反应详情

A solution of 3.5 g of 2-phenoxycarbonylamino-4-difluoromethoxy-6-methyl-pyrimidine (crude product) and 2.9 g of 2-(ethoxy-ethoxy)-benzenesulfonamide in 100 ml of absolute acetonitrile is decomposed with 1.8 g of 1,5-diazabicyclo[5.4.0]undec-5-ene; it is then stirred for 1 hour at 20° to 25° C., diluted with 500 ml of water and acidified with hydrochloric acid. The precipitated oil is taken up with 200 ml of ethyl acetate, dried over sodium sulfate and concentrated by evaporation. Crystallisation of the oily residue from diethyl ether and acetone yields, as colourless crystals, N-[2-(2-ethoxy-ethoxy)-phenyl-sulfonyl]-N'-(4-difluoromethoxy-6-methyl-pyrimidin-2-yl)-urea, m.p. 90° to 95° C. (decomposition); yield 2.7 g.

1. dry with materialdried over sodium sulfate
2. concentrationconcentrated by evaporation
3. customCrystallisation of the oily residue from diethyl ether and acetone