Ethoxysulfuron synthesis

Yield:-

Reaction Conditions:

with hydrogenchloride;sodium sulfate in dichloromethane;water

Steps:

2 3-(4,6-Dimethoxypyrimidin-2-yl)-1-(2-ethoxyphenoxysulfonyl)urea
EXAMPLE 2 3-(4,6-Dimethoxypyrimidin-2-yl)-1-(2-ethoxyphenoxysulfonyl)urea A solution of 97.2 g (0.4 mol) of the product of Example 1 in 100 ml of dichloromethane is added dropwise at 25° C. to 62.0 g (0.4 mol) of 2-amino-4,6-dimethoxypyrimidine in 600 ml of dichloromethane. Stirring at room temperature is continued for 16 hours, the mixture is diluted with 600 ml of dichloromethane, and the organic phase is washed twice with 500 ml portions of 2N hydrochloric acid and once with 500 ml of water. After the mixture has been dried using sodium sulfate and after the solvent has been removed on a rotary evaporator, an oily product remains which crystallizes on trituration with diethyl ether. 145.0 g (91% of theory) of 3-(4,6-dimethoxypyrimidin-2-yl)-1-(2-ethoxyphenoxysulfonyl)urea of melting point 145°-147° C. are obtained.

References:

Hoechst Aktiengesellschaft US5104443, 1992, A