Microwave-assisted synthesis, structural activity relationship and biological activity of some new quinoxaline Schiff base derivatives as highly potent spirochete bactericidal agents

The main aim of this work was to synthesise a new (E)-3-(4-or3-Aminophenylimino) quinoxaline-2(3H)-one oxime Schiff base derivatives and evaluate the anti-leptospiral activity against Leptospira icterohaemorrhagiae. The mentioned derivatives were prepared by performing microwave-assisted condensation reactions of (E)-3-(4-or3-Aminophenyl imino)quinoxaline-2(3H)-one and aromatic aldehydes. The structures of these interesting compounds were characterised by FT-IR, 1H NMR and mass spectroscopy. Furthermore, these compounds were screened for spirocidal activity against Leptospira icterohaemorrhagiae by using in vitro and in vivo method. The anti-leptospiral activity result reveals that most of the compounds were exhibiting considerable activity against Leptospira icterohaemorrhagiae. Compound 6c demonstrated remarkable activity at low concentration against the Leptospira icterohaemorrhagiae as compared to the standard drugs.