Sodium hydride → (R)-3-(2-methyl-6-nitro-2,3-dihydroimidazo[2,1-b]oxazol-2-ylmethyl)-5-(4-trifluoromethoxyphenyl)-3H-[1,3,4]oxadiazol-2-one

Participants

Reaction Steps

To a solution of (R)-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 539 (0.87 g, 1.88 mmol) in 1,4-dioxane (18 ml), sodium hydride (98 mg, 2.44 mmol) was added with cooling on ice-bath. The mixture was stirred under reflux for 5 hours, concentrated under reduced pressure, then water was added with cooling on ice-bath. The solution was extracted with ethyl acetate, and the organic phase was dried over magnesium sulfate and then concentrated under reduced pressure. The residue was purified by silica gel column chromatography (methylene chloride/ethyl acetate 9/1), and recrystallized from acetonitrile/isopropanol to afford (R)-3-(2-methyl-6-nitro-2,3-dihydroimidazo[2,1-b]oxazol-2-ylmethyl)-5-(4-trifluoromethoxyphenyl)-3H-[1,3,4]oxadiazol-2-one (0.32 g, yield 40%) as a white powder.

Provenance & Evidence