Hydrochloric Acid → (R)-2-methyl-6-nitro-2,3-dihydroimidazo[2,1-b]oxazol-2-ylmethyl N-(4-chlorophenyl)-N-methylcarbamate

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Reaction Steps

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.

Provenance & Evidence