(2R, 3R)-2-(2,5-Difluoro-phenyl)-1-[1 ,2,4]-triazol-1-yl-butane-2,3-diol (324 mg, 1.20 mmol) is dissolved in methylene chloride (13 ml) and then triethylamine (0.59 ml, 4.2.mmol) is added to the reaction mixture. The reaction mixture is cooled to 0 ℃ and methane sulfonyl chloride (0.21 ml, 2.72 mmol) dissolved in methylene chloride (4 ml) is added. After 4 hours, sodium hydroxide solution (0.98 ml) is added and the reaction mixture is stirred at room temperature overnight. Finally, 1-(((2R,3S)-2-(2,5-difluorophenyl)-3-Methyloxiran-2-yl)Methyl)-1H-1,2,4-triazole was obtained through purification.