Pyrazoles are a privileged class of heteroaromatic compounds and they represent the core motif,¹ in heterocyclic chemistry.²

The presence of the pyrazole nucleus in several structures leads to diversified applications in different areas such as technology, medicine and agriculture. In particular, they are described as inhibitors of protein glycation, antibacterial, antifungal, anticancer, antidepressant, anti-inflammatory, anti-tuberculosis, antioxidant as well as antiviral agents.³

Our contribution in the development of pyrazole derivatives synthesis has been to develop a new method of synthesis of the substituted pyrazole skeleton from the sydnone. Sydnones are considered among the most known mesoionic compounds studied for cycloaddition reactions with alkynes. In this work, a methodology for the 3 + 2 cycloaddition between sydnones and symmetric and non-symmetric alkynes has been developed.

References

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2. L. Browne, J. F. Vivat, A. Plant, E. G. Bengoa, J. P. A. Harrity. J. Am. Chem. Soc. 2009, 131, 7762.
3. (a) K. Karrouchi, S. Radi, Y. Ramli, J. Taoufik, Y. N. Mabkhot, F. A. Al-aizari and M. Ansar. Molecules. 2018, 23, 134; (b) S. Fustero, M. S. Roselló, P. Barrio, A. S. Fuentes. Rev. 2011, 111, 6984; (c) A. Ansari, A. Ali, M. Asif. New J. Chem. 2017, 41, 16.