Some pyrazole-based heterocycles such as pyrrolone, pyridazinone, and imidazole derivatives were synthesized utilizing the pyrazolyl-2(3H)-furanone derivative 3, which was obtained in a good yield via Perkin condensation of 5-chloro-4-formyl-3-methyl-1-phenylpyrazole with 3-(4-methylbenzoyl)propionic acid in the presence of cyclo-dehydrating agent (sodium acetate and acetic anhydride). Also, the acid hydrazide obtained was reacted with some carbonyl reagents such as acetic anhydride, benzoyl chloride, 4-chlorobenzaldehyde, and 1,3-diphenyl-4-formylpyrazole, aiming to achieve new pyrrolone derivatives. The antioxidant, antimicrobial, and antiviral activity screening of some synthesized compounds demonstrated that some of them offered strong potencies. An experimental trial was undertaken to explore the effect of different substances and applied against avian influenza HPAI-H5N1 (AIV) to evaluate the antiviral replication in specific pathogen-free chicken embryos. All the compounds were screened for their antimicrobial activities, and most of tested compounds showed potent inhibition growth activity toward Haemophilus (Gram-negative bacteria), Staphylococcus aureus (Gram-positive bacteria), and Candida albicans fungus. Upon antimicrobial screening, it was observed that the majority of the compounds were found to be active against Staphylococcus aureus, Haemophilus, and Candida albicans as compared to standard drugs. This experiment shows the potential usage of these compounds as antiviral agents and can be considered as a viable means to control the economically important avian influenza of poultry. These compounds can thus be recommended for their antiviral, antibacterial, and antifungal property and can very well be used as immunostimulants.