反应详情

At 55-60° C. and under argon, a solution of 5.0 g (17.9 mmol) of methyl 2-chlorosulfonyl-6-nitrobenzoate in 55 ml of dry dichloromethane is added dropwise over 2 h to a suspension of 2.79 g (17.9 mmol) of 2-amino-4,6-dimethoxy-1,3,5-triazine, 1.28 g (19.7 mmol) of sodium cyanate, 1.45 ml (17.9 mmol) of pyridine and 500 mg of freshly activated molecular sieve (pore size 3 Å) in 85 ml of dry acetonitrile. After 7 h of stirring at this temperature, the mixture is allowed to warm to room temperature. After a further 12 h, the reaction mixture is concentrated and the residue is suspended in 200 ml of water and adjusted to pH 10 using 2 N aqueous sodium hydroxide solution. The precipitated solid is filtered off with suction and the filtrate is extracted with ethyl acetate. The organic phase is separated off and the aqueous phase is adjusted to pH 1.5 using 3 N aqueous hydrochloric acid solution and stirred in an ice bath for 15 min. The precipitated solid is then filtered off with suction, washed first with water and then with methanol and dried under reduced pressure. This gives 2.88 g (36% of theory) of methyl 2-[([(4,6-dimethoxy-1,3,5-triazin-2-yl)amino]carbonylamino)sulfonyl]-6-nitrobenzoate of m.p. 185-195° C. (decomp.).

1. waitAfter a further 12 h
2. concentrationthe reaction mixture is concentrated
3. filtrationThe precipitated solid is filtered off with suction
4. extractionthe filtrate is extracted with ethyl acetate
5. customThe organic phase is separated off
6. stirringstirred in an ice bath for 15 min
7. filtrationThe precipitated solid is then filtered off with suction
8. washwashed first with water
9. dry with materialwith methanol and dried under reduced pressure