反应详情

A solution of 1.24 g of 6,7-dichloro-5-hydroxy-2-hydroxymethylbenzo[b]thiophene, 0.9 g of ethyl bromoacetate, 0.6 g of potassium carbonate, 25 ml of 2-butanone and 0.5 ml of dimethylformamide is stirred under reflux for 2 hrs. The aqueous layer is extracted twice with 50 ml portions of dichloromethane. The combined organic extracts, are washed with brine, dried over anhydrous magnesium sulfate, filtered and concentrated to give a clear oil which crystallizes on standing. Recrystallization of the crude product from acetone-hexane gives 1.8 g of ethyl[(6,7-dichloro-2-hydroxymethylbenzo[b]thien-5-yl)oxy]acetate mp 117°-118.5°.

1. temperatureunder reflux for 2 hrs
2. extractionThe aqueous layer is extracted twice with 50 ml portions of dichloromethane
3. washThe combined organic extracts, are washed with brine
4. dry with materialdried over anhydrous magnesium sulfate
5. filtrationfiltered
6. concentrationconcentrated
7. customto give a clear oil which
8. customcrystallizes
9. customRecrystallization of the crude product from acetone-hexane