反应详情

Iodomethane (0.71 ml, 11.4 mmol) and potassium hydroxide (0.64 g, 11.4 mmol) were added to a solution of (R)-3-(2-chloro-4-nitroimidazol-1-yl)-2-hydroxy-2-methylpropyl 4-chlorophenylcarbamate prepared in Example 64 (1.5 g, 3.8 mmol) in DMSO (40 ml) followed by stirring at room temperature for 4 hours. The mixture was cooled on ice-bath and added 10% hydrochloric acid. The resulting mixture was extracted with ethyl acetate, and the extract was washed with water, dried over magnesium sulfate and then concentrated under reduced pressure. The residue was purified by silica gel column chromatography (n-hexane/ethyl acetate=1/1) and recrystallized from isopropanol to afford (R)-2-methyl-6-nitro-2,3-dihydroimidazo[2,1-b]oxazol-2-ylmethyl N-(4-chlorophenyl)-N-methylcarbamate (0.67 g, 60%) as a white solid.

1. temperatureThe mixture was cooled on ice-bath
2. extractionThe resulting mixture was extracted with ethyl acetate
3. washthe extract was washed with water
4. dry with materialdried over magnesium sulfate
5. concentrationconcentrated under reduced pressure
6. customThe residue was purified by silica gel column chromatography (n-hexane/ethyl acetate=1/1)
7. customrecrystallized from isopropanol