A rapid, greener and sustainable synthesis of N-acyl hydrazones of isoniazid in a deep eutectic solvent

This study introduces an efficient, environmentally friendly, and sustainable methodology for synthesizing N-acyl hydrazone analogues by engaging isoniazid in a condensation reaction with variedly substituted benzaldehydes. A deep eutectic solvent (ZnCl2/Urea) employed in this study not only acted as a solvent but also a catalyst to facilitate the synthesis of target compounds within 2-6 minutes without the requirement of any lengthy purification techniques. The synthetic protocol is operationally simple and offers other remarkable advantages such as quick reaction time, good to excellent yields, scalable protocol, and recyclable and reusable catalyst. Additionally, the green metrics calculations suggested the present methodology to be environmentally benign. Finally, the Frontier Molecular Orbitals (FMOs) and the global reactivity parameters of the synthesized compounds were predicted using the Density Functional Theory (DFT) calculations.