Abstract: The present invention relates to isoindole derivatives, and more particularly to 5-(hydroxymethyl)oxazolidine-2-one derivatives which are substituted at the 3 position by an indazole, benzisoxazole or benzisothiazole ring system, to a process for their preparation and to their application in therapy.

Abstract: 3,3a,4,5-Tetrahydro-1H-oxazolo[3,4-a]quinolin-1-one derivatives of formula (I) ##STR1## in which: n is 0 or 1,R.sub.1 represents a hydrogen atom or an ethenyl, methyl, ethyl, phenyl, hydroxymethyl or methoxymethyl group, and(i) R.sub.2 is a methyl, trifluoromethyl or cyano group, R.sub.3 is a hydrogen atom or a hydroxyl or benzyloxy group and R.sub.4 and R.sub.5 are hydrogen atoms,or (ii) R.sub.2 and R.sub.4 together form a --(CH.sub.2).sub.4 -- group, R.sub.3 is a hydroxyl group and R.sub.5 is a hydrogen atom,or (iii) R.sub.2 and R.sub.5 together form an --O--(CH.sub.2).sub.3 -- group, and R.sub.3 and R.sub.4 are hydrogen atoms,or (iv) R.sub.2 and R.sub.5 together form a --(CH.sub.2).sub.4 group, R.sub.3 is a hydroxyl group and R.sub.4 is a hydrogen atom,are useful as selective inhibitors of MAO-A or as mixed inhibitors of MAO-A and MAO-B.

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.