Imidazolyl and pyridyl derivatives of phenyl substituted 1,4-dihydropyridines and process for their preparation

A compound having the following formula (I) ##STR76## wherein Het is ##STR77## A represents a direct linkage at the meta position of the phenyl ring;

• R is hydrogen, halogen, C.sub.1 -C.sub.3 alkyl or C.sub.2 -C.sub.3 alkoxy;
• each of R.sub.3 and R.sub.4, which may be the same of different, is a C.sub.1 -C.sub.3 alkyl group;
• one of R.sub.1 and R.sub.2 is a group --OR' wherein R' is C.sub.1 -C.sub.6 alkyl either unsubstituted or omega substituted by C.sub.1 -C.sub.3 alkoxy and the other is, independently,
• (a) a group --OR' as defined hereabove;
• or
• (b) a group --OR.sup.IV wherein R.sup.IV is a substituent ##STR78## wherein Ph is a phenyl group either unsubstituted or substituted by one to three substituents chosen among C.sub.1 -C.sub.3 alkyl, C.sub.1 -C.sub.3 alkoxy and halogen;
• Q is a C.sub.2 -C.sub.5 alkylene radical;
• n is zero, 1 or 2;
• and each R.sup.V is, independently, hydrogen, C.sub.1 -C.sub.3 alkyl or Ph, wherein Ph is as defined above;
• or a pharmaceutically acceptable salt thereof.