| abstract |
ABSTRACT OF THE DISCLOSURE Pyrimidones which are histamine H2-antagonists having the structure in which D is hydrogen or an aminoalkyl group, X is oxygen or sulphur, Y is oxygen, sulphur or methylene, n is 2 or 3, Z is hydrogen or lower alkyl, A is C1-C5 alkylene in which one methylene group can be replaced by oxygen or sulphur, and B is hydrogen or an organic group, are prepared by a process in which (a) a compound of the structure where Q is a group displaceable with a primary amine and B1 is B or a protected group B, is reacted with an amine of structure where E is D or a protected aminoalkyl group, or (b) where Y is sulphur, with an amine of structure GS(CH2)nNH2 where G is hydrogen or a thiol-protecting group, followed by removal of the latter where present, and reaction of the product with a compound of structure where L is a group displaceable with a thiol; and removal of any protecting group; and (i) where D is hydrogen, optionally reacting the product with a Mannich reagent, or (ii) where D is aminoalkyl, optionally reacting the product with formaldehyde and formic acid. |