Turkish Journal of Chemistry
Abstract
Cyclization reactions are among the most important and widely used methods for synthesizing biologically active fused heterocyclic compounds. In the present study, pyrazolopyrazinone derivatives (10a–i) were synthesized from N-propargylated pyrazoles via nucleophilic cyclization with hydrazine hydrate under a nitrogen atmosphere. Nuclear magnetic resonance (NMR) spectral analyses confirmed that ring closure proceeded in a manner consistent with the formation of a six-membered pyrazinone moiety. In addition, the pyrazolotriazepinone derivative 15c was synthesized using an alternative approach. In this method, substitution with chloroacetone was first carried out, followed by ring closure with hydrazine hydrate, affording a seven-membered triazepinone system. Comparison of the NMR spectra of the resulting compounds clearly revealed structural differences between the two systems.
DOI
10.55730/1300-0527.3790
Keywords
Nucleophilic cyclization, pyrazolopyrazinones, fused heterocycles, hydrazine hydrate, pyrazolotriazepinones
First Page
199
Last Page
206
Publisher
The Scientific and Technological Research Council of Türkiye (TÜBİTAK)
Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 International License.
Recommended Citation
MENGEŞ, M. F, & TAN UYGUN, M (2026). Nucleophilic cyclization of N-propargylated pyrazole-5-carboxylates: synthesis of pyrazolo[1,5-a]pyrazin-4(5H)-one derivatives. Turkish Journal of Chemistry 50 (2): 199-206. https://doi.org/10.55730/1300-0527.3790
