Acetic Acid → [1-(3-Ethoxy-4-methoxy-benzyl)-piperidin-4-yl]-carbamic acid tert-butyl ester

Participants

Reaction Conditions

Reaction Steps

A mixture of piperidin-4-yl-carbamic acid tert-butyl ester (10.0 g, 50.0 mmol, 1.0 equiv; commercially available), 3-ethoxy-4-methoxy-benzaldehyde (10.8 g, 60.0 mmol, 1.2 equiv; commercially available) and acetic acid (11.4 mL, 12.01 g, 200.0 mmol, 4.0 equiv) in ethanol (40 mL) was heated by microwave irradiation to 100° C. for 5 min. Sodium cyanoborohydride (6.27 g, 100.0 mmol, 2.0 equiv), dissolved in ethanol (20 mL), was added and the reaction mixture heated by microwave irradiation to 100° C. for an additional time period of 5 min. The solvent was removed under reduced pressure and the crude reaction product extracted from a solution of 1 M NaOH (200 mL) with ethyl acetate (3×100 mL). The combined organic phases were dried over MgSO4, concentrated by evaporation under reduced pressure and the crude material purified with column chromatography on silica eluting with ethyl acetate to yield 9.71 g (53%) of the title compound as a white solid. MS (ISP): 365.3 [M+H]+.

Provenance & Evidence