Abstract. The synthesis of novel Pyrano [2,3-d]

The synthesis of novel Pyrano[2,3-d]pyrimidine derivatives, had been synthesized by three component domino Knoevenagel hetero Diels-Alder reaction. The products were assayed for their in vitro biological assay antibacterial activity against with two Gram-positive bacteria Staphylococcus aureus MTCC-96, Streptococcus pyogenes MTCC 443, two Gram-negative bacteria Escherichia coli MTCC 442, Pseudomonas aeruginosa MTCC 441 and three fungal strains Candida albicans MTCC 227, Aspergillus Niger MTCC 282, Aspergillus clavatus MTCC 1323 taking ampicillin, chloramphenicol, ciprofloxacin, norfloxacin, nystatin, and griseofulvin as standard drugs. Among the various synthesized heterocyclic compounds, 1b, 1c and 1g are display broad spectrum antibacterial and antifungal activities against both gram-positive and gram-negative bacteria as compared with standard drugs.