反应详情

温度

0 °C

To a cold (0° C.) suspension of sodium hydride (0.589 g of a 60% w/w dispersion in mineral oil, 14.7 mmol) in N,N-dimethylformamide (50 mL) was added in portions 5-bromo-benzo[d]oxazol-2(3H)-one (3.0 g, 14.0 mmol). The reaction mixture was stirred for 1 h at 0° C. and benzhydryl bromide (3.81 g, 15.4 mmol) was added. The reaction mixture was allowed to warm to ambient temperature and stirred for 16 h. Further benzhydryl bromide (1.7 g. 6.9 mmol) was added and the reaction mixture was heated at 70° C. for 16 h, allowed to cool to ambient temperature and concentrated in vacuo. The residue was suspended in ethyl acetate (300 mL), washed with water (2 20 mL) and brine (2 20 mL), dried over anhydrous sodium sulphate, filtered and concentrated in vacuo. The residue was purified by column chromatography, eluting with a 0-50% gradient of ethyl acetate in hexanes to afford 3-benzhydryl-5-bromobenzo[d]oxazol-2(3H)-one as an orange solid in 71% yield (3.87 g): 1H NMR (300 MHz, CDCl3) δ7.41-7.34 (m, 6H), 7.27-7.21 (m, 4H), 7.19-7.14 (m, 1H), 7.06 (d, J=8.5 Hz, 1H), 6.78 (s, 1H), 6.46 (s, 1H).

1. temperatureto warm to ambient temperature
2. stirringstirred for 16 h
3. temperaturethe reaction mixture was heated at 70° C. for 16 h
4. temperatureto cool to ambient temperature
5. concentrationconcentrated in vacuo
6. washwashed with water (2 20 mL) and brine (2 20 mL)
7. dry with materialdried over anhydrous sodium sulphate
8. filtrationfiltered
9. concentrationconcentrated in vacuo
10. customThe residue was purified by column chromatography
11. washeluting with a 0-50% gradient of ethyl acetate in hexanes