反应详情

Acetic acid (2.24 mL, 7.4 mmol) was added to a mixture of acetic acid 4-methoxy-phenyl ester (1.0 g, 6.02 mmol) and sodium acetate (940 mg, 11.46 mmol). A solution of bromine (0.37 mL, 6.02 mmol) in acetic acid (2.1 mL) was added drop-wise and mixture stirred for 18 hr at ambient temperature. A further 0.6 mL of acetic acid was added followed by a further 0.1 mL of bromine. Mixture was stirred for 2 hours, then partitioned between ethyl acetate (100 mL) and water (100 mL). The phases were separated and organic layer was washed sequentially with sat. aqueous sodium bicarbonate solution (2×150 mL), sat. aqueous sodium thiosulphate solution (100 mL) and sat. aqueous sodium chloride solution (100 mL). Organic phase was dried over sodium sulphate, filtered and filtrate solvents removed in vacuo to afford a oil which was purified by flash chromatography on silica gel, eluting with a gradient of 0-10% ethyl acetate in hexane to afford title compound (1.2 g, 81%) as a light-brown oil.

1. stirringMixture was stirred for 2 hours
2. custompartitioned between ethyl acetate (100 mL) and water (100 mL)
3. customThe phases were separated
4. washorganic layer was washed sequentially with sat. aqueous sodium bicarbonate solution (2×150 mL), sat. aqueous sodium thiosulphate solution (100 mL) and sat. aqueous sodium chloride solution (100 mL)
5. dry with materialOrganic phase was dried over sodium sulphate
6. filtrationfiltered
7. customfiltrate solvents removed in vacuo
8. customto afford a oil which
9. customwas purified by flash chromatography on silica gel
10. washeluting with a gradient of 0-10% ethyl acetate in hexane