Synthesis and antitumor activity of 1-substituted-2-methyl-5-nitrobenzimidazoles

Different substituents were introduced in position 1 of 2-methyl-5(6)-nitro-1 H-benzimidazole ( 2) in order to obtain different side chains having different heterocyclic compounds, for example, thiadiazoles ( 5– 7), tetrazoles ( 8, 9a, b), triazoles ( 11– 13), thiazoles ( 14a– e), triazines ( 10, 16, 17), and imidazoles ( 18a– c). The antitumor effect of compounds 1, 2, 2a, 4, 5, 7, 8, 9a, 10, 13, 14a, 15, 16, and 18c was studied against breast cancer (MCF7) and compounds 2 [IC 50 = 4.52 μg] and 7 [IC 50 = 8.29 μg] were found to be active.