Novel 5-functionalized-pyrazoles: Synthesis, characterization and pharmacological screening

In the present study a series of O-substituted pyrazoles 7(a-f) and N-substituted pyrazoles 9(a-f) were synthesized via phase-transfer catalyzed reaction of ethyl 5-(bromomethyl)-1,3-diphenyl-1H-pyrazole-4-carboxylate 5 with various oxygen and nitrogen containing compounds in presence of tetrabutylammonium bromide (TBAB) in THF. The compound 5 was obtained by the efficient bromination with N-bromosuccinimide (NBS) in presence of a catalytic amount of azoiso-bis-butyro nitrile (AIBN) in refluxing CCl4. The synthesized compounds were evaluated for their in vitro antimicrobial and antidiabetic activity and were compared with standard drugs. Among the synthesized compounds, compound 9b emerged as an excellent antimicrobial and antidiabetic agent. Newly synthesized compounds were characterized by analytical and spectral (IR, H-1 NMR, C-13 NMR and LC-MS) methods. (C) 2015 Elsevier Ltd. All rights reserved.