3-(5-methyl-[1,2,4]oxadiazol-3-yl)-benzamide;
N-trans(4-{2-[4-(4-Fluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-4-methanesulfonyl-benzamide;
N-trans(4-{2-[4-(2-Chloro-4-fluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-4-methanesulfonyl-benzamide;
4-Chloro-N-trans(4-{2-[4-(2-chloro-4-fluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-benzamide;
N-trans(4-{2-[4-(2-Chloro-4-fluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-3-(5-methyl-[1,2,4]oxadiazol-3-yl)-benzamide;
4-Chloro-N-trans(4-{2-[4-(2-cyano-4-fluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-benzamide;
N-trans(4-{2-[4-(2-Cyano-4-fluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-4-methoxy-benzamide;
4-Methoxy-N-trans(4-{2-[4-(2,4,6-trifluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-benzamide;
4-Chloro-N-trans(4-{2-[4-(2,4,6-trifluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-benzamide;
4-Methoxy-N-trans(4-{2-[4-(2,4,5-trifluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-benzamide;
4-Chloro-N-trans(4-{2-[4-(2,4,5-trifluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-benzamide; and
N-trans(4-{2-[4-(2-Cyano-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-4-ethoxy-benzamide;
or a pharmaceutically-acceptable salt thereof.

11. A compound according to claim 1, wherein R1 is 5- to 12-membered heteroaryl.

12. A compound according to claim 11, said compound being selected from the group consisting of:
1H-Indole-2-carboxylic acid trans(4-{2-[4-(4-fluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-amide;
Quinoline-4-carboxylic acid trans(4-{2[4-(2-chloro-4-fluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-amide;
Quinoline-6-carboxylic acid trans(4-{2-[4-(2,4-difluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-amide;
Quinoline-4-carboxylic acid trans(4-{2-[4-(2,4-difluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-amide;
Thiophene-2-carboxylic acid trans(4-{2-[4-(2-cyano-4-fluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-amide;
Thiophene-2-carboxylic acid trans(4-{2-[4-(2,3-dichloro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-amide;
Thiophene-2-carboxylic acid trans(4-{2-[4-(2,6-dichloro-4-fluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-amide;
Thiophene-2-carboxylic acid trans(4-{2-[4-(2,4,5-trifluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-amide;
Thiophene-2-carboxylic acid trans(4-{2-[4-(4-cyano-2-fluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-amide;
Quinoline-4-carboxylic acid trans(4-{2-[4-(2-cyano-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-amide;
Quinoline-4-carboxylic acid (4-{2-[trans 4-(2-chloro-4-fluoro-phenoxy)-3-hydroxy-piperidin-1-yl]-ethyl}-cyclohexyl)-amide;
Quinoline-4-carboxylic acid trans(4-{2-[(3R,4R)-4-(2-chloro-4-fluoro-phenoxy)-3-hydroxy-piperidin-1-yl]-ethyl}-cyclohexyl)-amide;
Quinoline-4-carboxylic acid trans(4-{2-[(3S,4S)-4-(2-chloro-4-fluoro-phenoxy)-3-hydroxy-piperidin-1-yl]-ethyl}-cyclohexyl)-amide;
Quinoline-4-carboxylic acid trans(4-{2-[4-(4-fluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-amide;
Quinoline-4-carboxylic acid trans(4-{2-[4-(2,3-dichloro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-amide; and
Quinoline-4-carboxylic acid trans(4-{2-[4-(3,4-dichloro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-amide;
or a pharmaceutically-acceptable salt thereof.

13. A compound according to claim 1, wherein R1 is —NRbRc, Rb is hydrogen, and Rc is hydrogen or aryl optionally substituted by at least one Ra, wherein each Ra is independently selected from the group consisting of: halogen and C1-6-alkyl.

14. A compound according to claim 13, said compound being selected from the group consisting of:
1-(4-Chloro-phenyl)-3-trans(4-{2-[4-(4-fluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-urea;
1-trans(4-{2-[4-(4-Fluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-3-p-tolyl-urea;
1-trans(4-{2-[4-(2-Chloro-4-fluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-3-p-tolyl-urea; and
1-trans(4-{2-[4-(2-Chloro-4-fluoro-phenoxy)-piperidin-1-yl]-ethyl}-cyclohexyl)-3-(4-chloro-phenyl)-urea;
or a pharmaceutically-acceptable salt thereof of such compounds.

15. A process for the preparation of a compound according to claim 1 wherein:
A is aryl optionally substituted by at least one substituent, each said substituent independently selected from the group consisting of:
halogen,
cyano,
C1-6-alkyl optionally substituted by cyano or C1-6-alkoxy,
C1-6-alkoxy, and
—S(O)2—C1-6-alkyl;

R1 is selected from the group consisting of:
C1-6-alkyl optionally substituted by at least one substituent, each of said substituent being independently selected from the group consisting of: halogen, C1-6-alkoxy, and aryl optionally substituted by halogen;
C3-10-cycloalkyl optionally substituted by one or more Ra;
5- to 12-membered heterocycloalkyl optionally substituted by one or more Ra;
aryl optionally substituted by one or more Ra; and
5- to 12-membered heteroaryl optionally substituted by one or more Ra;

each Ra is independently selected from the group consisting of:
halogen;
—S(O)2—C1-6-alkyl;
cyano;
oxo;
C1-6-alkyl optionally substituted by aryl which is substituted by halogen;
C1-6-haloalkyl;
C1-6-haloalkoxy;
C1-6-alkoxy optionally substituted by 5- to 6-membered heteroaryl which is optionally substituted by C1-6-alkyl;
—NH(CO)—C1-6-alkyl;
5- to 6-membered heterocycloalkyl; and
5- to 6-membered heteroaryl optionally substituted by C1-6-alkyl or oxo; and

R2 is selected from the group consisting of hydrogen and hydroxyl;
said process comprising the step of
reacting a compound of the formula II,




with an acid of the formula III,


HOOCR1  (III)


in the presence of a coupling reagent.

16. A process for the preparation of a compound according to claim 1 wherein:
A is aryl and optionally substituted by at least one substituent, each said substituent independently selected from the group consisting of:
halogen,
cyano,
C1-6-alkyl optionally substituted by cyano or C1-6-alkoxy,
C1-6-alkoxy, and
—S(O)2—C1-6-alkyl;

R1 is —NRbRc, wherein Rb is hydrogen or C1-6-alkyl and Rc is aryl optionally substituted by one or more Ra;
each Ra is independently selected from the group consisting of:
halogen;
—S(O)2—C1-6-alkyl;
cyano;
oxo;
C1-6-alkyl optionally substituted by aryl which is substituted by halogen;
C1-6-haloalkyl;
C1-6-haloalkoxy;
C1-6-alkoxy optionally substituted by 5- to 6-membered heteroaryl which is optionally substituted by C1-6-alkyl;
—NH(CO)—C1-6-alkyl;
5- to 6-membered heterocycloalkyl; and
5- to 6-membered heteroaryl optionally substituted by C1-6-alkyl or oxo; and

R2 is selected from the group consisting of hydrogen and hydroxyl;
said process comprising the step of reacting a compound of the formula II,




with an isocyanate or para nitro carbamate.

17. A pharmaceutical composition comprising a compound according to claim 1 and a pharmaceutically acceptable excipient.