反应详情

温度

15 °C

To a 250 mL RB-flask was added 4,4′-dimethylbenzhydrol (1.06 g, 5.00 mmol) and 97% sulfuric acid (44.0 mL). The mixture was cooled to 15° C. by an ice/water bath and formic acid (12.0 mL) was added dropwise via an addition funnel over 0.5 h. The resulting foaming solution was stirred at 15° C. for 2 h. Water (300 mL) was added and the pH was adjusted to 3 with potassium hydroxide pellets and 10% KOH solution. The aqueous solution was extracted with ethyl acetate (3×100 mL) and the combined organic extracts were washed with brine (100 mL) and dried over sodium sulfate, filtered and concentrated in vacuo to give the desired product (0.281 g, 26%) as a pale yellow solid, which was used in the subsequent step without further purification: 1H NMR (400 MHz, CD3OD) δ 7.28–6.99 (m, 8H), 6.96 (br s, 1H), 4.94 (s, 1H), 2.29 (s, 6H).

1. extractionThe aqueous solution was extracted with ethyl acetate (3×100 mL)
2. washthe combined organic extracts were washed with brine (100 mL)
3. dry with materialdried over sodium sulfate
4. filtrationfiltered
5. concentrationconcentrated in vacuo