Synthesis And Antibacterial Activities Of Bis-benzimidazole Derivatives

Benzimidazole derivatives and Schiff base compounds have good biological activitiesand possess a variety of other characters. To find new hyperactivity broad-spectrum fungicidecompounds and study the relationship between structure and biological activities of thesecompounds, This study designs and synthesizes a new type of mother-benzimidazolecompounds containing imine structures according to principles of drug together,at the sametime, changes substituent group and the substituent group position of aldehyde, bonds the twobiological activity groups together, it maybe show more typical biological activity and otherproperties.In this paper,17Bis-benzimidazole derivatives and6Bis-benzimidazole Schiff basederivatives were synthesized from3,4-Diaminobenzoic acid and different aldehydecompounds under microwave irradiation, of which20derivatives were new compounds,except compound3a,3c and5n(all compounds were tested by SciFinder Scholar). Theirstructures were characterized by1H-NMR, IR, and MS. Secondly, the influence of the moleratio of materials, output power, reaction time and the ratio of catalyst, which was PPA andHCl, on yield were investigated．At the first reaction, optimal reaction condition wereobtained: the ratio of3,4-Diaminobenzoic acid to aldehyde compounds was1:1.2, outputpower300W, intermit radiate time30minutes; at the second reaction, optimal reactioncondition were obtained: the ratio of intermediates to o-Phenylenediamine was1:1.1, the ratioof PPA to HCl was1:1, output power500W, intermit radiate time15minutes. Compared tothe previous methods, this new method has the advantages of simple procedure, mildconditions, easy purification, and good yield. At the same time, it has a certain practicalvalue.23Compounds were tested in vitro against7fungi: Fusarium oxysporum vasinfectum,Fusarium oxysporium, Alternaria solani, Fusarium graminearum, Glomerellacin gulata,Alternaria alternata keissler, Botrytis cinerea in comparison wit tiabendazole andazoxystrobin at concentration of100mg/L. All compounds showed their fungicidal activities,among which compound3a,3b and5d had broad-spectrum characters,and they showed betteractivities than other compounds. But compound3n showed less activity than othercompounds. The relationship between the structures and the fungicidal activities of the compoundswas discussed.