Allyl bromide → 4-[10,11-dihydro-5-(2-propenyl)-5H-dibenzo[a,d]cyclohepten-5-yl]-1-methyl-1,2,5,6-tetrahydropyridine

Participants

Reaction Conditions

Reaction Steps

Dissolved 4-(10,11-dihydro-5H-dibenzo[a,d]cyclohepten-5-ylidene)-1-methylpiperidine (10 g, 34.6 mmol) in 200 mL of dry THF, and cooled to -78° C. under a nitrogen atmosphere. Added n-butyl lithium (15.2 mL of 2.5M in hexane, 38.0 mmol) dropwise via syringe. Warmed to 0° C., and stirred for 60 mins. Recooled to -78° C., and added allyl bromide (4.6 g, 3.3 mL, 38.0 mmol) dropwise via syringe. Warmed to room temperature slowly, and stirred for 5 hours. Added saturated NH4Cl, and extracted with ether. Dried the combined organic extracts with MgSO4, filtered, and evaporated. Purified the crude product by flash chromatography on silica gel eluting with 5:95:0.1 MeOH:EtOAc:NH4OH. Combined appropriate fractions, and evaporated to give 8.0 g (70% yield) of 4-[10,11-dihydro-5-(2-propenyl)-5H-dibenzo[a,d]cyclohepten-5-yl]-1-methyl-1,2,5,6-tetrahydropyridine as an oil. Dissolved free base in ether, and added 19 weight % HCl-EtOH until acidic. Added additional ether, and let stand to precipitate hydrochloride salt. Recrystallized salt from acetonitrile-ether.

Provenance & Evidence