反应详情

To 30 ml of concentrated hydrochloric acid was added 5.00 g of 5-[3-(1-acetylpiperidin-4-yl)-1-oxopropyl]-2,3-dihydrobenzofuran, and the mixture was refluxed for 14 hours. The reaction mixture was left standing for cooling and then made basic with a dilute aqueous solution of sodium hydroxide, followed by extraction with methylene chloride. Organic layers were combined and dried over anhydrous sodium sulfate, then the solvent was distilled off to leave 4.31 g (100%) of 2,3-dihydro-5-[1-oxo-3-(piperidin-4-yl)propyl]benzofuran (4). The solid matter thus obtained was dissolved in methanol, treated with hydrogen chloride and recrystallized from methanol--ethyl acetate to give colorless needles, m.p. 203°-205° C. (decomp.)

1. temperaturethe mixture was refluxed for 14 hours
2. waitThe reaction mixture was left
3. temperaturefor cooling
4. extractionfollowed by extraction with methylene chloride
5. dry with materialdried over anhydrous sodium sulfate
6. distillationthe solvent was distilled off