WO2007017094A1 - Substituted benzyloxy-phenylmethylcarbamate derivatives - Google Patents

Abstract

The present invention relates to novel substituted benzyloxy-phenylmethylcarbamate derivatives, processes for their preparation, and their use in medicaments, especially for the prophylaxis and treatment of diseases associated with Cold Menthol Receptor 1 (CMR-1) activity, in particular for the treatment of urological diseases or disorders, such as detrusor overactivity (overactive bladder), urinary incontinence, neurogenic detrusor oeractivity (detrusor hyperflexia), idiopathic detrusor overactivity (detrusor instability), benign prostatic hyperplasia, and lower urinary tract symptoms; chronic pain, neuropathic pain, postoperative pain, rheumatoid arthritic pain, neuralgia, neuropathies, algesia, nerve injury, ischaemia, neurodegeneration, stroke, and inflammatory disorders such as asthma and chronic obstructive pulmonary (or airways) disease (COPD).

Description

Substituted benzyloxy-phenylmethylcarbamate derivatives

The present invention relates to novel substituted benzyloxy-phenylmethylcarbamate derivatives, processes for their preparation, and their use in medicaments, especially for the prophylaxis and treatment of diseases associated with Cold Menthol Receptor 1 (CMR-I) activity, in particular for the treatment of urological diseases or disorders, such as detrusor overactivity (overactive bladder), urinary incontinence, neurogenic detrusor overactivity (detrusor hyperflexia), idiopathic detrusor overactivity (detrusor instability), benign prostatic hyperplasia, and lower urinary tract symptoms; chronic pain, neuropathic pain, postoperative pain, rheumatoid arthritic pain, neuralgia, neuropathies, algesia, nerve injury, ischaemia, neurodegeneration, stroke, and inflammatory disorders such as asthma and chronic obstructive pulmonary (or airways) disease (COPD).

There is abundant direct or indirect evidence that shows the relation between Transient Receptor Potential (TRPJ channel activity and diseases such as pain, ischaemia,^" and inflammatory disorders. Further, it has been demonstrated that TRP channels transduce reflex signals that are involved in the overactive bladder of patients who have damaged or abnormal spinal reflex pathways [De Groat WC: A neurologic basis for the overactive bladder. Urology 50 (6A Suppl): 36-52, 1997]. CMR-I , a nonselective cation channel is such a member of the TRP channel family (TRPM8). Recently, in 2002 the receptor was cloned and it was found to be sensitive to cold temperature and menthol and therefore named as cold menthol receptor - 1 (CMR-I) (McKemy et al, 2002; Peier et al., 2002). This receptor which is activated by 8 - 28⁰C temperature is expressed on the bladder urothelium and DRG (Dorsal Root Ganglia) and C-fibers. The intravesical ice water or menthol also induce C-fϊber mediated spinal micturition reflex in patients with urgency and urinary incontinence (UI). Clinically CMR-I is supposed to mediate the bladder cooling reflex seen after ice water test in overactive patients.

Therefore antagonism of the CMR-I receptor leads to the blockage of neurotransmitter release, resulting in prophylaxis and treatment of the conditions and diseases associated with CMR-I activity.

Antagonists of the CMR-I receptor can be used for prophylaxis and treatment of the conditions and diseases including chronic pain, neuropathic pain, postoperative pain, rheumatoid arthritic pain, neuralgia, neuropathies, algesia, nerve injury, ischaemia, neurodegeneration, stroke, inflammatory disorders, urinary incontinence (UI) such as urge urinary incontinence (UUI), and/or overactive bladder, Lower urinary tract symptoms secondary to or independent of benign prostatic hyperplasia. UI is the involuntary loss of urine. UUI is one of the most common types of UI together with stress urinary incontinence (SUI) which is usually caused by a defect in the urethral closure mechanism. UUI is often associated with neurological disorders or diseases causing neuronal damages such as dementia, Parkinson's disease, multiple sclerosis, stroke and diabetes, although it also occurs in individuals with no such disorders. One of the usual causes of UUI is overactive bladder (OAB) which is a medical condition referring to the symptoms of frequency and urgency derived from abnormal contractions and instability of the detrusor muscle.

There are several medications for urinary incontinence on the market today mainly to help treating UUI. Therapy for OAB is focused on drugs that affect peripheral neural control mechanisms or those that act directly on bladder detrusor smooth muscle contraction, with a major emphasis on development of anticholinergic agents. These agents can inhibit the parasympathetic nerves which control bladder voiding or can exert a direct spasmolytic effect on the detrusor muscle of the bladder. This results in a decrease in intravesicular pressure, an increase in capacity and a reduction in the frequency of bladder contraction. Orally active anticholinergic drugs which are commonly prescribed have serious drawbacks such as unacceptable side effects such as dry mouth, abnormal visions, constipation, and central nervous system disturbances. These side effects lead to poor compliance. Dry mouth symptoms alone are responsible for a 70% non-compliance rate with oxybutynin. The inadequacies of present therapies highlight the need for novel, efficacious, safe, orally available drugs that have fewer side effects.

In WO 03/037865 and Y. Lu, et al., Bioorg. Med. Chem. Lett. 2004, 14, 3957-3962 related benzyloxy-phenylmethylamide derivatives for the treatment of cancer are described.

The present invention relates to compounds of the general formula (I)

wherein

R represents hydrogen or halogen,

R represents hydrogen or halogen, R³ represents hydrogen or halogen,

R⁴ represents chlorine, fluorine, nitro, trifluoromethyl, trifluoromethoxy, Ci-C₄-alkyl or Ci-C₄-alkoxy,

R⁵ represents hydrogen or halogen,

R⁶ represents C₃-C₈-alkyl, C₃-C₇-cycloalkyl, C₆-Cio-aryl, 5- to 10-membered heteroaryl or a group of the formula -Y-R⁹,

wherein cycloalkyl can be further substituted with one to three identical or different radicals selected from the group consisting of C]-C₄-alkyl,

and

wherein aryl and heteroaryl can be further substituted with one to three identical or different radicals selected from the group consisting of halogen, nitro, amino, hydroxy, trifluoromethyl, C]-C₆-alkyl, Ci-C₆-alkoxy and Ci-C₆-alkylamino,

and

wherein

Y represents Ci-C₄-alkandiyl,

R⁹ represents C₃-C₇-cycloalkyl, phenyl or 5- to 10-membered heteroaryl,

wherein cycloalkyl can be further substituted with one to three identical or different radicals selected from the group consisting of Ci-C₄-alkyl,

and

wherein phenyl and heteroaryl can be further substituted with one to three identical or different radicals selected from the group consisting of halogen, nitro, amino, hydroxy, trifluoromethyl, Ci-Cό-alkyl, C_rC₆-alkoxy and C_rC₆-alkylamino,

R⁷ represents Ci-Cβ-alkyl,

wherein alkyl is further substituted with one radical selected from the group consisting of amino, mono-alkylamino, Ci-C₄-alkylcarbonylamino or Ci-C₄-alkoxycarbonylamino, R⁸ represents hydrogen or Ci-C₄-alkyl,

and their salts, hydrates and/or solvates.

Physiologically acceptable salts are preferred in the context of the present invention.

Physiologically acceptable salts according to the invention are non-toxic salts which in general are accessible by reaction of the compounds (I) with an inorganic or organic base or acid conventionally used for this purpose. Non-limiting examples of pharmaceutically acceptable salts of compounds (I) include the alkali metal salts, e.g. lithium, potassium and sodium salts, the alkaline earth metal salts such as magnesium and calcium salts, the quaternary ammonium salts such as, for example, triethyl ammonium salts, acetates, benzene sulphonates, benzoates, dicarbonates, disulphates, ditartrates, borates, bromides, carbonates, chlorides, citrates, dihydrochlorides, fumarates, gluconateSj-glutamates., hexyl resorcinates, _%hydrobromide.s, hydrochlorides, hydroxy- naphthoates, iodides, isothionates, lactates, laurates, malates, maleates, mandelates, mesylates, methylbromides, methylnitrates, methylsulphates, nitrates, oleates, oxalates, palmitates, pantothenates, phosphates, diphosphates, polygalacturonates, salicylates, stearates, sulphates, succinates, tartrates, tosylates, valerates, and other salts used for medicinal purposes.

Hydrates of the compounds of the invention or their salts are stoichiometric compositions of the compounds with water, such as for example hemi-, mono-, or dihydrates.

Solvates of the compounds of the invention or their salts are stoichiometric compositions of the compounds with solvents.

The present invention includes both the individual enantiomers or diastereomers and the corresponding racemates or diastereomeric mixtures of the compounds according to the invention and their respective salts. In addition, all possible tautomeric forms of the compounds described above are included according to the present invention. The diastereomeric mixtures can be separated into the individual isomers by chromatographic processes. The racemates can be resolved into the respective enantiomers either by chromatographic processes on chiral phases or by resolution.

In the context of the present invention, the substituents, if not stated otherwise, in general have the following meaning:

Alkyl in general represents a straight-chain or branched saturated hydrocarbon radical having 1 to 6, preferably 1 to 4 carbon atoms. Non-limiting examples include methyl, ethyl, n-propyl, iso- propyl, n-butyl, isobutyl, sec-butyl, tert-buty\, pentyl, isopentyl, hexyl, isohexyl..The same applies to radicals such as alkoxy, alkylamino, alkylcarbonylamino, alkoxycarbonylamino and the like.

Alkandiyl in general represents a straight-chain or branched saturated alkandiyl radical having 1 to 4 carbon atoms. Non-limiting examples include methylen, ethan-l,2-diyl, ethan-l,l-diyl, propan- 1 ,3-diyl, propan-l,2-diyl, propan-2,2-diyl, butan-l,4-diyl, butan-l,3-diyl and butan-2,4-diyl.

Alkenyl in general represents a straight-chain or branched alkenyl radical having 2 to 6, preferably 2 to 4 carbon atoms. Non-limiting examples include vinyl, allyl, n-prop-1-en-l-yl, n-but-2-en-l-yl, 2-methylprop-l-en-l-yl and 2-methylprop-2-en-l-yl.

Alkinyl in general represents a straight-chain or branched alkinyl radical having 2 to 6, preferably 2 to 4 carbon atoms. Non-limiting examples include ethinyl, propargyl (2-propinyl), 1-propinyl, but- 1-inyl, but-2-inyl,. _

Alkoxy illustratively and preferably represents methoxy, ethoxy, n-propoxy, isopropoxy, tert-butoxy, n-pentoxy and n-hexoxy.

Alkylcarbonylamino in general represents a straight-chain or branched hydrocarbon radical having 1 to 6, preferably 1 to 4 carbon atoms which has a carbonylamino (-CO-NH-) function at the position of attachment and which is bonded to the carbonyl group. Non-limiting examples include formylamino, acetylamino, n-propionylamino, n-butyrylamino, isobutyrylamino, pivaloylamino, n- hexanoylamino.

Alkoxycarbonylamino illustratively and preferably represents methoxycarbonylamino, ethoxy- carbonylamino, n-propoxycarbonylamino, isopropoxycarbonylamino, te/t-butoxycarbonylamino, n-pentoxycarbonylamino and n-hexoxycarbonylamino.

Alkylamino represents an alkylamino radical having one or two (independently selected) alkyl substituents, illustratively and preferably representing methylamino, ethylamino, n-propylamino, isopropylamino, /ert-butylamino, n-pentylamino, n-hexylamino, NN-dimethylamino, NN-diethyl- amino, N-ethyl-N-methylamino, N-methyl-N-n-propylamino, N-isopropyl-N-n-propylamino, N-tert- butyl-N-methylamino, N-ethyl-N-n-pentylamino and N-n-hexyl-N-methylamino.

Mono-alkylamino represents an alkylamino radical having one alkyl substituents, illustratively and preferably representing methylamino, ethylamino, n-propylamino, isopropylamino, tert-butylamino, n-pentylamino and n-hexylamino. Cycloalkyl in general represents a cyclic saturated hydrocarbon radical having 3.to 8, preferably 3 to 6 carbon atoms. Non-limiting examples include cycloprόpyl, cyclobutyl, cyclopentyl, cyclo- hexyl and cycloheptyl.

Aryl in general represents an aromatic mono- or bicyclic radical having 6 to 10 ring atoms, illustratively and preferably representing phenyl and naphthyl.

Heteroaryl per se and in heteroarylmethyl in general represents an aromatic mono- or bicyclic radical having 5 to 10 and preferably 5 or 6 ring atoms, and up to 5 and preferably up to 4 hetero- atoms selected from the group consisting of S, O and N, illustratively and preferably representing thienyl, furyl, pyrrolyl, pyrazolyl, thiazolyl, oxazolyl, isothiazolyl, isoxazolyl, imidazolyl, oxadiazolyl, thiadiazolyl, pyridyl, pyrimidyl, pyridazinyl, indolyl, indazolyl, benzofuranyl, benzo- thienyl, benzothiazolyl, quinolinyl, isoquinolinyl.

Halogen represents fluorine, chlorine, bromine and iodine.

In another preferred embodiment, the present invention relates to compounds of general formula (I), wherein

R¹ represents hydrogen or halogen, >

R² represents hydrogen or halogen,

R³ represents hydrogen,

R⁴ represents chlorine, nitro, trifluoromethoxy, Ci-C₃-alkyl or C_rC₃-alkoxy,

R⁵ represents hydrogen,

R⁶ represents C₃-C₈-alkyI, C₃-C₇-cycloalkyl, phenyl, 5- or 6-membered heteroaryl or a group of the formula -Y-R⁹,

wherein cycloalkyl can be further substituted with one to three identical or different radicals selected from the group consisting of Ci-C₄-alkyl,

and

wherein phenyl and heteroaryl can be further substituted with one to three identical or different radicals selected from the group consisting of halogen, nitro, trifluoromethyl, C_rC₆-alkyl and Ci-C₆-alkoxy, and

wherein

Y represents Ci-C₄-alkandiyl,

R⁹ represents C₃-C₇-cycloalkyl, phenyl or 5- or 6-membered heteroaryl,

wherein cycloalkyl can be further substituted with one to three identical or different radicals selected from the group consisting of CpGi-alkyl,

and

wherein phenyl and heteroaryl can be further substituted with, one to three _identical or different radicals selected from the group consisting of halogen, nitro, trifluoromethyl, C]-C₆-alkyl and Ci-C₆-alkoxy,

R⁷ represents Ci-C₃-alkyl,

wherein alkyl is further substituted with one radical selected from the group consisting of amino, mono-alkylamino or Ci-C₄-alkoxycarbonylamino,

R⁸ represents hydrogen,

and their salts, hydrates and/or solvates.

In another particularly preferred embodiment, the present invention relates to compounds of general formula (I), wherein

R¹ represents hydrogen, fluorine or chlorine,

R² represents hydrogen or fluorine,

R³ represents hydrogen,

R⁴ represents methoxy,

R⁵ represents hydrogen,

R⁶ represents C₃-C₆-alkyl, C₃-C₆-cycloalkyl, phenyl, thienyl, furyl, pyrazolyl or a group of the formula -Y-R⁹,

wherein cycloalkyl can be further substituted with one to two methyl groups, and

wherein phenyl, thienyl, furyl and pyrazolyl can be further substituted with one to three identical or different radicals selected from the group consisting of fluorine, chlorine, nitro, trifluoromethyl, methyl and methoxy,

and

wherein

Y represents methy len or ethan- 1 , 1 -diy 1,

R⁹ represents C₃-C₆-cycloalkyl, phenyl, thienyl, furyl or pyrazolyl,

_wherein cycloalkyl can be further substituted with one to two methyl groups,

and

wherein phenyl, thienyl, furyl and pyrazolyl can be further substituted with one to three identical or different radicals selected from the group consisting of fluorine, chlorine, nitro, trifluoromethyl, methyl and methoxy,

R⁷ represents Ci-C₂-alkyl,

wherein alkyl is further substituted with one radical selected from the group consisting of amino or tert-butoxycarbonylamino,

R⁸ represents hydrogen,

and their salts, hydrates and/or solvates.

In another preferred embodiment, the present invention relates to compounds of general formula (I), wherein R⁷ represents -CH₂NH₂ or -CH₂CH₂NH₂.

In another preferred embodiment, the present invention relates to compounds of general formula (I), wherein R¹, R² and R³ represent hydrogen.

In another preferred embodiment, the present invention relates to compounds of general formula (I), wherein R¹ represents halogen, R² represents hydrogen or halogen and R³ represents hydrogen or halogen. In another preferred embodiment, the present invention relates to compounds of general formula (I), wherein R¹ represents halogen, R² represents hydrogen or halogen and R³ represents hydrogen.

In another preferred embodiment, the present invention relates to compounds of general formula (I), wherein R¹ represents fluorine or chlorine, R² represents hydrogen or fluorine and R³ represents hydrogen.

In another preferred embodiment, the present invention relates to compounds of general formula (I), wherein R⁴ represents trifluoromethoxy or C]-C₄-alkoxy.

In another preferred embodiment, the present invention relates to compounds of general formula (I), wherein R⁶ represents phenyl, wherein phenyl can be further substituted with one to three identical or different radicals selected from the group consisting of fluorine, chlorine, nitro, trifluoromethyζ methyLand methqxy.

In another preferred embodiment, the present invention relates to compounds of general formula (I), wherein R⁶ represents a group of the formula -Y-R⁹, wherein Y represents methylen or ethan- 1,1-diyl, and R⁹ represents phenyl, wherein phenyl can be further substituted with one to three identical or different radicals selected from the group consisting of fluorine, chlorine, nitro, trifluoromethyl, methyl and methoxy.

Very particular preference is given to combinations of two or more of the abovementioned preference ranges.

The compounds of general formula (I) can be synthesized by condensing compounds of general formula (II)

wherein R , R , R ₁ R , R , R and R have the meaning indicated above, [A] with compounds of general formula (III)

wherein R⁶ has the meaning indicated above, and

X¹ represents a leaving group, such as halogen, preferably chlorine or bromine,

in the presence of a base

or

[B] with a mixture of a carbonic acid derivative and compounds of general formula (FV)

wherein R⁶ has the meaning indicated above.

In process [B] optionally 4-N,N-dimethylaminopyridine can be added to the reaction mixture. '

Amino groups in R⁷ of compounds of general formula (II) are protected with acid labile groups, preferred is a boc-group. After the synthesis of compounds of general formula (I) this acid labile group can be cleaved via standard procedures known by a person skilled in the art. Compounds of general formula (I) are obtained. Preferred are acidic cleavage conditions.

If a salt of a compound of general formula (I), for example a hydrochloride or trifluoroacetate, is isolated the free base can be obtained by reversed phase chromatography of the salt using a mixture of acetonitile and water as eluent in the presence of a base. Preferably a RPl 8 Phenomenex Luna C 18(2) column is used in the presence of diethylamine as base. Or the free base of a compound of general formula (I) can be obtained by neutralizing with a base and extraction.

The process [A] is in general carried out in a temperature range from -20⁰C to boiling point of the solvent, preferably from 0⁰C to +40⁰C.

The process is generally carried out at normal pressure. However, it is also possible to carry it out at elevated pressure or at reduced pressure (for example in a range from 0.5 to 5 bar). Suitable solvents for the process are ethers such as dioxan or tetrahydrofuran, or halogeno-hydro- carbons such as dichloromethane, dichloroethane or trichloromethane, or other solvents such as dimethylformamide, ethyl acetate or acetonitrile. It is also possible to use mixtures of the above- mentioned solvents. Preferred for the process is tetrahydrofuran or dichloromethane.

Suitable bases for the process are generally inorganic or organic bases. These preferably include alkali carbonates such as sodium or potassium carbonate or hydrogencarbonate, cyclic amines such as, for example, N-methylmorpholine, N-methylpiperidine, pyridine or 4-NN-dimethylamino- pyridine, or (C_rC₄)-trialkylamines such as, for example, triethylamine or diisopropylethylamine. Preference is given to triethylamine.

The process [B] is in general carried out in a temperature range from room temperature to +4O⁰C.

The process is .generally carried out at normal pressure._ΝHowever, it is also possible to carry it out at elevated pressure or at reduced pressure (for example in a range from 0.5 to 5 bar).

Suitable carbonic acid derivatives for the process are Ν,Ν-carbonyldiimidazole, phosgene, diphosgene, triphosgene, chloroformic acid phenyl ester or chloroformic acid 4-nitrophenyl ester. Preference is given to N,N-carbonyldiimidazole.

Suitable solvents for the process are ethers such as dioxan or tetrahydrofuran, or halogeno-hydro- carbons such as dichloromethane, dichloroethane or trichloromethane, or other solvents such as dimethylformamide, ethyl acetate or acetonitrile. It is also possible to use mixtures of the above- mentioned solvents. Preferred for the process is tetrahydrofuran or dichloromethane.

The compounds of the general formula (TH) and (IV) are known per se, or they can be prepared by customary methods.

The compounds of general formula (II) can be synthesized by condensing compounds of general formula (V)

wherein R > 1 , τ R> 2 , τ R> 3 , D R⁴ and A D R5 have the meaning indicated above, with compounds of general formula (VI)

wherein R⁷ and R⁸ have the meaning indicated above,

under conditions of a reductive amination.

The process is in general carried out in a temperature range from -2O⁰C to boiling point of the solvent, preferably from 0⁰C to +40⁰C.

The process is generally carried out at normal pressure. However, it is also possible to carry it out at elevated pressure or at reduced pressure (for example in a range from 0.5 to 5 bar).

Suitable solvents for the process are halogeno-hydrocarbons such as dichloromethane, dichloro- ethane or trichloromethane, or alcohols such as methanol, ethanol, n-propanol, iso-propanol, n- butanol or tert-butanol, or a mixture of alcohol and water. Preferred for the process is methanol or a mixture of methanol and water.

Suitable reducing agents for the process are sodium borohydride or triacetoxyborohydride.

The compounds of the general formula (VI) are known per se, or they can be prepared by customary methods.

The compounds of general formula (V) can be synthesized by condensing compounds of general formula (VET)

wherein R⁴ and R⁵ have the meaning indicated above, with compounds of general formula (VIII)-

wherein R¹, R² and R³ have the meaning indicated above, and

X² represents a leaving group, such as halogen, preferably chlorine or bromine,

in the presence of a base.

Optionally an alkali iodide such as sodium or potassium iodide can be added to the reaction mixture.

The process is_ in general carried out in a temperature range from_0°C to boiling point of the solvent, preferably from 20⁰C to boiling point of the solvent.

The process is generally carried out at normal pressure. However, it is also possible to carry it out at elevated pressure or at reduced pressure (for example in a range from 0.5 to 5 bar).

Suitable solvents for the process are ethers such as dioxan or tetrahydrofuran, or halogeno-hydro- carbons such as dichloromethane, dichloroethane or trichloromethane, or other solvents such as dimethylformamide, dimethylsulfoxide, ethyl acetate or acetonitrile. It is also possible to use mixtures of the above-mentioned solvents. Preferred for the process is acetonitrile.

Suitable bases for the process are generally inorganic or organic bases. These preferably include alkali carbonates such as sodium or potassium carbonate or hydrogencarbonate, cyclic amines such as, for example, N-methylmorpholine, N-methylpiperidine, pyridine or 4-NN-dimethylamino- pyridine, or (Ci-C₄)-trialkylamines such as, for example, triethylamine or diisopropylethylamine. Preference is given to potassium carbonate.

The compounds of the general formulas (VII) and (VIH) are known per se, or they can be prepared by customary methods.

The above-mentioned process can be illustrated by the following scheme: Scheme 1

isolation as free base or salt (TFA or HCI)

The compounds according to the invention exhibit an unforeseeable, useful pharmacological activity spectrum. They are therefore suitable for use as medicaments for the treatment and/or prophylaxis of disorders in humans and animals.

Surprisingly, the compounds of the present invention show excellent CMR-I antagonistic activity. They are, therefore suitable especially for the prophylaxis and treatment of diseases associated with CMR-I activity, in particular for the treatment of urological diseases or disorders, such as detrusor overactivity (overactive bladder), urinary incontinence, neurogenic detrusor oeractivity (detrusor hyperflexia), idiopathic detrusor overactivity (detrusor instability), benign prostatic hyperplasia, and lower urinary tract symptoms. The compounds of the present invention are also effective for treating or preventing a disease selected from the group consisting of chronic pain, neuropathic pain, postoperative pain, rheumatoid arthritic pain, neuralgia, neuropathies, algesia, nerve injury, ischaemia, neuro- degeneration and/or stroke, as well as respiratory diseases and inflammatory diseases such as asthma, COPD and allergic rhinitis since the diseases also relate to CMR-I activity.

The compounds of the present invention are also useful for the treatment and prophylaxis of neuropathic pain, which is a form of pain often associated with herpes zoster and post-herpetic neuralgia, painful diabetic neuropathy, neuropathic low back pain, posttraumatic and postoperative neuralgia, neuralgia due to nerve compression and other neuralgias, phantom pain, complex regional pain syndromes, infectious or parainfectious neuropathies like those associated with HTV infection, pain associated with central nervous system disorders like multiple sclerosis or Parkinson disease or spinal cord injury or traumatic brain injury, and post-stroke pain.

Furthermore, the compounds of the present invention are useful for the treatment of musculoskeletal pain, forms of pain often associated with osteoarthritis or rheumatoid arthritis or other forms of arthritis, and back pain.

In addition, the compounds of the present invention are useful for the treatment of pain associated with cancer, including visceral or neuropathic pain associated with cancer or cancer treatment.

The compounds of the present invention are furthermore useful for the treatment of visceral pain, e.g. pain associated with obstruction of hollow viscus like gallstone colik, pain associated with irritable bowel syndrome, pelvic pain, vulvodynia, orchialgia or prostatodynia, pain associated with inflammatory lesions of joints, skin, muscles or nerves, and orofascial pain and headache, e.g. migraine or tension-type headache.

The present invention further provides medicaments containing at least one compound according to the invention, preferably together with one or more pharmacologically safe excipient or carrier substances, and also their use for the above-mentioned purposes.

The active component can act systemically and/or locally. For this purpose, it can be applied in a suitable manner, for example orally, parenterally, pulmonally, nasally, sublingually, lingually, buccally, rectally, transdermally, conjunctival Iy, otically or as an implant.

For these application routes, the active component can be administered in suitable application forms. Useful oral application forms include application_, forms which release the active component rapidly and/or in modified form, such as for example tablets (non-coated and coated tablets, for example with an enteric coating), capsules, sugar-coated tablets, granules, pellets, powders, emulsions, suspensions, solutions and aerosols.

5 Parenteral application can be carried out with avoidance of an absorption step (intravenously, intraarterial Iy, intracardially, intraspinally or intralumbarly) or with inclusion of an absorption (intramuscularly, subcutaneously, intracutaneously, percutaneously or intraperitoneally). Useful parenteral application forms include injection and infusion preparations in the form of solutions, suspensions, emulsions, lyophilisates and sterile powders.

10 Forms suitable for other application routes include for example inhalatory pharmaceutical forms (including powder inhalers, nebulizers), nasal drops/solutions, sprays; tablets or capsules to be administered Iihgually7subrlingually or buccally, suppositories, ear and eye preparations, vaginal capsules, aqueous suspensions (lotions, shake mixtures), lipophilic suspensions, ointments, creams, milk, pastes, dusting powders or implants.

15 The active components can be converted into the recited application forms in a manner known per se. This is carried out using inert non-toxic, pharmaceutically suitable excipients. These include inter alia carriers (for example microcrystalline cellulose), solvents (for example liquid polyethylene glycols), emulsifϊers (for example sodium dodecyl sulphate), dispersing agents (for example polyvinylpyrrolidone), synthetic and natural biopolymers (for example albumin), -20 stabilizers (for example antioxidants such as ascorbic acid), colorants (for example inorganic pigments such as iron oxides) or taste and/or odor corrigents.

For human use, in the case of oral administration, it is recommendable to administer doses of from 0.001 to 50 mg/kg, preferably of 0.01 mg/kg to 20 mg/kg. In the case of parenteral administration, such as, for example, intravenously or via mucous membranes nasally, buccally or inhalationally, it is 25 recommendable to use doses of 0.001 mg/kg to 0.5 mg/kg.

In spite of this, it can be necessary in certain circumstances to depart from the amounts mentioned, namely as a function of body weight, application route, individual behaviour towards the active component, manner of preparation and time or interval at which application takes place. It can for instance be sufficient in some cases to use less than the aforementioned minimum amount, while in 30 other cases the upper limit mentioned will have to be exceeded. In the case of the application of larger amounts, it can be advisable to divide them into a plurality of individual doses spread through the day. The percentages in the tests and examples which follows are, unless otherwise stated, by weight; parts are by weight. Solvent ratios, dilution ratios and concentrations reported for liquid/liquid solutions are each based on the volume.

Examples

Abbreviations: aq. aqueous boc tørf-butoxycarbonyl

CDCl₃ deutero chloroform cone. concentrated

DCI direct chemical ionisation (for MS)

DMAP 4-N,N-dimethylaminopyridine

DMF NN-dimethylformamide

DMSO dimethylsulfoxide

EI electron impact ionisation (for MS)

ESI electro-spray ionisation (for MS) h hour(s)

HOBT hydroxybenzotriazole

HPLC high pressure liquid chromatography

LC-MS liquid chromatography coupled with mass spectroscopy min minute(s)

Mp. melting point

MS mass spectroscopy

NMR nuclear magnetic resonance spectroscopy ofth. of theoretical (yield)

RP reverse phase (for HPLC) rt room temperature

R, retention time (for HPLC) sat. saturated

TFA trifluoroacetic acid

THF tetrahydrofuran LC-MS / HPLC methods:

method 1 (LC-MS): Instrument MS: Micromass ZQ; Instrument HPLC: Waters Alliance 2795; column: Phenomenex Synergi 2μ Hydro-RP Mercury 20 mm x 4 mm; eluent A: 1 1 water + 0.5 ml 50% formic acid, eluent B: 1 1 acetonitrile + 0.5 ml 50% formic acid; gradient: 0.0 min 90% A → 2.5 min 30% A -> 3.0 min 5% A → 4.5 min 5% A; flow: 0.0 min 1 ml/min → 2.5 min/3.0 min/4.5 min 2 ml/min; oven: 5O⁰C; UV detection: 210 nm.

method 2 (HPLC): Instrument: HP 1100 with DAD detection; column: Kromasil 100 RP-18, 60 mm x 2.1 mm, 3.5 μm; eluent A: 5 ml HClO₄ (70%) /1 water, eluent B: acetonitrile; gradient: 0 min 2% B → 0.5 min 2% B → 4.5 min 90% B → 15.0 min 90%B → 15.2 min 2% B → 16 min 2% B; flow: 0.75 ml/min; oven: 3O⁰C; UV detection: 210 nm.

method 3 (LC-MS): Instrument MS: Micromass Quattro LCZ; Instrument HPLC: HP 1100 Series; UV DAD; column: Phenomenex Synergi 2μ Hydro-RP Mercury 20 mm x 4 mm; eluent A: 1 1 water + 0.5 ml 50% formic acid, eluent B: 1 1 acetonitrile + 0.5 ml 50% formic acid; gradient: 0.0 min 90% A → 2.5 min 30% A → 3.0 min 5% A → 4.5 min 5% A; flow: 0.0 min 1 ml/min → 2.5 min/3.0 min/4.5 min 2 ml/min; oven: 5O⁰C; UV detection: 210 nm.

Starting Materials and Intermediates:

Example IA tert-buty] (2-{[4-(benzyloxy)-3-methoxybenzyl]amino}ethyl)carbamate

33.8 g (139.6 mmol) 4-benzyloxy-3-methoxybenzaldehyde are dissolved in 160 ml methanol, 24.6 g (153.5 mmol) tert-butyl(2-aminoethyl)carbamate are added and the resulting suspension is stirred for 2 h at rt. The mixture is cooled to O⁰C and 26.4 g (697.9 mmol) sodium borohydride is added in portions. After stirring over night the solution is diluted with water and extracted three times with dichloromethane (aq. layer is saturated with sodium chloride). The combined organic layers are dried over magnesium sulfate and concentrated in vacuo. The crude product is purified by

' chromatography on silica gel (gradient dichloromethane / methanol 100:1, 50:1, 20:1.) to yield

47.68 g (88% of th.) of the title compound.

LC-MS (method 1): R₄ = 1.50 min, m/z = 387 (M+H)⁺

¹H-NMR (300 MHz, DMSO-d₆): δ = 7.50-7.25 (m, 5H), 6.90 (m, 2H), 6.80-6.70 (m, 2H), 5.05 (s, 2H), 3.75 (s, 3H), 3.60 (s, 2H), 3.00 (m, 2H), 2.50 (m, 2H), 1.40 (s, 9H).

Example 2A tert-buty l-(3 - { [4-(benzy loxy)-3 -methoxybenzy 1] amino } propy l)carbamate

6.31 g (26.04 mmol) 4-benzyloxy-3-methoxybenzaldehyde are dissolved in 30 ml methanol, 4.99 g (28.64 mmol) ter?-butyl(3-aminopropyl)carbamate are added and the resulting suspension is stirred for 2 h at rt. The mixture is cooled to O⁰C and 4.93 g (130.2 mmol) sodium borohydride is added in portions. After stirring over night the solution is diluted with water and extracted three times with dichloromethane (aq. layer is saturated with sodium chloride). The combined organic layers are dried over magnesium sulfate and concentrated in vacuo. The crude product is purified by chromatography on silica gel (gradient dichloromethane / methanol 100:1, 50:1, 20:1.) to yield 9.7 g (93% of th.) of the title compound.

HPLC (method 2): R₁ = 3.37 min,

MS: m/z = 401 (M+H)⁺

¹H-NMR (300 MHz, DMSO-d₆): δ = 7.47-7.27 (m, 5H), 6.90-6.95 (m, 2H), 6.81-6.70 (m, 2H), 5.04 (s, 2H), 3.75 (s, 3H), 3.58 (s, 2H), 3.00-2.90 (m, 2H), 2.47-2.40 (m, 2H), 1.58-1.48 (m, IH), 1.45 (s, 9H).

Preparation Examples:

Example 1 phenyl-[4-(benzyloxy)-3-methoxybenzyl] {2-[(re/-Nbutoxycarbonyl)amino]ethyl}carbamate

200 mg (0.52_mmol)_rerr-butyl(2-{[4-(benzyloxy)-3-methoxybenzyl]amino}ethyl)carbamate are dissolved in 2 ml dichloromethane and cooled between O⁰C and 10⁰C. 0.144 ml (1.04 mmol) triethylamine and 97.2 mg (0.62 mmol) phenylchloroformate are added. After addition is completed the cooling bath is removed and the mixture stirred at rt for 1 h. Die reaction mixture is diluted with dichloromethane, washed with water and brine, dried over sodium sulfate and concentrated in vacuo. The crude product is purified by chromatography on silica gel (gradient cyclohexane / ethyl acetate 3: 1 to 2: 1) to yield 260 mg (99% of th.) of the title compound.

LC-MS (method 1): R, = 2.66 min, m/z = 507 (M+H)⁺

¹H-NMR (300 MHz, DMSOd₆): δ = 7.50-7.27 (m, 10H), 6.96-6.65 (m, 4H), 5.12 (s, 2H), 5.05 (s, 2H), 4.48 (s, 2H), 3.72/3.62 (s, together 3H), 3.25-3.17 (m, 2H), 3.08-3.0 (m, 2H), 1.38 (s, 9H).

Example 2 benzyl-[4-(benzyloxy)-3-methoxybenzyl]{2-[(fer/-butoxycarbonyl)amino]ethyl}carbamate

200 mg (0.52 mmol) teA7-butyl(2-{[4-(benzyloxy)-3-methoxybenzyl]amino}ethyl)carbamate are dissolved in 2 ml dichloromethane and cooled between O⁰C and 1O⁰C. 0.144 ml (1.04 mmol) triethylamine and 106 mg (0.62 mmol) benzylchlorofprmate are added. After addition is completed the cooling bath is removed and the mixture stirred at rt for 1 h. Die reaction mixture is diluted with dichloromethane, washed with water and brine, dried over sodium sulfate and concentrated in vacuo. The crude product is purified by chromatography on silica gel (gradient cyclohexane / ethyl acetate 3:1 to 2:1) to yield 260 mg (99% of th.) of the title compound.

LC-MS (method 1): R, = 2.83 min, m/z = 520 (M+H)⁺

¹H-NMR (300 MHz, DMSO-d₆): δ = 7.50-6.70 (m, 14H), 5.15 (s, 2H), 5.05 (s, 2H), 4.45/3.92 (s, together 2H), 3.80 (s, 3H), 3.40-3.10 (m, 4H), 1.40/1.34 (s, together 9H).

Example 3 phenyl-[4-(benzyloxy)_:3-methoxybenzyl] {3-[(?erf-butoxycarbonyl)amino]propyl}carbamate

200 mg (0.5 mmol) ferNbutyl(3-{[4-(benzyloxy)-3-methoxybenzyl]amino}propyl)carbamate are dissolved in 2 ml dichloromethane and cooled between O⁰C and 1O⁰C. 0.14 ml (1.0 mmol) triethylamine and 93.8 mg (0.60 mmol) phenylchloroformate are added. After addition is completed the cooling bath is removed and the mixture stirred at rt for 1 h. Die reaction mixture is diluted with dichloromethane, washed with water and brine, dried over sodium sulfate and concentrated in vacuo. The crude product is purified by chromatography on silica gel (gradient cyclohexane / ethyl acetate 5:1 to 2:1) to yield 220 mg (85% of th.) of the title compound.

LC-MS (method 1): R, = 2.83 min, m/z = 520 (M+H)⁺

¹H-NMR (300 MHz, DMSO-(I₆): δ = 7.48-6.75 (m, 14H), 5.12 (s, 2H), 5.05 (s, 2H), 3.98 (d, 2H), 3.75 (s, 3H), 3.35-3.3 (m, 2H), 2.97-2.92 (m, 2H), 1.78-1.62 (m, 2H), 1.38 (s, 9H).

Example 4 benzyl-[4-(benzyloxy)-3-methoxybenzyl] {3-[(/er/-butoxycarbony])amino]propyl}carbamate

200 mg (0.52 mmol) ?err-butyl(3-{[4-(benzyloxy)-3-methoxybenzyl]amino}propyl)carbamate are dissolved in 2 ml dichloromethane and cooled between O⁰C and 10⁰C. 0.14 ml (1.0 mmol) triethylamine and 102 mg (0.6 mmol) benzylchloroformate are added. After addition is completed the cooling bath is removed and the mixture stirred at rt for 1 h. Die reaction mixture is diluted with dichloromethane, washed with water and brine, dried over sodium sulfate and concentrated in vacuo. The crude product is purified by chromatography on silica gel (gradient cyclohexane / ethyl acetate 3:1 to 2: 1) to yield 262 mg (98% of th.) of the title compound.

LC-MS (method 1): R, = 2.73 min, m/z = 535 (M+H)⁺

¹H-NMR (400 MHz, DMSO-d₆): δ = 7.55-7.28 (m, 10H), 6.96 (d, IH), 6.86-6.68 (m, 3H), 5.12 (s, 2H), 5.05 (s, 2H), 4.37 (s, 2H), 3.70/3.61 (s, together 3H), 3.20-3.12 (m, 2H), 2.93-2.85 (m, 2H), 1.63-1.55 (m, 2H), 1.35 (s, 9H).

Example S

4-nitrophenyl-[4-(benzyloxy)-3-methoxybenzyl]{2-[(/er?-butoxycarbonyl)amino]ethyl}carbamate

1 g (2.6 mmol) tert-buty 1(2- {[4-(benzyloxy)-3-methoxybenzyl] amino }ethyl)carbamate are dissolved in 20 ml ethanol. 0.54 ml (3.9 mmol) triethylamine and 678 mg (3.4 .mmol) A- nitrophenylchloroformate are added (temperature below 3O⁰C). After the addition is completed the mixture is stirred at rt for 1.5 h. Die reaction mixture is transferred ontα ice-water and the pH is adjusted to 3-4. The precipitated solid is collected by filtration, washed three times with water and dried in high vacuum to yield 1.1 g (77% of th.) of the title compound.

LC-MS (method 1): R₁ = 2.69 min, m/z = 552 (M+H)⁺

¹H-NMR (400 MHz, DMSO-d₆): δ = 8.34-8.27 (m, 2H), 7.50-7.30 (m, 6H), 7.10-6.94 (m, 3H), 6.85 (m, IH), 5.12 (s, 2H), 5.08 (s, 2H), 4.47/4.45 (s, together 2H), 3.79 (s, 3H), 3.40-3.30 (m, 2H), 3.23-3.16 (m, 2H), 1.40/1.32 (s, together 9H).

Example 6 rαc-l-phenylethyl-[4-(benzyloxy)-3-methoxybenzyl]{2-[(?e^-butoxycarbonyI)amino]ethyl carbamate

335.6 mg (2.07 mmol) carbonyldiimidazole are added to a solution of 0.175 ml (1.45 mmol) (+/-)- phenylethylalcohol in 2 ml anhydrous THF. The mixture is stirred 1 h at rt until 400 mg (1.04 mmol) ferr-butyl(2-{[4-(benzyloxy)-3-methoxybenzyl]amino}ethyl)carbamate are added. The mixture is stirred 5 h at rt, and after addition of a catalytic amount of 4-dimethylaminopyridine additional 96 h at reflux. After cooling to rt the mixture is diluted with dichloromethane, washed with IN hydrochloric acid solution and brine, dried over magnesium sulfate and concentrated in vacuo. The product is isolated from the crude mixture after purification by reverse phase HPLC (water-acetonitrile gradient) to yield 380 mg (69% of th.) of the title compound.

LC-MS (method 1): R, = 2.92 min, m/z = 535 (M+H)⁺

¹H-NMR (400 MHz, DMSOd₆): δ = 7.5-7.3 (m, 8H), 7.20-7.10 (m, 2H), 6.98-6.78 (m, 3H), 6.69 (t, IH), 5.75 (q, IH), 5.05 (d, 2H), 4.47-4.24 (m, 2H), 3.69 (bs, 3H), 3.35-3.0 (m, 4H), 1.47 (dd, 3H), 1.47 (s, 9H). Example 7 rac- 1 -(4-fluorophenyl)ethyl-[4-(benzyloxy)-3-methoxybenzyl] {2-[(ferf-butoxycarbonyl)amino]- ethyl} carbamate

335.6 mg (2.07 mmol) carbonyldiimidazole are added to a solution of 0.18 ml (1.45 mmol) (+/-)-4- fluoro-phenylethylalcotiol in 2 ml anhydrous THF. The mixture is sjtirred 1 h at rt until 400 mg (1.04 mmol) terf-butyl(2-{[4-(benzyloxy)-3-methoxybenzyl]amino}ethyl)carbamate are added. The mixture is stirred 5 h at rt, and after addition of a catalytic amount of 4-dimethylaminopyridine additional 96 h at reflux. After cooling to rt the mixture is diluted with dichloromethane, washed with IN hydrochloric acid solution and brine, dried over magnesium sulfate and concentrated in vacuo. The product is isolated from the crude mixture after purification by reverse phase HPLC (water-acetonitrile gradient) to yield 385 mg (67% of th.) of the title compound.

LC-MS (method 1): R, = 2.93 min, m/z = 553 (M+H)⁺

¹H-NMR (400 MHz, DMSOd₆): δ = 7.47-7.28 (m, 9H), 7.0-7.67 (m, 4H), 5.74 (q, IH), 5.04 (d, 2H), 4.51-4.25 (m, 2H), 3.50-3.0 (m, 4H), 1.48 (m, 3H), 1.47 (s, 9H).

General procedure A, cleavage of the BOC group:

A stirred solution of a BOC derivative in 1,4-dioxone (lg/ml) is treated with 10 equivalents of hydrochloric acid in 1,4-dioxane (4 molar solution) at rt for 1 h. Methanol is added to the mixture till a homogeneous solution is obtained. The product is isolated from the crude solution after purification by reverse phase HPLC (water-acetonitrile gradient) and concentration in vacuo as a hydrochloric acid salt. Example 8 phenyl-(3-aminopropyl)[4-(benzyloxy)-3-methoxybenzyl]carbamate hydrochloride

189 rag (0.36 mmol) phenyl-[4-(benzyloxy)-3-memoxybenzyl] {3-[(?erNbutoxycarbonyl)amino]- propyl} carbamate are deprotected according to general procedure A to yield 131 mg (79% of th.) of the title compound.

LC-MS (method 3): R, = 1.77 min, m/z = 421 (M-HCRH)⁺

¹H-NMR (300 MHz, DMSOd₆): δ = 7.76 (bs, 3H), 7.47-6.83 (m, 13H), 5.08 (s, 2H), 4.56/4.43 (s, together 2H), 3.89 (s, 3H), 3.75 (s, 3H), 3.4-3.3 (m, 2H), 2.87-2.79 (m, 2H), 1.95-1.70 (m, 2H).

Example 9

benzyl-(2-aminoethyl) [4-(benzyloxy)-3 -methoxybenzy 1] carbamate hydrochloride

190 mg (0.37 mmol) benzyl-[4-(benzyloxy)-3-methoxybenzyl] {2-[(/eτ-?-butoxycarbonyl)amino]- ethyl} carbamate are deprotected according to general procedure A to yield 147.6 mg (77% of th.) of the title compound.

LC-MS (method 3): R₄ = 1.83 min, m/z = 421 (M-HCHH)⁺

¹H-NMR (300 MHz, DMSO-d₆): δ = 7.98 (bs, 3H), 7.46-7.30 (m, 10H), 7.01-6.73 (m, 3H), 5.15 (s, 2H), 5.05 (s, 2H), 4.42 (s, 2H), 3.72/3.63 (s, together 3H), 3.50-3.40 (m, 2H), 2.97-2.90 (m, 2H). Example 10 phenyl-(2-aminoethyl)[4-(benzyloxy)-3-methoxybenzyl]carbamate hydrochloride

220 mg (0.43 mmol) phenyl-[4-(benzyloxy)-3-methoxybenzyl] {2-[(?erf-butoxycarbonyl)amino]- ethyl} carbamate are deprotected according to general procedure A to yield 67.6 mg (36% of th.) of the title compound.

LC-MS (method 3): R, = 1.74 min, m/z = 407 (M-HCRH)⁺

¹H-NMR (300 MHz, DMSOd₆): δ = 7.98 (bs, 3H), 7.48-7.32 (m, 7H), 7.28-6.84 (m, 6H), 5.09 (s, 2H), 4.52 (d, 2H), 3.79 (s, 3H), 3.60-3.45 (m, 2H), 3.09-2.98 (m, 2H).

Example 11 benzyl-(3-aminopropyl)[4-(benzyloxy)-3-methoxybenzyl]carbamate hydrochloride

207 mg (0.39 mmol) benzyl-[4-(benzyloxy)-3-methoxybenzyl]{3-[(fer^butoxycarbonyl)amino]- propyl} carbamate are deprotected according to general procedure A to yield 144 mg (79% of th.) of the title compound.

LC-MS (method 1): R₁ = 1.73 min, m/z = 435 (M-HCB-H)⁺

¹H-NMR (300 MHz, DMSOd₆): δ = 7.68 (bs, 3H), 7.47-7.30 (m, 10H), 6.98 (d, IH), 6.89-6.71 (m, 2H), 5.14 (s, 2H), 5.06 (s, 2H), 4.39 (s, 2H), 3.71/3.65 (s, together 3H), 3.35-3.25 (m, 2H), 2.79- 2.72 (m, 2H), 1.80-1.72 (m, 2H). Example 12 rac-l-(4-fluorophenyl)ethyl-(2-aminoethyl)[4-(benzyloxy)-3-methoxybenzyl]carbamate hydrochloride

200 mg (0.36 mmol) rαc-l-(4-fluorophenyl)ethyl-[4-(benzyloxy)-3-methoxybenzyl] {2-[(ter£- butoxycarbonyl)amino]ethyl}carbamate are deprotected according to general procedure A to yield 38.7 mg (22% of th.) of the^'title^* compound.

LC-MS (method 3): R, = 1.86 min, m/z = 453 (M-HC1+H)⁺

¹H-NMR (400 MHz, DMSO-Ci₆): δ = 7.95 (bs, 3H), 7.50-7.30 (m, 7H), 7.21-7.12 (m, 2H), 7.0 (m, IH), 6.83 (s, IH), 6.75 (m, IH), 5.79 (q, IH), 5.07 (s, 2H), 4.48-4.29 (m, 2H), 3.68 (s, 3H), 3.55- 3.35 (m, 2H), 2.95-2.88 (m, 2H), 1.50 (bs, 3H).

Example 13 rαc-l-phenylethyl-(2-aminoethyl)[4-(benzyloxy)-3-methoxybenzyl]carbamate hydrochloride

200 mg (0.36 mmol) rαc-l-phenylethyl-[4-(benzyloxy)-3-methoxybenzyl] {2-[(ter/-butoxy- carbonyl)amino]ethyl}carbamate are deprotected according to general procedure A to yield 77 mg (44% of th.) of the title compound.

LC-MS (method 3): R, = 1.84 min, m/z = 435 (M-HCKH)^{+ 1}H-NMR (400 MHz, DMSO-d₆): δ = 8.0 (bs, 3H), 7.44-7.27 (m, 10H), 7.03-6.72 (m, 3H), 5.78 (q, IH), 5.05 (s, 2H), 4.50-4.29 (m, 2H), 3.67 (s, 3H), 3.60-3.35 (m, 2H), 2.95-2.89 (m, 2H), 1.50 (bs, 3H).

B. Evaluation of physiological activity

The potential Cold Menthol Receptor - 1 (CMR-I) antagonistic activity of the compounds of the invention may be demonstrated, for example, using the following assays:

Measurement of the menthol-induced Ca²⁺ influx in HEK293 Cell expressing CMR-I receptor (Assay 1)

A cell-based calcium influx assay using HEK293 cells stably expressing human CMR-I is used to identify CMR-I receptor-antagonists. Menthol, a CMR-I specific agonist, is used for stimulation of these cells, inducing an increase in intracellular calcium. This menthol-induced Ca²⁺ increase is traced by fluorescence measurement. Therefore the cells are loaded with fluo4-AM prior to stimulation. For testing inhibitors the cells are preincubated with various concentrations of the compound before menthol stimulation. The potency of potential CMR-I inhibitors is quantified by measuring decrease of fluorescence .

Table A

Measurement of the menthol-induced Ca²⁺ influx in primary cultured rat dorsal root ganglia neurons (Assay 2)

Since CMR-I is expressed on DRG (C-fibers), in which this receptor mediates the altered afferent information in overactive bladder; primary cultures of rat DRG are used as functional in vitro test. Stimulation of the cells is done with menthol and cold and the induced calcium influx is quantified by fluorescence in the presence or absence of CMR-I inhibitors.

Preparation of primary cultured rat DRG neurons: DRG are prepared from Zucker rats (30 days in age) and neuronal cells are dispersed in 0.1% collagenase. After removal of Schwann cells by adhering to a culture plate, non-adherent neuronal cells are recovered and cultured on laminin- and poly-D-lysine coated 384 well plates for 2 days in the presence of 50 ng/ml rat NGF and 50 μM 5- fluorodeoxyuridine.

Measurement of Ca²⁺: Rat DRG neurons are suspended in a culture medium and seeded into 384- well plates (black walled clear-base / Nalge Nunc International). Following the culture for 48 hrs the medium is changed to 2 μM Fluo-4 AM (Molecular Probes) and 0.02% Puronic F-127 in assay buffer (Hank's balanced salt solution (HBSS), 17 mM HEPES (pH7.4), 1 mM Probenecid, 0.1% bovine serum albumin (BSA)) and the cells are incubated for 60 min at 25⁰C. After washing twice with assay buffer the cells are incubated with a test compound or vehicle (dimethylsulfoxide) for 20 min at 25⁰C. The fluorescence change indicating mobilization of cytoplasmic Ca²⁺ is measured for 60 sec after the stimulation with 50 μM menthol. The fluorescence change is calculated in the samples treated with a test compound and vehicle respectively. Inhibitory effect of the compound is calculated by a comparison of the values.

Measurement of the micturition frequency in guinea pigs in vivo (Assay 3)

Experiments are performed according to the principles of the national law for the protection of laboratory. Female Guinea Pigs (300-350g) are anaesthetized with urethane (1 mg/kg i.p.). A midline abdominal incision is performed, both ureters are exposed and ligated, a catheter is implanted in the bladder pole and ^"the abdomen is closed. For administration of the compounds the vena jugularis is exposed and canulated with a catheter. After this surgery the bladder catheter is connected via a t-shaped tube to an infusion pump (Braun Perfusor® compact) and to a pressure transducer (BioResearch Center, MLT0698, Nagoya). Saline is infused and intrabladder pressure is registered. After 1 h of equilibration period and the establishment of constant voiding cycles, menthol (0.6 mM) is added to the infused saline. At this point also vehicle (control group) or

CMR-I inhibitors are administered i.v. as bolus injection. The effect of treatment on the micturition interval (corresponding to bladder capacity) and micturition pressure is calculated and compared between vehicle-treated and compound-treated groups.

C; Operative examples relating to pharmaceutical compositions

The compounds according to the invention can be converted into pharmaceutical preparations as follows:

Tablet

Composition:

100 mg of the compound of Example 1, 50 mg of lactose (monohydrate), 50 mg of maize starch (native), 10 mg of polyvinylpyrrolidone (PVP 25) (from BASF, Ludwigshafen, Germany) and 2 mg of magnesium stearate.

Tablet weight 212 mg, diameter 8 mm, curvature radius 12 mm.

Preparation:

The mixture of active component, lactose and starch is granulated with a 5% solution (m/m) of the PVP in water. After drying, the granules are mixed with magnesium stearate for 5 min. This mixture is moulded using a customary tablet press (tablet format, see above). The moulding force applied is typically 15 kN. '

Orally administrable suspension

Composition:

1000 mg of the compound of Example 1, 1000 mg of ethanol (96%), 400 mg of Rhodigel (xanthan gum from FMC, Pennsylvania, USA) and 99 g of water.

A single dose of 100 mg of the compound according to the invention is provided by 10 ml of oral suspension.

Preparation:

The Rhodigel is suspended in ethanol and the active component is added to the suspension. The water is added with stirring. Stirring is continued for about 6h until the swelling of the Rhodigel is complete. % Solution for intravenous administration:

Composition:

1 mg of the compound of Example 1, 15 g of polyethylene glycol 400 and 250 g of water for injection.

Production:

The compound of Example 1 is dissolved with polyethylene glycol 400 in the water with stirring., The solution is sterilized by filtration (pore diameter 0.22 μm) and dispensed under aseptic conditions into heat-sterilized infusion bottles. These are closed with infusion stoppers and crimped caps.

Claims

We claim

1. A compound of the general formula (I)

wherein

R¹ -represents hydrogen or halogen,

R² represents hydrogen or halogen,

R³ represents hydrogen or halogen,

R⁴ represents chlorine, fluorine, nitro, trifluoromethyl, trifluoromethoxy, C_rC₄-alkyl or Ci-C₄-alkoxy,

R⁵ represents hydrogen or halogen,

R⁶ represents C₃-C₈-alkyl, C₃-C₇-cycloalkyl, C₆-Cio-aryl, 5- to 10-membered heteroaryl or a group of the formula -Y-R⁹,

wherein cycloalkyl can be further substituted with one to three identical or different radicals selected from the group consisting of Ci-C₄-alkyl,

and

wherein aryl and heteroaryl can be further substituted with one to three identical or different radicals selected from the group consisting of halogen, nitro, amino, hydroxy, trifluoromethyl, Q-Ce-alkyl, CpCβ-alkoxy and C_rC₆-alkylamino,

and

wherein Y represents Ci-C₄-alkandiyl,

R⁹ represents C₃-C₇-cycloalkyl, phenyl or 5- to 10-membered heteroaryl,

wherein cycloalkyl can be further substituted with one to three identical or different radicals selected from the group consisting of

C,-C₄-alkyl,

and

wherein phenyl and heteroaryl can be further substituted with one to three identical or different radicals selected from the group consisting of halogen, nitro, amino, hydroxy, trifluoromethyl, C_r

C_δ-alkyl, CpCg-alkoxy and Ci-Cβ-alkylamino,

R⁷ represents Ci-C₆-alkyl,

wherein alkyl is further substituted with one radical selected from the group consisting of amino, mono-alkylamino, Ci -C_halky lcarbonylamino or Ci-C₄- alkoxycarbonylamino,

R⁸ represents hydrogen or C_rC₄-alkyl,

or one of its salts, hydrates and/or solvates.

2. A compound of general formula (I) according to Claim 1, wherein

R¹ represents hydrogen or halogen,

R² represents hydrogen or halogen,

R³ represents hydrogen,

R⁴ represents chlorine, nitro, trifluoromethoxy, Ci-C₃-alkyl or Ci-C₃-alkoxy,

R⁵ represents hydrogen,

R⁶ represents C₃-C₈-alkyl, C₃-C₇-cycloalkyl, phenyl, 5- or 6-membered heteroaryl or a group of the formula -Y-R⁹, wherein cycloalkyl can be further substituted with one to three identical or different radicals selected from the group consisting of Ci-Gj-alkyl,

and

wherein phenyl and heteroaryl can be further substituted with one to three identical or different radicals selected from the group consisting of halogen, nitro, trifluoromethyl, CpCβ-alkyl and Ci-C₆-alkoxy,

and

wherein

Y represents Ci-C₄-alkandiyl,

R⁹ represents C₃-C₇-cycloalkyl, phenyl or 5- or 6-membered heteroaryl,

wherein cycloalkyl can be further substituted with one to three identical or different radicals selected from the group consisting of C_rC₄-alkyl,

and

wherein phenyl and heteroaryl can be further substituted with one to three identical or different radicals selected from the group consisting of halogen, nitro, trifluoromethyl, Ci-Cβ-alkyl and Ci-C₆-alkoxy,

R⁷ represents C_rC₃-alkyl,

wherein alkyl is further substituted with one radical selected from the group consisting of amino, mono-alkylamino or Ci-d-alkoxycarbonylamino,

R⁸ represents hydrogen,

or one of its salts, hydrates and/or solvates.

A compound of general formula (I) according to Claim 1 or 2, wherein

R¹ represents hydrogen, fluorine or chlorine, R² represents hydrogen or fluorine,

R³ represents hydrogen,

R⁴ represents methoxy,

R⁵ represents hydrogen,

R⁶ represents C₃-C₆-alkyl, C₃-C₆-cycloalkyl, phenyl, thienyl, furyl, pyrazolyl or a group of the formula -Y-R⁹,

wherein cycloalkyl can be further substituted with one to two methyl groups,

and

wherein phenyl, thienyl, furyl and pyrazolyl can be further substituted with one to three identical or different radicals selected from the group consisting of fluorine, chlorine, nitro, trifluoromethyl, methyl and methoxy,

and

wherein

Y represents methylen or ethan- 1 , 1 -diyl,

R⁹ represents Ca-Cβ-cycloalkyl, phenyl, thienyl, furyl or pyrazolyl,

wherein cycloalkyl can be further substituted with one to two methyl groups,

and

wherein phenyl, thienyl, furyl and pyrazolyl can be further substituted with one to three identical or different radicals selected from the group consisting of fluorine, chlorine, nitro, trifluoromethyl, methyl and methoxy,

R⁷ represents C₁ -C₂-alkyl, wherein alkyl is further substituted with one radical selected from the group consisting of amino or tert-butoxycarbonylamino,

R⁸ represents hydrogen,

or one of its salts, hydrates and/or solvates.

4. Process for synthesizing a compound of general formula (I) according to Claim 1, by condensing a compound of general formula (II)

wherein R¹, R², R³, R⁴, R⁵, R⁷ and R⁸ have the meaning indicated in Claim 1, [A] with a compound of general formula (LET)

wherein R⁶ has the meaning indicated in Claim 1 , and

X¹ represents a leaving group, such as halogen, preferably chlorine or bromine,

in the presence of a base

or

[B] with a mixture of a carbonic acid derivative and a compound of general formula (FV)

^RVOH Civ),

wherein R⁶ has the meaning indicated in Claim 1.

5. A compound of general formula (I) according to Claim 1, 2 or 3 for the treatment of diseases or disorders.

6. Use of a compound of general formula (I) according to Claim 1, 2 or 3 for the preparation of medicaments.

7. Use according to Claim 6 for the preparation of medicaments for the treatment of urological diseases or disorders.

8. The composition containing at least one compound of general formula (I) according to Claim 1 , 2 or 3 and a pharmacologically acceptable diluent.

9. A composition according to Claim 8 for the treatment of urological diseases or disorders.

10. The process for the preparation of compositions according to Claim 8 and 9 characterized in that the compounds of general formula (I) according to Claim 1 , 2 or 3 together with cu- stomary auxiliaries are brought into a suitable application form.