Water → 8-Bromo-9-methoxy-6,6-dimethyl-11-oxo-6,11-dihydro-5H-benzo[b]carbazole-3-carbonitrile

Participants

Reaction Steps

Phosphorus pentoxide-methanesulfonic acid (12 mL) was added with 2-[1-(3-bromo-4-methoxy-phenyl)-1-methyl-ethyl]-6-cyano-1H-indole-3-carboxylic acid ethyl ester (Compound K5, 1.0 g, 2.27 mmol), and the mixture was stirred at room temperature for 20 min. The reaction solution was diluted with MeCN (20 mL), poured into water (20 mL), and the precipitated solid was filtered to obtain the title compound (yellow solid, 763 mg, 85%).

Provenance & Evidence