Fabrication of Copper(II)-coated Magnetic Core-shell Nanoparticles an Engineered Nano-magnetic Catalyst for the Synthesis of Pyrano Pyrazole and Pyrazole Derivatives

Abstract

Pyrano[2,3-c]pyrazole and 5-amino-1H-Pyrazole-4-carbonitrile derivatives were used in the presence of new copper(II)-coated magnetic core-shell nanoparticles Fe₃O₄@SiO₂@Si(OEt)(CH₂)₃@melamine@TC to synthesize an engineered nanomagnetic catalyst in a mild green environment. The synthesized nanocatalyst was well characterized using different techniques. Fe₃O₄@SiO₂@Si(OEt)(CH₂)₃@melamine@TC@Cu(OAc)₂ is an environmentally friendly procedure to synthesize some novel Pyrano[2,3-c]pyrazole and 5-amino -1H-Pyrazole-4-carbonitrile. Relevant products were produced in green conditions with high to excellent yields. Interestingly, the catalyst can be easily separated from the reaction medium by an external magnet and can subsequently be used for successive reaction cycles (at least four times) without a significant reduction in catalytic activity. Energy dispersive X-ray analysis (EDX) was taken from the recovery catalyst for further investigation. The results showed no significant change in the percentage of synthesized catalyst elements. In this study, reaction conditions, i.e. the effect of temperature and amount of catalyst, were optimized using a systematic approach, namely, the design of experiment (DoE). The structures of the synthesized Pyrano[2,3-c]pyrazole and 5-amino-1H-Pyrazole-4-carbonitrile compounds were confirmed by ¹H NMR, ¹³C NMR, and FT-IR spectra.

Keywords:

• Pyrano [23-c]pyrazole
• 5-amino-1H-pyrazole-4-carbonitrile
• engineered nano-magnetic catalyst
• design of experiment (DoE)

Acknowledgments

The authors would like to appreciate the Research Council of Bu Ali Sina University for providing the facilities and financial support of this research.

Disclosure statement

No potential conflict of interest was reported by the author(s).