CYCLOADDITION REACTIONS OF 1,3-BENZOTHIAZINES-I. REACTIONS OF 2-PHENYL-4H- AND 4-PHENYL-2H-1,3-BENZOTHIAZINE DERIVATIVES WITH SUBSTITUTED ACETYL CHLORIDES

Article abstract of DOI:10.1016/S0040-4020(01)97668-9

6,7-Dimethoxy-2-phenyl-4H-1,3-benzothiazine (1) and 6,7-dimethoxy-4-phenyl-2H-1,3-benzothiazine (2) react with substituted acetyl chlorides to give linearly, and new angularly condensed β-lactam derivatives (4,5).Heating of the latter compounds with hydro