Publication Type Journal Article
Title Kinetics and mechanism of hydrolysis of benzimidazolylcarbamates
Authors F. P. Norberto M. Soledade C. S. Santos Jim Iley Daniel Silva M. Corte Real
Groups MET
Journal JOURNAL OF THE BRAZILIAN CHEMICAL SOCIETY
Year 2007
Month
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Volume 18
Number 1
Pages 171-178
Abstract Synthesis of new 2-aminobenzimidazole-1-carbamates was accomplished by carbamoylation of 2-aminobenzimidazole using different substituted phenyl chloroformates. The aqueous hydrolysis of the new compounds was examined in the pH range 1-13 at 25 degrees C. The evaluated kinetic parameters led to the conclusion that up to pH 4 reaction proceeds by a bimolecular attack of water to the N-protonated substrate. This is the first time this behavior is described for carbamates, and can be ascribed to the higher basicity of the benzimidazolyl moiety when compared with the carbonyl oxygen. For higher values of pH, the results are consistent with a B(Ac)2 mechanism with nucleophilic catalysis, but while between pH 4 and pH 7 water acts as the nucleophile, for pH > 7 the hydroxide ion is the acting species.
DOI http://dx.doi.org/10.1590/S0103-50532007000100019
ISBN
Publisher
Book Title
ISSN 0103-5053
EISSN
Conference Name
Bibtex ID ISI:000245195900018
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