Novel pyrazoline amidoxime and their 1,2,4-oxadiazole analogues: Synthesis and pharmacological screening

A novel series of pyrazoline amidoxime (2a–d) and pyrazoly-1,2,4-oxadiazole (3a–p) and (4) of pharmacological significance have been synthesised. Structures of newly synthesised compounds were characterized by spectral studies. New compounds were screened for their in vitro antioxidant, antimicrobial and antiinflammatory activities. Among the synthesized compounds, compound 2a, 3l and 3o were found to be active antimicrobial agents in addition to having potent antioxidant activity, while the compound 3f showed promising antiinflammatory activity in comparison with standard drug.

Scheme 1. Reagents and conditions: (i) acrylonitrile, chloramine-T, EtOH, reflux 3 h; (ii) NH2OH_HCl, Na2CO3, aq. EtOH, reflux 5–6 h; (iii) Ar2–COOH, EDC_HCl, CH2Cl, 0–30 °C 1–2 h, then rt for 6 h; (iv) heating 110 °C, 12 h; (v) Br2, CH2Cl2, reflux 1 h.Figure optionsDownload as PowerPoint slide