A new series of N-sec/tert-butyl 2-arylbenzimidazole derivatives was synthesised in 85–96% yields within 2–3.5 min by condensing ethyl 3-amino-4-butylamino benzoate with various substituted metabisulfite adducts of benzaldehyde under focused microwave irradiation. The benzimidazole analogues were characterised using 1H NMR, 13C NMR, high resolu