2.4 g of 2,6-dichlorophenyl sulfamate are added in portions at 0° C. to 2° C. to a mixture of 2.3 g of dicyclohexylcarbodiimide, 120 mg of 4-dimethylaminopyridine and 2.2 g of 4,6-dimethoxypyrimidine-2-carboxylic acid in 80 ml of absolute dichloromethane, and stirring is continued for 0.5 hour at 0° C. and 3 hours at room temperature. The mixture is filtered off with suction, the organic phase is washed with 100 ml of 1 N hydrochloric acid and then with water and dried over sodium sulfate. The solvent is distilled off, and the residue is recrystallized from diisopropyl ether. This gives 3.2 g of 2,6-dichlorophenyl N-[(4,6-dimethoxypyrimidin-2-yl)carbonyl]sulfamate of melting point 136°-139° C.
