Trifluoroacetic acid → HCID 58641163, compound

Participants

Reaction Steps

A solution of tert-butyl(2S)-4-(2,5-difluorophenyl)-2-phenyl-2,5-dihydro-1H-pyrrole-1-carboxylate (5-5, 50 mg, 0.14 mmol, 1 equiv) in a 1:1 mixture of dichloromethane and trifluoroacetic acid (10 mL) was stirred for 30 minutes, then concentrated. The residue was partitioned between aqueous saturated sodium bicarbonate solution (60 mL) and ethyl acetate (50 mL). The organic layer was dried over sodium sulfate and concentrated. A solution of the residue, ethyl bromoacetate (16 μL, 0.14 mmol, 1.0 equiv) and N,N-diisopropylethylamine (29 μL, 0.17 mmol, 1.2 equiv) in DMP (5 mL) was heated at 70° C. for 3 hours. The reaction mixture was partitioned between water (125 mL) and ethyl acetate (2×100 mL). The combined organic layers were dried over sodium sulfate and concentrated. A solution of the residue and sodium hydroxide (1N, 280 μL, 0.28 mmol, 2.0 equiv) in tert-butanol (10 mL) was heated at 45° C. for 20 hours. The reaction mixture was then partitioned between water and ethyl ether. The aqueous layer was acidified to pH 4 with aqueous HCl solution, then extracted with ethyl acetate (2×40 mL). The combined organic layers were dried over sodium sulfate and concentrated to provide [(2S)-4-(2,5-difluorophenyl)-2-phenyl-2,5-dihydro-1H-pyrrol-1-yl]acetic acid (28-1) as a colorless oil. LRMS m/z (M+H) 316.3 found, 316.1 required.

Provenance & Evidence