0.50 gram (1.82 millimoles) of 4-(5H-dibenzo[a,d]cyclohepten-5-yl)piperidine, 0.24 gram (1.82 millimoles) of 3-fluoro-2-chloropyridine, 0.47 gram (3.64 mole) of ethyl diisopropylamine and 10 milliliters of n-butanol were heated at reflux temperature protected from atmospheric moisture with a drying tube. After 19.25 hours heating, an additional 240 milligrams of the 3-fluoro-2-chloropyridine was added. After another 24 hours, 300 milligrams of ethyl dipropylamine was added and heating continued. After about 140 hours of refluxing, the mixture was concentrated, diluted with ether, washed successively with 10 percent aqueous sodium hydroxide and brine, dried, and the solvent vaporized to obtain a brown semi-solid residue. The residue was purified by chromatographing on silica gel with 7 percent ether in hexanes to obtain the 4-(5H-dibenzo[a,d]cyclohepten-5-yl)-1-(3-fluoro-1-pyridyl)piperidine product as a crystalline white solid, which after drying overnight in vacuo and 4 hours at 100° C. at 1 millimeter of mercury pressure had a melting point of 208°-210° C. Elemental analyses were as follows:
