Compounds of formula (I): ##STR1## (wherein A is an alkylene group substituted by an optionally substituted amino or heterocyclic group and optionally interrupted by an oxygen or sulfur atom, R.sup.2 is various organic groups, B is C.sub.1 -C.sub.2 alkylene and Y is sulfur or methylene) and pharmaceutically acceptable salts and esters thereof are valuable hypotensive agents which may be prepared by a condensation reaction of the corresponding compound having an amino group in place of the group A--CH(COOH)--NH--.
式子(I)的化合物:##STR1##(其中A是一个被可选择取代的
氨基或杂环基替代的烷基,且可被氧或
硫原子中断,R.sup.2是不同的有机基团,B是C.sub.1-C.sub.2烷基,Y是
硫或亚甲基),以及其药学上可接受的盐和酯,是有价值的降压剂,可以通过将具有
氨基代替A-CH(COOH)-NH-的相应化合物进行缩合反应来制备。