Nitro radical anions from megazol and related nitroimidazoles in aprotic media. A father-son type reaction triggered by an acidic proton

Bonta, M; Chauviere, G; Perie, J; Nunez-Vergara, LJ; Squella, JA

Abstract

We have studied the electrochemical reduction of some nitroimidazoles such as megazol(2-amino-5-(1-methyl-5-nitro-2-imidazolyl)-1,3,4-thiadiazol, CAS 19622-55-0) and two related derivatives in aprotic media (100% DMF, 0.1 M TBAP). All the studied compounds were easily reducible in aprotic media generating the corresponding nitro radical anions as products of the one electron reduction of the parent compound. The nitro radical anions decay by a dimerization reaction and the dimerization rate constants were obtained according to the Olmstead's approach by obtaining values of 150 ± 24, 1690 ± 42 and 640 ± 32 M-1 s-1 for megazol, GC-361 and GC-284, respectively. The existence of an acidic proton on the acetamide group in the GC-361 molecule triggered the appearance of father-son type reactions between the nitro radical anion from GC-361 (son compound) and GC-361 (father compound) generating the neutral radical and the conjugate base of GC-361. Thus the nitro radical anion from GC-361 acts as a Brönsted base abstracting the proton of the acetamide group in the GC-361 derivative of megazol. © 2002 Elsevier Science Ltd. All rights reserved.

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Título según WOS: Nitro radical anions from megazol and related nitroimidazoles in aprotic media. A father-son type reaction triggered by an acidic proton
Título según SCOPUS: Nitro radical anions from megazol and related nitroimidazoles in aprotic media. A father-son type reaction triggered by an acidic proton
Título de la Revista: ELECTROCHIMICA ACTA
Volumen: 47
Número: 25
Editorial: PERGAMON-ELSEVIER SCIENCE LTD
Fecha de publicación: 2002
Página de inicio: 4045
Página final: 4053
Idioma: English
URL: http://linkinghub.elsevier.com/retrieve/pii/S0013468602003900
DOI:

10.1016/S0013-4686(02)00390-0

Notas: ISI, SCOPUS