Hexamethylenetetramine → 3,4-Dihydro-6,7-dimethoxyisoquinoline

Participants

Reaction Steps

Acetic acid/trifluoroacetic acid (100 mL) was added to a solution of 2-(3,4-dimethoxyphenyl)ethanamine (20 g, 110.38 mmol, 1.00 equiv) and hexamethylenetetramine (31 g, 221.11 mmol, 2.00 equiv). The resulting solution was heated at reflux for about 5 hours in an oil bath. After adding water (100 mL), the solution was extracted with dichloromethane (3×200 mL), and the organic layers were combined and dried over anhydrous sodium sulfate. Solids were removed by filtration, and the resulting filtrate was concentrated in vacuo to give the title product as a yellow oil (20 g, yield=95%). LC-MS: m/z=192 (MH)+.

Provenance & Evidence