反应详情

62.00 g (298.0 mmol) of the compound obtained in Example 10(a), 85.00 g (446.0 mmol) of paratoluenesulphonic acid and 500 ml of toluene are introduced into a round-bottomed flask. The mixture is heated at reflux for two hours, cooled, water and ethyl acetate are then added and extraction is carried out with ethyl acetate. The organic phase is separated by settling, washed with water and then using a saturated sodium chloride solution and dried over magnesium sulphate, and the solvents are evaporated. 65.19 g of a yellow oil are obtained, which oil is distilled under reduced pressure (5×10−2 bar/120-122° C.) to produce 17.40 g (28%) of the expected compound in the form of a colourless oil.

1. temperatureThe mixture is heated
2. temperatureat reflux for two hours
3. temperaturecooled
4. extractionextraction
5. customThe organic phase is separated
6. washwashed with water
7. dry with materialdried over magnesium sulphate
8. customthe solvents are evaporated