INFIQC   05475
INSTITUTO DE INVESTIGACIONES EN FISICO- QUIMICA DE CORDOBA
Unidad Ejecutora - UE
artículos
Título:
From N-(dinitrophenyl) amino acids to benzimidazole N-oxides. Synthesis, kinetics and mechanism.
Autor/es:
ELBA I. BUJÁN; MARÍA LAURA SALUM
Revista:
JOURNAL OF PHYSICAL ORGANIC CHEMISTRY
Editorial:
John Wiley & Sons
Referencias:
Año: 2006 vol. 19 p. 187 - 195
ISSN:
0894-3230
Resumen:
Several benzimidazole N-oxide derivatives were synthesized in very good yields by heating at reflux the corresponding N-(2,4 or 2,6-dinitrophenyl) amino acid derivative with NaOH in 60% 1,4-dioxane-H2O.  The N-oxides obtained from glycine and a and b-alanine derivatives lost the carboxylic group.  The observed rate constant for the reaction of N-(2,4-dinitrophenyl) glycine (2a) in 10% 1,4-dioxane-H2O to give  5-nitro-1H-benzimidazole-3-oxide (4a) is first order on [NaOH]; the second order rate constant is kN = 1.7 x 10-3 M-1 s-1.  The mechanism proposed includes the formation of a N-alkylidene 2-nitrosoaniline type intermediate as the rate determining step.