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Updated: Jul 18, 2025

Synthesis of pH Dependent Pyrazole, Imidazole, and Isoindolone Dipyrrinone Fluorophores using a Claisen-Schmidt Condensation Approach
Published on: June 10, 2021
Advanced Guareschi-Thorpe synthesis of pyridines in green buffer, and pH-controlled aqueous medium with ammonium
Fatemeh Tamaddon1, Sajedeh Maddah-Roodan1
1Department of Chemistry, Faculty of Science, Yazd University Yazd 89195-741 Iran ftamaddon@yazd.ac.ir sajedeh.maddah@stu.yazd.ac.ir.
Abstract:
Hydroxy-cyanopyridines are easily synthesized via an advanced version of the Guareschi-Thorpe reaction by either three-component condensation of alkyl cyanoacetate or cyanoacetamide with 1,3-dicarbonyls and ammonium carbonate in an aqueous medium. Reactions proceed productively to give the desired products in high yields. Simple mechanistic monitoring showed the role of (NH4)2CO3 as both a nitrogen source for the pyridine ring and the reaction promoter. This new multicomponent approach for pyridine synthesis is inexpensive, user-friendly, and eco-friendly, while green buffer conditions, versatility, precipitation of products in the reaction medium, and simple work-up are extra advantages.
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