Potassium Carbonate → HCID 18416130, compound

Participants

Reaction Steps

To a solution of (±)-3,4-dihydro-3-hydroxy-7-nitro-4-(2,2,2-trifluoroethyl)-3-(trifluoromethyl)-2H-1,4-benzoxazine (0.10 g, 0.29 mmol) in 3 mL of trifluoroacetic acid and then sodium cyanoborohydride (3.0 g, 47.4 rmmol) was slowly added via an solid addition funnel under nitrogen at 0° C. over the course of 30 minutes the reaction was allowed to warm to rt and stirred for 12 hours. The reaction mixture was then diluted with water and cooled to 0° C. Solid potassium carbonate was then added slowly to pH 7.The solution was extracted with ethyl acetate (2×100 mL) and the combined organic layers were washed with brine (50 mL), dried over magnesium sulfate, filtered and evaporated under reduced pressure to give an oil. The oil was purified via flash chromatography (7:3 hexanes:EtOAc) to afford 51 mg (52%) of (±)-3,4-dihydro-7-nitro-4-(2,2,2-trifluoroethyl)-3-(trifluoromethyl)-2H-1,4-benzoxazine. 1H NMR (400 MHz, CDCl3) d 7.87 (dd, 1H, J=9.1, 2.8), 7.81 (d, 1H, J=2.5), 6.92 (d, 1H, J=9.1), 4.73 (d, 1H, J=12.1), 4.48–4.39 (m, 1H), 4.13–4.06 (m, 2H), 3.99–3.88 (mn, 1H).

Provenance & Evidence