To a solution of 5-[3-(4-fluoro-phenyl)-5-hydroxymethyl-isoxazol-4-ylmethoxy]-2-methyl-2H-pyrazole-3-carboxylic acid (100 mg, 0.29 mmol) in THF (10 mL) was added 1-hydroxybenzotriazole hydrate (45.0 mg, 0.29 mmol), N-ethyldiisopropylamine (126 μL, 0.76 mmol), N-(3-dimethylaminopropyl)-N′-ethylcarbodiimidazole hydrochloride (56.3 mg, 0.29 mmol) and rac-3-aminotetrahydrofuran (25.1 mg, 0.29 mmol) and the resulting mixture stirred overnight at room temperature. The reaction mixture was then poured into aqueous sodium chloride (saturated) and the mixture was extracted with ethyl acetate. The combined organic layers were then washed with water and saturated sodium hydrogen carbonate solution and then dried over sodium sulfate, filtered and evaporated. Concentration and purification by chromatography (silica, dichloromethane:methanol=99:1 to 95:5) afforded the title compound (60 mg, 50%) as a white solid. MS: m/e=415.1 [M−H]−.
