反应详情

温度

70 °C

To a stirred and heated (50° C.) solution of the product of step 1 (0.410 g, 2.08 mmol) in water (12 mL) was added, portionwise over 30 minutes, solid potassium permanganate (0.680 g, 4.30 mmol). Following the addition, reaction temperature was increased to 70° C. After 45 minutes the reaction was cooled to room temperature and treated with a solution of potassium hydroxide (0.230 g, 4.10 mmol) in water (6 mL) followed by a few drops of isopropanol. The mixture was stirred for about 5 minutes before filtering through Celite. The filtrate was concentrated to dryness under a nitrogen current. The resulting brown residue was dissolved in water (10 mL), adjusted to pH 2 with concentrated hydrochloric acid and extracted repeatedly with chloroform. The combined extracts were dried (sodium sulfate) and concentrated to afford 0.414 g (94%) of product as a pink-gray foam: 1H NMR (DMSO-d6) δ 8.23 (s, 1H), 7.5 8 (s, 1H), 4.81 (sept, J=6.0 Hz, 1H), 3.90 (s, 3H), 1.29 (d, J=6.0 Hz, 6H) ppm.

1. additionwas added, portionwise over 30 minutes
2. additionthe addition, reaction temperature
3. temperatureAfter 45 minutes the reaction was cooled to room temperature
4. stirringThe mixture was stirred for about 5 minutes
5. filtrationbefore filtering through Celite
6. concentrationThe filtrate was concentrated to dryness under a nitrogen current
7. dissolutionThe resulting brown residue was dissolved in water (10 mL)
8. extractionextracted repeatedly with chloroform
9. dry with materialThe combined extracts were dried (sodium sulfate)
10. concentrationconcentrated