Search results for "Intramolecular cyclization"

showing 5 items of 5 documents

Synthesis of a bridgehead nitrogen system. Imidazo[1,5-b]pyridazine derivatives

1979

3,4-Dibenzoyl-2-oxobutyrate 4-semicarbazone (6a), ethyl 2,4-dioxo-3-phenacylvalerate 3-semicarbazone (6b) and diethyl phenacyloxalectate 3-semicarbazone (6c) via acid catalysed intramolecular cyclization afforded 2-phenyl-4-R-3H-imidazo[1,5-d]pyridazine-5,7-(6H)diones (8d,e,f). Elemental analyses and spectroscopic data (ir, nmr, ms) were in good agreement with the assigned structures.

Pyridazinechemistry.chemical_compoundchemistryOrganic ChemistryIntramolecular cyclizationOrganic chemistrychemistry.chemical_elementMedicinal chemistryNitrogenJournal of Heterocyclic Chemistry
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Intramolecular cyclization of chloral allyl hemiacetal under the action of the Fe(CO)5-DMF system

1999

Chloral allyl hemiacetal undergoes cyclization in the presence of the Fe(CO)5-DMF system to form 3,3,5-trichloro-2-hydroxytetrahydropyran rather than a butyrolactone derivative.

chemistry.chemical_compoundChemistryIntramolecular cyclizationHemiacetalChloralGeneral ChemistryMedicinal chemistryDerivative (chemistry)Russian Chemical Bulletin
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Synthesis and NMR configurational study of imidazo[2,1-b]thiazoles from 1H-1,4-diazepine-7(6H)-thiones

1993

Abstract A thermal intramolecular cyclization of 1-vinyl2,3-dihydro-3 H -imidazole-2-thiones to imidazo[2,1-b]thiazoles is reported. A heteronuclear correlation study of these systems was made in order to establish the configuration of the products.

chemistry.chemical_compoundDiazepineBicyclic moleculeHeteronuclear moleculechemistryIntramolecular reactionStereochemistryOrganic ChemistryDrug DiscoveryIntramolecular cyclizationNuclear magnetic resonance spectroscopyBiochemistryTetrahedron
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ChemInform Abstract: Intramolecular Cyclization of Chloral Allyl Hemiacetal under the Action of the Fe(CO)5-DMF System.

2010

Chloral allyl hemiacetal undergoes cyclization in the presence of the Fe(CO)5-DMF system to form 3,3,5-trichloro-2-hydroxytetrahydropyran rather than a butyrolactone derivative.

chemistry.chemical_compoundchemistryIntramolecular cyclizationChloralHemiacetalOrganic chemistryGeneral MedicineMedicinal chemistryDerivative (chemistry)ChemInform
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A novel synthetic approach to pyran-2,4-dione scaffold production : microwave-assisted dimerization, cyclization, and expeditious regioselective conv…

2020

Here, we report a novel, green, simple, low-cost, and rapid methodology for the high-yield production of pyran-2,4-dione scaffolds under microwave irradiation. Regio- and stereoselective conversions of β-diketone systems into β-enaminones were achieved using 18 primary amines and four amino acid esters. Microwave-assisted further cyclization of 3-(β-substitutedvinyl)-6-phenyl-pyran-2,4-dione into 3-benzoyl-4,7-diphenyl-2H,5H-pyrano[4,3-b]pyran-2,5-dione via reaction with ethyl benzoyl acetate. peerReviewed

kemiallinen synteesimikroaallotmicrowavepyran-24-dioneintramolecular cyclizationorgaaniset yhdisteetβ-enaminones
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