Ethyl Acetate → 4-{1-[2,5-Difluoro-4-(1-hydroxy-ethyl)-phenyl]-piperidin-4-ylideneaminooxy}-piperidine-1-carboxylic acid isopropyl ester

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Reaction Steps

NaBH4 (0.15 g, 3.9 mmol) was added at 0° C. to a stirred solution of 50a (0.15 g, 0.34 mmol) in 5 mL of methanol. After 1 h, the mixture was diluted with 10 mL of saturated NaHCO3 and stirred for 20 minutes. The mixture was poured into ethyl acetate (25 mL), washed twice with brine (25 mL), dried and concentrated under vacuum. The residue was purified on an AS-H column (elution with 5% EtOH+0.1% triethylamine in hexane) to afford the 2 enantiomers of 4-{1-[2,5-difluoro-4-(1-hydroxy-ethyl)-phenyl]-piperidin-4-ylideneaminooxy}-piperidine-1-carboxylic acid isopropyl ester 50-1, LC-MS 422.2 (MFE-18), tR=6.45 (Method 2). EC50: 48 nM. 78 mg of the first enantiomer and 46 mg of the second enantiomer were obtained.

Provenance & Evidence