| abstract |
The present invention relates to compounds of formula (I) wherein R?1a and R1b¿ represent a variety of substituents; R3 represents an optionally substituted phenyl, biphenyl or naphthyl group; R4 represents hydrogen, C¿1-6?alkyl, carbonyl (=O), (CH2)pphenyl or a C1-2alkylene bridge across the piperazine ring; R?5¿ represents C¿1-6?alkyl, C3-7cycloalkyl, C3-7cycloalkylC1-4alkyl, C2-6alkenyl, phenyl, naphthyl, fluorenyl, heteroaryl, (CH2)ppphenyl, (CH2)pheteroaryl, CH(phenyl)2, CH(C1-6alkyl)(phenyl), C2-4alkenyl(phenyl), (CH2)pNR?cRd, (CH¿2)pCONR?cRd, (CH¿2)mCORc, (CH2)mCO2Rc or (CH¿2?)pOH; X represents an oxygen or a sulfur atom; m is zero or an integer from 1 to 4; n is an integer from 1 to 4; p is an integer from 1 to 4; or a pharmaceutically acceptable salt thereof. The compounds are of particular use in the treatment or prevention of depression, anxiety, pain, inflammation, migraine, emesis or postherpetic neuralgia. |