The reaction of 2-(2-methylphenyl)-4,5-dihydro-1H-imidazole (I) with n-BuLi in tetramethylethylenediamine gives the dilithium salt (II), which is cyclized with 4-(3,4,5-trimethoxybenzyloxy)benzoic acid methyl ester (III), yielding imidazoquinoline (IV). Finally, this compound is dehydrated in refluxing acetic acid or in refluxing toluene catalyzed by p-toluenesulfonic acid.
The reaction of 2-(2-methylphenyl)-4,5-dihydro-1H-imidazole (I) with n-BuLi in tetramethylethylenediamine gives the dilithium salt (II), which is cyclized with 4-[2-(3,4,5-trimethoxyphenyl)ethyl]benzoic acid methyl ester (III), yielding imidazoquinoline (IV). Finally, this compound is dehydrated in refluxing acetic acid or in refluxing toluene catalyzed by p-toluenesulfonic acid.