Triethylamine → (2S,3S)-2-(2,4-difluorophenyl)-3-methanesulfonyloxy-1-(1H-1,2,4-triazol-1-yl)-2-butanol

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Reaction Steps

In a mixture of ethyl acetate (2 ml) and dichloromethane (0.5 ml) was dissolved (2S,3S)-2-(2,4-difluorophenyl)-1-(1H-1,2,4-triazol-1-yl)-2,3-butanediol (58 mg). To the solution were added, under ice-cooling, triethylamine (66 μl) and methanesulfonyl chloride (37 μl). The mixture was stirred for two hours at room temperature. To the reaction mixture was added ethyl acetate (30 ml), which was washed with water, dried (anhydrous magnesium sulfate) and concentrated to afford (2S,3S)-2-(2,4-difluorophenyl)-3-methanesulfonyloxy-1-(1H -1,2,4-triazol-1-yl)-2-butanol as an oily product . This product was dissolved in methanol (2 ml), to which was added, under ice-cooling, 28% sodium methyl ate (116 μl), and the mixture was stirred for 30 minutes at room temperature. To the reaction mixture was added dichloromethane (30 ml), which was washed with water and dried (anhydrous magnesium sulfate), followed by distilling off the solvent under reduced pressure. The residue was purified by means of a silica gel chromatography (eluent: ethyl acetate-dichloromethane=4:1 ), followed by crystallization from hexane to afford (2S,3R)-2-(2,4-difluorophenyl)-3-methyl-2-(1H-1,2,4-triazol-1-yl)methyl oxirane (42 mg) as colorless needles. m.p. 89°-90° C. [α]D23 =+7.8° (c=1.0 in MeOH)

Provenance & Evidence