Reactions of Malonothioamide Derivatives with Azides*

The reactions of primary and tertiary malonothioamides with aryl and sulfonyl azides can take place in three directions, depending on the nature of the thioamides and azides. Ethoxycarbonylthioacetamide reacts with aryl azides with the formation of ethyl 5-amino-1-aryl-1,2,3-triazole-4-carboxylates. In reaction with aryl azides tertiary thioamides of cyanoacetic acid form 5-amino-1-aryl-1,2,3-triazole-4-carbothioamides, and in reaction with tosyl azide they form 5-amino-4-carboxamidino-1,2,3-thia-diazoles. Hypothetical mechanisms for the transformations are discussed.