FREE-RADICAL REACTIONS OF N-HETEROCYCLIC COMPOUNDS .14. OXIDATIVE CYCLIZATION OF ANILINOPYRAZOLES TO PYRAZOLO[1,5-A]BENZIMIDAZOLES

Authors
KLUGE R SCHULZ M POBISOVA M NUCHTER M
Citation
R. Kluge et al., FREE-RADICAL REACTIONS OF N-HETEROCYCLIC COMPOUNDS .14. OXIDATIVE CYCLIZATION OF ANILINOPYRAZOLES TO PYRAZOLO[1,5-A]BENZIMIDAZOLES, Chemische Berichte, 127(9), 1994, pp. 1729-1733
Citations number
25
Categorie Soggetti
Chemistry
Journal title
Chemische Berichte → ACNP
ISSN journal
00092940
Volume
127
Issue
9
Year of publication
1994
Pages
1729 - 1733
Database
ISI
SICI code
0009-2940(1994)127:9<1729:FRONC.>2.0.ZU;2-F
Abstract
Substituted Anilinopyrazoles 1 were oxidized by dibenzoyl peroxide or lead(TV) oxide. Different oxidation products were isolated depending o n the substituents in the anilino group of anilinopyrazoles 1. Interme diate pyrazolyl radicals 5, which could be trapped by triphenylmethyl or phenoxyl radicals, undergo cyclization reaction with formation of p yrazolo[1,5a]benzimidazoles 4. The structures of compounds 4 were prov en by H-1- and C-13-NMR spectroscopy, N-15 labeling and transformation of 4e to the betain 7e.