Synthesis and investigation of some biological activities of new benzimidazole compounds containing piperazine and morpholine derivatives

Benzimidazole ring are very effective to pharmacologically and are synthesized and studied by several study groups using various methods. In this study, new benzimidazole compounds were synthesized which containing morpholine or piperazine ring at the C-6 position. For this purpose, firstly, the starting compound 5-chloro-2-nitroaniline is reacted with 1-methyl piperazine or morpholine separately to give 5- (4-methylpiperazin-1-yl)-2-nitroaniline (1) and Morpholin-4-yl-2-nitrophenyl) amine (2), respectively. In the second step of the thesis work, compounds 1 or 2 were reacted with various aromatic aldehydes in the presence of Na2S2O4 (sodium dithionate) in ethanol-water with one-pot reaction and the target compound benzimidazole structures were obtained. It is known in the literature that the -NO2 group is first reduced to -NH2 group in the presence of expensive catalysts such as Pd, Pt and then the benzimidazole compounds are obtained from aldehydes by cyclization reaction. With this study, benzimidazole derivatives obtained both under mild contidion with inexpensive technique and only with 2 steps. As an alternative method, microwave radiation was used in all reactions and it was seen that the reaction time was shortened and product yield was increased. All obtained compounds in this study were also investigated for their -Glucosidase and antioxidant activities. The results of the work-up obtained compounds structure were clarified by IR, 1H-NMR, 13C-NMR and mass spectrometry methods.