反应详情

9.61 g of 4-acetylbenzoic acid ethyl ester (supplied from the firm Wako Pure Chem. Ind.) were dissolved in 200 ml of toluene and thereto were added 20 ml of ethylene glycol and 200 mg of p-toluenesulfonic acid hydrate under argon atmosphere, whereupon the mixture was heated under reflux for 24 hours on Dean-Stark apparatus while removing water. The reaction mixture was then cooled down to room temperature and the toluene layer was washed with water (twice with each 100 ml) and, then, with saturated aqueous sodium chloride solution (100 ml), followed by drying and evaporation to dryness under a reduced pressure, whereby the above-identified compound (12.76 g ) was obtained. Rf=0.58 (ethyl acetate/n-hexane of 1/2).

1. temperaturewhereupon the mixture was heated
2. temperatureunder reflux for 24 hours on Dean-Stark apparatus
3. customwhile removing water
4. washthe toluene layer was washed with water (twice with each 100 ml) and, then, with saturated aqueous sodium chloride solution (100 ml)
5. customby drying
6. customevaporation to dryness under a reduced pressure, whereby the above-identified compound (12.76 g )
7. customwas obtained