2-(((1S)-1-phenylethyl)amino)ethan-1-ol → (S)-1-methyl-1,2,3,4-tetrahydroisoquinoline

온도

0 °C

22.1 g(133.16 mmole) of (S)-(-)-N-(2-hydroxyethyl)-α-methylbezylamine produced in Example 11(1) above was suspended in 105 ml of 48% aqueous hydrobromic acid solution and the resulting suspension was reacted at 126° C. for 30 minutes under refluxing. Then, the reaction solution was distilled for 2 hours under normal pressure at constant temperature and 95 ml of aqueous hydrobromic acid and water, the reaction by-product, was removed. The residue was dissolved in 112 ml of acetone, and 100 ml of ethyl acetate and 150 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 70 ml of ethyl acetate and then dried to obtain 20 g of the first crop of the title compound. The filtrate was then concentrated. The residue was dissolved in 130 ml of ethanol and then concentrated under reduced pressure. The residue was dissolved in 104 ml of acetone, diluted with 143 ml of ether, and then allowed to stand at 0° C. for 12 hours. The resulting solid product was filtered, collected and washed with 75 ml of ethyl acetate to obtain 6.7 g of the second crop of the title compound.