ISSN:
0009-2940
Keywords:
Pyrazoles
;
Aminyls, heterocyclic
;
Pyrazolo[1,5-a]benzimidazoles
;
Chemistry
;
Inorganic Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
Free Radical Reactions of N-Heterocyclic Compounds, XIV[1]. - Oxidative Cyclization of Anilinopyrazoles to Pyrazolo[1,5-a]benzimidazolesHerrn Professor Christoph Rüchardt zum 65. Geburtstag gewidmet.Substituted Anilinopyrazoles 1 were oxidized by dibenzoyl peroxide or lead(IV) oxide. Different oxidation products were isolated depending on the substituents in the anilino group of anilinopyrazoles 1. Intermediate pyrazolyl radicals 5, which could be trapped by triphenylmethyl or phenoxyl radicals, undergo cyclization reaction with formation of pyrazolo[1,5-a]benzimidazoles 4. The structures of compounds 4 were proven by 1H- and 13C-NMR spectroscopy, 15N labeling and transformation of 4e to the betain 7e.
Additional Material:
2 Tab.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/cber.19941270924
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