Pyridine → 3-{4-[4-butyl-2-(4-trifluoromethyl-phenyl)-thiazol-5-ylmethoxy]-2-trifluoromethyl-phenyl}-4H-[1,2,4]oxadiazol-5-one

To a solution of 89.3 mg of 4-[4-butyl-2-(4-trifluoromethyl-phenyl)-thiazol-5-ylmethoxy]-N-hydroxy-2-trifluoromethyl-benzamidine in 2 ml of anhydrous dichloromethane were added 92 μl pyridine followed by 21.6 μl phenylchloroformate dropwise. The resulting mixture was stirred at room temperature for 1 h. The solvent was removed in vacuo. To a solution of the resulting residue in 2.5 ml of acetonitrile was added 88 μl of 1,8-diazabicyclo[5.4.0]undec-7-ene. The mixture was stirred under microwave heating at 180° C. for 10 minutes (or stirred at room temperature overnight). The solvent was removed in vacuo and the crude product was purified by column chromatography on silica gel (heptane 1/ethyl acetate 1 then dichloromethane 95/methanol 5 followed by another column with dichloromethane 90/acetone 10) to give 65 mg of 3-{4-[4-butyl-2-(4-trifluoromethyl-phenyl)-thiazol-5-ylmethoxy]-2-trifluoromethyl-phenyl}-4H-[1,2,4]oxadiazol-5-one.