Abstract Reduction of 4-oxo-1, 3-benzoxazinium perchlorates with sodium borohydride depending on the structure of starting salt and the reaction conditions leads to different products. 2-Alkyl-and 2-phenylsubstituted salts react with sodium borohydride to give 2, 3- dihydro-4-oxo-1, 3-benzoxazines. 2-Arylvinyl-and 2-heterylvinyl-substituted perchlorates either form 4-oxo-1, 3-benzoxazines or undergo hydrogenation to arylor ...
