SUBSTITUTED PYRIMIDONE DERIVATIVES

摘要

Compounds (1) …… in which… R<1> and R<2> are C1-C4 alkyl or together with the nitrogen atom to which they are attached form a pyrrolidino or piperidino group;… Y is methylene or sulphur;… X is methylene or oxygen provided that X is methylene when Y is sulphur;… Z is hydrogen or C1-C4 alkyl; and… R<5> is hydrogen, C1-4 alkyl or -A-B where… A is C1-C4 alkylene and… B is optionally substituted heteroaryl or phenyl are histamine H2-antagonists. Processes for their preparation and pharmaceutical compositions containing them are also described.