A series of 2-substituted benzimidazole derivatives have been synthesized via microwave mediated process. Different benzimidazole derivatives were titrated with tetrabutylammonium hydroxide in four non-aqueous solvents (isopropyl alcohol, N,N-dimethylformamide,tert-butyl alcohol and acetonitrile), using potentiometric method. The half neutralization potential values and the corresponding pKa values were determined for all cases.