Synthesis of the symmetrical 3,5-bis(difluoromethyl)-1,4-thiazine 1,1-dioxides

A convenient procedure for the preparation of 3,5-bis(difluoromethyl)-1,4-thiazine 1,1-dioxides was developed based on the reactions of bis(2,2,3,3-tetrafluoropropyl)sulfone with the excess of ammonia or with primary amines and triethylamine.