反应详情

Potassium hydroxide (3.4 g.) was fused at 180°C. with water (1 ml.), and 2,4-difluorophenol (5.2 g.) added. 2-(4-Iodophenyl)propionic acid (5.5 g.) and copper bronze (0.2 g.) were then added to the melt, and the resulting mixture was stirred at 160°-170°C. for 2 hours. The cooled solid was extracted with methylene chloride containing a little dilute hydrochloric acid, filtered, and the solution extracted with dilute potassium carbonate solution. The aqueous extract was washed with ether and acidified with dilute hydrochloric acid; the resulting oil was isolated in ether and evaporated to dryness. The resulting solid was purified by preparative layer chromatography using 5% acetic acid/petroleum ether b.p. 62°-68°C. and eluting with ethyl acetate; recrystallization from petroleum ether b.p. 80°-100°C. gave 2-[4-(2,4-difluorophenoxy)phenyl] propionic acid, m.p. 105°-106°C.

1. additionadded
2. extractionThe cooled solid was extracted with methylene chloride containing a little dilute hydrochloric acid
3. filtrationfiltered
4. extractionthe solution extracted with dilute potassium carbonate solution
5. extractionThe aqueous extract
6. washwas washed with ether
7. customthe resulting oil was isolated in ether
8. customevaporated to dryness
9. customThe resulting solid was purified by preparative layer chromatography
10. washeluting with ethyl acetate
11. customrecrystallization from petroleum ether b.p. 80°-100°C.