Synthesis and antimicrobial activities of new mono and bisphenyl linked bispyrazole and bispyrazolone derivatives

The entitled bispyrazole and bispyrazolone compounds (4a-4t) were synthesized in good yield using a simplified experimental procedure under both conventional and microwave heating from easily available starting materials. The structure of synthesized bispyrazole and bispyrazolone compounds (4a-4t) was established with the help of physico-chemical analysis and various spectroscopic techniques like FT-IR, Mass, 1H NMR and 13C NMR. The results of analyses are in good agreement with the proposed structure of all the synthesized compounds. Further, all the synthesized compounds were evaluated for their antimicrobial (antibacterial and antifungal) activities using various species like Bacillus subtilis, Escherichia coli, Aspergillous niger and Aspergillous flavus by using the agar cup method. The results of antimicrobial screening showed that compounds have mild to moderate activity. However, compounds 4g and 4h have shown good activity among all the tested compounds.