反应详情

0.8 g of 2-[(4,5-dimethoxy-2-pyridyl)methylthio]-5-(2,2,2-trifluoroethoxy)-1H-benzimidazole is dissolved in 15 ml of dioxane and 2.5 ml of 1N sodium hydroxide solution. A mixture of 3 ml of 8% strength sodium hypochlorite solution and 3.5 ml of 1N sodium hydroxide solution are added dropwise in the course of 2 hours, while cooling to 0°-5° C. After addition of 5 ml of 5% strength sodium thiosulfate solution, the mixture is concentrated to dryness, the residue is taken up in water and the mixture is brought to pH 7 with phosphate buffer. The solid which has precipitated out is filtered off with suction, dried and recrystallized from ethyl acetate/diisopropyl ether. 0.45 g (55% of theory) of the title compound is obtained as colorless crystals of m.p. 142°-143° C. (decomp.).

1. additionare added dropwise in the course of 2 hours
2. temperaturewhile cooling to 0°-5° C
3. concentrationthe mixture is concentrated to dryness
4. customThe solid which has precipitated out
5. filtrationis filtered off with suction
6. customdried
7. customrecrystallized from ethyl acetate/diisopropyl ether