The antitubercular activities of several nitrogen heterocyclic compounds have been extensively published in the scientific literature. For instance, a series of 1H-benzo[d]imidazole derivatives have been reported to possess promising activity against a clinically isolated strain resistant to p-aminosalicylic acid (PAS), INH, ethambutol (ETB) and RMP. Compound (7) (Figure 3) showed a MIC90 value of 0.75 μM against this wild strain and low cytotoxicity against human non-small lung cancer (A549) and pig kidney epithelial cell line (LLC-PK1) cell lines, with IC50 values of 11.15 and 43.94 μM, respectively . Later, the same authors published a novel series of 1H-benzo[d]imidazoles derivatives. Nevertheless, this new series exhibited worse activity than compound (7). The best compound (8) (Figure 3) showed an MIC90 value of 5 μM in the same MDR strain and IC50 values of 58 and 7.8 μM against neonatal human dermal fibroblasts (HDFn) and human epidermal keratinocyte progenitors (HEK) cell lines, respectively .