反应详情

The intermediate 4-cyclopropyloxybenzoic acid was prepared as follows: A 66.5 g. portion of ethyl 4-hydroxybenzoate was dissolved in 800 ml. of dimethylformamide and to the solution was added 83.0 g. of anhydrous potassium carbonate and 5 g. of potassium iodide. To the resulting stirred suspension was added 60.5 g. of cyclopropyl bromide. The stirred reaction mixture was refluxed for 6 days and the hot reaction mixture was filtered to remove the inorganic solids which were washed well with dimethylformamide. The combined filtrate and dimethylformamide washings were evaporated in vacuo and the remaining liquid-solid residue was taken up in a mixture of 500 ml. of water and 500 ml. of ether. The resulting mixture was shaken well and the layers were separated. The aqueous layer was extracted with 200 ml. of ether. The combined ether solutions were washed successively with two 250 ml. portions of aqueous potassium hydroxide solution, next with 200 ml. 0.5N hydrochloric acid and then with two 100 ml. portions of water. The ether solution was dried over anhydrous magnesium sulfate and the ether removed in vacuo to yield, as an amber liquid, 36.2 g. of ethyl 4-cyclopropyloxy-benzoate.

1. additionwas added 60.5 g
2. customThe stirred reaction mixture
3. temperaturewas refluxed for 6 days
4. filtrationthe hot reaction mixture was filtered
5. customto remove the inorganic solids which
6. washwere washed well with dimethylformamide
7. customThe combined filtrate and dimethylformamide washings were evaporated in vacuo
8. additionthe remaining liquid-solid residue was taken up in a mixture of 500 ml
9. stirringThe resulting mixture was shaken well
10. customthe layers were separated
11. extractionThe aqueous layer was extracted with 200 ml
12. washThe combined ether solutions were washed successively with two 250 ml
13. dry with materialThe ether solution was dried over anhydrous magnesium sulfate
14. customthe ether removed in vacuo
15. customto yield, as an amber liquid, 36.2 g