Tert-butyl 4-(4-bromo-3-fluorophenyl)-4-oxobutylcarbamate → 5-(4-bromo-3-fluorophenyl)-3,4-dihydro-2H-pyrrole

Participants

Reaction Steps

A solution of tert-butyl 4-(4-bromo-3-fluorophenyl)-4-oxobutylcarbamate (23 g, 64.07 mmol) in formic acid (290 mL) was heated at 40° C. for 5 hours. The reaction mixture was cooled, concentrated and the residue was partitioned between ethyl acetate and aqueous sodium hydroxide. The organic phase was washed with water, dried over magnesium sulfate, filtered and concentrated. The residue was purified by flash chromatography on silica gel, using a gradient of 20-60% ethyl acetate in petroleum ether to give 5-(4-bromo-3-fluorophenyl)-3,4-dihydro-2H-pyrrole (12.7 g, yield 82%). LC-MS (ESI) m/z: 242 (M+1)+.

Provenance & Evidence