Work

Sustainable Catalyst‐Free Synthesis of Substituted Pyrazoles Through an Annulation/Oxidation Cascade Under Batch and Continuous‐Flow Methods

Year: 2026

Type: article

Abstract: We describe a catalyst‐free synthesis of substituted pyrazoles in good to excellent yields using α,β‐unsaturated β‐ketoesters and aryl hydrazines under mild reaction conditions. The reaction proceeds through a Michael‐initiated ring closure reaction followed by in situ oxidation. A broad range of substrates bearing electron‐withdrawing and electron‐donating substituents was successfully converted to the corresponding pyrazole derivatives. The method was scalable under batch conditions, demonstrating its practical applicability. In addition, the ester group present in the products could be transformed into the corresponding carboxylic acid and amide derivatives, providing access to structurally diverse pyrazole scaffolds. The protocol was also translated to continuous‐flow conditions, offering an efficient and sustainable route to these valuable heterocyclic compounds.

Source: European Journal of Organic Chemistry

DOI: 10.1002/ejoc.70818

Authors: Himani Sharma, Akanksha Kumari, Suman K. Saha, Nirmal K. Rana

Institution: Indian Institute of Technology Jodhpur

Language: English

Topic: Synthesis of heterocyclic compounds

Subfield: Organic Chemistry

Field: Chemistry

Domain: Physical Sciences

Open Access status: bronze

Funders: Indian Institute of Technology Kanpur, Ministry of Education, India, Science and Engineering Research Board

Award: G4555977115