Imidazole → 1H-Imidazole, 1-[[2-(2,4-difluorophenyl)-3-methyloxiranyl]methyl]-, (2R-cis)-

Participants

Reaction Steps

To a N,N-dimethylformamide (35 ml) solution containing (2R,3R)-3-(2,4-difluorophenyl)-3,4-epoxy-2-butyl methanesulfonate (3.5 g) and imidazole (1.2 g) was added 60% sodium hydride in mineral oil (0.70 g) at 0° C. with constant stirring. After 10 minutes, the temperature was adjusted to 20° C. and the mixture was stirred for 20 hours. The reaction mixture was then poured into water (100 ml) and extracted with ethyl acetate (30 ml×4). The ethyl acetate layers were combined, washed with saturated aqueous sodium chloride solution (30 ml), dried over anhydrous magnesium sulfate and concentrated under reduced pressure. The residue was purified by silica gel chromatography (3 cm×15 cm) using methanol-ethyl acetate (5:95) as the eluent. The desired fraction was concentrated under reduced pressure and the residue was crystallized by addition of isopropyl ether and n-hexane to give (2R,3S)-2-(2,4-difluorophenyl)-2-(1-imidazolyl)methyl-3-methyloxirane (1.7 g) as colorless prisms. m.p. 73°-76° C.

Provenance & Evidence