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Synthesis of pH Dependent Pyrazole, Imidazole, and Isoindolone Dipyrrinone Fluorophores using a Claisen-Schmidt Condensation Approach
Published on: June 10, 2021
Four-component domino strategy for the combinatorial synthesis of novel 1,4-dihydropyrano[2,3-c]pyrazol-6-amines
Selvaraj Kanchithalaivan1, Sathiyamoorthi Sivakumar, Raju Ranjith Kumar
1Department of Organic Chemistry, School of Chemistry, Madurai Kamaraj University , Madurai 625 021, Tamil Nadu, India.
Abstract:
An efficient one-pot four-component domino protocol for the combinatorial synthesis of novel 1,4-dihydropyrano[2,3-c]pyrazol-6-amines has been achieved. This transformation presumably occurs via cyclization-Knoevenagel condensation-Michael addition-tautomerism-intramolecular O-cyclization-elimination sequence of reactions. The significant features of this reaction include expedient one-pot process, short reaction time, no column chromatographic purification, excellent yield, and readily available starting materials.
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Preparation of Amides
The DCC-promoted synthesis of amides begins with the protonation of DCC by carboxylic acid. The protonation makes it a better acceptor. Next, the addition of carboxylate to the protonated carbodiimide gives a reactive acylating agent.
Subsequently, the amine acts as a nucleophile that attacks the acylating agent to form a tetrahedral intermediate. In the...

