反应详情

Benzylchloroformate (6.96 g, 40.8 mmol) was added dropwise to a solution of Example 18B (10.3 g, 37.1 mmol,) and diisopropylethylamine (7.20 g, 55.7 mmol) in 120 mL CH2Cl2 at 0° C. The mixture was stirred for 18 hours gradually warming to ambient temperature after which the volatiles were evaporated under reduced pressure. The residue was purified on silica gel eluting with 25% EtOAc/hexanes which yielded the benzyl carbamate as a light brown oil (15.2 g, 36.9 mmol). This product was taken up in 100 mL THF followed by addition of 1.79 g (111 mmol) of triethylamine trihydrofluoride. After 24 hours, the mixture was concentrated under reduced pressure and the residue partitioned between EtOAc and 1N aq. HCl. The separated organic layer was washed with 1N aq. HCl, brine, dried (Na2SO4), and concentrated under reduced pressure. The crude product was triturated with Et2O, and the solid was collected by vacuum filtration and dried under vacuum at 50° C. resulting 8.82 g (80%) of the title compound as a white solid. 1H NMR (DMSO-d6) δ 8.82 (s, 1H), 7.45-7.30 (m, 5H), 7.14 (d, J=7.0 Hz, 1H), 7.05 (t, J=7.0 Hz, 1H), 6.90 (d, J=7.0 Hz, 1H), 5.12 (s, 2H), 4.77 (d, J=3.7 Hz, 1H), 3.87 (m, 1H), 2.86 (m, 2H), 2.72 (m, 1H), 2.43 (m, 1H), 1.84 (m, 1H), 1.58 (m, 1H); MS (ESI+) m/z 298 (M+H)+.

1. customwere evaporated under reduced pressure
2. customThe residue was purified on silica gel eluting with 25% EtOAc/hexanes which