反应详情

Mix under nitrogen atmosphere 4-bromo-2-fluorobenzyl alcohol, (4.1 g, 20 mmol), dihydropyran (2 g, 24 mmol),p-toluenesulfonic acid monohydrate (100 mg, 0.52 mmol), and anhydrous DCM (70 mL). Stir for 16 h at ambient temperature. Dilute with DCM, wash sequentially with saturated aqueous NaHCO3 then brine. Separate the organic layer, dry over Na2SO4 and concentrate in vacuo. Purify by chromatography on silica gel eluting with hexane/EtOAc (1:0 and 9:1) to obtain the desired intermediate as a clear oil (4.36 g, 75%). MS (ES+) m/z: 312 (M+Na)+.

1. washwash sequentially with saturated aqueous NaHCO3
2. customSeparate the organic layer
3. dry with materialdry over Na2SO4
4. concentrationconcentrate in vacuo
5. customPurify by chromatography on silica gel eluting with hexane/EtOAc (1:0 and 9:1)