Acetic Acid → HCID 46177418, compound

Participants

Reaction Steps

In a 100 mL flask, 2.00 g (8.0 mmol) of 3,3-difluoro-4,4-dihydroxy-1-trifluoroacetylpiperidine 13 (J. Org. Chem. 2010, 75, 929-932) and 2.15 g (20.0 mmol; 2.5 equiv) of benzylamine were dissolved in 50 mL of toluene. The mixture was heated under reflux with a Dean Stark trap during 15 hours. After cooling to room temperature, the solvent was removed in vacuo. The resulting oil was dissolved in 25 mL of absolute methanol and 0.56 g (8.8 mmol; 1.1 equiv) of sodium cyanoborohydride and 0.48 g (8.0 mmol; 1 equiv) of acetic acid were slowly added at room temperature. The solution was stirred during 4 hours at room temperature. After removing the solvent under vacuum, the crude oil was redissolved in 50 mL of dichloromethane and poured in 50 mL of a saturated aqueous NaHCO3 solution and was subsequently extracted with dichloromethane (3×50 mL). The combined organic layers were washed with brine and dried over MgSO4. Filtration of the solids and evaporation of the solvent resulted in a crude oil which was purified via flash chromatography (EtOAc, Rf=0.03) yielding 1.32 g (5.8 mmol; 73% yield) of benzyl-(3,3-difluoro-piperidin-4-yl)amine 14 as a yellow oil.

Provenance & Evidence