THIA-1 AZA-3 BUTADIENES SUBSTITUES: ACTION DU CETENE ET DERIVES

Abstract
Novel, diversely substituted 1-thia 3-aza butadienes have been prepared and reacted with ketene or its derivatives. Via a general (4 + 2) cycloaddition reaction, they afford functionalised 6H-1,3-thiazine 6-ones, the electrophilic properties of which are described. This cycloaddition gives rise to other reaction products resulting from the addition of two or three molecules of ketene according to the nature of the substituents.