Sulfuric Acid → 7,8-Dimethoxy-4-(3,4-dimethoxyphenyl)-1,2,3,4-tetrahydroisoquinoline

Participants

Reaction Steps

1.0 g of α-[[(2,3-dimethoxybenzyl)amino]methyl]-3,4-dimethoxybenzyl alcohol was dissolved in 7.5 ml of trifluoroacetic acid, and after adding thereto 0.23 ml of conc. sulfuric acid under ice cooling, the mixture was allowed to react for 30 minutes. The reaction solution was concentrated, and subjected to azeotropic distillation with toluene 2 times. After adding to the mixture chloroform, the mixture was basified by addition of 28% aqueous ammonia under ice cooling. After a separating procedure, the chloroform layer was collected, washed with water, and dried over anhydrous magnesium sulfate. The solvent was distilled off, and the residue thus obtained was recrystallized from chloroform-n-hexane, affording 750 mg of 7,8-dimethoxy-4-(3,4-dimethoxyphenyl)-1,2,3,4-tetrahydroisoquinoline (m.p. 109°-110° C.).

Provenance & Evidence