A novel combinatorial library of fused pyran derivatives has been designed and synthesized under microwave irradiation by one-pot three-component cyclocondensation reaction of 5-(1H-imidazol-1-yl)-3-methyl-1-phenyl-1H-pyrazole-4-carbaldehyde with two active methylene compounds and enolizable ketones/phenols in the presence of piperidine as a basic catalyst. All the newly synthesized compounds have been characterized by elemental analysis and various spectroscopic methods. All the final motifs have been screened for their preliminary in vitro antibacterial activity against a panel of pathogenic strains of bacteria and fungi, preliminary in vitro antituberculosis activity against Mycobacterium tuberculosis H37Rv and also for their antimalarial activity against Plasmodium falciparum.