反应详情

As before. (E)-5.5-bis(2-fluorophenyl)-2,4-pentadienoic acid ethyl ester (1.7 g) in methanol (15 mL) was carried out using 4N sodium hydroxide (2.5 mL). After acidification, the product was extracted into dichloromethane (2×50 mL). The combined extracts were dried and evaporated and the residue crystallized from ether-hexane to provide 1.45 g of (E)-5,5-bis(2-fluorophenyl)-2,4-pentadienoic acid, mp 159°-160° C. Anal. Calculated for C17H12F2O2 : C, 71.32; H, 4.22; F, 13.27 Found: C, 71.09; H, 4.42; F, 13.26.

1. extractionAfter acidification, the product was extracted into dichloromethane (2×50 mL)
2. customThe combined extracts were dried
3. customevaporated
4. customthe residue crystallized from ether-hexane