反应详情

温度

40 °C

Boron tribromide (3.09 ml, 1M solution in DCM, 3.09 mmol) was added dropwise at 0° C. to a stirred solution of 4-methoxy-benzothiazole (510 mg, 3.09 mmol) in dry DCM (30 ml). The resulting solution was warmed to 40° C. and allowed to stir overnight. The resulting solution was concentrated in vacuo and diluted with water and HCl (2N). The aqueous phase was neutralised to pH ˜7 with NaHCO3 and the solution extracted with EtOAc (3×100 ml) and the combined organic extracts dried (MgSO4) and the solvent removed in vacuo. The resulting oil was purified by flash chromatography eluting silica gel with hexane:EtOAc [4:1] to hexane:EtOAc [7:3] to give the title compound as a tan solid (730 mg, 80%); δH (300 MHz, CDCl3) 7.59 (1H, s, CH), 7.46 (1H, dd, Ar), 7.36 (1H, t, Ar), 7.02 (1H, dd, Ar).

1. concentrationThe resulting solution was concentrated in vacuo
2. additiondiluted with water and HCl (2N)
3. extractionthe solution extracted with EtOAc (3×100 ml)
4. dry with materialthe combined organic extracts dried (MgSO4)
5. customthe solvent removed in vacuo
6. customThe resulting oil was purified by flash chromatography
7. washeluting silica gel with hexane