反应详情

As in Example 115, (E)-5,5-bis(4-fluorophenyl)-2,4-pentadienoic acid (23.75 g) and 4-nitrophenol (12.7 g) in dichloromethane (250 mL) was treated with 1,3-dicyclohexylcarbodiimide (17.12 g). The mixture was stirred at 0°-5° C. for 60 minutes and then at room temperature for 1 hour. After the usual work up, the crude product was crystallized from 2-propanol to give 26.5 g of (E)-5,5-bis (4-fluorophenyl)-2,4-pentadienoic acid 4-nitrophenyl ester mp 112°-114° C. Recrystallization of a portion from the same solvent yielded the analytical sample, mp 112.5°-114° C. Anal. Calculated for C23H15F2NO4 :C, 67.81; H, 3.71; N, 3.44; F, 9.33 Found: C, 67.76; H, 3.77; N, 3.48; F, 9.11.

1. waitat room temperature for 1 hour
2. customAfter the usual work up, the crude product was crystallized from 2-propanol