Trifluoroacetic acid → (Z)-4-amino-N-[3-[2,3-dihydro-2-oxo-3-[(1H-pyrrol-2-yl)methylene]-1H-indol-4-yl]phenyl]cyclohexanecarboxamide

Participants

Reaction Steps

A solution of the (Z)-[4-[3-[2,3-dihydro-2-oxo-3-[(1H-pyrrol-2-yl)methylene]-1H-indol-4-yl]-phenylcarbamoyl]-cyclohexyl]-carbamic acid tert-butyl ester (51.4 mg, 0.098 mmol) in 3 mL of methylene chloride was then treated with 2 mL of trifluoroacetic acid. The reaction mixture was stirred at room temperature for 1 h, and the reaction mixture was diluted with 50 mL of ethyl acetate. The organic phase was carefully washed with a saturated aqueous sodium bicarbonate solution (3×20 mL), dried over sodium sulfate, filtered, and concentrated in vacuo to provide a yellow-brown solid. This crude solid was washed with 70% chloroform-hexanes, and the insoluble solid was collected by suction filtration to provide pure (Z)-4-amino-N-[3-[2,3-dihydro-2-oxo-3-[(1H-pyrrol-2-yl)methylene]-1H-indol-4-yl]phenyl]cyclohexanecarboxamide (yield: 17 mg, 40%) as a yellow solid (mp 210-212° C.).

Provenance & Evidence