Eunerpan,Nordmark,W. Germany,1965
A solution or dispersion consisting of 20.1 g (0.1 mol) of γ-chloro-pfluorobutyrophenone, 19.8 g (0.2 mol) of 4-methylpiperidine and 0.1 g of potassium iodide in 150 ml toluene is heated in a sealed glass tube for 15 hours at 100°C to 110°C. The potassium iodide and the 4-methylpiperidine hydrochloride formed in the reaction are separated by filtration and the solvent removed from the filtrate by evaporation in vacuum on a steam bath. The residue is distilled and the fraction obtained at 120°C to 125°C and at a pressure lower than 0.1 mm Hg is collected. The base is dissolved in ether and the 4-fluoro-γ-(4-methylpiperidino)-butyrophenone precipitated as the hydrochloride. The reaction product is purified by recrystallization in ethanol/ether.
Yield 22.0 g (73% of theory). MP 209°C to 211°C.
