反应详情

To a solution of 11.2 g (0.1 mol) of potassium tertbutylate in 125 ml of tetrahydrofuran are added at room temperature, with stirring, 13.9 g (0.1 mol) of 2-amino-4-methoxy-6-methylpyrimidine. Stirring is maintained for 2 hours at room temperature, and 32.3 g (0.1 mol) of N-(2-difluoromethoxy-benzenesulfonyl)-imido carbonic acid diethyl ester (obtained according to Example 1) are then added, the reaction mixture being stirred for a further 20 hours. The mixture is subsequently concentrated by evaporation, and the residue is taken up in water and rendered acid with hydrochloric acid. The acid solution is extracted with ethyl acetate; the organic phases are then collected, dried, and concentrated by evaporation to leave a solid residue, which is suspended in ether and again filtered off. The yield is 34.5 g (83% of theory) of the above sulfonylisourea, m.p. 131°-133° C.

1. stirringStirring
2. stirringthe reaction mixture being stirred for a further 20 hours
3. concentrationThe mixture is subsequently concentrated by evaporation
4. extractionThe acid solution is extracted with ethyl acetate
5. customthe organic phases are then collected
6. customdried
7. concentrationconcentrated by evaporation
8. customto leave a solid residue, which
9. filtrationagain filtered off