反应详情

780 mg (2.5 mmol) of N-(2-methoxy-3,4-methylenedioxybenzyl)-N-methylaminoacetaldehyde diethylacetal (3) was dissolved in 1.6 ml of ethanol. The solution was added with 5 ml of 6N sulfuric acid and refluxed under heating for 2 hours and 45 minutes. After cooling, this solution was made basic by adding a 25% aqueous solution of sodium hydroxide and extracted with 5 ml and then with 2 ml of methylene chloride successively. The extracts were joined, washed with 2 ml of water and dried over anhydrous magnesium sulfate. After filtration, the solvent was distilled off under reduced pressure and the residue was separated by silica gel column chromatography to obtain 360 mg of 4-hydroxy-8-methoxy-2-methyl-6,7-methylenedioxy-1,2,3,4-tetrahydroisoquinoline (6) (yield: 61%) and 110 mg of 4-ethoxy-8-methoxy-2-methyl-6,7-methylenedioxy-1,2,3,4-tetrahydroisoquinoline (8) (yield: 17%).

1. temperaturerefluxed
2. temperatureunder heating for 2 hours and 45 minutes
3. temperatureAfter cooling
4. extractionextracted with 5 ml
5. washwashed with 2 ml of water
6. dry with materialdried over anhydrous magnesium sulfate
7. filtrationAfter filtration
8. distillationthe solvent was distilled off under reduced pressure
9. customthe residue was separated by silica gel column chromatography