CA2297095A1

CA2297095A1 - 1-(n-phenylaminoalkyl)-piperazine derivatives substituted at position 2 of the phenyl ring

Info

Publication number: CA2297095A1
Application number: CA002297095A
Authority: CA
Inventors: Rodolfo Testa; Amedeo Leonardi; Gianni Motta; Carlo Riva
Original assignee: Individual
Current assignee: Recordati SA
Priority date: 1997-08-01
Filing date: 1998-07-31
Publication date: 1999-02-11
Also published as: IL134089A0; ITMI971864A1; US6071920A; EP1000047A1; IT1293807B1; KR20010022509A; PL338352A1; ATE256671T1; HUP0004926A2; CN1265654A; CN1127493C; EP1000047B1; NO315232B1; RU2199533C2; NO20000521D0; WO1999006384A1; NZ502804A; HUP0004926A3; NO20000521L; DE69820632D1

Abstract

1-(N-phenylaminoalkyl)-piperazine derivatives of formula (I), (R = H, alkyl-CO, cycloalkyl-CO, substituted cycloalkyl-CO or monocyclic heteroaryl-CO; R1 =
H or lower alkyl; R2 = halogen, alkoxy, phenoxy, NO2, CN, acyl, NH2, NH(acyl), alkyl-SO2NH, alkoxycarbonyl, NH2CO, (alkyl)NHCO, (alkyl)2NCO, (acyl)NHCO, CF3 or polyfluoroalkoxy; B = benzyl or mono- or bicyclic aryl or heteroaryl, all optionally substituted) bind to 5HT1A receptors and are useful for the treatment of neuromuscular dysfunctions of the lower urinary tract. The use of these compounds for the preparation of a medicament for this treatment is claimed, and some of the compounds (with restricted B values) are claimed per se.

Description

1-(N-PHENYLAMINOALKYL)-PIPERAZINE DERIVATIVES SUBSTITUTED AT POSITION 2 OF
TAE PHENYL RING
FIELD OF THE INVENTION
This invention relates to 1-(N-phenylaminoalkyl)-piperazine derivatives substituted at position 2 of the phenyl ring, to pharmaceutical compositions containing them and to uses for such derivatives and compositions.
BACKGROUND OF THE INVENTION
1o In mammals, micturition (urination) is a complex process that requires the integrated actions of the bladder, its internal and external sphincters, the musculature of the pelvic floor, and neurological control over these muscles at three levels (in the bladder wall or sphincter itself, in the autonomic centres of the spinal cord, and in the central nervous system at the level of the pontine micturition centre (PMC) in the brainstem (pons) under the control of cerebral cortex) (De Groat, Neurobiology of Incontinence, (Ciba Foundation Symposium 151:27, 1990). Micturition results from contraction of the detrusor muscle, which consists of interlacing smooth muscle fibres under parasympathetic autonomic control from the sacral spinal cord. A simple voiding reflex is formed by sensory nerves for pain, temperature, and distension that run from the bladder to the sacral cord.
2o However, sensory tracts from the bladder also reach the PMC. resulting in the generation of nerve impulses that normally suppress the sacral spinal reflex arc controlling bladder emptying. Thus, normal micturition is initiated by voluntary suppression of cortical inhibition of the reflex arc and by relaxation of the muscles of the pelvic floor and the external sphincter. Finally, the detrusor muscle contracts and voiding occurs.
Abnormalities of lower urinary tract function, e.g., dysuria, incontinence, and enuresis, are common in the general population. Dysuria includes urinary frequency, nocturia, and urgency, and may be caused by cystitis, prostatitis or benign prostatic hypertrophy (BPH) (which affects about 70% of elderly males), or by neurological disorders.
Incontinence syndromes include stress incontinence, urgency incontinence, and overflow incontinence.
3o Enuresis refers to the involuntary passage of urine at night or during sleep.
Prior to the work of the present inventors, treatment of neuromuscular dysfunction of the lower urinary tract has involved administration of compounds that act directly on the bladder muscles, such as flavoxate, a spasmolytic drug (Ruffman, J.
Int.Med.Res: 16:317, 1988) also active on the PMC (Guarneri et al., Drugs of Today 30:91, 1994), or anticholinergic compounds such as oxybutynin (Andersson, Drugs 35:477, 1988). The use of a~-adrenergic receptor antagonists for the treatment of BPH
is also common but is based on a different mechanism of action. (Lepor, Urology, 42:483, 1993).

However, treatments that involve direct inhibition of the pelvic musculature (including the detrusor muscle) may have unwanted side effects such as incomplete voiding or accommodation paralysis, tachycardia -and dry mouth (Andersson, Drugs 35:477, 1988).
Thus, it would be advantageous if compounds were available that act via the peripheral or central nervous system to, for example, affect the sacral spinal reflex arc and/or the PMC
inhibition pathways in a manner that restores normal functioning of the micturition mechanism.
1-(N-phenyl-N-cyclohexylcarbonyl-2-aminoethyl)-4-(2-methoxyphenyl)-piperazine (compound A) N\/~N~ OMe (A) O ~N \
i0 is described in GB 2263110 and is reported to be a 5-HT,;~ receptor antagonist. It is also disclosed that it can be used for the treatment of central nervous system disorders, for example as an anxiolytic agent in the treatment of anxiety'.
The compounds of the invention, described below, are structurally different from compound A because of the novel substituents present on the aniline ring at the 2 position.
Other differences between the compounds of the present invention and those disclosed in GB 2263110 are the substitutions on the aromatic ring at position 4 of the piperazine ring.
These structural variations are neither disclosed nor suggested by GB 2263110, particularly with regard to compounds that can be used to improve urinary tract function.
2o These structural variations result in compounds that are more potent than compound A in pharmacological tests predictive of activity on the lower urinary tract, in particular for activity against urinary incontinence.
Other compounds which have been found by the present inventors to be useful in the methods of the present invention, e.g., treatment of disorders of the urinary tract, are disclosed in US 4205173, EP 711757, DE 2405441, US 3472854, Chem. Pharm. Bull.
33:1826-1835 (1985), and J. Med. Chem. 7:721-725 (1964), all of which are incorporated by reference.
SUMMARY OF THE INVENTION
3o In one aspect, the invention relates to the use of compounds of the general formula I:

14/09/99 3 ; . ~ ' . rf12-wo2 ; I
R2 R, R~N~CH ~N

~N~B
(I) wherein R represents a cycloalkylcarbonyl, substituted cycloalkylcarbonyl or monocyclic heteroaryl-carbonyl group having from 5 to 7 ring atoms, R, represents a hydrogen atom or a lower alkyl group, R2 represents a halogen atom or an alkoxy, phenoxy, vitro, cyano, acyl, amino, acylamino, alkylsulphonylamino, allcoxycarbonyl, carbamoyl, alkylcarbamoyl, dialkylcarbamoyl, acylcarbamoyl, trifluoromethyl or polyfluoroalkoxy group, and 1o B represents a mono- or bicyclic (C6-C,2)-aryl group, a monocyclic heteroaryl group having from 5 to 7 ring atoms, a bicyclic heteroaryl group having from 9 to 12 ring atoms, or a benzyl group, each of which may be substituted or unsubstituted, for the preparation of a medicament for the treatment of neuromuscular dysfunction of the lower urinary tract in a mammal.
In another aspect, the invention provides compounds of the general formula I
(shown hereinbefore) wherein:
R represents a cycloalkylcarbonyl, substituted cycloalkylcarbonyl or monocyclic heteroaryl-carbonyl group having from 5 to 7 ring atoms, Rl represents a hydrogen atom or a lower alkyl group, 2o R2 represents a halogen atom or an alkoxy, phenoxy, vitro, cyano, acyl, amino, acylamino, alkylsulphonylamino, alkoxycarbonyl, carbamoyl, alkylcarbamoyl, dialkylcarbamoyl, acylcarbamoyl, trifluoromethyl or polyfluoroalkoxy group, and B represents a mono- or bicyclic (C6-C,Z)-aryl group, a monocyclic heteroaryl group having from 5 to 7 ring atoms, a bicyclic heteroaryl group having from 9 to 12 ring atoms, or a benzyl group, each of which may be substituted or unsubstituted, with the proviso that if B represents an alkoxy substituted aryl group, then the alkoxy group must be at position 2 of the aryl ring.
The invention also includes the enantiomers, diastereomers, N-oxides, crystalline forms, hydrates and pharmaceutically acceptable salts of these-compounds, as well as metabolites of these compounds having the same type of activity (hereafter sometimes referred to as "active metabolites").
The invention further provides pharmaceutical compositions comprising a compound of formula I or an enantiomer, diastereomer, N-oxide,. . crystalline form, hydrate or AMENDED SHEET

14/09/99 4 ; ~ ; ~ ~ rfl2-wo2 , , , ~ I , . ' pharmaceutically acceptable salt of such a compound, in admixture with a pharmaceutically acceptable diluent or carrier.
As used herein with reference to variable R cycloalkylcarbonyl includes cyclohexylcarbonyl, substituted cycloalkylcarbonyl includes cyclohexylcarbonyl substituted with alkyl or aryl groups and monocyclic heteroaryl radicals contain one or more hetero atoms (e.g., oxygen, nitrogen and sulphur). Monocyclic heteroarylcarbonyl has the same definition as monocyclic heteroaryl, but also comprises a carbonyl group linked to a carbon atom of the ring.
As used herein with reference to variable B, mono- or bicyclic (C6-C,Z)-aryl group are io exemplified by phenyl and naphthyl. Preferred substituents for aryl radicals include lower alkyl, lower alkoxy (e.g., methoxy, ethoxy, propoxy, and butoxy), lower haloalkoxy (e.g., 2,2,2-trifluoroethoxy), halogen, amino, acylamino, allcylsulphonylamino, and (lower)alkylamino substituents.
As used with respect to variable B, monocyclic heteroaryl radical has the same meaning as for R above, and bicyclic heteroaryl radical means a bicyclic aromatic radical containing one or more heteroatoms (e.g., nitrogen, oxygen, sulphur) and 9 to 12 ring atoms.
Preferred substituents for the benzyl groups B are alkyl, alkoxy, halogen, nitro, cyano, amido, amino, alkylamino, acylamino, alkylsulphonylamino or acyl substituents.
Preferred substituents at B are optionally substituted monocyclic aryl and bicyclic 2o heteroaryl. Most preferred substituents at B are alkoxyphenyl and mononitrogen containing bicyclic heteroaryl.
R preferably represents a cyclohexylcarbonyl, 1-methylcyclohexylcarbonyl, 1-phenylcyclohexylcarbonyl, 3-furylcarbonyl, 3-thienylcarbonyl, 4-pyridylcarbonyl, 3-pyridylcarbonyl or 2-pyrazinylcarbonyl group.
Rl preferably represents a hydrogen atom or a methyl group.
R2 preferably represents an iodine atom or a methoxy, phenoxy, vitro, cyario, acetyl, amino, acetamido, acetoxycarbonyl, carbamoyl, ethylcarbamoyl, dimethylcarbamoyl, cyclohexylcarbonylcarbamoyl, trifluoromethyl, trifluoromethoxy or 2,2,2-trifluoroethoxy group.
3o B preferably represents a 2-methoxyphenyl, 2,5-dichlorobenzyl or 4-indolyl group.
The compounds of the invention are useful treating neuromuscular dysfunctions of the lower urinary tract including without limitation dysuria, incontinence and enuresis. They may be used to ameliorate at least one of urinary urgency, increased urinary frequency, incontinence, urine leakage, enuresis, dysuria, urinary hesitancy, and di~culty in emptying bladder.
AMENDED SHEET

13/09/99 5 ~ : , ' ~ rfi?.-inio2 ~ /
The compounds of the invention are useful for blocking 5-HT1A serotonergic receptors, and, by virtue of this inhibitory activity, for the treatment of CNS disorders due to serotonergic dysfunction such as anxiety, depression, hypertension, sleep/wake cycle disorders, feeding behaviour, sexual function and cognition disorders in mammals, particularly in humans.
DETAILED DESCRIPTION OF THE INVENTION
All patents, patent applications, and literature references cited in the specification are hereby incorporated by reference in their entirety. In the case of inconsistencies, the 1 o present disclosure, including definitions, will prevail.
The present invention encompasses pharmaceutical formulations comprising the compounds disclosed above, as well as methods employing these formulations for treating neuromuscular dysfunction of the lower urinary tract such as dysuria, incontinence, enuresis, and the like. Dysuria includes urinary frequency, nocturia, urgency, and difficulty in emptying the bladder, i.e., a suboptimal volume of urine is expelled during micturition.
Incontinence syndromes include stress incontinence, urgency incontinence, and overflow incontinence. Enuresis refers to the involuntary passage of urine at night or during sleep.
Without wishing to be bound by theory, it is believed that administration of the 5-HTIA
2o receptor antagonists of the invention prevents unwanted activity of the sacral reflex arc and/or cortical mechanisms that control micturition. Thus it is contemplated that a wide range of neuromuscular dysfunctions of the lower urinary tract can be treated using the compounds of the present invention.
An "effective amount" of the compound for treating a urinary disorder is an amount that results in measurable amelioration of at least one symptom or parameter of the disorders described above.
An effective amount for treating the disorder can easily be determined by empirical methods known to those of ordinary skill in the art, such as by establishing a matrix of dosages and frequencies of administration and comparing a group of experimental units or 3o subjects to each point in the matrix. The exact amount to be administered to a patient will vary depending on the state and severity of the disorder and the physical condition of the patient. A measurable amelioration of any symptom or parameter can be determined by a physician skilled in the art or reported by the patient to the physician. It will be understood that any clinically or statistically significant attenuation or amelioration of any symptom or parameter of urinary tract disorders is within the scope of the invention.
Clinically significant attenuation or amelioration means perceptible to the patient and/or to the physician.
~MENL~~Q ~I-ll'~E"f 13/09/99 6 ~ ; , . ' rt1'2=wo2 ; ~ . . ' For example, a single patient may suffer from several symptoms of dysuria simultaneously, such as, for example, urgency and excessive frequency of urination, either or both of which may be reduced using the methods of the present invention. In the case of incontinence, any reduction in the frequency or volume of unwanted passage of urine is considered a beneficial effect of the present methods of treatment.
The -compounds of the present invention may be formulated into liquid dosage forms with a physiologically acceptable carrier, such as, for example, phosphate buffered saline or deionized water. The pharmaceutical formulation may also contain excipients, including preservatives and stabilisers, that are well-known in the art. The compounds can be to formulated into solid oral or non-oral dosage units such as, for example, tablets, capsules, powders, and suppositories, and may additionally include excipients, including without limitation lubricant(s), plasticizer(s), colorant(s), . absorption enhancer(s), bactericide(s), and the like.
Modes of administration include oral and enteral, intravenous, intramuscular, ~5 subcutaneous, transdermal, transmucosal (including rectal and buccal), and by-inhalation routes. Preferably, an oral or transdermal route is used (i.e., via solid or liquid oral formulations, or skin patches, respectively).
The amount of the agent to be administered can range from between about 0.01 and about 25 mg/kg/day, preferably from between about 0.1 and about 10 mg/kg/day and most 2o preferably from between about 0.2 and about 5 mg/kg/day. It will be understood that the single pharmaceutical formulations of the present invention need not contain the entire amount of the agent that is effective in treating the disorder, as such effective amounts can be reached by administration of a plurality of doses of such pharmaceutical formulations.
In a preferred embodiment of the present invention, compounds are formulated in capsules 25 or tablets, each preferably containing 50-200 mg of the compounds of the invention, and are most preferably administered to a patient at a total daily dose of 50-400 mg, preferably 150-250 mg, and most preferably about 200 mg for relief of urinary incontinence and dysfunctions amenable to treatment with 5-HT1A receptor ligands.
The methods, tables and examples provided below are intended to more fully describe 3o preferred embodiments of the invention and to demonstrate its advantages and applicability, without in any way limiting the scope of the invention.
SYNTHESIS OF THE COMPOUNDS OF THE INVENTION
The compounds of the invention may be prepared by the methods illustrated in the 35 following reaction schemes, or by modifications thereof, using readily available starting materials, reagents and conventional synthesis procedures well known to those of ordinary skill in the art.
,~4M~~~i~~t~ vF~t~~T

13/09/99 7 ; ~ ; ~ , v ' rfi12-wc2 ' ~ ' . : . ' , ~ ' ' , ' Unless otherwise specified, the substituents of the compounds and intermediates present in the reaction schemes are defined in the same manner as they are defined above in formula I. One method to synthesise compounds of formula I is depicted in Scheme I:
Scheme 1:
R~
X~~
l_Jn X, (~
I ~ R ~
R2 ~ R~ (I~
Y ~~ ~
(In H~N~X
R~
X NON-B H~N N-B
n ~ ~/
i I
R'-Hal R2 R~ /"'~ --~ I
H.N M N N_B
n Ortho-substituted anilines of formula II (Y = NH2) are alkylated with l,w-disubstituted alkanes (Z) to give product III. The reaction is carried out in an inert organic solvent, preferentially a polar aprotic solvent such as N,N-dimethylformamide (DMF), 1o dimethylsulphoxide (DMSO), dioxane, tetrahydrofuran (THF), acetone, acetonitrile or chlorinated solvents such as dichloromethane, chloroform, 1,2-dichloroethane or a protic solvent such as n-butanol (n-BuOI~. The reactions are generally performed at a temperature between 0 °C and +120 °C, in the presence of a proton acceptor such as triethylamine (Et3N), diisopropylethylamine, or the like, and optionally in the presence of potassium iodide.
In compounds of formula Z, X and X1 can be Cl, Br, I, aryl, or alkylsulphonyloxy groups.
Intermediates of formula III are used in the alkylation of suitable piperazine derivatives IV to give the compounds of formula X.
These alkylations may be carried out in a chlorinated solvent such as dichloromethane, 2o chloroform or 1,2-dichloroethane, or in a polar aprotic solvent such as DMF, THF, acetone, acetonitrile, or in a polar protic solvent such as n-BuOH, etc., or in an apolar ANIEI~DED SHEET

13/09/99 8 , ~ ~ ' ~ ! rf~i 2-wo2 r ~ I , ' ' solvent such as toluene, benzene, n-heptane, etc., at a temperature between 0 °C and 120 °C, optionally in the presence of a proton acceptor, such as Et3N, 4-dimethylaminopyridine, potassium carbonate, caesium carbonate, and the like, and optionally in the presence of potassium iodide.
Piperazines of formula IV which are not commercially available may be prepared by reaction of the suitable B-NH2 derivatives (which generally may be easily obtained by reduction of the corresponding B-N02 derivatives) with bis-(2-chloroethyl)amine or bis-(2-hydroxyethyl)amine in presence of excess hydrogen chloride. These reactions can be performed in aprotic solvents such as dimethylformamide, diglyme or toluene at a 1o temperature between +40 °C and the reflux temperature of the solvent, generally in the presence of a base such as potassium carbonate, caesium carbonate, or the like, and optionally in the presence of potassium iodide.
Compounds of formula V can be conveniently prepared starting from compounds V
in which X is a COO-lower alkyl group and n is n-1. Conventional reduction procedures (e.g., use of lithium aluminium hydride or other metal complex hydrides) afford the corresponding compounds V in which X is CH20H and n is n-1, which can be in turn conventionally converted into compounds of formula V in which X is a leaving group as described above. The starting esters can be prepared by the nucleophilic displacement reaction of a monosubstituted piperazine on the appropriate 2-haloester.
2o Alternative procedures to obtain compounds of formula V consists in alkylating the appropriate monosubstituted piperazine derivatives with a compound with the formula X-CH(RI)(CH2)n-iCHz-OPrG or X-(CH2)"CH(Rl)-X where X is a leaving group and n has the same meaning as above, and PrG is a protecting group (e.g. O-tetrahydropyranyl), which can be removed after alkylation of the piperazine.
2s Another approach to synthesise intermediate compounds of formula III
utilises starting materials with structure II (Y = halogen). These starting materials are reacted with compounds of formula Z in which X and XI are, respectively, NH2 and OH. These alkylation reactions are carried out in an aprotic solvent such as DMF, toluene, or in a polar protic solvent such as n-BuOH, etc., at a temperature between +40 °C and +140 °C, 3o in general using one equivalent or excess of a reagent of formula Z (X=NH2) as a proton acceptor, as described by G. Doleschall et al., Tetrahedron, 32, 57-64 (1976).
The resulting aminoalcohols of formula III (XI = OH) are reacted with a chlorinating agent such as POCl3, SOCl2 or PCIs to give the intermediates, also of formula III
(X1 = Cl), or with an alkyl or arylsulphonyl chloride to give the corresponding sulphonyl esters. These 35 reactions are carried out in an aprotic solvent such as chloroform, DMF, pyridine, and the like at a temperature between +50 °C and the reflux temperature of the solvent.
Compounds of formula X may also be obtained by alkylation of compounds of formula II
(Y = NH2) with intermediates of formula V, in which B, Rl and n have the same meanings AMENDED SHEET

«,. . , ,. , 15/09/99 9 ; ' ; , ' i r~l~-wc2 ; , as above and X is a halogen atom such as chlorine or bromine, or a leaving group such as methanesulphonyloxy or p-toluenesulphonyloxy groups.
These reactions may be carried out without solvent or in an aprotic solvent such as dichloromethane, chloroform, DMF, THF, acetone, acetonitrile or in a protic solvent such as n-butanol, etc. at a temperature between 0 °C and +160 °C, optionally in the presence of a proton acceptor, such as Et3N, potassium carbonate, caesium carbonate, 4-dimethylaminopyridine and the like, and optionally in the presence of potassium iodide. ' Compounds of formula I where R2 is CN can be also obtained from the compounds of formula I in which R2 is CONH2 by dehydration reactions. P205, PCIs, Ph3P, and the like 1 o may be used as dehydrating agents (J. March, Advanced Organic Chemistry, IV Ed., page 1041, Wiley Interscience, 1992). Dehydration reactions may be carried out in a chlorinated solvent such as dichloromethane, chloroform, carbon tetrachloride or in an aprotic solvent such as DMF, toluene, etc. at a temperature between +40 °C and the reflux temperature of the solvent, optionally in the presence of a base such as Et3N.
Alternatively, compounds of formula X may be obtained by arylation of intermediates of formula V (X=NH2) with a starting material of formula II (Y = Cl, Br, F, I or trifluoromethanesulphonyloxy). These reactions may be carried out using the same solvents and conditions as described above or by employing palladium complex catalysis (Synlett,p.329 (1996)).
2o Compounds of formula X are acylated to give compound I by reaction with an appropriate acyl halide R'Hal in which R' represents a cycloalkylcarbonyl or monocyclic heteroarylcarbonyl group and Hal represents a halogen atom. The reaction can be performed in aprotic solvents such as dichloromethane, chloroform, 1,2-dichloroethane, DMF, acetone, acetonitrile, toluene, etc., at temperatures between 0°C
and 100°C, optionally in the presence of an organic base as a proton acceptor such as Et3N, diisopropylethylamine (DIPEA), 4-dimethylaminopyridine, and the like.
Alternatively, compounds with formula I (i.e. where R2=Br, I, OS02F or OS02CF3) in which R is as defined above may be used to synthesise compounds of formula I
in which R2 is CN, CONH2, COCH3 or COOCH3 by reaction of reagents such as trimethylsilyl 3o isocyanate and t-butyl lithium (J. Org. Chem. 55, 3114 (1990)), lithium cyanide and tetrakis(triphenylphosphine)palladium(0) (EP 711757), carbon monoxide-methanol and palladium diacetate in the presence of 1,3-diphenylphosphinopropane (J. Org.
Chem. 59, 6683 (1994)). Such reactions may be carried out in polar or apolar solvent such as THF, toluene, benzene, DMSO, and the like.
Another method to synthesise compounds of formula I in which R, is H is depicted in Scheme 2, below.
AMEPdi~c~ ~H~ET

" . . .. , 15/09/99 lp ~ ~ , ~ ; . , , , . ~ , ; , . , ~ . , rt' 12-w~2 ; , , , ,. .. ., , ,.
Scheme 2.
O-Alk w X Mn _O-Alk I I
I
(~'In ~ R i RZ 20-Aik -'----~ RZ
Y ,N
(II) H ~ H~N~CHO (VIII') O-Alk (VIII) .
R'-Hal H~N N-B
i (IV) i RZ ~ RZ
~,N O-Alk R~.N~nCH R
O-Aik (IX~) (IX) R2 H.N~N N_B
n H~N N-B
R'-H al I (R1=~
Ortho-substituted halobenzenes of formula II (Y = halo) are used to arylate protected aminoalkylaldehydes of formula VII (X=NH2) to give the corresponding protected arylaminoalkylaldehydes VIII. The reaction may be carried out in an aprotic solvent such as pyridine, DMF, toluene, or the like at a temperature between +q.0°C
and 120°C, optionally in the presence of a base such as Et3N or employing palladium complex catalysts as above.
Another route for the preparation of intermediates of formula VIII consists in alkylating 1 o compounds of formula II (Y=NH2) with protected reactive compounds of formula VII (X
= halo) by conventional procedures known to those skilled in the art.
Compounds with formula VIII are stable and are deprotected by standard methods just before their use in the following steps.
Aldehydes of formula VIII', obtained from deprotection of compounds with formula VIII, may be reacted without isolation with N-substituted piperazines IV under reductive conditions to give compounds of formula XI. These reactions may be carried out in polar solvents such as methanol, ethanol or in chlorinated solvents, such as dichloromethane, AMENDED SHEE"f 15/09/99 11 1 ~ _ 1 rt12-..~nro2 chloroform, and the like, using alkali borohydrides such as NaBH4 and NaBH3CN, NaBH(OAc)3 or using borane complexes such as BH3-Py, optionally in the presence of acidic promoter, such as acetic acid, at temperatures between +10°C and 100°C.
Compounds of formula XI may be acylated with R'Hal to give compounds of formula I
by carrying out the reactions in the same conditions as described above for the final step of Scheme 1. Alternatively, intermediates of formula VIII may be acylated with R'Hal to give compounds of formula IX using the same conditions as described above.
Intermediates of formula IX are deprotected by well-known methods just before their use in the final step to give the corresponding aldehydes (IX'), which may be reacted with to appropriate N-substituted piperazines of formula IV using alkali borohydrides such as NaBH4, NaBH3CN or NaBH(OAc)3, optionally in the presence of catalytic amounts of acetic acid, or of a titanium catalyst such as titanium tetraisopropoxide, yielding compounds of formula I. These reactions may be carned out in chlorinated solvents such as dichloromethane or chloroform, or in polar aprotic solvents such as methanol or ethanol at temperatures between +10°C and +100°C.
Example 1 1-IN-(2-nitrophenvl)-N-cvclohexylcarbonvl-~-aminoethyll 4 (2 methoxynhenvll piperazine 2o A mixture of 3.03 g of 2-chloro-1-nitrobenzene, 4.52 g of 1-(2-aminoethyl)-4-(2-methoxyphenyl)-piperazine, and 3.18 g of anhydrous potassium carbonate in 30 ml of n-butanol was stirred for 32 h at reflux. After cooling, the mixture was poured into water, then extracted with ethyl acetate and the organic phase dried on anhydrous sodium sulphate. The crude obtained by evaporating the solvent was purified by flash chromatography (ethyl acetate : petroleum ether 4:6) and the residue obtained after evaporation of the solvents was taken up with diethyl ether, stirred and filtered giving 2.2 g (31%) of 1-[N-(2-nitrophenyl)-2-aminoethylJ-4-(2-methoxyphenyl)-piperazine.
M.p.
117-118 °C.
1H-NMR (CDCl3, 8): 8.50 (bs, 1H, NH), 8.19 (d,lH, aniline H3), 7.45 (dd, 1H, aniline 3o HS), 7.08-6.78 (m, SH, aniline H6 and methoxyphenyl ring CHs), 6.63 (dd, 1H, aniline H4), 3.86 (s, 3H, OCH3), 3.40 (dt, 2H, NHCH CH2), 3.27-3.04 (m, 4H, piperazine protons), 2.80-2.62 (m, 6H, NHCH2CH and piperazine protons).
AMENDED SMEET

13/09/99 12 ' 1 . . , rfi?.-Hra 2 v Cyclohexylcarbonyl chloride (0.98 ml) and triethylamine (1.03 ml) were added in sequence to a solution containing 2.1 g of the compound prepared as described above and 15 ml of 1,2-dichloroethane. The mixture was stirred for 16 h at reflex.
Finally it was cooled, diluted with chloroform, washed with 1N sodium hydroxide and water.
The organic phase was dried on anhydrous sodium sulphate and the crude obtained after evaporation of the solvents was purified via flash chromatography (ethyl acetate petroleum ether 1:1) and subsequently crystallised from cyclohexane giving 1.79 g (65%) of the title compound.
Melting point : 119-121 °C.
to IH-NMR (CDC13, 8): 8.04 (d, 1H, nitrophenyl ring H3), 7.65-7.47 (m, 3H, nitrophenyl ring H4,5,6), 7.10-6.75 (m, 4H, methoxyphenyl ring CHs), 4.15-3.92 (m, 1H, C(O)NCH(~CH2), 3.83 (s, 3H, OCH3), 3.70-3.50. (m, 1H, C(O)NCH(H)CH2), 3.10-2.80 (m, 4H, piperazine protons), 2.80-2.40 (m, 6H, piperazine protons and C(O)NCH2CH ), 2.10-0.75 (m, 11 H, cyclohexyl protons).
By conventional methods, the following salts of the compound of Example 1 were prepared monohydrochloride, m.p. 183-187°C (acetone : diethyl ether) ;
monomethanesulphonate, m.p. 150-153°C (acetone) ;
monomethanesulphonate hydrate, m.p. 136-140°C.
Example 2 1-fN-(2-trifluoromethoxwhenvll-N-cyclohexvlcarbonyl-2-aminoethvll 4 (2 methoxynhenvll-piperazine A solution of 2.09 g of 2-trifluoromethoxyaniline and 3.15 g of 1-(2-chloroethyl)-4-(2-methoxyphenyl)-piperazine in 20, ml of n-butanol was stirred at 100°C
for 2 hours. The mixture was then cooled, diluted with water, alkalinised with 2N sodium hydroxide and extracted with chloroform. The organic phase was dried on anhydrous sodium sulphate, evaporated until dry and the crude purified via flash chromatography (ethyl acetate petroleum ether 3:7) and subsequently crystallised from ethanol giving 0.55 g (12%) of 1-[N-(2-trifluoromethoxyphenyl)-2-aminoethyl]-4-(2-methoxyphenyl)-piperazine.
Melting point: 69.5-71 °C.
1H-NMR (CDCl3, b): 8.02-7.85 (br, 1H, NH), 7.43-7.27 (m, 2H, aniline CHs), 7.03-6.80 (m, 4H, methoxyphenyl ring CHs), 6.72 (dd, 1 H, aniline CH), 6.57 (t, 1 H, aniline CH), 3.86 (s, 3H, OCH3), 3.43-3.23 (m, 2H, NHCH CH2), 3.23-3.03 (m, 4H, piperazine protons), 2.85-2.60 (m, 6H, piperazine protons and NHCH2CH ).
The title compound was prepared following the procedure described in Example 1, second step, except that 1-[N-(2-trifluoromethoxyphenyl)-2-aminoethyl]-4-(2-methoxyphenyl)-piperazine, prepared as described above, was used in place of 1-[N-(2-nitrophenyl)-2-AMENDED SHEET

. ., .~, ,. ..
13109/99 13 ; ' : ~ , ' rf1,2=wo2 ; : 1 ' ' ; ' ' ' , aminoethyl]-4-(2-methoxyphenyl)-piperazine and that 4-dimethylaminopyridine was used in place of triethylamine, the mixture being heated for 1.5 h at reflux. The crude material was purified via flash chromatography (ethyl acetate : petroleum ether 4:6).
Yield: 44%.
1H-NMR (CDC13, 8): 7.48-7.25 (m, 4H, trifluoromethoxyaniline ring CHs), 7.02-6.81 (m, 4H, methoxyphenyl ring CHs), 4.40-4.20 (m, 1H, C(O)NCH(H~CH2), 3.84 (s, 3H, OCH3), 3.36-3.18 (m, 1H, C(O)NCH(H)CH2), 3.10-2.90 (m, 4H, piperazine protons), 2.75-2.45 (m, 6H, piperazine protons and C(O)NCH2CH ), and 2.03-1.80 {m, 1H, CHC(O)), 1.75-0.80 (m, lOH, cyclohexyl protons).
to Example 3 1-f N-(2-nhenoxvnhenvll-N-cvclohexvlcarbonyl-2-aminoethvl]-4-(2-methoxyphenvl) piperazine Operating as described in Example 2, first step, but using 2-phenoxyaniline in place of 2 trifluoromethoxyaniline, crude 1-[N-(2-phenoxyphenyl)-2-aminoethyl]-4-(2 methoxyphenyl)-piperazine was obtained. This was purified via flash chromatography (ethyl acetate). The residue was dissolved in ethanol, the solution was acidified by using 2N ethanolic hydrogen chloride and subsequently diethyl ether was added giving 45% of 1-[N-{2-phenoxyphenyl)-2-aminoethyl]-4.-(2-methoxyphenyl)-piperazine . 3HCl after filtration.
2o Melting point: 184-187 °C.
1H-NMR (DMSO-d6, 8): 8.70-7.60 (m, 4H, 3+NH and NH), 7.32 (t, 2H, aromatics), 7.10-6.85 (m, 9H, aromatics), 6.80 (dd, 1H, aromatic), 6.63 (t, 1H, aromatic), 3.78 (s, 3H, OCH3), 3.65-3.00 (m, 12H, piperazine protons and NHCH CH ).
The title compound was prepared following the procedure described in Example 2, second step, except that 1-[N-(2-phenoxyphenyl)-2-aminoethyl]-4-(2-methoxyphenyl)-piperazine, prepared as described above, was used in place of 1-[N-(2-trifluoromethoxyphenyl)-2 aminoethyl]-4-(2-methoxyphenyl)-piperazine, the mixture being heated for 2.5 h at reflux.
The crude was purified via flash chromatography (ethyl acetate : petroleum ether 7:3).
Yield: 32%.
1H-NMR (CDC13, 8): 7.40-7.20 (m, 4H, aromatics), 7.10 (t, 2H, aromatics), 7.05-6.80 (m, 7H, aromatics), 4.21-4.03 (m, 1H, C(O)NC(H)HCH2), 3.83 (s, 3H, OCH3), 3.55-3.40 (m, 1H, C(O)NC(H)HCH2), 3.10-2.93 (m, 4H, piperazine protons), 2.75-2.50 (m, 6H, piperazine protons and C(O)NCH2CH ), and 2.25-2.05 (m, 1H, CHC(O)), 1.80-0.80 (m, l OH, cyclohexyl protons).
Example 4 1-f N-(2-iodonhenvll-N-cvclohexvlcarbonvl-2-aminoethvl]-4-(2-methoxyphen~,l piperazine Ai~~~Vr 13/09/99 14 : ~ ~ ~ ~rt12-wo2 , ~ ' , , : ' ' , , : ' 1-[N-(2-Iodophenyl)-2-aminoethyl]-4-(2-methoxyphenyl)-piperazine was prepared following the procedure described in Example 2, first step, except that 2-iodoaniline was used in place of 2-trifluoromethoxyaniline and that heating was at 90°C
for 7 h. The crude was purified via flash chromatography (ethyl acetate : petroleum ether 1:4).
Yield: 37%.
1H-NMR (CDC13, 8): 7.65 (dd, 1H, aniline H3), 7.20 (dd, 1H, aniline HS), 7.07-6.80 (m, 4H, methoxyphenyl ring CHs), 6.55 (dd,lH, aniline H4), 6.45 (dd, 1H, aniline H6), 5.15-5.03 (br, 1H, NH), 3.87 (s, 3H, OCH3), 3.30-3.05 (m, 6H, piperazine protons and NHCH CH2), 2.83-2.65 (m, 6H, piperazine protons and NHCH2CH ).
The title compound was prepared following the procedure described in Example 2, second to step, except that 1-[N-{2-iodophenyl)-2-aminoethyl]-4-(2-methoxyphenyl) piperazine, prepared as described above, was used in place of 1-[N-(2-trifluoromethoxyphenyl)-2 aminoethyl]-4-(2-methoxyphenyl)-piperazine, the mixture being heated for 7 h at reflux.
Yield: 73%.
'H-NMR (CDC13, 8): 8.95 (dd, 1H, iodophenyl ring H3), 7.45-7.35 (m, 2H, iodophenyl ring CHs), 7.15-6.80 (m, SH, methoxyphenyl ring CHs and remaining iodophenyl ring CH), 4.53-4.37 (m, 1H, C(O)NC(I-~HCH2), 3.84 (s, 3H, OCH3), 3.20-2.95 (m, SH, C(O)NC I(_-I)HCHz and piperazine protons), 2.77-2.50 (m, 7H, C(O)NCH2CH , piperazine protons and CHC(O)), 1.90-0.80 (m, l OH, cyclohexyl protons).
2o Example 5 1-[N-(2-nitrophenyll-N-cyclohexylcarbonyl-2-aminoethyll-4-(4-indol~)-piperazine A mixture containing 0.49 g of N-(2-chloroethyl)-2-nitroaniline, prepared according to the procedure described by Ramage G.R. et al. in J. Chem. Soc. 4406-4409 (i952), 0.55 g of 1-(4-indolyl)-piperazine (prepared according to WO 95/33743), 1 ml of triethylamine and 3 ml of dimethylformamide was heated at reflex while stirring under nitrogen for 2.5 h.
After cooling at room temperature, the mixture was poured into water and extracted with dichloromethane. The organic phase was dried on anhydrous sodium sulphate and evaporated to dryness. The residue was purified via flash chromatography (ethyl acetate petroleum ether 3:7) giving 0.35 g (40%) of 1-[N-(2-nitrophenyl)-2-aminoethyl]-4-(4-3o indolyl)-piperazine.
1H-NMR (CDC13, 8): 8.60-8.45 (br, 1H, aniline NH), 8.18 (dd, 1H, aniline H3), 8.20-8.10 (br, 1H, indole NH), 7.43 (td, 1H, aniline HS), 7.20-7.05 (m, 3H, indole H3,6,7 ), 6.85 (dd, 1H, aniline H4), 6.70-6.57 (m, 2H, aniline H6 and indole HS), 6.50 (t, 1H, indolylic H2), 3.45 (q, 2H, NHCH CH2), 3.35-3.25 (m, 4H, piperazine protons), 3.85-2.70 (m, 6H, NHCH2CH and piperazine protons).
The title compound was prepared following the procedure described in Example 2, second step, except that 1-[N-(2-nitrophenyl)-2-aminoethyl]-4-(4-indolyl)-piperazine, prepared as described above, was used in place of 1-(N-(2-trifluoromethoxyphenyl)-2-aminoethyl]-4-P ~ 1='lv ~', r..~., ~ y,:,- ~.-.~
,S ~ i~ ~-~~ s-: L ;.... ~... i 13/09/99 15 ~ ~ ~ rf12~ wo2 ~ . , ; , ' , , : ' (2-methoxyphenyl)-piperazine, the mixture being heated for 5 h at reflux. The crude was purified via flash chromatography (ethyl acetate : petroleum ether 7:3, then only ethyl acetate was used and at the end only dichloromethane). Yield: 32%
IH-NMR (CDC13, 8): 8.37-8.20 (br, 1H, NH), 8.05 (dd, 1H, nitrophenyl ring H3), 7.65 7.45 (m, 3H, nitrophenyl ring H4,5,6), 7.20-7.00 (m, 3H, indole H3,6,7), 6.55 (dd, 1H, indole HS), 6.50 (t, 1H, indole H2), 4.15-3.95 (m, 1H, C(O)NC~i HCH2), 3.70-3.55 (m, 1H, C(O)NC(I~HCHz), 3.25-2.95 (m, 4H, piperazine protons), 2.75-2.45 (m, 7H, C(O)NCH2CH , CHC(O), piperazine protons), 2.10-0.80 (rn, l OH, cyclohexyl protons).
Example 6 1-f N-(2-nitrophenyll-N-cvclohexvlcarbonyl-2-aminoethyll-4-(2.5-dichlorobenzvl)-piperazine 2,5-Dichlorobenzyl chloride (2.01 g) was added to a mixture of 1.94 g of 1 ethoxycarbonyl-piperazine and 3.45 g of anhydrous potassium carbonate in 20 ml of dimethylformamide stirred at room temperature under a nitrogen atmosphere.
After 24 h of stirnng at the same temperature, the reaction mixture was poured into water and extracted with ethyl acetate. The organic phase, which was dried on anhydrous sodium sulphate, was evaporated to dryness under vacuum. The oily residue was purified via flash chromatography (petroleum ether : ethyl acetate 85:15) giving 2 g (63%) of 1-(2,5-dichlorobenzyl)-4-ethoxycarbonyl-piperazine.
1H-NMR (CDCI3, b): 7.50 (d, 1H, aromatic H6), 7.27 (d, 1H, aromatic H3), 7.15 (dd, 1H, aromatic H4), 4.13 (q, 2H, CH3CH O), 3.58 (s, 2H, benzyl CH2), 3.55-3.45 (m, 4H, piperazine protons), 2.50-2.42 (m, 4H, piperazine protons), 1.26 (t, 3H, CH
CH20).
A solution containing 13 g of 1-(2,5-dichlorobenzyl)-4-ethoxycarbonyl-piperazine, prepared as above described, in 35 ml of 37% hydrochloric acid was stirred for 40 h at reflux. Subsequently, 30 ml of water and 30 ml of ethyl acetate were added at room temperature, adjusting the pH to 11 via addition of 35% sodium hydroxide. The organic phase was dried on anhydrous sodium sulphate and evaporated to dryness under vacuum.
The crude was purified via flash chromatography (chloroform : methanol 7:3) giving 4.46 3o g (50%) of 1-(2,5-dichlorobenzyl)-piperazine .
1H-NMR (CDC13, 8): 7.50 (d, 1H, aromatic H6), 7.26 (d, 1H, aromatic H3), 7.14 (dd, 1H, aromatic H4), 3.55 (s, 2H, benzyl CH2), 3.00-2.85 (m, 4H, piperazine protons), 2.55-2.48 (m, 4H, piperazine protons), 1.76 (s, 1H, NH).
1-[N-(2-nitrophenyl)-2-aminoethyl)-4-(2,5-dichlorobenzyl)-piperazine was prepared and 3s purified following the method described in Example 5, first step, but using 1-(2,5-dichlorobenzyl)-piperazine, prepared as above described, in place of 1-(4-indolyl)-piperazine and using 4-dimethylaminopyridine in place of triethylamine and carrying out the reaction at 120°C for 8 h. Yield: 35%.

13/09/99 16 ~ ' : , , 'rf1,2_~.fl2 ; ; r ; , ' . .
'H-NMR (CDC13, 8): 8.45 (bs, 1H, NH), 8.10 (d, 1H, aniline H3), 7.45 (d, 1H, dichlorophenyl ring H6), 7.38 (dd, 1H, aniline H5), 7.25 (d, 1H, dichlorophenyl ring H3), 7.10 (dd, 1H, dichlorophenyl ring H4), 6.77 (d, 1H, aniline H6), 6.55 (dd, 1H, aniline H4), 3.59 (s, 2H, benzyl CH2), 3.35 (dt, 2H, NHCH CH2), 2.73 (t, 2H, NHCH2CH~), 2.70-2.38 (m, 8H, piperazine protons).
The title compound was prepared following the procedure described in Example 1, second step, except that 1-[N-(2-nitrophenyl)-2-aminoethyl)-4-(2,5-dichlorobenzyl)-piperazine, prepared as described above, was used in place of 1-[N-(2-nitrophenyl)-2-aminoethyl]-4-(2-methoxyphenyl)-piperazine, and heating was 12 h at reflux. The crude was purified via 1 o flash chromatography (ethyl acetate : petroleum ether 4:6). Yield: 22%.
1H-NMR (CDCl3, 8): 8.03 (dd, 1H, nitrophenyl ring H3), 7.75-7.40 (m, 4H, dichlorophenyl ring H6 and nitrophenyl ring H4,5,6), 7.25 (d, 1H, dichlorophenyl ring H3), 7.10 (dd, 1H, dichlorophenyl ring H4), 4.05-3.90 (m, 1H, C(O)NC(H)HCH2), 3.65-3.50 (m, 1H, C(O)NC(I~HCH2, 3.52 (s, 2H, benzyl CH2), 2.70-2.20 (m, lOH, C(O)NCH2CH , piperazine protons), 2.00-0.70 (m, 11H, cyclohexyl protons).
Example 7 1- fN-(2-cvclohexylcarbamovlphenvl)-N-cvclohexvlcarbonyl-~-aminoethyl)-4-(~-methoxyphenvlZpinerazine 1-[N-(2-Carbamoylphenyl)-2-aminoethyl]-4-(2-methoxyphenyl)-piperazine was prepared following the procedure described in Example 2, first step, except that 2-aminobenzamide was used in place of 2-trifluoromethoxyaniline. The crude was purified via flash chromatography (ethyl acetate) and subsequently crystallised from ethanol.
Yield: 36%. Melting point: 134-136° C
iH-NMR (CDC13, 8): 8.02-7.85 (br, 1H, NH), 7.41-7.26 (m, 2H, aniline H3,5), 7.05-6.78 (m, 4H, methoxyphenyl ring CHs ), 6.73 (dd, l H, aniline H6), 6.58 (t, 1 H, aniline H4), 5.80-5.45 (br, 2H, CONH2), 3.86 (s, 3H, OCH3), 3.33 (t, 2H, NHCH CH2), 3.20-3.02 (m, 4H, piperazine protons), 2.83-2.62 (m, 6H, NHCH2CH~, and piperazine protons).
The title compound was prepared following the procedure described in Example 2, second 3o step, except that 1-[N-(2-carbamoylphenyl)-2-aminoethyl]-4-(2-methoxyphenyl) piperazine, prepared as above described, was used in place of 1-[N-(2 trifluoromethoxyphenyl)-2-aminoethylJ-4-(2-methoxyphenyl)-piperazine, the mixture being heated for 6 h at reflux in the presence of 2 molar equivalents of cyclohexylcarbonyl chloride. The crude was purified via flash chromatography (dichloromethane :
methanol 95:5). Yield: 55%.
'H-NMR (DMSO-d6, 8): 12.10-11.80 (br, 1H, NH), 8.08 (dd,lH, phenylcarbonyl H3), 7.88-7.68 (m, 2H, phenylcarbonyl H5,6), 7.47 (dt, 1H, phenylcarbonyl H4), 7.00-6.80 (m, 4H, methoxyphenyl ring CHs), 4.50-4.33 (m, 2H, C(O)NCH CH2), 3.75 (s, 3H, OCH3), - . f-,_~ _.~ y I.',, , - .~

13/09/99 17 : , . ~ . 'rf12-wc2 ~ . . : , ' . . : ' , .
3.15-2.85 (m, SH, CHC(O) and piperazine protons), 2.80-2.68 (m, 2H, C(O)NCH2CH
), 2.68-2.54 (m, 4H, piperazine protons), 2.28-2.08 (m, 1H, CHC(O)), 1.97-1.05 (m, 20H, cyclohexyl protons).
Example 8 1-[N-(2-methox c~onylphenvll-N-cvclohexvlcarbonvl-2-aminoethv~-4-(2-methoxyphenvll piperazine A mixture of 0.93 g of methyl anthranilate, 2 g of 1-(2-chloroethyl)-4-(2-methoxyphenyl) piperazine, 0.88 g of sodium acetate and 5 ml of water was stirred for 24 h at reflux. After to cooling to room temperature, the mixture was extracted with ethyl acetate.
The organic phase was dried on anhydrous sodium sulphate and evaporated to dryness. The residue was purified by flash chromatography (dichloromethane : methanol 98:2) giving 0.41 g (18%) of 1-[N-(2-methoxycarbonylphenyl)-2-aminoethyl]-4-(2-methoxyphenyl)-piperazine.
1H-NMR (CDCl3, 8): 7.90 (dd, 1H, aniline H3), 7.90-7.70 (br, 1H, NH), 7.35 (td,lH, aniline HS), 7.06-6.80 (m, 4H, methoxyphenyl ring CHs), 6.70 (dd, 1H, aniline H6), 6.58 (td, 1H, aniline H4), 3.87 and 3.85 (2s, 6H, COOCH3 and OCH3), 3.43-3.30 (m, 2H, NHCH CH2), 3.22-3.05 (m, 4H, piperazine protons), 2.83-2.67 (m, 6H, NHCH2CH~
and piperazine protons).
2o The title compound was prepared following the procedure described in Example 2, second step, except that 1-[N-(2-methoxycarbonylphenyl)-2-aminoethyl]-4-(2-methoxyphenyl)-piperazine, prepared as above described, was used in place of 1-[N-(2-trifluoromethoxyphenyl)-2-aminoethyl]-4-(2-methoxyphenyl)-piperazine, the mixture being heated for 9 h at reflux. The crude was purified by flash chromatography (dichloromethane : methanol 95:5). Yield: 38%
IH-NMR (CDCl3, b): 8.03 (dd, 1H, methoxycarbonylphenyl ring H3), 7.57 (dt, 1H, methoxycarbonylphenyl ring H4), 7.45 (dt, 1H, methoxycarbonylphenyl ring HS), 7.37 (dd, 1H, methoxycarbonylphenyl ring H6), 7.03-6.80 (m, 4H, methoxyphenyl ring CHs), 4.38-4.15 (m, 1H, C(O)NC(H)HCH2), 3.86 and 3.83 (2s, 6H, COOCH3 and OCH3), 3.33-3.15 (m, 1H C(O)NC(HJHCH2), 3.10-2.93 (m, 4H, piperazine protons), 2.75-2.50 (m, 4H, piperazine protons), 2.56 (t, 2H, C(O)NCH2CH ), 2.00-1.83 (m, 1H, CHC(O)), 1.80-0.80 (m, lOH, cyclohexyl protons).
Example 9 1-fN-f2-dimethvlcarbamovl-nhenvl)-N-cvclohexvlcarbonvl-2-aminoethvll-4-(2-methoxyphenyl)-piperazine 1-[N-(2-dimethylcarbamoyl-phenyl)-2-aminoethyl]-4-(2-methoxyphenyl)-piperazine was prepared following the procedure described in Example 2, first step, except that N,N-~~NDED SHEET

13109/99 18 ~ I ' . . rt12-v;~o2 : ; . ; ~ ' ~ . ' ' , dimethyl-2-aminobenzamide was used in place of 2-trifluoromethoxyaniline. The crude was purified via flash chromatography (ethyl acetate : methanol 97:3). Yield:
19%.
1H-NMR (CDCl3, S): 7.25 (dt, 1H, aniline HS), 7.09 (dd, 1H, aniline H3), 7.06-6.80 (m, 4H, methoxyphenyl ring CHs), 6.68 (dd, 1 H, aniline H6), 6.66 (dt, 1 H, aniline H4), 5.50-5.10 (br, 1H, NH), 3.86 (s, 3H, OCH3), 3.23 (t, 2H, NHCH~CH2), 3.18-3.08 (m, 4H, piperazine protons), 3.05 (s, 6H, N(CH3)2), 2.78-2.62 (m, 6H, NHCH2CH~ and piperazine protons).
The title compound was prepared following the procedure described in Example 2, second step, except that 1-[N-(2-dimethylcarbamoyl-phenyl)-2-aminoethyl]-4-(2-methoxyphenyl) lo piperazine, prepared as described above, was used in place of 1-[N-(2 trifluoromethoxyphenyl)-2-aminoethyl]-4-(2-methoxyphenyl)-piperazine, the mixture being heated for 5 h at reflux. The crude was purified by flash chromatography (dichloromethane : methanol 93:7). Yield : 36%.
'H-NMR (CDC13, 8) : 7.50-7.30 (m, 4H, benzamide ring CHs), 7.06-6.80 (m, 4H, methoxyphenyl ring CHs), 4.85 (s, 3H, OCH3), 4.60-4.40 (m, 1H, CONCH(H)CHzN), 3.67-3.40 (m, 1H, CONCH(I~CH~N), 3.35-2.95 (m, 4H, piperazine protons), 3.10 and 2.90 (2s, 6H, N(CH3)z), 2.85-2.45 (m, 6H, piperazine protons and CONCH~CH N), 2.10 1.90 (m, 1 H, CHC(O)), 1.90-0.80 (m, 1 OH, cyclohexyl protons).
Example 10 1-IN-(2-methoxvnhenvll-N-cvclohexylcarbonvl-2-aminoethyl]-4-(2-methoxvphenYll piperazine 1-[N-(2-Methoxyphenyl)-2-aminoethyl]-4-(2-methoxyphenyl)-piperazine was prepared and purified following the procedure described in Example 2, first step, except that 2 methoxyaniline was used in place of 2-trifluoromethoxyaniline, and heating was at 100°C
for 4 h. Yield: 50%
1H-NMR (CDC13, 8): 7.05-6.85 (m, SH, methoxyphenyl ring CHs and aniline CH), 6.85 6.60 (m, 3H, aniline CHs), 3.87 and 3.85 (2s, 6H, 2 OCH3), 3.25 (t, 2H, NHCH
CH2), 3.18-3.05 (m, 4H, piperazine protons), 2.80-2.65 (m, 6H, NHCH2CH, and piperazine 3o protons).
The title compound was prepared following the procedure described in Example 1, second step, except that 1-[N-(2-methoxyphenyl)-2-aminoethyl]-4-{2-methoxyphenyl)-piperazine, prepared as described above, was used in place of 1-[N-(2-nitrophenyl)-2-aminoethyl]-4-(2-methoxyphenyl)-piperazine and that the mixture was refluxed for 6 h. The crude was purified by flash chromatography (CHzCl2-MeOH 9.5:0.5). Yield: 59%.
'H-NMR (CDCl3, 8): 7.38 (dd, 1H, methoxyphenylaniline H6), 7.26 (dd, 1H, methoxyphenylaniline H4), 7.10-6.85 (m, 6H, methoxyphenylaniline H3, HS and methoxyphenyl protons), 4.35-4.12 (m, 1H, CONCH(H)CHZ), 3.89 (s, 3H, OCH3), 3.86 AMENDED sHEE~

13/09/99 19 ~ f ~ 1 ~ ' rt12=wo2~ ;
(s, 3H, OCH3), 3.55-3.33 (m, 1H, CONCH(~CH2), 3.20-2.98 (m, 4H, piperazine protons), 2.80-2.50 (m, 6H, piperazine protons and CONCH2CH ), 2.05 (tt, 1H, CHC(O)), 1.30-0.85 (m, lOH, cyclohexyl protons).
Example 11 1-fN-(2-ethvlcarbamovl-t~henvll-N-cvclohexvlcarbonvl-2-aminoethvl)-4 (2 methoxynhenvll-piperazine 1-[N-(2-Ethylcarbamoyl-phenyl)-2-aminoethyl)-4-(2-methoxyphenyl)-piperazine was prepared following the procedure described in Example 2, fust step, except that 2 to ethylcarbamoyl-aniline was used in place of 2-trifluoromethoxyaniline and the mixture was refluxed for 5 h. The crude was purified by flash chromatography (dichloromethane methanol 9.7:0.3). Yield: 12%.
'H-NMR (CDC13, 8): 7.50 (t, 1H, CONHEt), 7.38-7.23 (m, 2H, aniline H4, H6), 7.07-6.83 (m, 4H, methoxyphenyl ring CHs), 6.70 (dd, 1H, aniline H3), 6.60 (dd, 1H, aniline HS), 6.13-5.90 (br, 1H, NHCHZCHz), 3.86 (s, 3H, OCH3), 3.53-3.40 (m, 2H, CONHCH
CH3), 3.33 (q, 2H, NHCH CHz), 3.18-3.02 (m, 4H, piperazine protons), 2.83-2.63 (m, 6H, piperazine protons and NHCHZCH2), 1.23 (t, 3H, CONHCHzCH ).
The title compound was prepared following the procedure described in Example 1, second step, except that 1-[N-(2-ethylcarbamoyl-phenyl)-2-aminoethyl)-4-(2-methoxyphenyl) 2o piperazine, prepared as described above, was used in place of 1-[N-(2-nitrophenyl)-2 aminoethyl]-4-(2-methoxyphenyl)-piperazine and that the mixture was refluxed for 12 h using toluene as solvent instead of 1,2-dichloroethane. The crude was purified by flash chromatography (dichloromethane : methanol 9.5:0.5). Yield: 43%.
'H-NMR (CDCl3, 8): 9.30-9.12 (br, 1H, CONHEt), 7.80 (dd, 1H, aniline H6), 7.45 (dd, 1H, aniline H4), 7.35 (dd, 1H, aniline HS), 7.20 (dd, 1H, aniline H3), 7.05-6.75 (m, 4H, methoxyphenyl ring CHs), 4.47 (dt, 1H, CONCH(H~CHZN), 3.82 (s, 3H, OCH3), 3.73-3.50 (m, 1H, CONHCH(F-~I CH3), 3.32-3.10 (m, 1H, CONHCH(H)CH3), 3.03-2.25 (m, SH, CONCH(H)CHZN and piperazine protons), 2.65-2.16 (m, 7H, CONCHZCH , piperazine protons and CHC(O)), 1.70-0.80 (m, lOH, cyclohexyl protons), 1.18 (t, 3H, 3o CONHCHzCH ).
Example 12 1-fN-(2-trifluoromethvlphenvl)-N-cvclohexylcarbonyl-2-aminoethyl] 4 (2 methoxyphenvll-piperazine A solution of 2-trifluoromethylaniline (3 ml), triethylamine (3.5 ml) and dichloromethane (30 ml) was stirred at room temperature under nitrogen. 3.34 ml of cyclohexylcarbonyl chloride was added dropwise. After stirring for 2%z hours at room temperature, the mixture was poured into water and alkalinised with 1N sodium hydroxide. The organic phase was I4NlENE7E~ ~f-~~r' 13/09199 20 ; ~ ; ~ , vrf12~-wo2 dried on anhydrous sodium sulphate and the crude was crystallised from ethanol to give 3.82 g (59%) of 1-cyclohexylcarbamoyl-2-trifluoromethyl-benzene. M.p. 153-154°C.
1H-NMR (CDCl3, S): 8.20 (dd, 1H, trifluoromethylphenyl ring CH), 7.60-7.40 (m, 3H, trifluoromethylphenyl ring CHs and NIA, 7.12 (ddd, 1H, trifluoromethylphenyl ring CH), 2.30 (tt, 1H, CHC(O)), 2.10-1.20 (m, lOH, cyclohexyl protons).
A mixture of 0.2 g of 1-cyclohexylcarbamoyl-2-trifluoromethyl-benzene, prepared as above described, 0.37 g of 1-(2-chloroethyl)-4-(2-methoxyphenyl)-piperazine, 0.5 ml of 50% (w/w) sodium hydroxide, 0.16 g of TEBAC and 2 ml of toluene was stirred at 80°C
for 3.5 h. An additional 0.2 g of 1-cyclohexylcarbamoyl-2-trifluoromethyl-benzene was to then added and after 6 h stirring at 80°C the mixture was poured into water and extracted with dichloromethane. The organic phase was dried on anhydrous sodium sulphate and evaporated to dryness. The residue was purified by flash chromatography (ethyl acetate petroleum ether 3:7) to give 0.12 g (17%) of the title compound.
1H-NMR (CDC13, 8): 7.77 (dd, 1H, trifluoromethylphenyl ring CH), 7.70-7.45 (m, 3H, trifluoromethylphenyl ring CHs), 7.10-6.80 (m, 4H, methoxyphenyl ring CHs), 4.70-4.50 (m, 1H, CONCH(H)CHZN), 3.85 (s, 3H, OCH3), 3.20-2.90 (m, 5H, CONCH(I~CH2N and piperazine protons), 2.85-2.45 (m, 7H, CHC(O), CONCHzCH N and piperazine protons), 1.90-0.75 (m, l OH, cyclohexyl protons).
2o Example 13 1-fN-(2-aminophenvl)-N-cvclohexvlcarbonyl-2-aminoethyll-4-(2-methoxyphen~l)-piperazine A mixture of 1.05 g of 1-[N-(2-nitrophenyl)-N-cyclohexylcarbonyl-2-aminoethyl]-4-(2-methoxyphenyl)-piperazine, prepared as described in Example 1, 2 ml of hydrazine hydrate and 1 g of Raney nickel in 70 ml of methanol was stirred at 50°C for 1.5 h. The insoluble matter was separated off by filtration and the solution was evaporated to dryness.
The residue was crystallised from ethanol to give 0.69 g (71 %) of the title compound.
Melting point: 138.5-140°C.
1H-NMR (CDC13, 8): 7.15 (dd, 1H, aminophenyl ring CH), 7.10-6.80 (m, 5H, 3o aminophenyl ring CH and methoxyphenyl ring CHs), 6.80-6.65 (m, 2H, aminophenyl ring CHs), 4.96 (s, 2H, NHZ), 4.96-4.65 (m, 1H, CONCH(I~CH2N), 3.86 (s, 3H, OCH3), 3.20 2.80 (m, 7H, CONCH(H~CH,N and piperazine protons), 2.45-2.65 (m, 4H, piperazine protons), 2.10 (tt, 1H, CH(O)), 1.90-0.80 (m, lOH, cyclohexyl protons).
Ezample 14 1-(N-(2-acetylaminonhenyll-N-cyclohexylcarbonyl-2-aminoethyll-4-(2-methoxvphenvll-piperazine 2 i ~ rt~,2-~;.oz . ; ~ ' , A solution of 0.04 ml of acetyl chloride in 0.5 ml of dichloromethane was added at room temperature to a stirred solution of 0.22 g of 1-[N-(2-aminophenyl)-N-cyclohexylcarbonyl-2-aminoethyl]-4-(2-methoxyphenyl)-piperazine, prepared as described in Example 13, and 0.08 ml of triethylamine in 5 ml of dichloromethane. After 2 h stirring at the same temperature, the solvent was evaporated off and the residue was purified by flash chromatography (dichloromethane : acetonitrile 98:2) to give 0.12 g (50%) of the title compound.
'H-NMR (CDCl3, 8): 9.90 (s, 1H, NH), 7.85 (dd, 1H, acetylaminophenyl ring CH), 7.40 (td, 1H, acetylaminophenyl ring CH), 7.23-7.10 (m, 2H, acetylaminophenyl ring CHs), io 7.05-6.80 (m, 4H, methoxyphenyl ring CHs), 5.00-4.80 (m, 1H, CONCH(H)CHzN), 3.83 (s, 3H, OCH3), 3.20-2.25 (m, 11H, CONCH(H~CH N and piperazine protons), 2.15 (s, 3H, COCH3), 2.05-1.85 (m, 1H, CHC(O)), 1.75-0.80 (m, l OH, cyclohexyl protons).
Example 15 1-fN-(2-nitronhenvl)-N-cvclohexvlcarbonvl-2 aminoeth~l] 4 (2 methoxyphenvll niperazine N'-oxide A suspension of 0.89 g of 83% magnesium monoperoxyphthalate Ø6 H20 in 10 ml of water was added dropwise into a solution of 1.4 g of 1-[N-(2-nitrophenyl)-N-cyclohexylcarbonyl-2-aminoethyl]-4-(2-methoxyphenyl)-piperazine, prepared as described 2o in Example l, in 10 ml of chloroform and 45 ml of methanol at 5°C.
After overnight resting at room temperature, the solvents were evaporated off. The residue was taken up in 50 ml of water, alkalinised with 20% sodium carbonate and extracted with chloroform.
The organic phase was dried on anhydrous sodium sulphate and evaporated to dryness.
The residue was purified by flash chromatography (chloroform : 2N methanolic ammonia, gradient 100:7 to 100:20) to give 0.5 g of a crude. Crystallisation from acetone yielded 0.35 g (24%) of the title compound. Melting point: 128-132°C.
1H-NMR (CDCl3, 8): 8.05 (dd, 1H, nitrophenyl ring H3), 7.70 (ddd, 1H, nitrophenyl ring H5), 7.50 (ddd, 1 H, nitrophenyl ring H4), 7.41 (dd, 1 H, nitrophenyl ring H6), 7.07-6.76 (m, 4H, methoxyphenyl ring CHs), 4.40-4.12 (m, 2H, CONCH CHZN), 3.85 (s, 3H, 3o OCH3), 3.70-3.35 (m, 6H, CONCHZCH N and piperazine protons), 3.35-3.07 (m, 4H, piperazine protons), 2.05-1.80 (m, 1H, CHC(O)), 1.75-0.75 (m, lOH, cyclohexyl protons).
Example 16 1-fN-(2-nitronhenvll-N-cvclohexylcarbonyl-2-aminoethvl] 4 (2 methoxyphenyll pinerazine N°-oxide The title compound was isolated during purification of the compound described in Example 15. Yield 0.23 g (16%) as a vitreous solid.
~P~f :~~':~'~y~:'~~ .~~ -l~~ ~'~

' CA 02297095 2000-O1-20 13/09/99 22 ~ , ~ rf12=wc2 ~ .
IH-NMR (CDC13, 8): 8.75 (dd, 1H, methoxyphenyl ring H6), 8.05 (d(d,, 1H, nitrophenyl ring H3), 7.71 (ddd, 1H, nitrophenyl ring HS), 7.57 (ddd, 1H, nitrophenyl ring H4), 7.47 (dd, 1H, nitrophenyl ring H6), 7.37 (ddd, 1H, methoxyphenyl ring H4 (HS)), 7.10 (ddd, IH, methoxyphenyl ring HS (H4)), 6.98 (dd, IH, methoxyphenyl ring H3), 4.72-4.41 (m, 2H, piperazine protons), 4.03 (s, 3H, OCH3), 3.83 (t, 2H, CONCH CHZN), 3.35-3.09 (m, 2H, piperazine protons), 2.98-2.77 (m, 2H, CONCHZCH N), 2.77-2.30 (m, 4H, piperazine protons), 2.05-0.83 (m, 11H, cyclohexyl protons).
Example 17 1-f N-(2-nitrophenvll-N-cvclohexvlcarbonvl ~ aminoethvll 4 (2 methoxyphenvll piperazine N'.N4-dioxide The title compound was synthesised as described in Example 15 but using equimolar amounts of magnesium monoperoxyphthalate and 1-[N-(2-nitrophenyl)-N-cyclohexylcarbonyl-2-aminoethyl]-4-(2-methoxyphenyl)-piperazine. Yield 43%
after crystallisation from acetonitrile. Melting point: 153-157°C.
1H-NMR (CDC13, 8): 8.70 (dd, 1H, methoxyphenyl ring H6), 8.05 (dd, 1H, nitrophenyl ring H3), 7.70 (ddd, 1H, nitrophenyl ring HS), 7.58 (ddd, 1H, nitrophenyl ring H4), 7.49-7.32 (m, 2H, nitrophenyl ring H6 and methoxyphenyl ring H4), 7.13 (ddd, 1H, methoxyphenyl ring HS), 7.00 (dd, 1H, methoxyphenyl ring H3), 5.92-5.67 (m, 2H, piperazine protons), 4.70-4.45 (m, 2H, piperazine protons), 4.45-4.05 (m, 2H, CONCH CHZN), 4.00 (s, 2H, CONCHZCH~N), 3.30-3.08 (m, 2H, piperazine protons), 3.05-2.85 (m, 2H, piperazine protons), 2.05-1.78 (m, 1H, CHC(O)), 1.78-0.70 (m, lOH, cyclohexyl protons).
Example 18 1-fN-(2-nitroohenyll-N-(3-furvlcarbonyll 2 aminoethvll 4 (2 methoxyphenyll ninerazme A suspension of 0.77 g of the monohydrochloride of 1-[N-(2-nitrophenyl)-2-aminoethyl]-4-(2-methoxyphenyl)-piperazine, prepared as described in Example 1, first step, in 50 ml of toluene was stirred at reflux removing about 20 ml of distillate. After cooling to 60-70°C, 0.9 ml of 97% diisopropylethylamine (DIPEA) was added and the mixture was stirred for 15 minutes. 0.66 g of 3-furylcarbonyl chloride was then added. The mixture was stirred at reflex for 5 h, cooled to room temperature, washed sequentially with water, 1N
sodium hydroxide and water, dried on anhydrous sodium sulphate and evaporated to dryness. The residue was purified by flash chromatography (ethyl acetate :
petroleum ether, gradient 1:1 to 7:3) affording 0.67 g (75%) of the title compound.
1H-NMR (CDCl3, 8): 8.05 (dd, 1H, nitrophenyl ring H3), 7.73-7.58 (m, 2H, nitrophenyl ring HS and H6), 7.58-7.45 (m, 1 H, nitrophenyl ring H4), 7.15 (bs, 1 H, furan ring H2), 7.02-6.77 (m, SH, furan ring HS and methoxyphenyl ring CHs), 6.13 (bs, I H, furan ring A ': ~ ,~~_t 13/09/99 23 , , , " ; ' " , , ' 1 " ' " X12-;wo% " ' ~ ' ' " ' H4), 4.30-4.08 (m, 1H, CONCH(H)CHZN), 3.90-3.70 (m, 1H, CONCH(~H CH,N), 3.83 (s, 3H,OCH3), 3.05-2.80 (m, 4H, piperazine protons), 2.80-2.62 (m, 2H, CONCHZCH,N), 2.62-2.45 (m; 4H, piperazine protons).
Example 19 1- - 2-nitro hen 1 -N- 2-furvlcarbonvl -2-aminoethvl -4- 2-metho henvl - i erazine The title compound was prepared following the procedure described in Example 18, but using 2-furylcarbonyl chloride in place of 3-furylcarbonyl chloride. Yield 77%.
~H-NMR (CDCl3, b): 8.05 (dd, 1H, nitrophenyl ring H3), 7.72-7.45 (m, 3H, other 1o nitrophenyl ring CHs), 7.20 (bs, IH, furan ring H3), 7.05-6.75 (m, 4H, methoxyphenyl ring CHs), 6.49 (bs, 1H, furan ring H4), 6.25 (bs, 1H, furan ring H5), 4.30-4.10 (m, 1H, CONCH(H)CH2N), 3.98-3.75 (m, 1H, CONCH(HJCHzN), 3.83 (s, 3H,OCH3), 3.15-2.85 (m, 4H, piperazine protons), 2.85-2.65 (m, 2H, CONCHzCH N), 2.65-2.48 (m, 4H, piperazine protons).
Example 20 1-(N-l2-nitrophenyl)-N-(2-thienvlcarbonvl) 2 aminoethvll-4 h methoxvnhenvll plperazlne The title compound was prepared following the procedure described in Example 18, but 2o using 2-thienylcarbonyl chloride in place of 3-furylcarbonyl chloride and refluxing for 8 h.
Yield 59%.
1H-NMR (CDCl3, b): 8.03 (dd, 1H, nitrophenyl ring H3), 7.71-7.60 (m, 2H, nitrophenyl ring H5 and H6), 7.60-7.45 (m, 1H, nitrophenyl ring H4), 7.27 (dd, 1H, thiophen ring H3 (H5)), 7.05-6.70 (m, 6H, thiophen H4 and H5 (H3) and methoxyphenyl ring CHs), 4.22-4.10 (m, 1H, CONCH(H)CHZN), 3.92-3.71 (m, 1H, CONCH(H~CHzN), 3.80 (s, 3H,OCH3), 3.10-2.80 (m, 4H, piperazine protons), 2.80-2.65 (m, 2H, CONCHZCH~N), 2.65-2.45 (m, 4H, piperazine protons).
Example 21 1-fN-(2-nitronhenvl)-N-(3-thienvlcarbonvll 2 aminoethvll 4 (2 methoxvtihenyl) piperazlne The title compound was prepared following the procedure described in Example 18, but using 3-thienylcarbonyl chloride in place of 3-furylcarbonyl chloride and refluxing for 7 h.
Yield 88%.
'H-NMR (CDCl3, b): 7.93 (dd, 1H, nitrophenyl ring H3), 7.70-7.55 (m, 2H, nitrophenyl ring H5 and H6), 7.48-7.35 (m, 1H, nitrophenyl ring H4), 7.25-7.12 (m, 1H, thiophen ring H2), 7.12-7.02 (m, 1 H, thiophen ring H5) 7.02-6.91 (m, 1 H, thiophen ring H4), 6.91-6.78 (m, 4H, methoxyphenyl ring CHs), 4.32-4.10 (m, IH, CONCH(I-~CHZN), 3.90-3.70 (m, .. . ". ~,__ 13/09/99 24 . , , ; , y " " , " , , " , " "
rt12-woe ~,. . ". .,.
1H, CONCH~i CHZN), 3.81 (s, 3H,OCH3), 3.05-2.78 (m, 4H, piperazine protons), 2.78-2.65 (m, 2H, CONCHiCH N), 2.65-2.45 (m, 4H, piperazine protons).
Ezan~~le 22 1 jN-(2-nitronhenvl)-N-(4-pvridylcarbonvl) ~ aminoethvll 4 (2 methoxynhenvll plnerazine The title compound was prepared following the procedure described in Example 18, but using 4-pyridylcarbonyl chloride in place of 3-furylcarbonyl chloride and refluxing for 14 h. The crude was purified by flash chromatography (chloroform : 2.5N
methanolic 1o ammonia, gradient 100:1.5 to I00:3). Yield 39%.
1H-NMR (CDCl3, 8): 8.42 (dd, 2H, pyridine ring H2 and H6), 7.90 (dd, 1H, nitrophenyl ring H3), 7.62-7.45 (m, 2H, nitrophenyl ring H5 and H6), 7.45-7.30 (m, 1H, nitrophenyl ring H4), 7.15 (dd, 2H, pyridine ring H3 and H5) 7.08-6.75 (m, 4H, methoxyphenyl ring CHs), 4.50-4.20 (m, 1 H, CONCH(H)CHzN), 3.90-3.65 (m, 1 H, CONCH(~CHZN), 3.80 (s, 3H,OCH3), 3.15-2.28 (m, l OH, CONCHZCH N and piperazine protons).
Example 23 _1-fN-(2-nitronhenyll-N-f3-nvridylcarbonvl) 2 aminoethvll 4 (2 methoxvnhenvll piperazine 2o The title compound was prepared following the procedure described in Example 18, but using 3-pyridylcarbonyl chloride in place of 3-furylcarbonyl chloride and refluxing for 12 h. The crude was purified by flash chromatography (chloroform : 2.5N
methanolic ammonia 100:3). Yield 46%.
'H-NMR (CDC13, b): 8.50-8.35 (m, 2H, pyridine ring H2 and H6), 7.90 (dd, IH, nitrophenyl ring H3), 7.72 (dd, 1H, pyridine ring H4), 7.60-7.50 (m, 2H, nitrophenyl ring H5 and H6), 7.43-7.28 (m, 1H, nitrophenyl ring H4) 7.30-7.15 (m, 1H, pyridine ring H5), 7.03-6.76 (m, 4H, methoxyphenyl ring CHs), 4.35-4.15 (m, 1H, CONCH(H)CHZN), 4.00 3.75 (m, 1H, CONCH(I-~CHZN), 3.80 (s, 3H,OCH3), 3.10-2.40 (m, lOH, CONCHZCH N
and piperazine protons).
Example 24 1-fN-(2-nitrophenvll-N-(2-pyrazinvlcarbonyll 2 aminoethvll-4 (2 methoxyphenyll piperazine The title compound was prepared following the procedure described Example 18, but using 2-pyrazinylcarbonyl chloride in place of 3-furylcarbonyl chloride and refluxing for 1 h. The crude was purified by flash chromatography (chloroform : 2.5N
methanolic ammonia, gradient 100:1 to 100:3). Yield 89%.
1y4;.'- " ~ ._ 13/09/99 25 ; - - ~ ~ ~ , , ~ ~ ~ ~ ~ ' . ' , rf i 2=wo2 ' 1H-NNIR (CDC13, 8): 9.08 (d, 1H, pyrazine ring H3), 8.40 (d, lH,,pyrazine ring H6), 8.07 (d, 1H, pyrazlne rmg HS), 7.97 (dd, 1H, nitrophenyl ring H3), 7.62-7.50 (m, 2H, nitrophenyl ring HS and H6) 7.48-7.31 {m, 1H, nitrophenyl ring H4), 7.05-6.80 (m, 4H, methoxyphenyl ring CHs), 4.31-4.15 (m, 1H, CONCH{I-~CH2N), 4.08-3.92 (m, 1H, CONCH(I-~I CHZN), 3.82 (s, 3H,OCH3), 3.05-2.40 (m, l OH, CONCH2CH,N and piperazine protons).
Example 25 1-fN-(2-nitronhenyll-N-(1-methvlcyclohexylcarbonyl) 2 aminoethyll-4 (2 1 o methoxvnhenyl)-piperazine Operating as described in the first step of Example 12, but using 1-methylcyclohexylcarbonyl chloride [J. Org. Chem. 47 3242 (1982)] in place of cyclohexylcarbonyl chloride and refluxing for 50 h, gave crude 1-methyl-N-(2-nitrophenyl)-cyclohexylcarboxamide. This was purified by flash chromatography (petroleum ether : ethyl acetate 100:2). Yield 90%.
'H-NMR (CDCl3, 8): 10.75 (s, 1H, NH), 8.85 (dd, 1H, nitrophenyl ring H6), 8.22 (dd, 1H, nitrophenyl ring H3), 7.62 (ddd, 1H, nitrophenyl ring HS), 7.15 (ddd, 1H, nitrophenyl ring H4) 2.20-1.95 (m, 2H, cyclohexyl protons), 1.75-1.35 (m, 8H, cyclohexyl protons), 1.25 (s, 3H, CH3).
2o A mixture of 0.3 g of 1-methyl-N-(2-nitrophenyl)-cyclohexylcarboxamide, prepared as above described, SO ml of toluene and 0.26 g of potassium t-butoxide was stirred at reflux, removing about 11 ml of distillate. A solution of 0.32 g of 1-(2-chloroethyl)-4-(2-methoxyphenyl)-piperazine in 10 ml of toluene was then added to the mixture.
After 16 h stirring at reflux, the mixture was cooled and washed with water. The organic layer was dried on anhydrous sodium sulphate and evaporated to dryness. The crude was purified by flash chromatography (petroleum ether : ethyl acetate 7:3) to give 0.51 g (43%) of the title compound.
1H-NMR (CDC13, S): 7.98 (dd, 1H, nitrophenyl ring H3), 7.40 (ddd, 1H, nitrophenyl ring HS), 7.08-6.80 (m, 6H, nitrophenyl ring H4 and H6 and methoxyphenyl ring CHs), 4.31 4.10 (m, 2H, CONCH CHz), 3.85 (s, 3H, OCH3), 3.20-2.98 {m, 4H, piperazine protons), 2.88-2.62 (m, 6H, CONCHzCH and piperazine protons), 1.90-1.70 {m, 2H, cyclohexyl protons), 1.53-1.22 (m, 8H, cyclohexyl protons), 1.18 (s, 3H, CH3).
Example 26 1-fN-(2-nitronhenvll-N-(1-nhenvlcyclohexvlcarbonvll 2 aminoethvl]-4 (2 methoxvohenvll-piperazine 1-phenyl-N-{2-nitrophenyl)-cyclohexylcarboxamide was prepared following the procedure described in the first step of Example 25, except that 1-phenylcyclohexylcarbonyl chloride ,ANtfl1'~u. ru.. .'~;HEET

13/09/99 26 , . : ~ , . ~ ,rt i 2=wo2 ~ " : , . : , . ;
[J. Am. Chem. Soc. 68 2345-7 (1946)] was used in place of 1-methylcyclohexylcarbonyl' chloride, toluene was used in place of dichloromethane, DIPEA was used in place of triethylamine and the reaction mixture was refluxed for 15 h. The crude was purified by flash chromatography (petroleum ether : ethyl acetate 98:2). Yield 91 %.
1H-NMR (CDCI3, 8): 10.32 (s, 1 H, NH), 8.76 (dd, 1 H, nitrophenyl ring H6), 8.12 (dd, 1 H, nitrophenyl ring H3), 7.64-7.32 (m, SH, phenyl ring CHs), 7.28 (ddd, 1H, nitrophenyl ring HS), 7.08 (ddd, 1H, nitrophenyl ring H4), 2.54-2.34 (m, 2H, cyclohexyl protons), 2.22-2.02 (m, 2H, cyclohexyl protons), 1.76-1.28 (m, 6H, cyclohexyl protons).
The title compound was prepared as described in the second step of Example 25, except to that 1-phenyl-N-(2-nitrophenyl)-cyclohexylcarboxamide was used in place of 1-methyl-N-(2-nitrophenyl)-cyclohexylcarboxamide and refluxing lasted 22 h. The crude was purified by flash chromatography (petroleum ether : ethyl acetate, gradient 8:2 to 7:3). Yield 37%.
'H-NMR (CDCl3, 8): 7.90 (dd, 1H, nitrophenyl ring H3), 7.45-7.10 (m, 7H, phenyl ring CHs and nitrophenyl ring HS and H6), 7.04-6.78 (m, SH, nitrophenyl ring H4 and methoxyphenyl ring CHs), 4.30-4.12 (m, 2H, CONCH CHz), 3.82 (s, 3H, OCH3), 3.18-2.93 (m, 4H, piperazine protons), 2.80-2.50 (m, 6H, CONCHZCH and piperazine protons), 2.30-2.10 (m, 2H, cyclohexyl protons), 1.92-1.75 (m, 2H, cyclohexyl protons), 1.74-1.35 (m, 6H, cyclohexyl protons).
Exam,~le 27 1-~I~T-f2-(2.2.2-trifluoroethoxvl-nhenvll N cyclohexylcarbonyl ~ aminoethvll 4 (2 methoxynhenyl)=piperazine 1-[N-[2-(2,2,2-Trifluoroethoxy)-phenyl]-2-aminoethyl]-4-(2-methoxyphenyl)-piperazine was prepared following the procedure described in Example 2, first step, except that 2-(2,2,2-trifluoroethoxy)aniline (EP 748800) was used in place of 2-trifluoromethoxyaniline and the reaction mixture was refluxed for 7 h. The crude was purified by flash chromatography (petroleum ether : ethyl acetate, gradient 9:1 to 8:2). Yield 38%.
iH-NMR (CDC13, 8): 7.08-6.80 (m, SH, methoxyphenyl ring CHs and trifluoroethoxyphenyl ring CH), 6.80-6.57 (m, 3H, trifluoroethoxyphenyl ring CHs), 5.11 4.70 (m, 1H, NH), 4.35 (q, 2H, OCHZCF3), 3.85 (s, 3H, OCH3), 3.38-3.19 (m, 2H, NHCH CHI, 3.19-2.98 (m, 4H, piperazine protons), 2.88-2.60 (m, 6H, NHCH2CH and piperazine protons).
A mixture of 0.41 g of 1-[N-[2-(2,2,2-trifluoroethoxy)-phenyl]-2-aminoethyl]-4-(2 methoxyphenyl)-piperazine, prepared as described above, 5.4 ml of 97% DIPEA, and 3.9 ml of cyclohexylcarbonyl chloride in 30 ml of toluene was stirred at reflux for 10 h. After cooling to room temperature, the mixture was washed sequentially with water, 1N sodium hydroxide and water. The organic layer was dried on anhydrous sodium sulphate and evaporated to dryness. The crude was purified by flash chromatography (petroleum ether AMEMDED SHEET

13/09/99 27 , . ~ , v rt1'2-,~02 ~ . , ; . ; ' . , ethyl acetate 1:1) followed by crystallisation from diethyl ether to give 0.2 g (37%) of the title compound. Melting point: 109.6-112°C.
'H-NMR (CDC13, 8): 7.42-7.22 (m, 2H, trifluoroethoxyphenyl ring CHs), 7.15-6.77 (m, 6H, trifluoroethoxyphenyl ring CHs and methoxyphenyl ring CHs), 4.38 (q, 2H, OCHZCF3), 4.22-402 (m, 1H, CONCH(1~CH2N), 3.82 (s, 3H, OCH3), 3.58-3.39 (m, 1H, CONCH~i CHZN), 3.15-2.90 (m, 4H, piperazine protons), 2.80-2.45 (m, 6H, CONCHzCH N and piperazine protons), 2.05-1.88 (m, 1H, CHC(O)), 1.75-0.80 (m, lOH, cyclohexyl protons).
1 o Erample 28 1-fN-(2-cvanouhenyll-N-cvclohexylcarbonvl-2 aminoethyll-4 (2 methoxvphenvll piperazine hydrochloride N-(2-cyanophenyl)-cyclohexylcarboxamide was prepared following the procedure described in the first step of Example 12, except that 2-cyanoaniline was used in place of 2-trifluoromethylaniline. Yield 75%. M.p. 135-137°C.
1H-NMR (CDCl3, b): 8.40 (dd, 1H, cyanophenyl ring H3), 7.70-7.50 (m, 3H, cyanophenyl ring H5 and H6 and NH), 7.12 (ddd, 1H, cyanophenyl ring H4), 2.30 (tt, 1H, CHC(O)), 2.05-1.10 (m, lOH, cyclohexyl protons).
The title compound was prepared following the procedure described in the second step of 2o Example 25, except that N-(2-cyanophenyl)-cyclohexylcarboxamide, prepared as above described, was used in place of 1-methyl-N-(2-nitrophenyl)-cyclohexylcarboxamide and reflux lasted 1 h. The crude was purified by flash chromatography (dichloromethane methanol 98:2). The residue was dissolved in acetone and ethereal hydrogen chloride, was added. The solution was evaporated to dryness, and crystallised from acetone :
diethyl ether to give the title compound. Yield 7%.
1H-NMR (DMSO-db, b): 11.28-11.07 (br, 1H, NH+), 8.05 (dd, 1H, cyanophenyl ring H6), 7.92-7.80 (m, 2H, cyanophenyl ring CHs), 7.72-7.60 (m, 1H, cyanophenyl ring CH), 7.05-6.82 (m, 4H, methoxyphenyl ring CHs), 4.45-4.30 (m, 1H, CONCH(H)CHZN), 3.92-3.75 (m, 1H, CONCH(I~CHZN), 3.80 (s, 3H, OCH3), 3.70-3.40 (m, 4H, piperazine protons), 3.40-3.00 (m, 6H, CONCHZCH2N and piperazine protons), 1.98-1.80 (m, 1H, CHC(O)), 1.80-0.75 (m, l OH, cyclohexyl protons).
Example 29 1-IN-(2-nitrophenvll-N-cvclohexvlcarbonvl-1-amino 2 nronvll-4 (2 methox henvl) piperazine A mixture of 1 g of 1-(2-methoxyphenyl)-piperazine, 0.57 g of 2-chloropropionamide, 1 ml of DIPEA and 5 ml of toluene was stirred at reflux for 3 h under nitrogen.
After cooling to room temperature the mixture was poured into water and extracted with ethyl acetate.
AMENI~EQ ~~EET

13/09/99 28 ~ v , ~ , , ° , rf5 2=w~2 ~ ~ , , . ' I . : ' . . ' The organic layer was dried on anhydrous sodium sulphate and the solvents were evaporated off. The residue was purified by flash chromatography (dichloromethane : 2N
methanolic ammonia 95:5) to give 0.88 g (63%) of 2-[4-(2-methoxyphenyl)-1-piperazinyl]-propionamide.
iH-NMR (CDCl3, b): 7.25-7.10 (br, 1H, CONH(H)), 7.10-6.80 (m, 4H, methoxyphenyl ring CHs), 5.75-5.60 (br, 1H, CONH~H)), 3.85 (s, 3H, OCH3), 3.20-3.00 (m, 5H, piperazine protons, NCH(CH3)CO), 2.85-2.60 (m, 4H, piperazine protons), 1.30 (d, 3H, NCH(CH )CO).
2 ml . of a 2M solution of diborane dimethylsulphide in tetrahydrofuran was added dropwise to a solution of 0.28 g of 2-[4-(2-methoxyphenyl}-1-piperazinyl]-propionamide, prepared as above described, in 7 ml of tetrahydrofuran stirred at -4°C
under nitrogen. The mixture was refluxed for 6.5 h, and then 3 ml of methanol was added. The solvents were evaporated off and the residue was taken up in water. The organic phase, obtained by extraction with ethyl acetate, was dried on anhydrous sodium sulphate and evaporated to 1 s dryness. The residue was purified by flash chromatography (dichloromethane : 2N
methanolic ammonia 95:5) to give 0.07 g (24%) of 2-[4-(2-methoxyphenyl)-1-piperazinyl]-propylamine.
1H-NMR (CDC13, 8): 7.10-6.80 (m, 4H, methoxyphenyl ring CHs), 3.85 (s, 3H, OCH3), 3.20-2.90 (m, 4H, piperazine protons), 2.85-2.50 (m, 7H, piperazine protons and 2o NCH(CH3)CH ), 2.05-1.85- (br, 2H, NHz), 0.95 (d, 3H, CH3).
A mixture of 0.08 g of 2-[4-(2-methoxyphenyl)-1-piperazinyl]-propylamine, prepared as above described, 0.03 ml of 2-nitrofluorobenzene, 0.3 ml of DIPEA and 5 ml of DMF was stirred at 140°C for 3 h under nitrogen. The cooled mixture was diluted with water and extracted with diethyl ether. The organic phase was dried on anhydrous sodium sulphate 2s and evaporated to dryness. The residue was purified by flash chromatography (petroleum ether : ethyl acetate 8:2) to give 0.07 g (62%) of 1-[N-(2-nitrophenyl}-1-amino-2-propyl]-4-(2-methoxyphenyl)-piperazine.
1H-NMR (CDC13, 8): 8.90-8.70 (br, 1H, NH), 8.15 (dd, 1H, nitrophenyl ring H3), 7.40 (ddd, 1H, nitrophenyl ring HS), 7.15-6.70 (m, 5H, nitrophenyl ring H6 and methoxyphenyl 3o ring CHs), 6.63 (ddd, 1H, nitrophenyl ring H4), 3.85 (s, 3H, OCH3), 3.70-2.60 (m, 11H, piperazine protons and NHCH CH(CH3)), 1.10 (d, 3H, CH3).
The title compound was prepared following the procedure described in Example 2, second step, except that 1-[N-(2-nitrophenyl}-1-amino-2-propyl]-4-(2-methoxyphenyl)-piperazine, prepared as described above, was used in place of 1-[N-(2-trifluoromethoxyphenyl)-2-3 s aminoethyl]-4-(2-methoxyphenyl)-piperazine, toluene was used instead of 1,2-dichloroethane, and the mixture was heated for 13 h at reflux. The mixture was purified by flash chromatography (petroleum ether : ethyl acetate 1:1 ). Yield: 61 %.
~6~~1~(~L~~!~ ~!.~~~'~

13/09/99 , , , , .: " , . . , , . , ~ " , 29 : ~ ; y , ' , rf ~ 2;-wa2~ , , ; , , , . . ;
iH-NMR (CDC13, 8): 8.05 (dd, 1H, nitrophenyl ring H3), 7.85-7.45. (m, 3H, nitrophenyl. ~ . , ring H4, H5 and H6), 7.10-6.75 (m, 4H, methoxyphenyl ring CHs), 3.85 (s, 3H, OCH3), 3.90-3.75 (m, 1H, CONCH(H)CH(CHj)), 3.65-2.30 (m, lOH, piperazine protons and CONCH(/-~I CH(CH3)), 2.10-1.80 (m, 1H, CHC(O)), 1.80-0.80 (m, 13H, cyclohexyl protons and CH3).
Ezample 30 Effects on Volume-Induced Rhythmic Bladder Voiding Contractions in Anaesthetised Rats I o A. Metlsods:
Female Sprague Dawley rats weighing 225-275 g (Crl: CDo BR, Charles River Italia) were used. The animals were housed with free access to food and water and were maintained on a forced 12 h alternating light-dark cycle at 22-24°C for at least one week, except during the experiment. The activity on the rhythmic bladder voiding contractions was evaluated according to the method of Dray (J. Pharmacol. Methods, 13:157, 1985), with some modifications as in Guarneri (Pharmacol. Res., 27:173, 1993).
Briefly, rats were anaesthetised by subcutaneous injection of 1.25 glkg (5 ml/kg) urethane, after which the urinary bladder was catheterised via the urethra using PE 50 polyethylene tubing filled with physiological saline. The catheter was tied in place with a ligature around the external 2o urethral orifice and was connected with conventional pressure transducers (Statham P23 ID/P23 XL). The intravesical pressure was displayed continuously on a chart recorder (Battaglia Rangoni KV 135 with DCl/TI amplifier). The bladder was then filled via the recording catheter by incremental volumes of warm (37°C) saline until reflex bladder voiding contractions occurred (usually 0.8-1.5 ml). For intravenous (i.v.) injection of bioactive compounds, PE 50 polyethylene tubing filled with physiological saline was inserted into the jugular vein.
From the cystometrogram, the number of contractions recorded 15 min before (basal values) and after treatment, as well as the mean amplitude of these contractions (mean height of the peaks in mmHg) was evaluated.
3o Since most compounds produced an effect that was relatively rapid in onset and led to a complete cessation of bladder contractions, bioactivity was conveniently estimated by measuring the duration of bladder quiescence (i.e., the duration of time during which no contractions occurred). The number of animals tested showing a reduction in the number of contractions >30% of that observed in the basal period was also recorded.
To compare the potency of the tested compounds for inhibiting bladder voiding contractions, equieffective doses which resulted in a contraction disappearance time of 10 minutes (EDlom",) were computed by means of least square linear regression analysis.
Also computed in this manner were extrapolated doses which induced a reduction of the - A' '..:'i.._~
u~r~._.

13/09/99 30 : ; ~ , ~ , ~ , rf'l2-wb2 ' y - ~ , . ' ' . , ;
number of contractions of greater than 30% in 50% of treated rats (EDSp, frequency) by the method of Bliss (Bliss C.L, Quart. J. Pharm. Pharmacol. 11. 192-216, 1938).
After the suppressive effects of drug injection wore off, the height of the contractile peaks was compared with the height of the peaks previously recorded after the control intravenous administration of vehicle. The potency of the tested compounds (ED;o value:
the extrapolated doses inducing a 30% reduction of amplitude of the contractions in SO% of treated rats) was evaluated on a quantal basis by the method of Bliss (Bliss C.L, Quart. J.
Pharm. Pharmacol. 11, 192-216, 1938).
1 o B. Results The rapid distension of the urinary bladder in urethane-anaesthetised rats produced a series of rhythmic bladder voiding contractions whose characteristics have been described and are well-known in the art (Maggi et al., Brain Res., 380:83, 1986; Maggi, et al., J.
Pharmacol. Exp. Ther., 230:500, 1984). The frequency of these contractions is related to the sensory afferent arm of reflex micturition and to the integrity of the micturition centre, while their amplitude is a property of the efferent arm of the reflex. In this model system, compounds that act mainly on the CNS (such as morphine) cause a block in voiding contraction, whereas drugs that act at the level of the detrusor muscle, such as oxybutynin, lower the amplitude of the bladder contractions.
2o The results obtained after administration of prior art compounds and compounds of the invention are shown in Table 1.
Compound A, a prior art compound, was more potent than flavoxate and oxybutynin in inhibiting voiding contractions. This compound, in contrast to oxybutynin, did not affect the amplitude of the contraction, indicating no impairment of bladder contractility.
Surprisingly, however, compounds with substituents (e.g. N02) at position 2 of the aniline ring in Formula I, such as the compound of Example 1, have significantly higher potency than unsubstituted compound A, particular with regard to the ED~omin v~ues.
Like compound A, the compound of Example 1 does not affect bladder contractility.
The comparative compounds B and C, with the nitro group at position 3 and 4 of the phenyl 3o ring respectively, showed no pharmacological activity.
r '_' C i ~'~-t _, 13109/99 31 ,' , ',rf12=wok .. ._;

Effects on rhythmic bladder voiding contractions after intravenous administration.
Data represent the ED~pm~n values (the extrapolated dose inducing 10 min of disappearance of the contractions); the EDso values (the extrapolated doses inducing a reduction of the number of contractions >30% in 50% of treated rats) (frequency), and the EDso values (the extrapolated doses inducing 30% reduction of amplitude of the contractions in 50% of treated rats) (amplitude).
Compound EDlOmin pY~kg ED50 (frequency) ED50(amplitude) pg/kg pg/kg Compound A 650 33 n.a.

Compound B >1000 >1000 n.a.

Compound C >1000 >1000 n.a.

Compound D >1000 >1000 n.a.

Compound E >1000 >1000 n.a.

Compound AA 663 244 n.a.

Example 1 60 9 n.a.

Example 5 266 29 n.a.

Example 8 101 17 n.a.

Example 10 93 18 n.a.

Example 13 131 13 n.a.

Flavoxate > 10000 2648 n.a.

Oxybutinin 7770 > 10000 240 n.a. = not active; no significant reduction of the height of peaks Comgound A
1-(N-phenyl-N-cyclohexylcarbonyl-2-aminoethyl)-4-(2-methoxyphenyl)-piperazine.
Compound AA
1-(N-phenyl-2-aminoethyl)-4-(2-methoxyphenyl)-piperazine.
Compound B
1-[N-(3-nitrophenyl)-N-cyclohexylcarbonyl-2-aminoethyl]-4-(2-methoxyphenyl)-piperazine.
Compound C
1-[N-(4-nitrophenyl)-N-cyclohexylcarbonyl-2-aminoethyl]-4-(2-methoxyphenyl)-piperazine.
Compound D
1-[N-(3-nitrophenyl)-2-aminoethyl]-4-(2-methoxyphenyl)-piperazine.
Compound E
1-[N-{4-nitrophenyl)-2-aminoethyl]-4-{2-methoxyphenyl)-piperazine.
r ;~~~ . , >_6'Yd a ~ _ 13109/99 32 w ~ rf~l2-wo2 ~ .
E$amnle 31 Effects on Cystometric Parameters in Conscious Rats A. Methods:
Male Sprague Dawley rats (Crl: CDo BR) weighing 250-350 g were used. The animals were housed with free access to food and water and maintained on a forced 12 h alternating light-dark cycle at 22-24°C for at least one week, except during performance of the experiment. To quantify urodynamic parameters in conscious rats, cystometrographic studies were performed using procedures previously described (Guarneri et al., Pharmacol.
Res., 24:175, 1991). Male rats were anaesthetised with nembutal (30 mg/kg) and chloral to hydrate (125 mg/kg) i.p. and were placed in a supine position. An approximately 10 mm long midline incision was made in the shaved and cleaned abdominal wall. The urinary bladder was gently freed from adhering tissues, emptied, and then cannulated, via an incision at the dome, with a polyethylene cannula (Portex PP30), which was permanently sutured with silk thread. The cannula was exteriorized through a subcutaneous tunnel in the retroscapular area, where it was connected with a plastic adapter to avoid the risk of removal by the animal. For intravenous (i.v.) injection of test compounds, a polyethylene tubing filled with physiological saline was inserted into the jugular vein and exteriorized in the retroscapular area. The rats were utilised exclusively one day after implantation. On the day of the experiment, the rats were placed in Bollman's cages; after 2o a stabilisation period of 20 min, and the free tip of the bladder catheter was connected through a T-shaped tube to a pressure transducer (Bentley T 800/Marb P 82) and to a peristaltic pump (Gilson minipuls 2) for a continuous infusion, at the constant rate of 0.1 ml/min, of saline solution into the urinary bladder. The intraluminal pressure signal during infusion was continuously recorded on a polygraph (Battaglia Rangoni KO 380 with ADCI/T amplifier).
Two urodynamic parameters were evaluated: bladder volume capacity (BVC) and micturition pressure (1VB'). BVC (in ml) is defined as the minimum volume infused after which detrusor contraction (followed by micturition) occurs. MP (in mm Hg) is defined as the maximal intravesical pressure induced by the contraction of detrusor during 3o micturition. Basal BVC and MP values were calculated as the means of the first two recorded cystometrograms. At this point in the assay, the inftision was interrupted and the test compounds were administered. Fifteen minutes after intravenous administration two additional cystometrograms were recorded in each animal and the mean values of the two cystometrographic parameters were calculated. The statistical significance of the differences in urodynamic parameter values was evaluated by Student's t test for paired data.
B. Results:
~1N1ENDEp SHEET

. . ., ..,. , .~ , ., .. . . . , . a 13/09/99 33 ~ ~ , , . rf~l2twd2a , ' .;., '..' ,. .,' ,. ,.' The effects of different doses of the tested compounds are shown in Table 2.
Compound A
behaved similarly to flavoxate by increasing BVC. Neither compound impaired bladder contractility, since no consistent changes in MP were observed. In contrast, oxybutynin markedly and dose-dependently decreased MP without effects on BVC. The compound of Example 1 was more potent than compound A and flavoxate; a significant increase in BVC was observed after the i.v. administration of 0.3 mg/kg of the compound of Example 2, compared with the requirement for administration of 1.0 mg/kg of flavoxate or compound A. The compound of Example 1 induced a slight, albeit significant, decrease in MP. This effect, however, was not dose-dependent and was markedly lower than that 1 o induced by oxybutynin.

Effects on cystometrogram in conscious rats.
Data represent mean values t S.E. of bladder volume capacity (BVC; ml) and of micturition pressure (MP; mmH~, before and IS min after i.v. injection of the compounds.
COMPOUND Dose BVC

ug/kg before after of change treat.

Compound A 300 0.81 t 0.05 0.87 t 0.05+ 7.4 1000 0.78 t 0.11 0.97 t 0.11+ 24.4 **

Example 1 300 0.71 t 0.09 0.87 f 0.10+ 22.5 *

1000 0.62 t 0.09 0.75 t 0.10+ 21.0 * *

Example 4 300 0.59 f 0.04 0.71 t 0.05+ 21.0 *

1000 0.6510.10 0.88 f 0.12+ 35.0 **

FLAVOXATE 300 0.76 t 0.11 0.87 t 0.11+ 14.5 1000 0.88 t 0.15 1.11 t 0.16+ 26.1 **

OXYBUTYNIN 100 0.82 t 0.15 0.89 t 0.18+ 8.5 300 0.8310.13 0.8310.12 ~ 0.0 1000 0.94 t 0.19 1.00 t 0.18t 6.4 COMPOUND Dose MP

pg/kg before after of change treat.

Compound A 300 90.6 f 10.4 85.6 t 11.3- 5.5 1000 90.2 t 6.5 84.1 f 5.2 - 6.8 Example 1 300 95.4 t 6.4 80.4 t 6.5 - 15.7 **

1000 109.0 t 12.1 99.6 t 11.2- 8.6 *

Example 4 300 116.1 117.4 98.3 t 17.2- 15.0 **

1000 81.3 t 9.0 64.8 t 10.5- 20.0 *

FLAVOXATE 300 89.2 f 10.7 95.0 ~ 10.9+ 6.5 1000 90.4 t 10.7 80.1 t 11.1- 11.4 OXYBUT1'NIN 100 95.2 t 9.2 77.4 t 10.3- 18.7 * *

300 82.318.7 50.516.3 - 38.6 **

*=P<0.05, * *=P<0.01 versus basal values; Student's t test for paired data AM~IVD~D, ~H~~T

13/09/99 34 ~. ~ ~ ~ ~ ~ ~ rt12-wc~2 ~ ~ ~ . ' . ' ' , , Example 32 Radioreceptor Binding to 5-HTIa and other different neurotransmitter binding sites.
A. Methods:
Recombinant J:uman SHTIA receptors:
Genomic clone G-21 coding for the human 5-HT1A serotonergic receptor is stably transfected in a human cell line (HeLa). HeLa cells were grown as monolayers in Dulbecco's modified Eagle's medium (DMEM), supplemented with 10 % fetal calf serum and gentamicin (100 mg/ml), 5% C02 at 37°C. Cells were detached from the growth flask io at 95% confluence by a cell scraper and were lysed in ice-cold 5 mM Tris and 5 mM
EDTA buffer (pH 7.4). Homogenates were centrifuged at 40000 x g x 20 min and pellets were resuspended in a small volume of ice-cold 5 mM Tris and S mM EDTA buffer (pH
7.4) and immediately frozen and stored at -70°C until use. On the day of experiment, cell membranes were resuspended in binding buffer: 50 rnM Tris HCl (pH 7.4), 2.5 mM
MgCl2, IO~tM pargiline (Fargin et al., Nature 335, 358-360, 1988). Membranes were incubated in a final volume of 1 ml for 30 min at 30°C with 0.2 - 1 nM
[3H]8-OH-DPAT, in absence or presence of competing drugs; non-specific binding was determined in the presence of 10 ~M 5-HT. The incubation was stopped by addition of ice-cold Tris-HCl buffer and rapid filtration through 0.2% polyethyleneimine pretreated Whatman GF/B or 2o Schleicher & Schuell GF52 filters.
Native S-HT2A serotoninergic receptors and a2 -adrenoceptors (from animal tissues) Binding studies on native a2 adrenergic receptors (Diop L. et al, J.
Neurochem. 41 710-715, 1983), and 5-HT2A serotonergic receptors (Craig A. and Kenneth J., Life Sci. 38.
117-127, 1986) were carried out in membranes of rat cerebral cortex. Male Sprague Dawley rats (200-300g, SD Harlan/Nossan, Italy) were killed by cervical dislocation and cerebral cortexes were excised and immediately frozen in liquid nitrogen and stored at -70°C until use. Tissues were homogenized (2x20 sec) in 50 volumes of cold 50 mM Tris-HCl buffer pH 7.4, using a Polytron homogenizer (speed 7). Homogenates were centrifuged at 49000xg for 10 min, resuspended in 50 volumes of the same buffer, 3o incubated at 37°C for 15 min and centrifuged and resuspended twice more. The final pellets were suspended in 100 volumes of 50 mM Tris-HCl buffer pH 7.4, containing IOpM pargiline and 0.1% ascorbic acid (a2 adrenergic receptors) or in 100 volumes of 50 mM Tris-HCl buffer pH 7.7 (5-HT2A serotonergic receptors). Membranes were incubated in a final volume of 1 ml for 30 min at 25°C with 0.5-1.5 nM
[3H]rauwolscine (a2-adrenergic receptors) or for 20 min at 37°C with 0.7-1.3 nM
[3H]ketanserin (5-HT~
receptors), in absence or presence of competing drugs. Non-specific binding was determined in the presence of 10 ~M phentolamine (a2-adrenergic receptors) or 2 g.M
ketanserin (5-HT2,e, serotoninergic receptors). The incubation was stopped by addition of ice-cold 50 mM Tris-HCl buffer and rapid filtration through 0.2%
polyethyleneimine AMEh~D~L3 S~'EET

13/09/99 35 ' ' ' . rf'i 2-wo2 pretreated Whatman GFB or Schleicher & Schuell GF~2 filters. The filters are then washed with ice-cold buffer and the radioactivity retained on the filters was counted by liquid scintillation spectrometry.
B. Results:
The inhibition of specific binding of the radioligands by the tested drugs was analyzed to estimate the ICSO value by using the non-linear curve-fitting program Allfit (De Lean et al., Am. J. Physiol. 235, E97-E102, 1978). The ICso value was converted to an affinity constant (Ki) by the equation of Cheng & Prusoff (Cheng, Y.C.; Prusoff,. W.H.
Biochem.
to Pharmacol. 22, 3099-3108, 1973).
The results shown in Table 3A demonstrate that compound A and the compound of Example 1 both have a very high affinity for 5-HT1A receptors, but their binding profile is different. The compound of Example 1 was much more selective than compound A
for the 5-HT1A receptor versus the 5-HT2A and the a2-adrenoceptors. All the other compounds of the invention tested (Table 3B) had high affinity for the 5-HT1A receptor.

Binding affinity for the 5-HT1A receptor and other neurotransmitter binding sites Data are expressed as Ki (nll~.
Compound 5-HTip 5-HTZA a2 Compound A 0.10 629 2625 Example 1 0.05 >10000 >10000 Example 4 0.36 1065 2342 Example 8 0.60 1829 314 t~611~Li'~f~'~'" i~~ ~-~; E~cl 13/09/99 36 ~ , ~ ~ , , rf 1 ~-w~2 . , Binding affinity for the 5-HT1A receptor Data are expressed as Ki (n~.
Compound 5-HT1A

Ex. 2 0.64 Ex. 3 0.45 Ex. 4 0.36 Ex. 5 0.50 Ex 6 6.20 Ex. 7 2.90 Ex. 8 0.60 Ex. 9 2.72 Ex. 10 0.14 Ex. 11 8.91 Ex. 12 2.69 Ex. 13 0.57 Ex. 14 18.78 Ex. 16 7.96 Ex. 18 19.36 Ex. 20 16.27 Ex. 21 8.00 Ex. 24 1.02 Measurement of Pre- and Post-Synaptic 5-HT1A Receptor Antagonist Activity A. Methods:
Antagonism ojhypotl:ermia induced by 8-OH DPAT in mice (pre synaptic antagonism).
The antagonistic effect of the 5-HT1A receptor antagonists of the invention on hypothermia 1o induced by 8-OH-DPAT was evaluated by the method of Moser (Mosey, Eur.J.Pharmacol., 193:165, 1991) with minor modifications as described below. Male CD-1 mice (28-38 g) obtained from Charles River (Italy) were housed in a climate-controlled room (temperature 22 t 2 C; humidity 55 t 15%) and maintained on a 12 h light/dark cycle with free access to food and water. On the day of experiment, mice were placed singly in clear plastic i5 boxes under the same ambient conditions. Body temperature was measured by the insertion of a temperature probe (Termist TM-S, LSI) into the rectum to a depth of 2 cm.
Rectal temperature was measured immediately prior to intravenous injection of the test compound. All animals then received 8-OH-DPAT (0.5 mg/kg s.c.) and their temperature was measured 30 min later. For each animal, temperature changes were calculated with 2o respect to pretreatment values and the mean values were calculated for each treatment group. A linear regression equation was used in order to evaluate IDSO values, defined as the dose of antagonist needed to block 50% of the hypothermic effect induced by 0.5 mg/kg 8-OH-DPAT administered subcutaneously.
jl~~~~'t..~u..L~ ~~e i~..~' 13/09/99 37 ~ ~ ~ ~ rfl2-w~2 ~ .
Inhibition of forepaw treading induced by 8-OH DPAT in rats (post synaptic antag onism).
The inhibitory effect of 5-HTIA receptor antagonists on the forepaw treading induced in rats by subcutaneous injection of 8-OH-DPAT was evaluated by the method of Tricklebank (Tricklebank et al., Eur. J.Pharmacol., 117:15, 1980 with minor modifications as described below.
Male Sprague-Dawley rats (150-175 g) obtained from Charles River (Italy), were housed in a climate-controlled room and maintained on a 12 h light/dark cycle with free access to food and water. On the day of experiment, rats were placed singly in clear plastic boxes.
to Rats were treated with reserpine, 1 mg/kg s.c., 18-24 h before the test to deplete intracellular stores of noradrenaline. For evaluation of antagonistic activity, compounds were i.v. administered 16 min before 8-OH-DPAT (1 mg/kg s.c.). Observation sessions of 30 s duration began 3 min after treatment with the agonist and were repeated every 3 min over a period of 15 min. The appearance of the forepaw treading symptom induced by postsynaptic stimulation of the SHT1A receptors was noted, and its intensity was scored using a ranked intensity scale in which: 0 = absent, 1 = equivocal, 2 =
present and 3 =
intense. Behavioral scores for each treated rat were accumulated over the time course (5 observation periods) and expressed as mean values of 8-10 rats. A linear regression equation was used in order to evaluate IDso values, defined as the dose of antagonist 2o needed to block 50% of the forepaw treading intensity induced by 1 mg/kg 8-OH-DPAT
administered subcutaneously.
B. Results:
The results are shown in Table 4. These results demonstrate that compound of Example 1 exhibits significant pre-synaptic and post-synaptic 5-HT1A receptor antagonist activity.
Compound A, by contrast, proved at least 10 fold less active than compound of Example 1 in both models.

Antagonistic activity for the pre- and post-synaptic 5-HT1A receptor.
Data are expressed as IDso in mglkg.
Compound Pre-synaptic Post-synaptic m50 m50 Compound A 221 350 Example 1 20 36 Example 5 - g2 Example 8 n.a. 84 Example 10 - 177 ~'~_., d r , ..,) ,, i is:

pretreated Whatman GFB or Schleicher & Schuell GF52 filters. The filters are then washed with ice-cold buffer and the radioactivity retained on the filters was counted by liquid scintillation spectrometry.
B. Results:
The inhibition of specific binding of the radioligands by the tested drugs was analyzed to estimate the ICSo value by using the non-linear curve-fitting program Allfit (De Lean et al., Am. J. Physiol. 235, E97-E102, 1978). The ICSO value was converted to an affinity constant (Ki) by the equation of Cheng & Prusoff (Cheng, Y.C.; Prusoff, W.H.
Biochem.
1o Pharmacol. 22, 3099-3108, 1973).
The results shown in Table 3A demonstrate that compound A and the compound of Example 2 both have a very high affinity for 5-HT,A receptors, but their binding profile is different. The compound of Example 2 was much more selective than compound A
for the 5-HT,A receptor versus the 5-HT2A and the a2-adrenoceptors. All the other compounds of is the invention tested (Table 3B) had high affinity for the 5-HT,A receptor.

Binding affinity for the 5-HT1A receptor arid other neurotransmitter binding sites Data are expressed as Ki (ntL~.
Compound 5-HTIA 5-HT2p a2 Compound O.10 629 262s A

Example 2 O.OS > I > 10000 Example 8 0.36 106s 2342 Example 18 0.60 I 1829 314 I

Binding affinity for the 5-HT1A receptor Data are expressed as Ki (ntl~.
Compound 5-HT1A

Ex. 3 10.28 Ex. 4 0.64 Ex. 5 14.85 Ex. 6 0.45 Ex. 7 3.82 Ex. 8 0.36 Ex. 10 17.23 Ex. I 1 2.92 Ex. 12 4.77 Ex. 13 0.50 Ex 14 10.32 Ex 15 6.20 Ex. 16 2.90 Ex. 17 20.15 Ex. 18 0.60 Ex.20 24.62 Ex. 21 2.72 Ex. 22 18.18 Ex. 23 0.14 Ex. 25 8.91 Ex. 26 2.69 Ex. 27 0.57 Ex.28 18.78 Ex. 30 7.96 Ex. 32 19.36 Ex. 34 16.27 Ex. 3 S 8.00 Ex. 38 1.02 Measurement of Pre- and Post-Synaptic 5-HT1A Receptor Antagonist Activity A. Methods:
Antagonism of hypothermia induced by 8-OH DPAT in mice (pre synaptic antagonism).
The antagonistic effect of the 5-HT1A receptor antagonists of the invention on hypothermia l0 induced by 8-OH-DPAT was evaluated by the method of Mosey (Mosey, Eur.J.Pharmacol., 193:165, 1991) with minor modifications as described below. Male CD-1 mice (28-38 g) obtained from Charles River (Italy) were housed in a climate-controlled room (temperature 22 t 2 C; humidity 55 ~ 15%) and maintained on a 12 h light/dark cycle with free access to food and water. On the day of experiment, mice were placed singly in clear plastic 1 s boxes under the same ambient conditions. Body temperature was measured by the insertion of a temperature probe (Termist TM-S, LSI) into the rectum to a depth of 2 cm.
Rectal temperature was measured immediately prior to intravenous injection of the test compound. All animals then received 8-OH-DPAT (0.5 mg/kg s.c.) and their temperature was measured 30 min later. For each animal, temperature changes were calculated with respect to pretreatment values and the mean values were calculated for each treatment group. A linear regression equation was used in order to evaluate IDSO values, defined as 5 the dose of antagonist needed to block 50% of the hypothermic effect induced by 0.5 mg/kg 8-OH-DPAT administered subcutaneously.
Inhibition of forepalv treading induced by 8-OH DPAT in rats (post synaptic antagonism).
The inhibitory effect of 5-HT1A receptor antagonists on the forepaw treading induced in 1o rats by subcutaneous injection of 8-OH-DPAT was evaluated by the method of Tricklebank (Tricklebank et al., Eur. J.Pharmacol., 117:15, 1985) with minor modifications as described below.
Male Sprague-Dawley rats (150-175 g) obtained from Charles River (Italy), were housed in a climate-controlled room and maintained on a 12 h light/dark cycle with free access to ~5 food and water. On the day of experiment, rats were placed singly in clear plastic boxes.
Rats were treated with reserpine, 1 mg/kg s.c., 18-24 h before the test to deplete intracellular stores of noradrenaline. For evaluation of antagonistic activity, compounds were i.v. administered 16 min before 8-OH-DPAT (1 mg/kg s.c.). Observation sessions of 30 s duration began 3 min after treatment with the agonist and were repeated every 3 min 20 over a period of 15 min. The appearance of the forepaw treading symptom induced by postsynaptic stimulation of the SHT1A receptors was noted, and its intensity was scored using a ranked intensity scale in which: 0 = absent, 1 = equivocal, 2 =
present and 3 =
intense. Behavioral scores for each treated rat were accumulated over the time course (5 observation periods) and expressed as mean values of 8-10 rats. A linear regression 25 equation was used in order to evaluate IDSO values, defined as the dose of antagonist needed to block 50% of the forepaw treading intensity induced by 1 mg/kg 8-OH-DPAT
administered subcutaneously.
B. Results:
The results are shown in Table 4. These results demonstrate that compound of Example 2 3o exhibits significant pre-synaptic and post-synaptic 5-HT,A receptor antagonist activity.
Compound A, by contrast, proved at least 10 fold less active than compound of Example 2 in both models.

Antagonistic activity for the pre- and post-synaptic 5-HT1A receptor.
Data are expressed as IDso in mglkg.
Compound Pre-synaptic Post-synaptic IDSp ID50 Compound A 221 350 Example 2 20 36 Example 13 - 82 Example 18 n.a. 84 Example 23 - 1 ~~

Claims

42

1. A compound having the general formula I:
wherein R represents a cycloalkylcarbonyl, substituted cycloalkylcarbonyl or monocyclic heteroaryl-carbonyl group having from 5 to 7 ring atoms, R1 represents a hydrogen atom or a lower alkyl group, R2 represents a halogen atom or an alkoxy, phenoxy, nitro, cyano, acyl, amino, acylamino, alkylsulphonylamino, alkoxycarbonyl, carbamoyl, alkylcarbamoyl, dialkylcarbamoyl, acylcarbamoyl, trifluoromethyl or polyfluoroalkoxy group, and B represents a mono- or bicyclic (C6-C12)-aryl group, a monocyclic heteroaryl group having from 5 to 7 ring atoms, a bicyclic heteroaryl group having from 9 to 12 ring atoms, or a benzyl group, each of which may be substituted or unsubstituted, with the proviso that if B represents an alkoxy substituted aryl group, then the alkoxy group must be at position 2 of the aryl ring;
or an enantiomer, N-oxide, hydrate or pharmaceutically acceptable salt of such a compound.

2. A compound according to claim 1 wherein B represents a 2-methoxyphenyl, 2,5-dichlorobenzyl or 4-indolyl group.

3. A compound according to claim 1 or claim 2 wherein R2 represents an iodine atom or a methoxy, phenoxy, nitro, cyano, acetyl, amino, acetamido, acetoxycarbonyl, carbamoyl, ethylcarbamoyl, dimethylcarbamoyl, cyclohexylcarbonylcarbamoyl, trifluoromethyl, trifluoromethoxy or 2,2,2-trifluoroethoxy group.

4. A compound according to any preceding claim wherein R represents a hydrogen atom or a cyclohexylcarbonyl, 1-methylcyclohexylcarbonyl, 1-phenylcyclohexylcarbonyl, 3-furylcarbonyl, 3-thienylcarbonyl, 4-pyridylcarbonyl, 3-pyridylcarbonyl or 2-pyrazinylcarbonyl group.

5. A compound according to any preceding claim wherein R, represents a hydrogen atom or a methyl group.

6. Any one of the following compounds:
1-[N-(2-nitrophenyl)-N-cyclohexylcarbonyl-2-aminoethyl]-4-(2-methoxyphenyl)-piperazine, 1-[N-(2-trifluoromethoxyphenyl)-N-cyclohexylcarbonyl-2-aminoethyl]-4-(2-methoxyphenyl)-piperazine, 1-[N-(2-phenoxyphenyl)-N-cyclohexylcarbonyl-2-aminoethyl)-4-(2-methoxyphenyl)-piperazine, 1-(N-(2-iodophenyl)-N-cyclohexylcarbonyl-2-aminoethyl)-4-(2-methoxyphenyl)-piperazine, 1-[N-(2-nitrophenyl)-N-cyclohexanecarbonyl-2-aminoethyl)-4-(4-indolyl)-piperazine, 1-(N-(2-nitrophenyl)-N-cyclohexylcarbonyl-2-aminoethyl]-4-(2,5-dichlorobenzyl)-piperazine, 1-(N-(2-cyclohexylcarbonylaminocarbonylphenyl)-N-cyclohexylcarbonyl-2-aminoethyl)-4-(2-methoxyphenyl)-piperazine, 1-[N-(2-methoxycarbonylphenyl)-N-cyclohexylcarbonyl-2-aminoethyl]-4-(2-methoxyphenyl)-piperazine, 1-[N-(2-dimethylcarbamoyl-phenyl)-N-cyclohexylcarbonyl-2-aminoethyl]-4-(2-methoxyphenyl)-piperazine 1-[N-(2-methoxyphenyl)-N-cyclohexylcarbonyl-2-aminoethyl]-4-(2-methoxyphenyl)-piperazine, 1-[N-(2-ethylcarbamoyl-phenyl)-N-cyclohexylcarbonyl-2-aminoethyl)-4-(2-methoxyphenyl)-piperazine, 1-[N-(2-trifluoromethylphenyl)-N-cyclohexylcarbonyl-2-aminoethyl)-4-(2-methoxyphenyl)-piperazine, 1-[N-(2-aminophenyl)-N-cyclohexylcarbonyl-2-aminoethyl)-4-(2-methoxyphenyl)-piperazine, 1-[N-(2-acetylaminophenyl)-N-cyclohexylcarbonyl-2-aminoethyl)-4-(2-methoxyphenyl)-piperazine, 1-[N-(2-nitrophenyl)-N-cyclohexylcarbonyl-2-aminoethyl)-4-(2-methoxyphenyl)-piperazine N1-oxide, 1-[N-(2-nitrophenyl)-N-cyclohexylcarbonyl-2-aminoethyl]-4-(2-methoxyphenyl)-piperazine N4-oxide, 1-[N-(2-nitrophenyl)-N-cyclohexylcarbonyl-2-aminoethyl]-4-(2-methoxyphenyl)-piperazine N1,N4-dioxide, 1-[N-(2-nitrophenyl)-N-(3-furylcarbonyl)-2-aminoethyl]-4-(2-methoxyphenyl)-piperazine, 1-[N-(2-nitrophenyl)-N-(2-furylcarbonyl)-2-aminoethyl]-4-(2-methoxyphenyl)-piperazine, 1-[N-(2-nitrophenyl)-N-(2-thienylcarbonyl)-2-aminoethyl]-4-(2-methoxyphenyl)-piperazine, 1-[N-(2-nitrophenyl)-N-(3-thienylcarbonyl)-2-aminoethyl]-4.-(2-methoxyphenyl)-piperazine, 1-[N-(2-nitrophenyl)-N-(4-pyridylcarbonyl)-2-aminoethyl]-4-(2-methoxyphenyl)-piperazine, 1-[N-(2-nitrophenyl)-N-(3-pyridylcarbonyl)-2-aminoethyl]-4-(2-methoxyphenyl)-piperazine, 1-[N-(2-nitrophenyl)-N-(2-pyrazinylcarbonyl)-2-aminoethyl]-4-(2-methoxyphenyl)-piperazine, 1-[N-(2-nitrophenyl)-N-( 1-methylcyclohexylcarbonyl)-2-aminoethyl]-4-(2-methoxyphenyl)-piperazine, 1-[N-(2-nitrophenyl)-N-( 1-phenylcyclohexylcarbonyl)-2-aminoethyl]-4-(2-methoxyphenyl)-piperazine, 1-[N-[2-(2,2,2-trifluoroethoxy)-phenyl]-N-cyclohexylcarbonyl-2-aminoethyl]-4-(2-methoxyphenyl)-piperazine, 1-[N-(2-cyanophenyl)-N-cyclohexylcarbonyl-2-aminoethyl]-4-(2-methoxyphenyl)-piperazine, 1-[N-(2-nitrophenyl)-N-cyclohexylcarbonyl-1-amino-2-propyl]-4-(2-methoxyphenyl)-piperazine;
or an enantiomer, N-oxide, hydrate or pharmaceutically acceptable salt of such a compound.

7. A pharmaceutical composition comprising a compound according to any preceding claim in admixture with a pharmaceutically acceptable diluent or carrier.

8. Use of a compound having the general formula I:
wherein R represents a cycloalkylcarbonyl, substituted cycloalkylcarbonyl or monocyclic heteroaryl-carbonyl group having from 5 to 7 ring atoms, R1 represents a hydrogen atom or a lower alkyl group, R2 represents a halogen atom or an alkoxy, phenoxy, nitro, cyano, acyl, amino, acylamino, alkylsulphonylamino, alkoxycarbonyl, carbamoyl, alkylcarbamoyl, dialkylcarbamoyl, acylcarbamoyl, trifluoromethyl or polyfluoroalkoxy group, and B represents a mono- or bicyclic (C6-C12)-aryl group, a monocyclic heteroaryl group having from 5 to 7 ring atoms, a bicyclic heteroaryl group having from 9 to 12 ring atoms, or a benzyl group, each of which may be substituted or unsubstituted, or of an enantiomer, N-oxide, hydrate or pharmaceutically acceptable salt of such a compound, for the preparation of a medicament for the treatment of neuromuscular dysfunction of the lower urinary tract in a mammal.

9. Use according to claim 8 of a compound according to any of claims 1 to 6.

10. Use according to claim 8 or claim 9 for the preparation of a medicament which contains a pharmaceutically acceptable diluent or carrier.

11. Use according to any of claims 8 to 10 for the preparation of a medicament in a form suitable for oral administration.

12. Use according to claim 11 for the preparation of a medicament which contains from 50 to 400 mg of the compound in single dose form.