3.0 g of dimethylamine are introduced at 20°-30° C., with cooling, into a solution of 8.2 g of N-(2-difluoromethoxyphenyl-sulfonyl)-N'-(4-chloro-6-methoxy-1,3,5-triazin-2-yl)-urea in 80 ml of dioxane. After the formed suspension has been stirred for a further 30 minutes, it is taken up in 500 ml of 0.1 N hydrochloric acid, and the product which has precipitated is separated by filtration; yield: 7.7 g of N-(2-difluoromethoxyphenyl-sulfonyl)-N'-(4-dimethylamino-6-methoxy-l,3,5-triazin-2-yl)-urea, m.p. 171°-172° C.
