Related Experiment Video
Updated: Jun 8, 2026

Synthesis of pH Dependent Pyrazole, Imidazole, and Isoindolone Dipyrrinone Fluorophores using a Claisen-Schmidt Condensation Approach
Published on: June 10, 2021
3-Hydroxypyrrolo[2,3-b]pyridine and related compounds - indoxyl analogues with fused electron deficient rings
Alexander P Gaywood1, Hamish McNab
1School of Chemistry, The University of Edinburgh, West Mains Road, Edinburgh, UK EH9 3JJ.
Abstract:
Flash vacuum pyrolysis (FVP) of 4-acetyltetrazolo[1,5-a]pyridine 5 at 400 °C provides 3-methyl isoxazolo[3,4-b]pyridine 6 whose structure was confirmed by X-ray crystallography. At higher pyrolysis temperatures, the unstable heteroindoxyl 8 was obtained, which exists as the keto form (1,2-dihydropyrrolo[2,3-b]pyridin-3-one) 8K in CDCl(3) solution and the enol tautomer (3-hydroxypyrrolo[2,3-b]pyridine) 8E in DMSO. The heteroindoxyl 8 oxidatively dimerises to the heteroindigotin 9, undergoes condensation reactions at the 2-position and reacts with methoxymethylene Meldrum's acid at the 1-position. FVP of the corresponding acetyltetrazolo[1,5-a]quinoline 19 was much more complex, with 2-(cyanophenyl)acetonitrile 30 (rather than a heteroindoxyl) the major product at 750 °C. FVP of 3-acetyl-4-azidoquinoline 24 at 400 °C gave 3-methylisoxazolo[4,3-c]quinoline 33, but rearrangement to the heteroindoxyl was not observed at higher temperatures.
More Related Videos
06:18Syntheses, Crystallization, and Spectroscopic Characterization of 3,5-Lutidine N-Oxide Dehydrate
Published on: April 24, 2018
07:30A Direct, Regioselective and Atom-Economical Synthesis of 3-Aroyl-N-hydroxy-5-nitroindoles by Cycloaddition of 4-Nitronitrosobenzene with Alkynones
Published on: January 21, 2020
Related Concept Videos
Five-Membered Heterocyclic Aromatic Compounds: Overview
Basicity of Heterocyclic Aromatic Amines
Aryldiazonium Salts to Azo Dyes: Diazo Coupling
ortho–para-Directing Activators: –CH3, –OH, –⁠NH2, –OCH3
Nomenclature of Aryl and Heterocyclic Amines
Aromatic Hydrocarbon Cations: Structural Overview
Removing one hydrogen from the intervening CH2 group with both...