反应详情

100 g of 4-octyloxybiphenyl-4′carboxylic acid and 62 g of pentafluorophenol are introduced into 1 liter of dichloromethane. Agitation is carried out for 15 minutes and 69.6 g of N,N′-dicyclohexylcarbodiimide in solution in 500 ml of dichloromethane is added over 15 minutes. The dark beige suspension is agitated for 20 hours at ambient temperature. The dicyclohexylurea is filtered and the filtrate is concentrated. Distillation to constant volume is carried out by the regular addition of ethanol up to the vapour temperature of 74° C. The reaction medium is cooled down to ambient temperature, followed by agitating for one hour, filtering then washing with ethanol. After drying, 145.7 g of sought product is obtained in the form of crystals.

1. filtrationThe dicyclohexylurea is filtered
2. concentrationthe filtrate is concentrated
3. distillationDistillation to constant volume
4. additionis carried out by the regular addition of ethanol up to the vapour temperature of 74° C
5. temperatureThe reaction medium is cooled down to ambient temperature
6. stirringby agitating for one hour
7. filtrationfiltering
8. washthen washing with ethanol
9. customAfter drying