反应详情

55 g of 4-(2',4'-dichlorophenoxy)-α-phenoxy-propionic acid were suspended in 500 ml of isopropanol. While stirring, hydrogen chloride was fed in, whereupon the temperature rose to about 50° C. While the feed of hydrogen chloride was continued, the suspension was refluxed for 5 hours and the reaction mixture was then allowed to stand overnight. After the excess alcohol had been distilled off, the solution was poured on water and then extracted with methylene chloride. The methylene chloride extract was washed with dilute bicarbonte solution and then twice with water and dried over sodium sulfate. After filtration the solution was concentrated and then distilled under greatly reduced pressure. 34 g of 4-(2',4'-dichlorophenoxy)-α-phenoxy-propionic acid isopropyl ester were obtained, boiling point 182°-185° C. under a pressure of 0.04 mm mercury.

1. customrose to about 50° C
2. temperaturethe suspension was refluxed for 5 hours
3. distillationAfter the excess alcohol had been distilled off
4. additionthe solution was poured on water
5. extractionextracted with methylene chloride
6. extractionThe methylene chloride extract
7. washwas washed
8. additionwith dilute bicarbonte solution
9. dry with materialtwice with water and dried over sodium sulfate
10. filtrationAfter filtration the solution
11. concentrationwas concentrated
12. distillationdistilled under greatly reduced pressure