Hydrogen Bromide → 4-[Bis(4-Fluorophenyl)methylene]piperidine hydrobromide

Participants

Reaction Steps

A mixture of 164 g (0.342 mole) of α,α-bis(4-fluorophenyl)-1-(phenylsulfonyl)-4-piperidinemethanol and 80 g (0.85 mole) of phenol in 700 ml of 48% hydrobromic acid was heated at reflux for 7 hr and then was stirred at room temperature for 9 hr. The hydrobromic acid solution was decanted from a gum in the bottom of the reaction flask. The gum was triturated with ~1 liter of ether, and a tan solid formed. The solid was washed with several portions of ether and was dried under high vacuum to give 9.13 g (73%) of slightly impure title product, mp 211°-215° C. A small sample of this solid was recrystallized from methanol to give an analytically pure sample as a crystalline solid, mp 216°-218° C.

Provenance & Evidence