Acetic Anhydride → HCID 69036363, compound

Participants

Reaction Steps

2,2,2-Trichloroethyl 3-t-butyl-1-(3-nitrophenyl)-1H-pyrazol-5-ylcarbamate (0.67 g, 1.538 mmol, 1.00 eq) in EtOAc (30 ml) was shaken under H2 (3.5 arm) at 22° C. over 10% Pd/C (0.327 g, 0.154 mmol, 0.10 eq, 50% H2O) overnight. The completed hydrogenation was treated with Ac2O (3 ml) and stirred at RT. After 45 min, the mixture was filtered through Celite, rinsing forward with EtOAc. The filtrate was treated with a roughly equal volume of satd. NaHCO3 and stirred briskly at RT for 3 h. The layers were separated and the organic layer washed with satd. NaHCO3 (2×). The combined aqueous layers were extracted with EtOAc (1×). The combined organics were washed with brine (1×), dried (MgSO4), filtered and evaporated to afford 2,2,2-trichloroethyl 1-(3-acetamidophenyl)-3-t-butyl-1H-pyrazol-5-ylcarbamate (0.50 g, 73% yield) as a white solid which was used as is in the next reaction. 1H NMR (400 MHz, DMSO-d6): δ 10.10 (s, 1H), 9.95 (brs, 1H), 7.74 (brs, 1H), 7.54-7.51 (m, 1H), 7.37-7.31 (m, 1H), 7.08 (d, J=7.6 Hz, 1H), 6.26 (s, 1H), 4.84 (s, 2H), 2.03 (s, 3H), 1.26 (s, 9H); MS (ESI) m/z: 447.0 (M+H), 449.0 ((M+2+H).

Provenance & Evidence