反应详情

A mixture of 63.5 grams (0.31 mole) of 4-(2,2-dimethyl-1-oxopropyl)benzoic acid, 156 ml. of ethylene glycol, and 1 gram of toluenesulfonic acid in 600 ml of toluene is refluxed for 24 hours using a Dean-Stark trap to remove water. The mixture is then cooled and partially evaporated; and to the residue, 4.5 grams of solid potassium hydroxide are carefully added followed by 225 ml of water. The resulting mixture is refluxed for 11/2 hours, cooled, filtered and the layers separated. The aqueous layer is acidified with 2N hydrochloric acid, and the resulting precipitate is removed by filtration. The precipitate is washed with water, then water/ethanol (5/1), and then petroleum ether. The product is dried in vacuo to yield the title product (m.p. 213.5°-215.5° C.).

1. customto remove water
2. temperatureThe mixture is then cooled
3. custompartially evaporated
4. additionand to the residue, 4.5 grams of solid potassium hydroxide are carefully added
5. temperatureThe resulting mixture is refluxed for 11/2 hours
6. temperaturecooled
7. filtrationfiltered
8. customthe layers separated
9. customthe resulting precipitate is removed by filtration
10. washThe precipitate is washed with water
11. customThe product is dried in vacuo