Zinc chloride catalyzed multicomponent synthesis of pyrazolopyridocoumarin scaffolds

Abstract

An efficient synthesis of a series of pyrazolopyridocoumarins is reported by condensation of 4hydroxycoumarin, benzaldehydes and 1-alkyl-5-amino-pyrazoles in the presence of 10 mol% zinc chloride in ethanol under reflux conditions through one-pot reaction. The significant attraction of this protocol is being a simple procedure, mild reaction condition, and excellent yield. The molecular structure of the compound (4e) is established by single crystal X-ray structure determination.

Zinc‐Catalysed Multi‐Component Reactions: An Overview

“…Shivashankar and co‐workers have established a procedure towards pyrazolopyridocoumarin synthesis catalysed by zinc chloride . Pyridocoumarins are known to possess photophysical, antimicrobial, analgesic and antiosteoporotic traits.…”

Carbon–nitrogen bond formation using modified graphene oxide derivatives decorated with copper complexes and nanoparticles

“…Catalytic activity of transition metals for carbon–nitrogen bond formation has been approved during the years. [ 33 ] Synthesis of propargyl amines by gold nanoparticles (NP)‐decorated with dithiocarbamate, [ 34 ] one‐pot synthesis of amidoalkyl naphthols using magnetic nanoparticles (MNP)‐supported acidic ionic liquid, [ 35 ] synthesis of tetrahydropyridines by silver, iron, and nickel immobilized on hydroxyapatite‐core–shell γ‐Fe 2 O 3 MNPs, [ 36 ] construction of pyrimido[1,2‐ b ]indazole derivatives by silver NPs, [ 37 ] and synthesis of pyrazolopyridocoumarin scaffolds by zinc chloride [ 38 ] are some examples of transition metals' applications for carbon–nitrogen bond formation. Furthermore, copper and palladium transition metal complexes were investigated as catalysts or stoichiometric agents in C–N cross‐coupling reactions using ligand or ligand‐free conditions.…”

Montmorillonite K10-catalyzed synthesis of N-fused imino-1,2,4-thiadiazolo isoquinoline derivatives

“…[26] However, to the best of our knowledge, there seems to be no reports in the literature on montmorillonite K10-catalyzed N−S bond formation reactions for the synthesis of 1,2,4-thiadiazoles. As part of our continued interest on the development of efficient synthetic methods, [27][28][29][30][31][32][33][34][35] here we wish to report for the first time the establishment of N−S bond by involving montmorillonite K10 as a catalyst for the rapid construction of biologically significant N-fused imino 1,2,4-thiadiazolo isoquinoline scaffolds.…”