Hydrochloric Acid → Hydrocotarnine

Participants

Reaction Steps

8-Methoxy-2-methyl-6,7-methylenedioxyisoquinolinium methyl sulfate (6) in an amount of 1.47 g (4.47 mmol) was dissolved in 20 ml of water, to which 0.34 g (9 mmol) of sodium boron hydride was portionwise added under cooling with water. After stirring the mixture for two hours, 10 ml of methylene chloride was added and the solution was rendered acidic with concentrated hydrochloric acid. The solution was separated and the methylene chloride layer was extracted with 2N hydrochloric acid. The aqueous layers were combined and rendered basic with 25% aqueous solution of sodium hydroxide. This was extracted with 15 ml and then 10 ml of methylene chloride successively, washed with 10 ml of water, and dried over anhydrous magnesium sulfate. The solvent was distilled off to obtain 780 mg of 8-methoxy-2-methyl-6,7-methylenedioxy-1,2,3,4-tetrahydroisoquinoline (7) (hydrocotarnine) with a yield of 79%.

Provenance & Evidence