反应详情

温度

75 °C

To a solution of 20 gram (0.11 moles) of 2-hydroxy-1,4-naphthoquinone in 150 ml of DMSO and 20 ml of concentrated hydrochloride (37%) solution at 75° C., 20 ml of n-butyraldehyde (0.23 mol) was added. The mixture was vigorously stirred at the temperature of 72-78° C. for 4 hours, and then cooled by addition of 300 ml of ice water, and the resulting mixture was extracted with 300 ml of dichloromethane twice. The combined organic phases was washed successively with 500 ml of water, and 500 ml of 5% sodium bisulfite, and 500 ml of 4% sodium bicarbonate, and finally extracted with 400 ml of 5% sodium carbonate twice. The combined sodium carbonate extract was neutralized by addition of concentrated hydrochloric acid to pH 7.2-7.6. After chilling to 0° C., the mixture was filtered, and the resulting brick red solid was washed with cold water and dried under vacuum. 9.6 gram of product was obtained: 38.6% yield. 1H NMR (in CDCl3) δ 1.12 (t, J=8, 3H), 2.31 (m, 2H), 6.60-6.65 (m, 1H), 7.07-7.15 (m, 1H), 7.66-7.77 (m, 3H), 8.06-8.15 (m, 2H).

1. extractionthe resulting mixture was extracted with 300 ml of dichloromethane twice
2. washThe combined organic phases was washed successively with 500 ml of water, and 500 ml of 5% sodium bisulfite, and 500 ml of 4% sodium bicarbonate
3. extractionfinally extracted with 400 ml of 5% sodium carbonate twice
4. extractionThe combined sodium carbonate extract
5. additionwas neutralized by addition of concentrated hydrochloric acid to pH 7.2-7.6
6. temperatureAfter chilling to 0° C.
7. filtrationthe mixture was filtered
8. washthe resulting brick red solid was washed with cold water
9. customdried under vacuum