反应详情

To a solution of 2,3-dihydroxy-4-fluorobenzaldehyde (3.0 g, 19.23 mmol) in DMSO (100 mL), NaOBu-t (3.692 g, 38.46 mmol) was added in portions at room temperature and stirred for 15 min. Then iodoethane was added dropwise at room temperature and stirred for 18 h. The reaction mixture was poured onto crushed ice (200 mL) and acidified with 2.5 M HCl to pH 3.0. The product was extracted with ethyl acetate (2×100 mL), concentrated and the product was chromatographed on a column of silica gel (Hex:EtOAc=95:5) to give the title compound as a crystalline solid (2.3 g, 65%). 1H NMR (400 MHz, CHLOROFORM-d) δ ppm: 11.36 (s, 1H), 9.83 (s, 1H), 7.39-7.19 (m, 1H), 6.77 (t, J=9.2 Hz, 1H), 4.22 (q, J=7.0 Hz, 2H), 1.40 (t, J=7.0 Hz, 3H); MS (ESI) m/z=183 (M+1, positive).

1. stirringstirred for 18 h
2. additionThe reaction mixture was poured
3. extractionThe product was extracted with ethyl acetate (2×100 mL)
4. concentrationconcentrated
5. customthe product was chromatographed on a column of silica gel (Hex:EtOAc=95:5)