Potassium Hydroxide → 3,3-dimethyl-3,4-dihydroisoquinoline

Participants

Reaction Steps

To a nitrogen-blanketed mixture of potassium hydroxide (KOH, 30 g) and methanol (CH3OH, 60 mL) was added of N-toluenesulfonyl-3,3-dimethyl-1,2,3,4-tetrahydroisoquinoline (4.0 g, 0.013 mol.). The reaction mixture was heated at reflux for 17 hours and the reaction was followed by gas chromatography. The reaction mixture was cooled to ambient temperature, quenched with water (100 mL) and 10% HCl was slowly added until pH=7 was obtained. The aqueous mixture was extracted with methylene chloride (3×100 mL) and the organic layers were combined and stirred with charcoal and sodium sulfate (Na2 SO4). The solution was filtered through celite and the filtrate was concentrated (25°/150 torr) to give 3,3-dimethyl-3,4-dihydroisoquinoline (1.79 g, yield=90%).

Provenance & Evidence