反应详情

As in Example 115, (E)-5,5-bis(4-methylphenyl)-2,4-pentadienoic acid (7.25 g) and 4-nitrophenol (4.4 g) in dichloromethane (60 mL) was treated with 1.3-dicyclohexylcarbodiimide (5.36 g). The mixture was stirred at 0°-5° C. for 30 minutes and then at room temperature for 18 hours. After the usual work up. the ester was crystallized from 2-propanol to yield 8.9 g of (E)-5,5-bis(4-methylphenyl)-2,4-pentadienoic acid 4-nitrophenyl ester, mp 153.5°-154.5° C.

1. waitat room temperature for 18 hours
2. customthe ester was crystallized from 2-propanol