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

Temperature

51 °C

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.

1. customthe reaction
2. additionwas added
3. customthe solution thereby obtained
4. customto react at 126° C. for 30 minutes
5. temperatureunder refluxing
6. distillationThe reaction solution was distilled for 2 hours under normal pressure at constant temperature
7. customto remove 580 ml of water as the by-product and aqueous hydrobromic acid solution
8. dissolutionThe residue was dissolved in 760 ml of isopropyl alcohol
9. temperaturewith refluxing for 30 minutes
10. temperaturethis solution was cooled to 10° C.
11. waitto stand for 3 hours
12. filtrationThe resulting solid product was filtered
13. washwashed with 150 ml of ethyl acetate
14. customdried

ORD record

ord-6ec8322b270747fdafca506c92e0713e

Source dataset

uspto-grants-1999_11

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05990311