Synthesis of Pyrazolin‐5‐one Derivatives Clubbed with Thiazole and/or Thiadiazole and Evaluation of Their Antioxidant and Cytotoxic Activities

Synthesis of some new thiazolyl 2‐pyrazolin‐5‐one analogues was succeeded through the reaction of 3‐methyl‐1‐thiocarbamoyl‐2‐pyrazolin‐5‐one with different α‐halogenated derivatives via different routes. The physical and spectral analysis techniques were performed to demonstrate the proper structures of all incorporated analogues. The synthesized derivatives were investigated as cytotoxic agents against some important cell lines, in which the results displayed persuasive activities relative to the results of antibiotic standards. In addition, the antioxidant activity of the synthesized analogues was evaluated using ABTS•+ method. The preps analogues displayed respectable results as antioxidant agents, especially derivatives 14 a‐c and 11 a‐c due to the existence of thiadiazolyl and bis‐thaizolyl arms for pyrazoline ring, respectively. A new method was developed to synthesize thiazolyl 2‐pyrazolin‐5‐one analogues in several stages. All of the preps derivatives demonstrated reasonable anticancer efficacy toward diverse cell lines and the results represented persuasive activity.