Ethanol → HCID 12788384, compound

Participants

Reaction Steps

A mixture of 0.9 g of the free base, 3-phenyl-4-piperidone of Example 50c, above, 0.19 g of sodium borohydride and 15 ml of absolute ethanol is stirred at room temperature for 6 hours under a nitrogen atmosphere. The mixture is then treated with 25 ml of saturated aqueous NaCl solution and extracted with dichloromethane. The combined organic extracts are washed with saturated aqueous NaCl solution, dried over anhydrous Na2SO4 and concentrated in vacuo to a gum which TLC shows to be a mixture of cis and trans isomers, with the trans isomer predominant. Trituration of this material with benzene gives a well formed solid which is filtered off after allowing the mixture to stand 18 hours. The solid is washed with benzene and then hexane, and dried in vacuo to afford a solid, m.p. s 99°, 115°-127° C., which TLC showed contained only a small amount of the cis isomer. This material is taken up in 10 ml of boiling benzene, filtered, and boiled down to a volume of approximately 5 ml of solution to afford a solid of trans-3-phenyl-4-piperidinol, m.p. s 125.5°, 127°-128.5°, which TLC showed to be pure trans isomer.

Provenance & Evidence