8-Hydroxyquinoline → N-ethyl-8-hydroxyquinolinium ethylsulfate

Participants

Reaction Steps

Into a 2-liter three-neck flask, provided with a mechanical agitator, with a reflux condenser and calcium chloride tube, and with a dropping funnel, one introduces 580 g of 8-hydroxyquinoline (i.e. 4 moles) and 800 ml of dimethylacetamide. After dissolution of the 8-hydroxyquinoline one adds, drop by drop, 616 g of freshly distilled ethyl sulfate, and then cools the reaction mixture with a bath of ice water. After heating on a steam bath for 2 hours, the solution becomes orange-yellow. One removes the dimethylformamide by means of distillation in a water-jet pump vacuum. The yellow residue is washed with anhydrous ether. The quaternary salt crystallizes after scraping. One recrystallizes the quaternary salt by dissolution in isopropanol at the rate of 1 g of quaternary salt per 1.5 ml of isopropanol. One obtains 920 g of yellow crystals which are washed thoroughly with ethyl ether.

Provenance & Evidence