The compounds are substituted isocytosines which are histamine H.sub.2 -antagonists. Two specific compounds of the present inventon are 2-[2-(5-methyl-4-imidazolylmethylthio)ethylamino]-5-(3-pyridylmethyl)-4-py rimidone and 2-[2-(3-bromo-2-pyridylmethylthio)ethylamino]-5-(4-pyridylmethyl)-4-pyrimi done.
这些化合物是取代的异
胞嘧啶,是
组织胺H.sub.2-拮抗剂。本发明的两种具体化合物是2-[2-(5-甲基-4-
咪唑基甲
硫基)乙基]
氨基-5-(3-
吡啶甲基)-4-
吡咯酮和2-[2-(3-溴-2-
吡啶甲
硫基)乙基]
氨基-5-(4-
吡啶甲基)-4-
吡咯酮。