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The regiochemistry of the NO 3 ‐promoted gas phase nitration of toluene and phenol with NO 2
Author(s) -
Bolzacchini Ezio,
Bruschi Maurizio,
Galliani Guido,
Hjorth Jens,
Orlandi Marco,
Rindone Bruno
Publication year - 2006
Publication title -
journal of physical organic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.325
H-Index - 66
eISSN - 1099-1395
pISSN - 0894-3230
DOI - 10.1002/poc.1060
Subject(s) - nitration , chemistry , toluene , phenol , regioselectivity , nitric acid , kinetic energy , kinetic isotope effect , hydrogen , medicinal chemistry , organic chemistry , photochemistry , catalysis , deuterium , physics , quantum mechanics
Abstract Product studies, kinetic isotope effect measurements, linear free energy relationships and calculations have been used to study the NO 3 ‐promoted nitration of toluene and phenol in presence of NO 2 . The competition between of a rate‐determining hydrogen abstraction of NO 3 to give the benzyl radical and HNO 3 and of a rate‐determining addition‐elimination pathway has been evaluated. The preference for the nitration in ortho and para position of toluene and for the ortho position of phenol is suggested to derive from the concerted loss of nitric acid from an intermediate cyclohexadiene.A kinetic analysis suggests reasons for the dependence of the ratio ortho : para ‐nitration from the initial concentration of reactants. Copyright © 2006 John Wiley & Sons, Ltd.