Phosphorus oxychloride → 4-Methoxy-7,8-dihydro-[1,3]dioxolo[4,5-g]isoquinoline

Participants

Reaction Conditions

Reaction Steps

2.23 g (10 mmol) of N-[2-(3-methoxy-4,5-methylenedioxyphenyl)ethyl]formamide (C) was dissolved in 25.5 ml of methylene chloride, and to this mixture was added 1.87 ml (20 mmol) of phosphorus oxychloride. The resulting mixture was refluxed under heating for 7 hours and concentrated under reduced pressure. The residue was added with 50 ml of toluene and 50 ml of water, then further added with 14 ml of 20% sodium hydroxide aqueous solution, stirred under heating at 100° C. for one hour and cooled. The reaction mixture was separated and the aqueous layer was extracted with 25 ml of toluene. The toluene layers were combined, washed with 25 ml of water and dried over anhydrous magnesium sulfate. Distillation off the solvent gave 2.00 g of 8-methoxy-6,7-methylenedioxy-3,4-dihydroisoquinoline (D) (yield: 98%).

Provenance & Evidence