Sulfuric Acid → Hydrocotarnine

Participants

Reaction Steps

1.19 g (5 mmol) of 4-hydroxy-8-methoxy-2-methyl-6,7-methylenedioxy-1,2,3,4-tetrahydroisoquinoline (6) was dissolved in 15 ml of acetic acid, and this solution was subjected to catalytic reduction for 2 hours at 75° C. by adding 0.33 ml (6 mmol) of 97% sulfuric acid and 500 mg of 5% palladium carbon. The catalyst was filtered off, and the filtrate was added with 2 ml of 25% aqueous solution of sodium hydroxide and 5 ml of water and then concentrated under reduced pressure. The residue was added with 10 ml of water, made basic with 25% aqueous solution of sodium hydroxide under ice cooling and extracted with 10 ml and then with 5 ml of methylene chloride successively. The extract layer was washed with 5 ml of water, dried over anhydrous magnesium sulfate and concentrated under reduced pressure to obtain 1.03 g of 8-methoxy-2-methyl-6,7-methylenedioxy-1,2,3,4-tetrahydroisoquinoline. Yield: 93%.

Provenance & Evidence