Trifluoroacetic acid → HCID 58641434, 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, 113 mg, 0.316 mmol, 1 equiv) in a 1:1 mixture of dichloromethane and trifluoroacetic acid (20 mL) was stirred for 30 minutes, then concentrated. The residue was dried via toluene azeotrope (1×10 mL), then dissolved in DMF (4 mL). Triethylamine (0.176 mL, 1.27 mmol, 4.00 equiv), (2S)-2-hydroxy-3,3-dimethylbutanoic acid (84 mg, 0.632 mmol, 2.00 equiv), and PYBOP (329 mg, 0.632 mmol, 2.00 equiv) were added, and the resulting mixture was stirred at 23° C. for 24 hours. Additional triethylamine (0.176 mL, 1.27 mmol, 4.00 equiv), (2S)-2-hydroxy-3,3-dimethylbutanoic acid (84 mg, 0.632 mmol, 2.00 equiv), and PYBOP (329 mg, 0.632 mmol, 2.00 equiv) were added, and the resulting mixture was stirred at 23° C. for 20 hours. The reaction mixture was partitioned between water (70 mL) and ethyl acetate (2×55 mL). The combined organic layers were dried over sodium sulfate and concentrated. The residue was purified by reverse-phase LC (H2O/CH3CN gradient w/0.1% TFA present) to provide (2S)-1-[(2S)-4-(2,5-difluorophenyl)-2-phenyl-2,5-dihydro-1H-pyrrol-1-yl]-3,3-dimethyl-1-oxobutan-2-ol (22-1) as a white solid. 1H NMR (500 MHz, CDCl3) rotamers: δ 7.43-7.02 (m, 8H), 6.42 (m, 1H), 5.93 (m, 1H), 5.01-4.82 (m, 2H), 4.16 (major rotamer, s, 1H), 3.85 (minor rotamer, s, 1H), 1.00 (minor, s, 9H), 0.92 (major, s, 9H). LRMS m/z (M+H) 372.0 found, 372.2 required.

Provenance & Evidence