3-Diazobenzo[b]thiophen-2(3H)-one synthesis

Yield:54518-09-1 90%

Reaction Conditions:

Stage #1: benzo-[b]thiophene-2,3-dionewith toluene-4-sulfonic acid hydrazide in tetrahydrofuran; for 2 h;Inert atmosphere;Reflux;
Stage #2: with sodium hydroxide in dichloromethane;water at 40; for 2 h;Inert atmosphere;

References:

Cui, Xiao-Yuan;Zhao, Yu-Lei;Chen, Yan-Mei;Dong, Su-Zhen;Zhou, Feng;Wu, Hai-Hong;Zhou, Jian [Organic Letters,2021,vol. 23,# 12,p. 4864 - 4869] Location in patent:supporting information