2-oxoazetidines, methods for their preparation, and their use

Abstract

The invention relates to new 2-oxoazetidines having the formulas ##STR1## where R.sub.1 stands for a lower fluoroalkyl or an optionally protected lower hydroxyalkyl group; R.sub.2 for chlorine, bromine, iodine, fluorine, an ##STR2## group in which n is 0, 1 or 2 and R.sub.5 is a lower alkyl, lower alkenyl, an optionally substituted benzyl group, optionally substituted phenyl group, a --CH.sub.2 COX group in which X means a lower alkyl, lower alkoxy or the amino group, or a ##STR3## group in which Y and Z are the same or different and in each case stand for oxygen, nitrogen or sulphur and R.sub.6 stands for a lower alkyl, lower alkoxy, lower alkylthio, lower dialkylamino, an aryl, aryloxy or arylthio group, or for a group having the formula ##STR4## where W stands for --CH.sub.2 CH.sub.2 --, --CH.dbd.CH-- or C.sub.6 H.sub.4 ; R.sub.3 stands for bromine, chlorine, iodine, SeC.sub.6 H.sub.5 or SC.sub.6 H.sub.5 ; and R.sub.4 stands for hydrogen, a group having the formula ##STR5## in which R.sub.7 is a lower alkyl, an optionally substituted benzyl or an optionally substituted benzohydryl group; or they represent a protecting group, with the proviso that in compounds of formula Ia R.sub.2 does not stand for SCH.sub.3 when R.sub.1 means hydroxyethyl, R.sub.3 means bromine and R.sub.4 means the group of formula IIa, as well as to methods for their preparation and to their use.