Design, Synthesis and Antiinflammatory Evaluation of 5(6)-(un)-substituted-1H-Benzimidazol-2-ylthioacetylpiperazine Derivatives

Benzimidazole-2-thione derivatives are known to possess broad spectrum of biological activities, and the most prominent being the antiinflammatory activity. The synthesis of these compounds involve three steps, William’s reaction of 5(6)-(un)-substituted-1H-benzimidazol-2-thiols with chloroacetic acid in presence of sodium hydroxide and refluxing, which was further reacted with acetic anhydride in pyridine medium on a steam bath followed by hydrolysis with a N-mono substituted piperazine in ethanol medium under reflux conditions to get 5(6)-(un)-substituted(1H-benzimidazol-2-yl-thio)acetyl piperazine derivatives. Molecular docking experiments were carried out against cox-2 enzyme using GOLD software 5.1.0. Docking studies revealed important binding interactions of synthesized derivatives with cox-2 enzyme indicating non-selective interactions, which were in agreement with the in vivo antiinflammatory activity. Absorption, distribution, metabolism, and excretion properties of the synthesized derivatives were determined by QikProp. These derivatives were tested in the carrageenan-induced rat paw edema model to determine the antiinflammatory activity.