Enhanced production of Pirfenidone through a microfluidic system: A novel and thorough chemical kinetics investigation

Abstract

Batch and continuous systems were fabricated to synthesize Pirfenidone (PFD). Effects of parameters on reaction yield including; microreactors, micromixer, solvents, temperature, reaction time, and catalysts were understudied. Moreover, FTIR, NMR and HPLC analyses used to evaluate the prepared PFD. Its yield in microfluidic (30.5 %) was higher than that of batch (17.1 %) reactor. Besides, reaction yield in the presence of DMSO was higher than DMF in both reactors. It was shown that, adding a micromixer enhanced reaction time. leading to a higher PFD yield. Nonetheless, the yield was reduced by enhancing the temperature when DMF was utilized. Additionally, the traditional synthesis method of PFD in a batch system, which reached a yield of 53.7 % after 19 h, now reached 30.5 % in a microreactor under similar conditions within 40 min. Utilizing the Design Expert Software, the results revealed a maximum overall reaction yield of 31 % achieved at reactant ratio of K₂CO₃ to 2‑hydroxy-5-methylpyridine of 7, Temperature of 160 °C and reaction time of 60 min completely matching the experimental results. Ultimately, kinetics of PFD was understudied incorporating a Molecular Dynamic Software where a new 3-steps mechanism was proposed. Moreover, a power law model revealed an empirical reaction order of 1.45.