ISSN:
0030-4921
Keywords:
Chemistry
;
Analytical Chemistry and Spectroscopy
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Description / Table of Contents:
Five substituted anilides of general formula were studied in acidic media (H2SO4—MeOH and HSO3Cl—Me2CO). The unsolved problem of the protonation site (O-protonation and N-protonation) is discussed in terms of the observed NMR shifts [(δNH) and δ(CO—H)] taking into account several factors including hydrogen bonding and solvent effects.New dramatic evidence is presented of N-protonation of the amide group; in the case of 2,4-dinitro formanilide, the NO2 groups in the molecule enhance the relative basicity of the nitrogen atom in such a way that the amount of N-protonated amide can be detected.N-protonation is a function of the acidity, showing a maximum in the region of 40 to 50%.
Notes:
En étudiant par RMN cinq anilides de formule générale en milieu acide, les auteurs ont mis en évidence la protonation de l'atome d'azote de l'ion amidonium formé.
Additional Material:
5 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/mrc.1270020211
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