Abstract: 1,4-dihydropyridines of formula I ##STR1## wherein X is --CO.sub.2 R.sub.1, cyano, nitro, --COCH.sub.3 ; each of R and R.sub.1, which are the same or different, is a primary, secondary or tertiary, saturated or unsaturated, linear or branched C.sub.1 -C.sub.6 alkyl group optionally substituted by one or more hydroxy, C.sub.1 -C.sub.7 -monoalkylamino, di-C.sub.1 -C.sub.7 -alkylamino, benzylamino, C.sub.1 -C.sub.6 -alkoxy, phenoxy groups which are optionally substituted; R.sub.2 is hydrogen; R.sub.3 is hydrogen or hydroxy, --OCOR.sub.5, OSO.sub.2 R.sub.6, azide, amino, --NHPO(OR.sub.7).sub.2, --NHCOR.sub.5, C.sub.1 -C.sub.4 -alkoxy or fluorine, chlorine, bromine or iodine, SH, SCOR.sub.6 or C.sub.1 -C.sub.6 -alkylthio, phenylthio or benzylthio; R.sub.4 is an optionally substituted aromatic or an optionally substituted 5- or 6-membered heteroaromatic group; Y is one or more substituents, which may be the same or different, selected from C.sub.1 -C.sub.4 -alkoxy, halogen, nitro, cyano, C.sub.1 -C.sub.