Scheme 1. Synthetic strategy for the benzimidazole monopeptides (7a–l). aReagents and conditions: (a) EtOH, conc. H2SO4 (catalytic), reflux; (b) cyclohexylamine (2.5 equiv.), TEA (3.0 equiv.), THF, r.t.; (c) substituted benzaldehyde (1 equiv.), Na2S2O4 (3 equiv.), DMSO, 90 °C; (d) NaOH (1.1 equiv.), water, reflux; (e) amino acid methyl ester hydrochloride (1 equiv.), NMM (2.5 equiv.), TBTU (1.25 equiv.), DMF, r.t.; (f) LiOH·H2O (1 equiv.), water : THF (2 : 1), 0 °C. 
= 4-F, 4-OCH3, 2-Cl-6-F; 
= CH3, CH(CH3)2, CH2–CH(CH3)2, 3-indolylmethyl. * Further for the substitution pattern see Table 1.
