Triazines and related products. Part IV. Methylation of 3-aryl-3,4-dihydro-4-imino-1,2,3-benzotriazines

Abstract

The title compounds undergo ring-opening in sodium ethoxide solution and subsequent treatment with methyl iodide affords mixtures of isomeric methylated o-cyanophenyltriazenes. The structures of the products have been elucidated by reduction to the component amines with stannous chloride in hydrochloric acid, and the applicability of this reagent in the study of other o-cyanophenyltriazenes has been explored. Catalytic hydrogenation of o-nitrophenyltriazenes yields benzotriazole as one of the products. Mechanisms for the ring-opening and reduction reactions have been proposed.