A novel nanocatalyst praseodymium oxide (Pr6O11) for the efficient and sustainable synthesis of chromene derivatives via ultrasound irradiation in an aqueous hydrotropic medium.

The development of sustainable and efficient catalytic methods for organic synthesis is a key focus in green chemistry. In this study, we report for the first time the novel application of praseodymium oxide (Pr6O11) as a nanocatalyst for the eco-friendly synthesis of 2-amino-3-cyano-7-hydroxy-4H-chromenes. The hydrothermal synthesis of praseodymium oxide (Pr6O11) nanoparticles was performed, and their structural studies were conducted using FTIR, XRD, TGA-DTA, SEM, EDX, BET, and TEM analysis. The Pr6O11 NPs were used as a nanocatalyst in the synthesis of 2-amino-3-cyano-7-hydroxy-4H-chromenes. The reactions were conducted under ultrasound irradiation in an aqueous hydrotropic medium, eliminating the need for hazardous organic solvents. The unique catalytic properties of Pr6O11 facilitated high yields of chromene derivatives, with excellent selectivity within short reaction times. The synergistic effect of ultrasound irradiation and hydrotropy enhanced the reaction kinetics, leading to improved efficiency and sustainability. The catalyst exhibited remarkable reusability and stability, maintaining its activity over multiple cycles without any significant loss in efficiency. This novel approach highlights the potential of Pr6O11 as a green and reusable nanocatalyst, offering a sustainable alternative for the synthesis of valuable heterocyclic compounds in aqueous hydrotropic media. The significant features of this method are the shorter reaction time, high product yield and use of a non-toxic, reusable, inexpensive, and biodegradable catalyst.