Facile Synthesis of New Imidazoles from Direct Reaction of 2,3-Diamino-1,4-naphthoquinone with Aldehydes

New imidazoles were easily prepared from 2,3-diamino-1,4-naphthoquinone and stoichiometric quantities of the appropriate aldehydes in dimethyl sulfoxide as a solvent. The reaction proceeded for few hours. The procedure can be generalized to different classes of aldehydes. 2-Methyl-1H-naphtho[2,3-d]imidazole-4,9-dione was also obtained in good yield during refluxing of 2,3-diaminonaphthoquinone in acetic acid. The structure of the newly synthesized imidazoles was extensively investigated using NMR experiments.