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 are novel anti-ulcer agents which are prepared by ring closure of a substituted ethanediimidamide of the formula ##STR2##
本发明涉及一种组成式为##STR1##其中A,m,Z,n和R.sup.1如本文所定义的
组织胺H.sub.2受体拮抗剂及其无毒药学上可接受的盐,该拮抗剂是一种新的抗溃疡剂,其通过环闭合替代的乙二
亚胺衍
生物的制备而得。