Three-component condensation of 2,4-diaminothiazoles with aldehydes and Meldrum's acid: synthesis of 7-aryl(alkyl)-substituted 6,7-dihydro-4H-thiazolo[4,5-b]pyridin-5-ones

The new method of the synthesis of 6,7-dihydro-4H-thiazolo[4,5-b]pyridin-5-ones, based on decarboxylation of corresponding 2,4-diamino-5-thiazolecarboxylic acids has been elaborated; unstable derivatives of 2,4-diaminothiazole, generated in situ as a result of decarboxylation, react with aldehydes and Meldrum's acid forming target compounds.