反应详情

A solution of 1-(3,4-dichlorophenyl)-1-hydroxy-3-methylurea (15 grams; 0.06 mol) is isopropyl alcohol (50 ml), and pyridine (7 ml) were charged into a glass reaction vessel equipped with a mechanical stirrer. Ethyl chloroformate (7 ml; 0.09 mol) was then slowly added, with stirring, at a temperature of 10° to 15°C. After the addition was completed stirring was continued for an additional period of about one-half hour resulting in the formation of a precipitate. After this time, the reaction mixture was poured onto ice and the precipitate recovered by filtration. The precipitate was recrystallized from a benzene-hexane mixture to yield 1-(3,4-dichlorophenyl)-1-ethoxycarbonyloxy-3-methylurea having a melting point of 97°-98°C and having the following elemental analysis as calculated for C11H12Cl2N2O4 :

1. additionwere charged into a glass reaction vessel
2. customequipped with a mechanical stirrer
3. additionAfter the addition
4. stirringwas completed stirring
5. waitwas continued for an additional period of about one-half hour
6. customresulting in the formation of a precipitate
7. additionAfter this time, the reaction mixture was poured onto ice
8. filtrationthe precipitate recovered by filtration
9. customThe precipitate was recrystallized from a benzene-hexane mixture