反应详情

温度

0 °C

The product of Example 38A (1.15 g, 6.9 mmol) was dissolved in absolute ethanol (14 mL) and cooled to 0° C. Concentrated sulfuric acid (13.54 g, 7.36 mL, 138 mmol) was added, and the reaction mixture was allowed to warm to ambient temperature. The reaction was then heated at reflux for 2 hours, cooled, and poured onto ice. The mixture was neutralized with saturated aqueous sodium bicarbonate, and extracted with two portions of ethyl acetate. The organic layers were separated and concentrated to give the title compound (1.34 g, 91%) which was used without further purification. 1H NMR (300 MHz, DMSO-d6) δ ppm8.49 (dd, J=1.5, 4.7, 1H), 7.93 (dd, J=1.5, 8.1, 1H), 7.36 (dd, J=4.7, 8.1, 1H), 4.29 (q, J=7.1, 1H), 4.07 (q, J=7.1, 2H), 1.42 (d, J=7.1, 3H), 1.11 (t, J=7.1, 3H). MS (DCI) m/z 214 (M+H)+.

1. temperatureto warm to ambient temperature
2. temperatureThe reaction was then heated
3. temperatureat reflux for 2 hours
4. temperaturecooled
5. additionpoured onto ice
6. extractionextracted with two portions of ethyl acetate
7. customThe organic layers were separated
8. concentrationconcentrated