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Kinetics and mechanism for oxime formation from benzoylformic acid: Electrostatic interactions in the dehydration of carbinolamines
Author(s) -
Malpica A.,
Calzadilla M.,
Mejias I.
Publication year - 2008
Publication title -
international journal of chemical kinetics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.341
H-Index - 68
eISSN - 1097-4601
pISSN - 0538-8066
DOI - 10.1002/kin.20342
Subject(s) - chemistry , hydronium , oxime , reaction rate constant , dehydration , kinetics , ion , substrate (aquarium) , inorganic chemistry , medicinal chemistry , organic chemistry , biochemistry , physics , oceanography , quantum mechanics , geology
The evidence establishes that oxime formation from benzoylformic acid in the pH range from 0.25 to 5.5 occurs with acid‐catalyzed dehydration of carbinolamines derived from the acid and its anion. The pH‐rate profile shows in order of decreasing pH in two regions: (1) In the pH range from 5.5 to ∼2.2 the second‐order rate constants are linearly dependent on the concentration of hydronium ion and (2) from pH ∼2.2 to 0.25 the rate constants deviate slightly from the line of slope = −1. This slight deviation is a consequence of the very similar values of limiting rate constants of the two forms of the substrate. Electrostatic interactions between charged carbinolamines and hydronium ions are analyzed. © 2008 Wiley Periodicals, Inc. Int J Chem Kinet 40: 554–558, 2008