Temperature‐Dependent Regioselective Synthesis of 1,2,4‐Triazino[2,3‐<i>b</i>]indazoles and 3<i>H</i>‐1,4‐Benzodiazepines by Domino‐Staudinger/Aza‐Wittig/Isomerization Reaction

Abstract

Abstract o ‐Azidobenzaldimine 8 reacted with triphenylphosphane at 0 °C with warming to room temperature to give 1,2,4‐triazino[2,3‐ b ]indazoles 12 by a domino‐Staudinger/aza‐Wittig/isomerization reaction. However, when heated to 80 °C the same reaction mixture afforded 3 H ‐1,4‐benzodiazepines 14 by a tandem‐Staudinger/aza‐Wittig reaction.