Synthesis of Novel Substituted Thiourea and Benzimidazole Derivatives Containing a Pyrazolone Ring as Anti-Inflammatory Agents

Chem Biol Drug Des. 2016 May;87(5):784-93. doi: 10.1111/cbdd.12712. Epub 2016 Jan 17.

Abstract

Two series of new 1-(alkyl/aryl)-3-{2-[(5-oxo-4,5-dihydro-1H-pyrazol-3-yl)amino]phenyl}thioureas 2a-h and 5-[2-(substituted amino)-1H-benzimidazol-1-yl]-4H-pyrazol-3-ols 3a-i were designed and synthesized as anti-inflammatory agents. The cyclooxygenase inhibitory activity of the newly synthesized compounds was investigated. All the compounds showed non-selective inhibition of COX-1 and COX-2 enzymes which was consistent with their docking results. Compounds 2c, 2f, 2g, 3b, and 3g that showed the highest COX-2 inhibitory activity were selected for further in vivo testing as anti-inflammatory agents using diclofenac as a reference drug. Two of the test compounds (2c and 3b) showed potent anti-inflammatory activity comparable to that of diclofenac with lower ulcerogenic effect relative to indomethacin. SAR study of the two series as cyclooxygenase inhibitors and anti-inflammatory agents was also provided.

Keywords: COX inhibitors; anti-inflammatory activity; benzimidazole; pyrazolone; thiourea.

MeSH terms

  • Anti-Inflammatory Agents / chemical synthesis*
  • Anti-Inflammatory Agents / chemistry
  • Anti-Inflammatory Agents / pharmacology*
  • Benzimidazoles / chemistry*
  • Pyrazolones / chemistry*
  • Structure-Activity Relationship
  • Thiourea / chemistry*

Substances

  • Anti-Inflammatory Agents
  • Benzimidazoles
  • Pyrazolones
  • pyrazolone
  • Thiourea