Aluminum(III) Chloride → (S)-1-methyl-1,2,3,4-tetrahydroisoquinoline

Participants

Reaction Conditions

Reaction Steps

5.0 g (16.18 mmole) of (S)-(−)-N-(2-bromoethyl)-α-methylbenzylamine hydrobromide produced in Example (2) above was suspended in 50 ml of decalin and then heated to 140° C. 6.47 g (48.54 mmole) of anhydrous aluminum chloride (AlCl3) was added thereto over 40 minutes. The reaction solution was stirred for further 30 minutes at constant temperature, and cooled to room temperature. The supernatant was removed and the lower layer was added to 70 g of ice-water with stirring. 20 ml of con. hydrochloric acid was added thereto and the mixture was stirred for 10 minutes. This solution was washed three times, each time with 100 ml of ethyl acetate, and the aqueous layer was separated, adjusted to pH 12 with sodium hydroxide and then extracted three times, each time with 250 ml of ethyl acetate. The extracts were combined, washed with 40 ml of saturated saline, dehydrated with anhydrous magnesium sulfate, and then evaporated under reduced pressure to remove ethyl acetate. The residue was distilled to obtain 1.75 g of the title compound.

Provenance & Evidence