Water → Trifluoro-methanesulfonic acid 3-cyano-6,6-dimethyl-11-oxo-6,11-dihydro-5H-benzo[b]carbazol-8-yl ester

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Reaction Steps

8-Hydroxy-6,6-dimethyl-11-oxo-6,11-dihydro-5H-benzo[b]carbazole-3-carbonitrile (Compound A6, 550 mg, 0.189 mmol) was dissolved in pyridine (18 mL), added with anhydrous trifluoromethanesulfonic acid (0.758 ml, 3 eq.), and stirred at room temperature for 30 min. The reaction solution was added to water and then extracted with dichloromethane. The organic layer was dried over magnesium sulfate. The drying agent was removed by filtration and the residues obtained after concentration under reduced pressure were purified by silica gel column chromatography (ethyl acetate/hexane) to obtain the target compound (white powder, 641 mg, 81%).

Provenance & Evidence