反应详情

Benzofarane-2-acetic acid 4 (305 g, 1.73 mol) was dissolved in methanol (1,000 ml) and concentrated sulfuric acid (20 ml). The mixture, which was originally a suspension, was stirred at reflux for 120 minutes. Half of the methanol was distilled off and a mixture consisting of water, KOH, and ethyl acetate (2,000 ml/65 g/1,000 ml) was added. After mixing well, the organic layer was allowed to separate and was isolated. The aqueous phase was extracted once more with ethyl acetate (500 ml) and the combined organic extracts were dried over sodium sulfate, filtered, and evaporated. The crude product was a reddish oil weighing 316 g, which was purified by flash vacuum distillation at 0.1 mm Hg (bp 80-90° C.). The yield of distilled product, a colorless oil, was 288 g (1.51 mol, 86%). Anal. (C11H10O3) C, H: calculated 69.46, 5.30; found 69.49, 5.36.

1. temperatureat reflux for 120 minutes
2. distillationHalf of the methanol was distilled off
3. additionwas added
4. additionAfter mixing well
5. customto separate
6. customwas isolated
7. extractionThe aqueous phase was extracted once more with ethyl acetate (500 ml)
8. dry with materialthe combined organic extracts were dried over sodium sulfate
9. filtrationfiltered
10. customevaporated
11. distillationwas purified by flash vacuum distillation at 0.1 mm Hg (bp 80-90° C.)