Sodium Hydroxide → 1,2,3,4-Tetrahydroisoquinoline

Temperature

-30 °C

A solution of 467 mg (3.5 mmol) of AlCl3 in 10 ml of THF is added dropwise at room temperature to a suspension of 400 mg (10.5 mmol) of LiAlH4 in 20 ml of tetrahydrofuran (THF), as a result of which AlH3 is formed. After 15 minutes the solution is cooled to -30° C. and a solution of 2.5 g (6.74 mmol) of the dihydroisoquinoline according to b. in 100 ml of THF is added dropwise in 15 minutes. The reaction mixture is then slowly heated to room temperature. After 1.5 hours an NaOH solution in H2O is added until everything has dissolved. The organic phase is separated, and the aqueous phase is washed once with ethyl acetate/ether and four times with ether. The combined organic phases are washed with saline solution and dried with Na2SO4. After evaporation the tetrahydroisoquinoline (melting-point 160° C.) is obtained as a light-yellow powder (2.45 g, i.e. (2.45 g, i.e. 97%).

1. customis formed
2. temperatureThe reaction mixture is then slowly heated to room temperature
3. dissolutionhas dissolved
4. customThe organic phase is separated
5. washthe aqueous phase is washed once with ethyl acetate/ether and four times with ether
6. washThe combined organic phases are washed with saline solution
7. dry with materialdried with Na2SO4
8. customAfter evaporation the tetrahydroisoquinoline (melting-point 160° C.)
9. customis obtained as a light-yellow powder (2.45 g, i.e. (2.45 g, i.e. 97%)

ORD record

ord-74ae74e11c364ab08c574d80b56385b8

Source dataset

uspto-grants-1992_11

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05162335