Transformations of imidazo[4, 5-f]quinoline

Treatment of imidazo4, 5-f]quinoline and some of its 3-substitmion products with methyl halides and methyl benzenesulfonate gives as the main reaction products N-methylimidazoquinolinium salts, which can also be synthesized from 5, 6-dimainoquinolines. Methylation at the N atom of the imidazole ring is only a side reaction. Treatment with trimethylphenylammonium hydroxide introduces a methyl radical into the NH group of imidazoquinoline, giving a mixture of 1-and 3-substitution products.