Studies on derivatives of imidazo[1,2-a]benzimidazole
It has been found that 9-methyl-2-phenyl- and 2,9-dimethylimidazo[1,2-a]benzimidazoles undergo direct formylation at position 3. The formyl derivatives obtained take part in a series of condensations characteristic for aldehydes, but they do not undergo the Cannizzaro disproportionation.