Acetic Acid → 4-(2,3-Difluoro-phenyl)-1,3-dihydro-indol-2-one

Participants

Reaction Steps

To the suspension of 4-(2,3-difluoro-phenyl)-1H-indole (2.85 g, 12.4 mmol) in t-BuOH: ethanol: acetic acid (78.5 mL: 46.5 mL: 24.13 mL) was added pyridinium tribromide (11.93 g, 37.3 mmol) portionwise. The mixture was stirred at room temperature for 3 hours, and then to the mixture was added with acetic acid (60 mL). Zinc dust (4.1 g, 62.2 mmol) was added to the reaction mixture portionwise. After stirring for one hour, any unreacted zinc was filtered off and most of the solvent was removed under reduced pressure. The residue was diluted with ethyl acetate, washed with water (5×), sat NaHCO3, brine, dried over Na2SO4, concentrated and triturated with ether to give 2.32 g (76%) of 4-(2,3-difluoro-phenyl)-1,3-dihydro-indol-2-one as an earth colored solid.

Provenance & Evidence