2-{[(1R)-1-phenylethyl]amino}ethan-1-ol → (R)-1-Methyl-1,2,3,4-tetrahydroisoquinoline

Participants

Reaction Conditions

Reaction Steps

11.0 g(66.58 mmole) of (R)-(+)-N-(2-hydroxyethyl)-α-methylbenzylamine produced in Example 8(1) above was suspended in 52 ml of 48% aqueous hydrobromic acid solution and the resulting suspension was reacted at 126° C. for 30 minutes under refluxing. The reaction solution was distilled for 2 hours under normal pressure at constant temperature and 47 ml of aqueous hydrobromic acid and water, the reaction by-product, was removed. The residue was dissolved in 55 ml of acetone, and 50 ml of ethyl acetate and 70 ml of ether were added thereto. The reaction solution was stirred for 30 minutes, cooled to 0° C. and then allowed to stand for 3 hours. The resulting solid product was filtered, washed with 30 ml of ethyl acetate and then dried to obtain 10 g of the first crop of the title compound. The filtrate was then concentrated. The residue was dissolved in 60 ml of ethanol and the resulting mixture was concentrated under reduced pressure. The residue was dissolved in 50 ml of acetone, diluted with 70 ml of ether and then allowed to stand at 0° C. for 12 hours. The resulting solid product was filtered, collected and washed with 30 ml of ethyl acetate to obtain 3.1 g of the second crop of the title compound.

Provenance & Evidence