Different analogues of Benzotriazoles and Benzimidazoles were synthesized using different O-phenylene diammines as main reactant and further analogues were prepared by substituting the benzene ring and the heterocyclic ring of the above mentioned benzo-fused moieties using reagents e.g. chloroacetic acid, halogenating agents and hydrazine. Characterization of the synthesized compounds was done by IR and NMR spectroscopic techniques. The synthesized compounds were also screened for antimicrobial activity and were found to have significant antifungal and antibacterial activity against aspergillus niger and gram negative Bascillus specie.