Methyl 6-bromo-9-(2-methyl-4-nitrophenyl)carbazole-4-carboxylate 、
dihydroxyborane 在
silica gel 、
甲醇 、
二氯甲烷 作用下,
以
乙腈 为溶剂,
反应 24.0h,
以Chromatography on silica gel with 1-2% MeOH in DCM gave 0.41 g of compound 9 as white solid的产率得到6-bromo-9-(2-methyl-4-nitrophenyl)carbazole-4-carboxylic acid