Hydrogen Bromide → (S)-1-methyl-1,2,3,4-tetrahydroisoquinoline

Participants

Reaction Conditions

Reaction Steps

176.20 g(1449 mmole) of (S)-(-)-α-methylbenzylamine was dissolved in 185 ml of dichloromethane and 218.04 g(1748 mmole) of 2-bromoethanol was added thereto. This mixture was stirred at 51° C. for 50 hours to complete the reaction. The reaction solution was concentrated under reduced pressure and 658 ml(5750 mmole) of 48% aqueous hydrobromic acid solution was added thereto and the solution thereby obtained was allowed to react at 126° C. for 30 minutes under refluxing. The reaction solution was distilled for 2 hours under normal pressure at constant temperature to remove 580 ml of water as the by-product and aqueous hydrobromic acid solution. The residue was dissolved in 760 ml of isopropyl alcohol with refluxing for 30 minutes, and this solution was cooled to 10° C. and then allowed to stand for 3 hours. The resulting solid product was filtered, washed with 150 ml of ethyl acetate and then dried to obtain 306.5 g of the title compound.

Provenance & Evidence