Synthesis, Structure Characterization And Biological Activity Of Benzimidazoles Derivatives

Heterocyclic compounds especially heterocyclic with "N" have been widely used in the fields of medicine and pesticide. Benzimidazole,1,2,4-triazole and 1,3,4-oxadiazole compounds which are five heterocyclic compounds especially heterocyclic with "N" occupy the important position and are widely reported. They can have a better effect on weeding, plant growth regulating, sterilization, insecticidal, etc. In addition, the applications in pharmacological are aroused great interest.Substituted benzoic acid was used as the starting materials, based on the methods of esterification, reaction with hydtazine hydate, Reid and Heindel reaction,11 kinds of 1,2,4-triazole and 10 kinds of 1,3,4-oxadiazole were obtained; 2 kinds of substituted 2-cholrlmethyl-benzimidazole were synthesized using substituted o-phenylenediamine and monochlorocetic acid as the starting materials; benzimidazole,1,2,4-triazole or 1,3,4-oxadiazole were connected by thiomethyl which was got by cholrlmethyl and thiol in sodium hydroxide and all 27 synthesized target compounds have not been reported in the literatures, the structures of which were elucidated and confirmed by IR, NMR and elemental analysis. A Co2+ coordination compounds were got through target compoundsⅣ8 coordinated with transition metal ions. The structure of target compoundⅣ8 was attested right through the structure of the complex. The complex was assembled to a linear molecular structure along axis b by the intermolecular hydrogen bonds and intramolecular hydrogen bonds, Crystal data: Orthorhombic, space group Pbca.Primary biological activity experiments have been done to all the target compounds. The activity effects on wheat gemma in the concentration of 10 ppm and the germination process of mubg bean in the concentration of 5 ppm are studied, it is found from the results that the activities of all the target compounds are not high, the activities of planting growth regulating which are substituted benzimidazole containing 1,2,4-triazole are higher than which are substituted benzimidazole containing 1,3,4-oxadiazole. When 3 position of the 1,2,4-triazole and 2 position of the 1,3,4-oxadiazole are substituted which group is bromine in the phenyl ring, the compounds have a inhibiting effect on the wheat gemma and germination process of mung bean. Besides, The diameters of the bacteriostasis circles caused by target compounds which in the concentration of 100 ppm on 8 bacteriums are determined by the means of filter paper, S taphylococcus aureus and Escherichia coli inhibiting experimental results showed that:the biological activity of target compounds are not obvious, while they have stronger antifungal, theⅣ26's diameter of the restrained Alternaria alternat A is to 15 mm, it is middling sensitivity; the compounds ofⅣ29,Ⅳ29,Ⅳ31 andⅣ34 all have better antifungal, they are laigh or middling sensitivity.