Synthesis and antimicrobial evaluation of some novel benzoimidazole Schiff's bases and their C-nucleoside derivatives

Background and objectives
The discovery of C-nucleosides and continuous study of their biological activities led us to construct new compounds containing 4-(5-benzoyl-benzoimidazol-2)-benzoic acid hydrazide Schiff's bases incorporated into different aldoses, thiazolidinones, and/or their C-nucleoside analogues. The aim of this study is to describe the synthesis of some new heterocycles derived from 4-(5-benzoyl-benzoimidazol-2)-benzoic acid hydrazide and to evaluate their antimicrobial activities.
Materials and methods
The starting material 4-(5-benzoyl-1H-benzoimidazol-2-yl)-benzonitrile () was prepared through the reaction of (3,4-diamino-phenyl)-phenyl-methanone () with 4-cyanobenzaldehyde in absolute ethanol. Stirring compound with 70% sulfuric acid yielded benzoic acid derivative 3, followed by esterification and refluxing with hydrazine hydrate to yield the corresponding 4-(5-benzoyl-1H-benzoimidazol-2-yl)-benzoic acid hydrazide (). A series of Schiff's bases derivatives and were prepared by condensation of hydrazide with different monosaccharides and/or with arenaldehydes. Treatment of with thioglycolic acid led to the formation of the C-nucleosides (), whereas treatment of with thioglycolic acid yielded the corresponding 2-arylthiazolidin-4-one ().
Results and conclusion
Compound showed the highest antimicrobial activity against , (gram-positive bacteria), , and (gramnegative bacteria), and and (fungi).