Hydrochloric Acid → 4-[(5E)-5-(5,6-difluoro-2-oxo-1,2-dihydro-3H-indol-3-ylidene)-2,2-dimethyl-2,5-dihydro furan-3-yl]benzoic acid

Participants

Reaction Conditions

Reaction Steps

To a solution of methyl 4-[(5E)-5-(5,6-difluoro-2-oxo-1,2-dihydro-3H-indol-3-ylidene)-2,2-dimethyl-2,5-dihydrofuran-3-yl]benzoate (100 mg, 0.25 mmol) in a 1:1 mixture of THF/MeOH (5 mL/5 mL), was added 1M NaOH (2 mL). The mixture was heated in 60° C. bath for 1.5 hours, poured into 100 mL of water and acidified with 2M HCl (2 mL). The precipitates were filtered, washed with water, and dried in vacuum to give 4-[(5E)-5-(5,6-difluoro-2-oxo-1,2-dihydro-3H-indol-3-ylidene)-2,2-dimethyl-2,5-dihydrofuran-3-yl]benzoic acid as yellow solid. Yield: 90 mg, 93%.

Provenance & Evidence