Synthesis and Biological Evaluation of Schiff Bases

Cinchophen (I) was synthesized from pyruvic acid, aniline and benzaldehyde by Doebner synthesis. Cinchophen acid chloride (II) was synthesised from cinchophen and oxalyl chloride by acylation reaction. The 2phenylquinoline-4-carboxylic acid amide (III) was synthesized from acid chloride and ammonia by simple reaction. The 2-phenylquinoline-4-carboxylic acid amine (IV) was synthesized from cinchophen amide by the reduction reaction by using lithium alluminium hydride as reducing agent in the proper solvent like THF and ether. Then the compound V was prepared according to scheme III by the use of aldehyde The newly synthesized compound are characterized by spectral ( I R, H NMR and Mass ) data. The purity of the compounds was confirmed by TLC. The physicochemical properties such as melting point and % yield were determined. A number of molecular docking experiments were carried out to identify potential inhibitor of AmpC enzyme of E. Coli HKY28. All these compounds were evaluated for their in vitro activity against several microbes. The results indicate that all the synthesized compound shown mild to good activity against the pathogenic bacteria and fungi and have been shown to be more potent than cinchophen with the reference standard ciprofloxacin and fluconazole.