New isothiazole derivatives: synthesis, reactivity, physicochemical properties and pharmacological activity.

The synthesis and biological investigation of the series of amide and ester derivatives 10-20 of 5-(4-chlorobenzoyl)amino-3-methyl-4-isothiazolecarboxylic acid 5 are presented. Because the amide series of 5-benzoylamino-3-methyl-4-isothiazolecarboxylic acid 2 has been studied extensively and from this series denotivir (vratizolin) 4 became the antiviral drug. The influence of exchanging the N-benzoyl for a N-(4-chlorobenzoyl) group at position 5 of the isothiazole ring on the pharmacological activity of 5-benzoylamino-3-methyl-4-isothiazolecarboxylic acid 2 derivatives is dealt with here.

A new method for the synthesis of ranitidine.

An improved synthesis of the antiulcer drug Ranitidine from an oxazolidine derivative is reported.