反应详情

Potassium hydroxide (3.71 g, 66.31 mmol) was added to a stirred solution of 188 (4.83 g, 18.95 mmol) in anhydrous methanol (80 mL) and the reaction mixture heated at reflux for 3 h. The reaction mixture was allowed to cool and acidified to pH 2 with 1 N HCl and the solid precipitate was filtered and washed with water (50 mL) and left to air dry to afford the product as a yellow-beige solid (189) (3.69 g, 15.31 mmol, 81%); 1H NMR (270 MHz, CDCl3) δ 13.88 (br s, 1H), 7.23 (s, 1H), 3.90 (s, 3H), 3.75 (s, 3H), 2.14 (s, 3H); 1C NMR (67.8 MHz, CDCl3) δ 164.09, 158.65, 150.09, 139.38, 125.70, 122.50, 107.24, 62.78, 56.34, 9.62.

1. temperaturethe reaction mixture heated
2. temperatureat reflux for 3 h
3. temperatureto cool
4. filtrationthe solid precipitate was filtered
5. washwashed with water (50 mL)
6. waitleft to air
7. customdry