反应详情

6,7-Dichloro-2-ethyl-5-hydroxy-1-indanone (24.5 g., 0.1 mole) and anhydrous potassium carbonate (15.2 g., 0.11 mole) is stirred in dimethylformamide (100 ml.) while ethyl 4-bromobutyrate (21.4 g., 0.1 mole) is added dropwise. The mixture is stirred and heated at 55°-60° C. for two hours. Potassium hydroxide (7.92 g., 0.141 mole) in methanol (60 ml.) is then added. The solid mass that forms is broken up and the mixture is stirred at 80°-85° C. for 11/2 hours and poured into water (500 ml.). The aqueous mixture is heated to boiling, filtered and acidified (6N HCl). The solid that separates is collected, washed with water, air-dried and recrystallized from ethylacetate to obtain 25.6 g. of 4-(1(1-oxo-2-ethyl-6,7-dichloro-5-indanyloxy)butyric acid, m.p. 146°-148° C.

1. additionis added dropwise
2. temperatureheated at 55°-60° C. for two hours
3. stirringthe mixture is stirred at 80°-85° C. for 11/2 hours
4. temperatureThe aqueous mixture is heated
5. filtrationfiltered
6. customThe solid that separates is collected
7. washwashed with water
8. customair-dried
9. customrecrystallized from ethylacetate
10. customto obtain 25.6 g