Microwave-Assisted Synthesis and Antimicrobial Evaluation of Coumarin–Pyridine Hybrids as Novel Heterocyclic Scaffolds

An efficient and rapid microwave-assisted synthesis of a series of novel (E)-N2-1-(2-oxo-2H-chromen-3-yl)ethylideneisonicotinohydrazide derivatives was accomplished via the condensation of isonicotinohydrazide with substituted 3-acetyl-2H-chromen-2-ones. The use of microwave irradiation in this work enabled the synthesis of the target compounds with shorter reaction times, higher yields, and minimal solvent requirements, contributing to greener chemical practices. All newly synthesized compounds were characterized using spectroscopic techniques (IR, 1H and 13C NMR, and mass spectrometry). The derivatives were evaluated for their antimicrobial activity against a panel of microorganisms, including Gram-positive and Gram-negative bacteria, as well as pathogenic fungi.