反应详情

To a solution of 3-[3-(2-chloro-4-nitroimidazol-1-yl)-2-hydroxy-2-methylpropyl]-5-(4-trifluoromethoxyphenyl)-3H-[1,3,4]oxadiazol-2-one prepared in Example 516 (3.27 g, 7.05 mmol) in 1,4-dioxane (70 ml), sodium hydride (0.37 g, 9.17 mmol) was added with cooling on ice-bath followed by stirring under reflux for 3 hours. The reaction mixture was concentrated under reduced-pressure. To the solution, water was added with cooling on ice-bath, and the mixture was extracted with ethyl acetate. The extract was dried over magnesium sulfate, and then concentrated under reduced pressure. The residue was purified by silica gel column chromatography (methylene chloride/ethyl acetate=4/1) and recrystallized from acetonitrile-ethanol to afford 3-(2-methyl-6-nitro-2,3-dihydroimidazo[2,1-b]oxazol-2-ylmethyl)-5-(4-trifluoromethoxyphenyl)-3H-[1,3,4]oxadiazol-2-one (1.43 g, yield 48%) as a white solid.

1. temperaturewith cooling on ice-bath
2. temperatureunder reflux for 3 hours
3. concentrationThe reaction mixture was concentrated under reduced-pressure
4. additionTo the solution, water was added
5. temperaturewith cooling on ice-bath
6. extractionthe mixture was extracted with ethyl acetate
7. dry with materialThe extract was dried over magnesium sulfate
8. concentrationconcentrated under reduced pressure
9. customThe residue was purified by silica gel column chromatography (methylene chloride/ethyl acetate=4/1)
10. customrecrystallized from acetonitrile-ethanol