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##
式中A,m,Z,n和R1的定义如下,其非毒性药学上可接受的盐,
水合物和溶剂化物是新型抗溃疡药物,通过环闭合取代的乙二
亚胺衍
生物的制备而得到。 HiSTamine H.sub.2 -受体拮抗剂的
化学式为##STR1##,