Synthesis and evaluation of new chromene based [1,8]naphthyridines derivatives as potential antimicrobial agents

Abstract

Novel chromeno[4,3-f][1,8]naphthyridines derivatives were prepared by multicomponent reaction between 2-((sub)amino)quinoline-3-carbaldehyde 1a–f/2a–f, ethyl 2-cyanoacetate 3 and cyclohexane-1,3-dione 4 in ethanol with L-proline as a catalyst. This approach provided the title compounds 5a–f/6a–f in good yields and under mild simple one-step reaction conditions. The structures of the new compounds were unambiguously established by spectroscopic and analytical techniques. In addition, synthesized compounds were further evaluated for antimicrobial activity using a broth microdilution method.