反应详情

5.0 g of N-(3-methyl-2,2-dioxo-1,2-benzoxathiin-8-ylsulfonyl)-N'-methylurea are dispersed in 150 ml of absolute chlorobenzene and the dispersion is saturated with phosgene at 130° C. A clear solution forms during this addition. The solvent is subsequently distilled off in vacuo with the exclusion of moisture. The 3-methyl-2,2-dioxo-1,2-benzoxathiin-8-ylsulfonylisocyanate obtained as oily residue can be used without further purification for the preparation of the pyrimidinylureas and triazinylureas of the formula I.

1. additionA clear solution forms during this addition
2. distillationThe solvent is subsequently distilled off in vacuo with the exclusion of moisture