反应详情

To 16 g of ethyl[ (6,7-dichloro-2-(1-hydroxyethyl)benzo[b]thien-5-yl)oxy]acetate in 300 ml 95% ethanol is added 300 ml of a 6 N sodium hydroxide and the mixture is refluxed at 100° for 30 mins. The cooled mixture is concentrated to a white slurry which is diluted with 200 ml of ice-water and 200 ml of ethyl ether. With stirring and efficient cooling, the mixture is acidified with 6 N hydrochloric acid. The acidic mixture is extracted with ethyl ether. The ether extracts are washed, dried over anhydrous magnesium sulfate, filtered and the solvent is removed. Recrystallization of the crude product from acetone and hexane gives 11.4 g of [(6,7-dichloro-2-(1-hydroxyethyl)benzo[b]thien-5-yl)oxy]acetic acid, mp 173°-175°.

1. temperaturethe mixture is refluxed at 100° for 30 mins
2. concentrationThe cooled mixture is concentrated to a white slurry which
3. additionis diluted with 200 ml of ice-water and 200 ml of ethyl ether
4. extractionThe acidic mixture is extracted with ethyl ether
5. washThe ether extracts are washed
6. dry with materialdried over anhydrous magnesium sulfate
7. filtrationfiltered
8. customthe solvent is removed
9. customRecrystallization of the crude product from acetone and hexane