Catalyst free regiospecific amination, structural elucidation, and potential utilization of pyran-2,4-dione derivatives as novel antimicrobial agents

Catalyst-free regiospecific amination at the C-4 position of 3-benzoyl-4-chloro-6-phenyl-2H-pyran-2-one precursor 3 was explored using various aminating agents such as ammonium acetate, primary aliphatic and aromatic amines in methanol. Structural investigation mainly based on NMR and X-ray single crystal analyses are presented. In addition, topology analysis of molecular packing was performed using Hirshfeld calculations. The antimicrobial activity of the newly synthesized aminated analogues compared to their (1-enamino-pyran2,4-dione isomers was assessed against S. aureus and C. albicans. In general, the (1-enamino-pyran-2,4-diones displayed better antimicrobial activity against S. aureus and C. albicans compared to their C4-aminated isomers and conventional medications (Neomycin, Streptomycin, and Amoxicillin + Co-amoxiclav).