Abstract: 1,3,4-Oxadiazol-2(3H)-one derivatives, of formula ##STR1## in which R.sub.1 represents either a hydrogen atom or a linear or branched (C.sub.1-4)alkyl group which is substituted with a hydroxyl group, a phenoxy group, a (C.sub.1-4)alkoxy group, a (C.sub.1-4)alkylthio group, a mercapto group, a (C.sub.1-4)alkoxy-(C.sub.1-4)alkoxy group, a di(C.sub.1-4)alkylamino group or an N-(C.sub.1-4)alkyl-N-propynylamino group, or represents a (C.sub.3-4)alkynyl group, andR.sub.2 either represents a linear or branched (C.sub.1-8)alkyl group which is substituted with one or more halogen atoms and/or a hydroxyl group, a 1-imidazolyl group or a 3-tetrahydropyranyl group, or represents a trifluoro(C.sub.3-5)alkenyl group,in the form of pure enantiomers or mixtures of enantiomers, including racemic mixtures, as well as the addition salts thereof with pharmaceutically acceptable acids, are useful as inhibitors of monoamine oxidase B.

Abstract: A compound which is a piperidine derivative of formula (I) ##STR1## in which R represents hydrogen, or unbranched or branched C.sub.1 -C.sub.6 alkyl group; andAr represents phenyl optionally substituted with one or more radicals selected from the halogens, amino, C.sub.1 -C.sub.2 alkoxy and (C.sub.3 -C.sub.6)cycloalkyl(C.sub.1 -C.sub.2)alkoxy, or a heteroaryl group;or a pharmaceutically acceptable acid addition salt thereof;provided that when R is hydrogen Ar is not phenyl or 4 -chlorophenyl.The compounds are useful in therapy as ligands for 5-HT.sub.3 and 5-HT.sub.4 receptors.

Abstract: The invention provides a compound which is a piperidine derivative of formula (I) ##STR1## in which R.sub.1 is hydrogen or straight or branched (C.sub.1 -C.sub.6) alkyl, R.sub.2 is hydrogen or straight or branched (C.sub.1 -C.sub.8) alkyl, Z and Z.sub.1 which may be the same or different, each is hydrogen, chlorine, hydroxyl, amino, nitro, hydroxymethyl, (C.sub.1 -C.sub.2) alkyl, (C.sub.1 -C.sub.8) alkoxy straight or branched (C.sub.1 -C.sub.5) alkoxycarbonyl or aryl (C.sub.1 -C.sub.2) alkoxy, Z is in position 4, 6 or 7 and Z and Z.sub.1 cannot both be hydrogen, or its addition salt with a pharmaceutically acceptable acid and its therapeutic application.

Abstract: A compound which is a piperidine derivative of general formula (I) ##STR1## in which R.sub.1 represents a hydrogen atom, a linear or branched (C.sub.1-6)alkyl group or a cyclo(C.sub.3-8)alkyl group, X represents an oxygen atom, a sulphur atom or a group of general formula N--R.sub.3 in which R.sub.3 is a hydrogen atom, or a linear or branched (C.sub.1-8)alkyl, cyclo(C.sub.3-6)alkyl, cyclo(C.sub.3-6)alkylmethyl, (C.sub.1-4)alkoxy-(C.sub.1-4)alkyl, phenyl, pyridin-4-yl, pyridin-3-yl, pyridin-4-ylmethyl or pyridin-3-ylmethyl group and Z represents a hydrogen or fluorine atom and acid addition salts thereof with pharmaceutically acceptable acids, can be used for the treatment and prevention of disorders in which 5-HT receptors are involved.