反应详情

As in Example 115, (E)-5,5-bis(4-methoxyphenyl)-2,4-pentadienoic acid (21.0 g) and 4-nitrophenol (11.2 g) in dichloromethane (300 mL) was treated with 1,3-dicyclohexylcarbodiimide (14 g). The mixture was stirred at 0°-5° C. for 1 hour, then at room temperature overnight. After the usual work up, the crude product was crystallized from ether-hexane to give 24.7 g of (E)-5,5-bis(4-methoxyphenyl)-2,4-pentadienoic acid 4-nitrophenyl ester mp 121°-123° C. Recrystallization of the material from 2-propanol afforded the purified ester, mp 125°-126° C. Anal. Calculated for C25H21NO6 : C, 69.60; H, 4.91; N, 3.23 Found: C, 69.19; H, 4.94; N, 3.25.

1. customat room temperature
2. customovernight
3. customAfter the usual work up, the crude product was crystallized from ether-hexane