反应详情

As in Example 115, (E)-5,5-bis(3-methoxyphenyl)-2,4-pentadienoic acid (49.6) and 4-nitrophenol (25 g) in dichloromethane (600 mL) was treated with 1,3-dicyclohexylcarbodiimide (33 g). The mixture was stirred at 0°-5° C. for 1 hour, then at room temperature for 2 hours. After the usual work up, the crude product (67 g) was crystallized from 2-propanol-ether-hexane to give 61.0 g of (E)-5,5-bis (3-methoxyphenyl)-2,4-pentadienoic acid 4-nitrophenyl ester mp 95°-97° C. Recrystallization of a portion from dichloromethane-hexane yielded the analytical sample, mp 99°-100° C.

1. waitat room temperature for 2 hours
2. customAfter the usual work up, the crude product (67 g) was crystallized from 2-propanol-ether-hexane