An Efficient One-Pot Synthesis of Highly Substituted Pyridone Derivatives and Their Antimicrobial and Antifungal Activity

Abstract

A series of carboxamide and cyano functionalized pyridone derivatives 4a–q have been synthesized via one-pot synthesis of various aldehydes 1a–q, acetoacetanilide 2, and cyanoacetamide 3. The reaction was simple and afforded pyridone derivatives in good yield, 89 to 93%. The novel pyridone derivatives were achieved by Hantzch one-pot synthesis. Moreover, the synthesized compounds were screened against Gram-positive and Gram-negative bacteria and fungi for their activity. Among them, compound 4c shows highest inhibition at 4.25 mm against Staphylococcus aureus and 3.75 mm against Escherichia coli Grampositive and Gram-negative bacteria, respectively General synthesis of 5-cyano-2-methyl-6-oxo-N-phenyl-4- aryl-1,6-dihydropyridine-3-carboxamide 4a–q. To a solution of various aldehydes (5.6 mmol) (1a–q) in ethanol (10 mL), piperidine was added in catalytical amount and stirred for 5 min at room temperature. Then, cyanoacetamide (5.6 mmol) and acetoacetanilide (5.6 mmol) was added and refluxed on boiling water bath at 78°C for appropriate time. The reaction was being monitored by thin-layer chromatography using Hexane : EtOAc (8:2). After completion of the reaction, the reaction was cooled in refrigerator for overnight. The separated product was filtered off and air dried to obtain the desired products 4a–q in high yields.