Green Synthesis of Novel Pyridines via One-Pot Multicomponent Reaction and Their Anti-Inflammatory Evaluation.

A functional and environmentally green procedure for the design of novel pyridine 5a - h and 7a - d derivatives through two pathways is presented. The first pathway is via a one-pot, four-component reaction of p -formylphenyl-4-toluenesulfonate ( 1 ), ethyl cyanoacetate ( 2 ), acetophenone derivatives 3a-h or acetyl derivatives 6a - d , and ammonium acetate ( 4 ) under microwave irradiation in ethanol. The advantages of this method are an excellent yield (82%-94%), pure products, a short reaction time (2-7 min), and low-cost processing. The second pathway was obtained by the traditional method with treatment of the same mixture under refluxing in ethanol, which afforded the same products, 5a - h and 7a - d , in less yield (71%-88%) and over a longer reaction time (6-9 h). The constructions of the novel compounds were articulated via spectral and elemental analysis. Overall, the compounds have been designed, synthesized, and studied for their in vitro anti-inflammatory activity using diclofenac as a reference drug (5 mg/kg). The most potent four compounds, 5a , 5f , 5g , and 5h , showed promising anti-inflammatory activity.