Oxazolidinone derivatives, their preparation and therapeutical use

Process for the preparation of compounds of formula (I) ##STR5## in which:

• X represents an oxygen atom, A sulphur atom or a group NR, R being a hydrogen atom or a linear or branched C.sub.1-C.sub.4, alkyl chain,
• R.sub.1 represents a methyl group, and
• R.sub.2 represents a group R.sub.3 O in which R.sub.3 represents alternatively a hydrogen atom, or a benzyl group which is optionally substituted with a halogen atom or with a nitro or methylenedioxy group, or represents a methoxyethyl, butyl, 4,4,4,-trifluorobutyl, 4,4,4-trifluoro-3-hydroxybutyl or 4,4,4-trifluorobut-2-enyl group,
• characterized in that the compound of formula II ##STR6## is treated with one of the 4(R) or 4(S) isomers of 4-methoxymethyl-1,3-dioxolan-2-one of formula (IIIa) ##STR7## in the presence of potassium carbonate in order to obtain the 5 (S) or 5(R) isomer of the compound of formula (Ia) ##STR8## which is debenzylated by catalytic hydrogenation or with the aid of a Lewis acid in order to obtain the 5(S) or 5(R) isomer of the compound of formula ((Ib), R.sub.1 .dbd.CH.sub.3) ##STR9## which is treated either with a compound of formula R.sub.3 Y in which R.sub.3 is defined as in formula (I), with the exception of the meanings hydrogen and unsubstituted benzyl, and Y is a leaving group, in the presence of potassium carbonate, or with a compound of formula R.sub.3 OH in which R.sub.3 is defined as in formula (I), with the exception of the meanings hydrogen unsubstituted benzyl, in the presence of triphenylphosphine and diethyl azodicarboxylate, in order to obtain the 5(S) or 5(R) isomers of the compounds of formula ((Ic) R.sub.1 .dbd.CH.sub.3) ##STR10## and, if necessary, the compounds in which X.dbd.NCH.sub.3 are treated with benzoyl peroxide in order to obtain the compounds of formula (Ih) in which X.dbd.NH ##STR11##

Process for the preparation of compounds of formula (I) ##STR18## in which:

• X represents an oxygen atom, a sulphur atom or a group NR, R being a hydrogen atom or a linear or branched C.sub.1 -C.sub.4 alkyl chain,
• R.sub.1 represents a hydrogen atom or a methyl group, and
• R.sub.1 represents a group --CH.dbd.CH--R.sub.4 or --CH.sub.2 --CH.sub.2 --R.sub.4, in which
• R.sub.4 represents a hydrogen atom, or a phenyl, 3,3,3-trifluoropropyl or 3,3,3-trifluoro-2-hydroxypropyl group, characterized in that it consists in treating the compound of formula ((Ib), R.sub.1 .dbd.CH.sub.3) ##STR19## with trifluoromethanesulphonic anhydride, in reacting the resulting compound of formula (IV) ##STR20## with tributylvinyl tin in the presence of lithium chloride and tetrakis(triphenylphosphine)palladium, in treating the resulting compound of formula (Id) ##STR21## with ozone and then with dimethyl sulphide, in reacting the resulting compound of formula (V) ##STR22## with a triphenylphosphonium iodide of formula R.sub.4 CH.sub.2 PPh.sub.3.sup.+ I.sup.- in which R.sub.4 is defined as in formula (I) above, with the exception of the meaning hydrogen, in the presence of potassium carbonate, in reducing the resulting compound of formula (Ie) ##STR23## with hydrogen in the presence of a catalyst in order to obtain the compound of formula (If) ##STR24## in which R.sub.4 is defined as above, and finally in treating the compound of formula (Id), (Ie) or (If) with boron tribromide in order to obtain the compound of formula (Ig) ##STR25##