反应详情

Bromine (1.65 g, 10.3 mmol, 1.03 equiv) was added drop-wise to a stirred solution of 3-oxo-3-o-tolyl-propionic acid ethyl ester (2.06 g, 10.0 mmol, 1.0 equiv) in 1,4-dioxane (25 mL) at ambient temperature. The mixture was stirred for 1 hour and then diluted with tert-butyl methyl ether (50 mL). The resultant solution was washed sequentially with water, aqueous potassium carbonate solution and saturated aqueous sodium chloride solution. The collected organic was dried over magnesium sulphate, filtered, and concentrated under vacuum to afford 2.74 g (96%) of 2-bromo-3-oxo-3-o-tolyl-propionic acid ethyl ester as a dark brown residue. 1H NMR (400 MHz, CDCl3) δ: 7.66 (d, 1H), 7.46-7.37 (m, 1H), 7.28 (m, 2H), 5.62 (s, 1H), 4.29-4.22 (q, 2H), 2.52 (s, 3H), 1.28-1.19 (t, 3H).

1. washThe resultant solution was washed sequentially with water, aqueous potassium carbonate solution and saturated aqueous sodium chloride solution
2. dry with materialThe collected organic was dried over magnesium sulphate
3. filtrationfiltered
4. concentrationconcentrated under vacuum