To a solution of 650 mg (1.25 mmol) 1-[2-(2-methyl-4-{2-[2-(E)-(2-fluoro-4-trifluoromethyl-phenyl)-vinyl]-oxazol-4-ylmethoxy}-benzylsulfanyl)-ethyl]-1H[1,2,3]triazole in 35 ml dichloromethane at −30° C. were added dropwise during 20 min. 493 mg (2.20 mmol) 3-chloro-benzenecarboperoxoic acid (77% peracid) dissolved in 20 ml ethyl acetate. After 1 hour stirring at −30° C. the mixture was allowed to warm up over night, stirred another 48 hours at room temperature, diluted with dichloromethane, washed with sodium bicarbonate solution, then with water, dried and evaporated. Elution from silica with ethyl acetate (1–10% methanol gradient) furnished as the second fraction 310 mg (46%) title compound as white solid.
