Histamine H.sub.2 -receptor antagonists of the formula ##STR1## wherein A, m, Z, n and R.sup.1 are as defined herein, and their nontoxic pharmaceutically acceptable salts, hydrates and solvates are novel anti-ulcer agents which are prepared by ring closure of a substituted ethanediimidamide of the formula ##STR2## with a compound of the formula R--S--R in which R is as defined herein.
组成式为##STR1##的
组胺H.sub.2-受体拮抗剂,其中A、m、Z、n和R.sup.1如本文所定义,以及它们的无毒药用可接受的盐、
水合物和溶剂化合物是新型抗溃疡剂,通过将组成式为##STR2##的取代乙二
亚胺环闭合物与组成式为R--S--R的化合物进行环闭合制备。