反应详情

Following the procedure of Example 1, 573 g of N,N'-diphenyl urea and 2080 g of ethanol (approximately 96%) were reacted for 1.5 hours at 190° C. in the pressure apparatus described in Example 1. After cooling this mixture, 162 g of urea and 5.8 g of zinc octoate were added to the pressure reactor and then reacted for 5.5 hours at 200° C. with removal of the ammonia formed. After cooling and venting of the apparatus, the reaction mixture was removed, filtered and subjected to fractional distillation. Excess alcohol was separated from the reaction mixture at atmospheric pressure. 783 g (87.8% of the theoretical yield) of N-phenyl carbamic acid ethyl ester distilled off at 0.2 mbar. The N-phenyl carbamic acid ethyl ester crystals melted at 49° to 51° C.

1. customwere reacted for 1.5 hours at 190° C. in the pressure apparatus
2. additionwere added to the pressure reactor
3. customformed
4. temperatureAfter cooling
5. customthe reaction mixture was removed
6. filtrationfiltered
7. distillationsubjected to fractional distillation
8. customExcess alcohol was separated from the reaction mixture at atmospheric pressure