反应详情

To 36.2 g. (0.55 mole) of purified zinc dust is added portionwise a solution of 80 g p-anisaldehyde (0.58 mole) in 80 ml of anhydrous benzene, 20 ml anhydrous ether and 98 g (0.54 mole) of ethyl 2-bromopropionate from a separatory funnel. About 15 ml of this solution is added to the zinc and the flask is warmed until the reaction starts and then heating is removed and allowed to continue exothermally. The addition takes about an hour. The reaction mixture is refluxed for 40 minutes and then cooled in an ice bath and hydrolyzed by the addition of 250 ml of cold 10% sulfuric acid with vigorous stirring. The acid layer is drawn off and the benzene solution is extracted twice with 63 ml of 5% sulfuric acid followed by 30 ml of 10% sodium carbonate solution, then with 3 × 30 ml of 5% sulfuric acid, and finally with 2 × 30 ml of water. The combined acid solution is extracted with 2 × 100 ml of ether and the combined ether and benzene solution is washed with 2 × 50 ml of saturated sodium chloride, then it is dried over sodium sulfate for 11/2 hours and filtered. Most of the solvent is removed on an evaporator. The rest is distilled under vacuum to obtain ethyl β-(p-methoxyphenyl)-β-hydroxy-α-methylpropionate.

1. temperaturethe flask is warmed until the reaction starts
2. temperatureheating
3. customis removed
4. additionThe addition
5. waittakes about an hour
6. temperatureThe reaction mixture is refluxed for 40 minutes
7. temperaturecooled in an ice bath and hydrolyzed by the addition of 250 ml of cold 10% sulfuric acid with vigorous stirring
8. extractionthe benzene solution is extracted twice with 63 ml of 5% sulfuric acid
9. extractionThe combined acid solution is extracted with 2 × 100 ml of ether
10. washthe combined ether and benzene solution is washed with 2 × 50 ml of saturated sodium chloride
11. dry with materialit is dried over sodium sulfate for 11/2 hours
12. filtrationfiltered
13. customMost of the solvent is removed on an evaporator
14. distillationThe rest is distilled under vacuum