Abstract
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.