Cyclization of .ALPHA.- and .BETA.-alkylthio-substituted amines possessing positively charged carbon at the nitrogen. A new synthetic method for thiazolidines, thiomorpholines and dihydro-1,4-benzothiazines.
Cyclization of .ALPHA.- and .BETA.-alkylthio-substituted amines possessing positively charged carbon at the nitrogen. A new synthetic method for thiazolidines, thiomorpholines and dihydro-1,4-benzothiazines.
o-Benzenedisulfonimide has been used to efficientlycatalyse the reaction between 2-aminothiophenol, 2-aminophenol, o-phenylenediamine and various ortho esters (28 examples; average yield 90%) or aldehydes (17 examples; average yield 72%) giving the corresponding benzofused azoles in excellent yields. Reaction conditions were very simple. In addition, other carboxylic acid derivatives have been tested