反应详情

A flask is charged with 3-hydroxybenzoic acid methyl ester (2.54 g, 16.0 mmol) and acetone (50 mL). 1,2-Dibromo-ethane (5.69 mL, 66.0 mmol) and potassium carbonate (2.76 g, 19.0 mmol) are added and the mixture is refluxed for 24 h. The reaction mixture is then cooled to room temperature. The solids are filtered off and the filtrate concentrated in vacuo. The residue is purified by silica gel flash chromatography (heptane-ethyl acetate, 3:1) to afford 3-(2-bromo-ethoxy)-benzoic acid methyl ester as a colorless oil. 1H NMR (400 MHz, CDCl3) δ ppm 3.66 (t, J=6.2 Hz, 2H), 3.93 (s, 3H), 4.35 (t, J=6.2 Hz, 2H), 7.14 (m, 1H) 7.37 (m, 1H) 7.57 (m, 1H) 7.68 (m, 1H).

1. temperaturethe mixture is refluxed for 24 h
2. filtrationThe solids are filtered off
3. concentrationthe filtrate concentrated in vacuo
4. customThe residue is purified by silica gel flash chromatography (heptane-ethyl acetate, 3:1)