The general procedure for the synthesis of 8-chloro-11-(1-methylpiperidin-4-ylidene)-6,11-dihydro-5H-benzo[5,6]cyclohepta[1 ,2-b]pyridine using (1-methyl-4-piperidinyl)[3-[2-(3-chlorophenyl)ethyl]pyridin-2-yl]methanone hydrochloride as a starting material was as follows: in Example 2, the preparation of 8-chloro-6,11-dihydro-1H -(N-methyl-4-piperidinylidene)-5H-benzo[5,6]cyclohepta[1,2-b]pyridine (XII). This was done by preparing Compound XIII (100 g) according to the standard method described in U.S. Patent No. 4,659,716 by first azeotropic de-watering in toluene without drying. Subsequently, boric acid (115 g) and concentrated sulfuric acid (415 g) were added and the reaction was heated at 105-110°C for 4-8 hours. After completion of the reaction, the reaction mixture was slowly poured into cold water and extracted with ethyl acetate. Finally, the solvent was removed by distillation under reduced pressure to afford the target product 8-chloro-11-(1-methylpiperidin-4-ylmethylene)-6,11-dihydro-5H-benzo[5,6]cyclohepta[1,2-b]pyridine as a solid form in 85% yield and 99.5% purity (determined by OAB and HPLC).
![(1-Methyl-4-piperidinyl)[3-[2-(3-chlorophenyl)ethyl]pyridinyl]methanone hydrochloride](/CAS/GIF/119770-60-4.gif)
