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

Participants

Reaction Steps

α-[[(2,3-Dimethoxybenzyl)amino]methyl]-3,4-dimethoxybenzyl alcohol 6.56 g, 18.9 mmol) was dissolved in trifluoroacetic acid (50 ml). Concentrated sulfuric acid was added to the solution under stirring and under cooling with ice and the reaction was conducted under these conditions for 40 minutes. The reaction solution was concentrated. Water was added to the residue and then it was made basic with aqueous ammonia under stirring and under cooling with ice. After extraction with dichloromethane, the dichloromethane layer was washed with a saturated sodium chloride aqueous solution and dried over anhydrous magnesium sulfate. The solvent was distilled off under reduced pressure and the resultant crystals were washed with isopropyl ether to obtain 5.23 g of 7,8-dimethoxy-4-(3,4-dimethoxyphenyl)-1,2,3,4-tetrahydroisoquinoline.

Provenance & Evidence