反应详情

A solution of 1-(3,4-dichlorophenyl)-1-hydroxy-3-methylurea (15 grams; 0.06 mol) in isopropyl alcohol (50 ml), and pyridine (8 ml) were charged into a glass reaction flask equipped with a mechanical stirrer. Methyl 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 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 first from a benzene-hexane mixture and then from a methyl alcohol-water mixture to yield 1-(3,4-dichlorophenyl)-1-methoxycarbonyloxy-3-methylurea having a melting point of 110°C with decomposition and having the following elemental analysis as calculated for C10H10Cl2N2O4 :

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