A simple and highly efficient catalyst-free for the synthesis of dihydro pyrido[1, 2-a]quinoxaline derivatives by four component reactions and evaluation of their antibacterial activity

In the current work, a new series of methyl-10-amino-9-cyano-6-oxo-8-aryl-6,8-dihydro-5H-pyrido[1,2-a]quinoxaline-7-carboxylate derivatives were efficiently designed and prepared using a convenient route in excellent yields by four-component reactions among benzene-1,2-diamine, dimethyl acetylenedicarboxylate, various aromatic aldehydes and malononitrile. These reactions were carried out in acetonitrile at ambient temperature under catalyst-free conditions for 7 h. The structures of the new obtained compounds were confirmed by NMR, IR, EI-MS and elemental analysis. The antibacterial activity of the synthesized products was studied using bacterial strains: Staphylococcus aureus, Bacillus subtilis, Escherichia coli, and Pseudomonas aeruginosa. The results showed that all the synthesized compounds are effective against Staphylococcus aureus, Bacillus subtilis and Escherichia coli bacteria.