Eco-friendly one-pot solvent-free synthesis of bioactive 2-substituted benzimidazoles. N-Mannich bases synthesized from benzimidazoles, secondary amines and formaldehyde. Compounds evaluated by qualitative & quantitative methods against 9 bacterial strains. Density functional theory (DFT) modeling is accomplished with GAMESS 2012 software. Discussion on the laser-processing of such compounds for antimicrobial coatings.