反应详情

To a solution of 2-hydroxybenzoic acid (63) (5.0 g, 36.2 mmol) in anhydrous EtOH (150 ml) was added 98% H2SO4 (4 ml). The mixture was refluxed for 4 h and concentrated. The residue was extracted with CH2Cl2 dried over MgSO4 and evaporated. The crude was purified by distillation to give 68 as colorless liquid. (5.85 g, 35.21 mmol). Yield: 97.25%; MS (EI, 70 eV): m/z 166.2 (M+); 1H-NMR (CDCl3, 200 MHz): δ 1.39 (t, J=7.2 Hz, 3H), 4.37 (q, J=7.2, 7.0 Hz, 2H), 6.81 (t, J=6.6 Hz, 1H), 6.89 (d, J=8.0 Hz, 1H), 7.42 (t, J=7.2 Hz, 1H), 7.82 (dd, J1=8.0, 1.8 Hz, 1H), 10.83 (s, 1H); 13C-NMR (CDCl3, 50 MHz) δ: 170.20, 161.64, 135.56, 129.89, 119.06, 117.53, 61.40, 14.18; Anal. Calcd for C9H10O3: C, 65.05; H, 6.07.

1. temperatureThe mixture was refluxed for 4 h
2. concentrationconcentrated
3. extractionThe residue was extracted with CH2Cl2
4. dry with materialdried over MgSO4
5. customevaporated
6. distillationThe crude was purified by distillation