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

Participants

Reaction Conditions

Reaction Steps

73.45 g (240 mmole) of (S)-(−)-N-(2-bromoethyl)-α-methylbenzylamine hydrobromide produced in Example 12(1) above was suspended in 260 ml of decalin and the resulting suspension was heated to 150° C. 95.10 g (710 mmole) of anhydrous aluminum chloride was added thereto over 40 minutes. The reaction solution was stirred for a further 30 minutes at constant temperature and then cooled to room temperature. The supernatant was removed and the lower layer was poured onto 1600 g of ice-water with stirring. 70 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 700 ml of ethyl acetate, and then the aqueous layer was separated, adjusted to pH 12 with sodium hydroxide, and then extracted three times, each time with 900 ml of ethyl acetate. The extracts were combined, washed with 200 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 27.6 g of the title compound.

Provenance & Evidence