反应详情

1.9 g of methyl isocyanate are added to a suspension of 6.7 g of 2-(1,2-dichlorovinyloxy)phenylsulfonamide in 50 ml of methylene chloride. 3.3 g of triethylamine are added dropwise to this mixture at 20° to 25° C. in the course of 10 minutes, a clear solution being formed. Stirring of this solution is continued for a further hour, and the solution is then evaporated to dryness. The residue is dissolved in 5% aqueous sodium carbonate solution and acidified with 10% hydrochloric acid, whereupon the product precipitates as crystals. After filtration and drying, 7.8 g of N-[2-(1,2-dichlorovinyloxy)phenylsulfonyl]-N'-methylurea are obtained. Melting point: 228°-229° C.

1. customa clear solution being formed
2. waitis continued for a further hour
3. customthe solution is then evaporated to dryness
4. dissolutionThe residue is dissolved in 5% aqueous sodium carbonate solution
5. customprecipitates as crystals
6. filtrationAfter filtration
7. customdrying