An anomalous course of the reduction of 2‐(3‐oxo‐3,4‐dihydro‐quinoxalin‐2‐yl)benzene diazonium salt. Synthesis of a new quinoxalino[1,2‐<i>c</i>][1,2,3]benzotriazine system

Abstract

Abstract By diazotization of 3‐(2‐aminophenyl)quinoxaline‐2(l H )‐one la and 3‐(2‐aminophenyl)‐6,7‐dimethylquinoxaline‐2(l H )‐one 1b followed by the reaction with sodium sulphite new quinoxalino[1,2‐ c ]‐[1,2,3]benzotriazins 4a and 4b were prepared, respectively.