反应详情

2,4-Difluoroaniline (25 g) and 25.2 g of pyridine were dissolved in 200 ml of dichloromethane and, with ice cooling, 33.3 g of phenyl chloroformate was added dropwise thereinto. The reaction solution was stirred with ice cooling for 30 minutes, washed with water and dried. The solvent was distilled off to give a mixture of phenyl 2,4-difluorophenylcarbamate and pyridine. To the mixture was added 30.7 g of 2-(diethoxy)ethylamine, and the resulting mixture was stirred at room temperature. The crystals separated out were collected by filtration and washed with petroleum ether to give 37.8 g of N-(2,2-diethoxyethyl)-N'-(2,4-difluorophenyl)urea as colorless crystals.

1. additionwas added dropwise
2. washwashed with water
3. customdried
4. distillationThe solvent was distilled off
5. customto give
6. stirringthe resulting mixture was stirred at room temperature
7. customThe crystals separated out
8. filtrationwere collected by filtration
9. washwashed with petroleum ether