反应详情

Fifty-four grams (0.364 mol) of the product prepared in (a) are refluxed with 800 ml of a 25% aqueous solution of potassium hydroxide for 16 hours. After cooling, the reaction solution is adjusted to a pH of 6 by the addition of acetic acid and then extracted several times, each time with one-half liter of ethyl acetate. The combined extracts are dried with sodium sulfate, and the ethyl acetate is distilled off. The residue is purified by column chromatography [silica gel; ethylene chloride/acetone (19:1)]. The uniform fractions are concentrated to dryness.

1. temperatureAfter cooling
2. extractionextracted several times
3. dry with materialThe combined extracts are dried with sodium sulfate
4. distillationthe ethyl acetate is distilled off
5. customThe residue is purified by column chromatography [silica gel; ethylene chloride/acetone (19:1)]
6. concentrationThe uniform fractions are concentrated to dryness