This work presents the synthesis and spectroscopic characterization of novel amidino substituted 1,2-phenylenediamines 8-9 and hydrochloride salts of benzimidazoles 15-28 and benzothiazoles 32-36. Target compounds were prepared by conventional reactions of organic syntheses as well as by microwave assisted reactions. The main precursors for the synthesis of amidino substituted benzimidazoles 15-28, amidino substituted 1,2-phenylenediamines 8-9, were prepared by Pinner reaction in acid medium starting from 4-amino-3-nitrobenzonitrile 4 and microwave-assisted catalytic hydrogenation with 10% Pd/C. Target compounds 15-26 were synthesized by condensation of the prepared precursors 8-9 with the corresponding aldehydes 10-13 using p-beznoquinone as an oxidant. Also, the synthetic method of preparation of amidino-substituted benzimidazole hydrochlorides 27 and 28 was investigated, using solutions of the corresponding aldehydes 10-11 and amidine 9 in DMSO with Na2S2O5, which did not give the desired products. The possibility of preparing amidino-substituted benzothiazole hydrochlorides 32-36 was investigated by two methods. According to method A, in a solution of the corresponding zwitter ion 29-31 in glacial acetic acid was added the corresponding aldehyde 10-11 and the reaction mixture was stirred under nitrogen to form a free base which was suspended in ethanol and an equimolar amount of 36% HCl. According to method B, in a solution of the corresponding zwitter ion 30 in glycerol was added the corresponding aldehyde 11 and an equimolar amount of 36% HCl. The desired products were not isolated by above synthetic methods. The structures of prepared products were confirmed by 1H and 13C NMR spectroscopy. The Pinner reaction was monitored by IR spectroscopy. In order to investigate the possibility of using the compounds as biologically active agents, the antioxidative activity was determined by DPPH, FRAP and ABTS method. N,N-diethylamino substituted derivatives 24-25 with both cyclic amidino supstituents showed improved activity in comparison to BHT standard.