Abstract: A mixture of the 4 stereoisomers of formula (I) below, each of the pairs of corresponding racemic diastereoisomers and each of the enantiomers corresponding to each pair, that is to say each of said stereoisomers: ##STR1## in which R.sub.1 represents: a hydrogen atom,an alkoxy group comprising from 1 to 4 carbon atoms,a trifluoromethyl group, orone or two halogen atoms;and the pair (R.sub.2, R.sub.3) has one of the following meanings: (H, H), (H, C.sub.1 -C.sub.4 alkyl), (C.sub.1 -C.sub.4 alkyl, C.sub.1 -C.sub.4 alkyl), as well as their organic and inorganic acid addition salts.The compounds of formula (I) are therapeutically useful.

Abstract: N-arylated oxazolidine-2-one derivatives corresponding to the formula: ##STR1## and of S(+) configuration, A representing in this case the hydroxyl radical or of R (+) configuration, A designating then the N-methylamino group, as well as the acid addition salts thereof.Application in therapeutics more particularly as monoamine oxidase inhibitors.

Abstract: Derivatives corresponding to the general formula: ##STR1## in which Ar represents a phenyl group; a phenyl group substituted by a halogen atom or by a trifluoromethyl group; or the (chloro-3 fluoro-4) phenyl group and n is either equal to zero or equal to 1 in which case X is a chain chosen from the following: --CH.sub.2 --CH.sub.2 --, --CH.dbd.CH--, --C.tbd.C--, --CH.sub.2 --O-- whose CH.sub.2 group is linked to Ar.These compounds are useful as medicaments more especially for the treatment of troubles of the central nervous system and senescence.

Abstract: Method of treating the central nervous system troubles such as the Parkinson's disease and the senescence troubles, generally treated by the B type monoamine oxidase inhibitors, which comprises administering internally to a human being requiring such treatment a therapeutically effective amount of N-aryl 5-aminomethyl oxazolidine-2-one derivatives.