PROCESS FOR PRODUCING SUBSTITUTED IMIDAZOLYL-METHYL-THIO-PYRAMI DONE DERIVATIVES

Prepn. of 2-(HetCH2S(CH2)nNH) 5-A-B 6-Z 4-pyrimidones of formula (I) and their acid addn. salts comprises (i) reacting the corresp. 2-(HS(CH2)nNH) cpd. of formula (II) or its acid addn. salt with the cpd. Het-CH2-L (III)\ or its acid addn. salt, where any substits. in (II) and (III) which would interfere with the reaction are protected, followed by (ii) removing any protecting gps. and opt. converting the prod. to its acid addn. salt.\ (Het is an N-contg. 5- or 6-membered fully unsatd. heterocyclic ring opt. substd. by 1-4C alkyl, CF3, halogen, OH, 1-4C alkoxy and/or amino;\ n is 2 or 3;\ Z is H or 1-4C alkyl;\ A is 1-5C alkylene opt. interrupted with O or S;\ B is H, Me, 3-6C cycloalkyl, heteroaryl (opt. substd. by 1-4C alkyl, 1-4C alkoxy and/or OH), naphthyl, 5- or 6-(2,3-dihydro 1,4-benzodioxinyl), 4- or 5-(1,3-benzodioxolyl), or phenyl (opt. substd. by 1-4C alkyl, 1-4C alkoxy, halogen, aryl- (1-4C)alkoxy, OH (1-4C)alkoxy-(1-4C)alkoxy, CF3, di(1-4C alkyl)amino, phenoxy, halophenyl and/or 1-4C alkoxyphenyl); and\ L is a gp. displaceable with thiol).. Cpds. (I) are useful as inhibitors of gastric acid secretion, as antiinflammatory agents and as agents which inhibit the effects of histamine on blood pressure.