Methanol → cis-4-[[3,5-Bis(trifluoromethyl)benzyl]oxy]-1-ethyl-3-phenylpiperidine oxalate

Participants

Reaction Conditions

Reaction Steps

To a solution of the compound (0.88 g) obtained in Example 2 in THF (10 ml), 1 M borane and THF complex (10 ml) was added at 0° C., and the reaction mixture was stirred at 80° C. for 2 hours. The reaction mixture was cooled, and then methanol (2 ml) was added thereto, and concentrated under reduced pressure. To the obtained residue, 6 N hydrogen chloride (6 ml) and methanol (6 ml) were added, and the reaction mixture was stirred at 100° C. for 2 hours. The reaction mixture was cooled, and then made basic with an aqueous 12 N sodium hydroxide solution. The mixture was concentrated under reduced pressure, and then the product was extracted with ethyl acetate. The organic layer was washed with saturated brine, dried, and then the solvent was evaporated under reduced pressure. The obtained residue was isolated and purified by silica gel column chromatography (acetone:methanol=20:1), and treated with 1 equivalent of oxalic acid to obtain the title compound as colorless crystals (0.52 g, 61%).

Provenance & Evidence