反应详情

50 ml of 35% w/v aqueous hydrochloric acid were added to a mixture of 20 g of the 1-(4-aminophenoxy)-propane-2-one hydrochloride [prepared as described in step (a) above] and 400 ml of acetone, and then a solution of 12 g of sodium nitrite in 20 ml of water was added dropwise to the resulting mixture, whilst ice-cooling; the mixture was then stirred at the sane temperature for 20 minutes. At the end of this time, 130 g of ethyl acrylate and then 3.2 g of cuprous oxide were added in portions to the mixture, and the resulting mixture was stirred at room temperature for 1 hour. The reaction mixture was then concentrated by evaporation under reduced pressure, and the concentrate was mixed with water and ethyl acetate. The ethyl acetate layer was separated, washed with water and dried over anhydrous sodium sulfate; the solvent was then removed by distillation under reduced pressure. The resulting residue was purified by column chromatography through silica gel, using a 5:1 by volume mixture of hexane and ethyl acetate as the eluent, to give 11.3 g of the title compound having an Rf=0.31 (thin layer chromatography over silica gel, using a 5:1 by volume mixture of hexane and ethyl acetate as the developing solvent).

1. temperaturecooling
2. stirringthe resulting mixture was stirred at room temperature for 1 hour
3. concentrationThe reaction mixture was then concentrated by evaporation under reduced pressure
4. additionthe concentrate was mixed with water and ethyl acetate
5. customThe ethyl acetate layer was separated
6. washwashed with water
7. dry with materialdried over anhydrous sodium sulfate
8. customthe solvent was then removed by distillation under reduced pressure
9. customThe resulting residue was purified by column chromatography through silica gel
10. additionby volume mixture of hexane and ethyl acetate as the eluent