反应详情

A mixture of 2-hydroxyxanthone (4.39 g, 20.6 mmol) prepared as described above, ethyl bromoacetate (4.5 mL, 40 mmol), and anhydrous potassium carbonate (16.6 g, 0.12 mol) in acetone (200 mL) plus DMF (10 mL) was refluxed for 6 hours. The cooled reaction mixture was filtered to remove inorganic salts, washed with acetone (2×50 mL), concentrated, and placed under hexane whereupon crystals formed. Yield: 4.87 g (79%), TLC: Rf 0.81 [one spot, benzene-EtOH (20:3)], m.p. 122°-123° C.; 1H-NMR (CDCl3, 200 MHz) 8.32 (d,J=7.9 Hz, 1H), 7.63-7.75 (m, 2H), 7.33-7.50 (m, 4H), 4.74 [s, 2H, OCH2 (C=O)], 4.29 (q,J=7.1 Hz, 2H), 1.32 (t,J=7.1 Hz, 3H).

1. customprepared
2. temperaturewas refluxed for 6 hours
3. customThe cooled reaction mixture
4. filtrationwas filtered
5. customto remove inorganic salts
6. washwashed with acetone (2×50 mL)
7. concentrationconcentrated
8. customformed