Uses
2,3,4,5-Tetrahydro-1H-1,5-methano-3-benzazepine Hydrochloride is used in the preparation of the main band impurity of Varenicline (V098490), a nicotinic α4β2 acetylcholine receptor partial agonist. Aid in smoking cessation.
Synthesis
The general procedure for the synthesis of 2,3,4,5-tetrahydro-3-benzyl-1,5-methano-1H-3-benzazepine hydrochloride from 2,3,4,5-tetrahydro-3-benzyl-1,5-methanolbenzo[d]azepine hydrochloride is as follows: methanol hydrochloride (116.6 g, 13.8%) was slowly added to 10-benzyl-10-azabenzotriene at 0°C to 5°C [ 6.3.1.02,7]dodeca-2(7),3,5-triene (100 g) in a methanol (600 ml) suspension. Subsequently, the reaction mixture was subjected to hydrogenation reaction catalyzed by 20% palladium hydroxide (26 g) under hydrogen pressure of 5 to 6 kg/cm2 at 20°C to 40°C for 3 to 6 hours. The reaction process was monitored by HPLC. After completion of the reaction, the mixture was filtered through a diatomaceous earth pad and the filtrate was distilled under reduced pressure to remove the solvent. Dichloromethane (500 ml) was added to the residue and the solvent was again completely evaporated under reduced pressure to give the crude product. The crude product was purified by recrystallization with acetone (450 ml) to finally obtain high purity 10-aza-tricyclo[6.3.1.02,7]dodeca-2(7),3,5-triene hydrochloride (HPLC purity 98.23%, yield 89.24%).
References
[1] Patent: US2009/318695, 2009, A1. Location in patent: Page/Page column 9
[2] Patent: WO2010/23561, 2010, A1. Location in patent: Page/Page column 16
