Design and Synthesis of New Series of 2-Oxo-2H-Selenopyrano[2,3-b]Quinoline-3-Carboxylates and Evaluation of Their Antibacterial Activity

In the present work, newly designed ethyl 2-oxo-2 H -selenopyrano[2, 3- b ]quinoline-3-carboxylates (4a–4f) were synthesized by reaction of 3-formyl-2-selenoquinolines (3a–3f) with diethyl malonate in the presence of catalytic amounts of piperidine. The intermediate 3-formyl-2-selenoquinolines (3a–3f) were synthesized by the action of NaHSe on substituted 2-chloroquinoline-3-carbaldehydes (2a–2f) . The new series of 2-chloroquinoline-3-carbaldehydes ( 2a–2f) were synthesized from the corresponding substituted acetanilides ( 1a–1f) using available literature methods. The structures of all synthesized compounds were characterized by elemental analysis, IR, 1 H NMR, and mass spectroscopy data. Newly synthesized compounds were evaluated for their antibacterial properties and found to exhibit a wide spectrum of antibacterial activity. In particular, compounds 4d and 4e were highly active against S. aureus and M. roseus species .