Pyrimidine compounds

A compound of the formula:

• ##STR7## in which D is hydrogen or R.sup.1 R.sup.2 N(CH.sub.2).sub.m --, R.sup.1 and R.sup.2 are hydrogen, lower alkyl, phenyl(lower alkyl) or R.sup.1 and R.sup.2 taken together with the nitrogen atom shown can form a pyrrolidino or piperidino group, m is from 1 to 6, X is oxygen or sulphur, Y is sulphur, oxygen or methylene, n is 2 or 3, Z is hydrogen or lower alkyl, A is C.sub.1 -C.sub.5 alkylene or --(CH.sub.2).sub.p W(CH.sub.2).sub.q -- where W is oxygen or sulphur and p and q are such that their sum is from 1 to 4, and B is hydrogen, methyl, C.sub.3 -C.sub.6 cycloalkyl, a heteroaryl group selected from furyl, thienyl, thiazolyl, oxazolyl, isothiazolyl, imidazolyl, thiadiazolyl, benzimidazolyl and benzthiazolyl, said heteroaryl group being optionally substituted by one or more of the groups lower alkyl, lower alkoxy, halo, hydroxy and amino, or B is a naphthyl, or a 4- or 5-(1,3-benzodioxolyl) group, or a phenyl group optionally substituted with one or more lower alkyl, lower alkoxy, halogen, phenyl(lower alkoxy), hydroxy, lower alkoxylower alkoxy, trifluoromethyl, di(lower alkyl)amino, phenoxy, halophenoxy, lower alkoxyphenoxy, phenyl, halophenyl or lower alkoxyphenyl groups, in the form of the free base or its pharmaceutically acceptable acid addition salts.