Isoureas and isothioureas

Claim 1

A compound of the formula ##STR10## ##STR11## in which R 1 and R 2 are hydrogen or lower alkyl; Y is sulphur or oxygen; n is from 3 to 8; X is oxygen or sulphur; Z is hydrogen or lower alkyl; A is straight or branched C 1 -C 5 alkylene or --(CH 2 ) p W(CH 2 ) q -- where W is oxygen or sulphur and the sum of p and q is 1 to 4; and B is methyl, C 3 -C 6 cycloalkyl, a heteroaryl group selected from furyl, thienyl, thiazolyl, oxazolyl, isothiazolyl, imidazolyl, thiadiazolyl, benzimidazolyl and benzthiazolyl, said heteroaryl being optionally substituted by one or more lower alkyl, lower alkoxy, halo, hydroxy or amino groups or B is a naphthyl, 5- or 6-(2,3-dihydro-1,4-benzodioxinyl) or 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 alkoxy-lower alkoxy, trifluoromethyl, di(lower alkyl)amino, phenoxy, halophenoxy, lower alkoxyphenoxy, phenyl, halophenyl or lower alkoxyphenyl group, or, provided A is alkylene, B can be hydrogen, in the form of the free base or a pharmaceutically acceptable acid addition salt thereof.