反应详情

To a solution of 3-chloro-4-hydroxybenzaldehyde (4.697 g, 30.0 mmol) and to trimethoxyborate (0.5 mL) in THF (20 mL) and EtOH (20 mL) was added NaBH4 (2.0 g, 52.87 mmol) in small portions over a period of 8 hours. The mixture was stirred overnight and EtOAc (100 mL) and water (50 mL) were added. The organic layer was separated and washed with 2M KHSO4 (30 mL) and brine (30 mL), dried (MgSO4) and concentrated under reduced pressure. The residue was purified by flash chromatography [SiO2, CHCl3/acetone (0.3:1)] followed by recrystallistion from EtOAc/hexane to give CAB06028 (3.82 g, 80%) as fine colorless needles: Mp. 126-127° C.; 1H NMR (400 MHz, DMSO-d6) δ 4.36 (d, J=6.5 Hz, 2H), 5.11 (t, J=6.5 Hz, 1H), 6.90 (d, J=8.2 Hz, 1H), 7.06 (dd, J=82, 2.0 Hz, 1H), 7.25 (d, J=2.0 Hz, 1H), 9.99 (s, 1H); 13C NMR (100.6 MHz, DMSO-d6) δ 62.1, 116.3, 119.2, 126.4, 128.1, 134.5, 151.7; LRMS (ES−): m/z 156.9 (100%, [M−H]).

1. customThe organic layer was separated
2. washwashed with 2M KHSO4 (30 mL) and brine (30 mL)
3. dry with materialdried (MgSO4)
4. concentrationconcentrated under reduced pressure
5. customThe residue was purified by flash chromatography [SiO2, CHCl3/acetone (0.3:1)]
6. customto give CAB06028 (3.82 g, 80%) as fine colorless needles