Synthesis
A solution of 70.6 of 1-acetyl-4-(4-fluorobenzoyl)piperidine in 200 ml
of 6N HCl is refluxed for 2 hours. The cooled solution is extracted
twice with ether, the aqueous solution basified with sodium hydroxide
and then extracted with benzene. The benzene extracts are dried,
filtered and the filtrate is concentrated under reduced pressure. The
residual oil is dissolved in ether and HCl gas is bubbled into the
solution with stirring. The salt is collected by filtration, washed with
ether and dried. The salt is recrystallized from isopropanol to give
the solid product of 4-(4-fluorobenzoyl)piperidine hydrochloride, mp
222°-224° C.