Trifluoroacetic acid → 4-chloro-3-(6-hydroxy-1,3-benzodioxol-5-yl)-1,3-dihydro-2H-indol-2-one

Participants

Reaction Steps

To a solution of 4-chloro-3-hydroxy-3-(6-hydroxy-1,3-benzodioxol-5-yl)-1,3-dihydro-2H-indol-2-one (6.00 g, 18.8 mmol) in anhydrous dichloromethane (70.0 mL) was added trifluoroacetic acid (30.7 g, 269 mmol) and triethylsilane (18.0 mL, 13.1 g, 113 mmol) at ambient temperature. The reaction mixture was stirred at ambient temperature for 2 h. The reaction mixture was quenched with water (100.0 mL) and the solid was filtered. The solid was triturated with diethyl ether to afford 4-chloro-3-(6-hydroxy-1,3-benzodioxol-5-yl)-1,3-dihydro-2H-indol-2-one (4.71 g, 83%) as a colourless solid: mp 210-225° C. (dec.); MS (ES+) m/z 304.1 (M+1), 302.1 (M+1).

Provenance & Evidence