Trifluoroacetic acid → HCID 118069695, compound

Participants

Reaction Steps

A suspension of 3-(4-amino-1,2,5-oxadiazol-3-yl)-4-(3-bromo-4-fluorophenyl)-1,2,4-oxadiazol-5(4H)-one (5, 0.680 g, 1.99 mmol) and 2,2,2-trichloroethyl {[(2,2-dimethoxyethyl)amino]sulfonyl}carbamate (17d, 2.22 g, 6.17 mmol, 3.1 equiv.) in dichloromethane (DCM, 6.0 mL) was stirred at room temperature. To this mixture was added triethylsilane (1.27 mL, 7.95 mmol, 4.0 equiv.) and a solution of trifluoroacetic acid (TFA, 3.0 mL, 39.0 mmol) in dichloromethane (DCM, 2.0 mL) while maintaining the reaction temperature below 30° C. The reaction mixture became homogenous after 5 min with agitation at room temperature and was stirred at room temperature for 1 h. HPLC indicated reaction completion. The reaction was filtered and the precipitate was suspended in a mixture of dichloromethane and heptane (ratio of dichloromethane to heptane was 1 to 9 by volume). The suspension was stirred at room temperature overnight. The precipitate was collected by filtration and washed with 10% dichloromethane in heptane and dried in vacuum to give the desired product (1.15 g, 90.4%) as an off-white solid, which was used in the subsequent reaction without further purification. 1H NMR (300 MHz, DMSO-d6) δ 11.85 (s, 1H), 8.07 (m, 2H), 7.70 (m, 1H), 7.57 (t, 1H, J=8.7 Hz), 6.56 (m, 1H), 4.88 (m, 2H), 3.37 (m, 2H), 3.16 (m, 2H); C15H12BrCl3FN7O7S (MW 639.62), LCMS (EI) m/e 638/640/642 (M++H).

Provenance & Evidence