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Amination of Benzene and Toluene with Hydroxylamine in the Presence of Transition Metal Redox Catalysts Full article

Journal Journal of Molecular Catalysis A: Chemical
ISSN: 1381-1169
Output data Year: 2000, Volume: 161, Number: 1-2, Pages: 1-9 Pages count : 9 DOI: 10.1016/S1381-1169(00)00206-5
Tags Acid media catalysis, Benzene amination, Hydroxylamine
Authors Kuznetsova N.I. 1 , Kuznetsova L.I. 1 , Detusheva L.G. 1 , Likholobov V.A. 1 , Pez G. 2 , Cheng H. 2
Affiliations
1 Boreskov Institute of Catalysis 630090, Novosibirsk, Russia
2 Air Products and Chemicals, Inc., Corporate Science and Technology Center, 7201 Hamilton BlÕd., Allentown, PA 18195-1501 USA

Funding (1)

1 Air Products and Chemicals

Abstract: The amination of benzene and toluene to aniline and toluidines with hydroxylamine sulfate has been investigated in water–acetic acid and water–acetic acid–sulfuric acid media in the presence of transition metal compounds as catalysts. The process yields are strongly dependent on the temperature, added sulfuric acid and the composition of catalyst. For the amination of benzene, the soluble catalysts, NaVO3 and Fe(III) salts produce high yields of aniline without addition of H2SO4, whereas Na2MoO4 and FeSO4 exhibit substantial activity only in 5 M H2SO4. Amination is accompanied by a disproportionation of hydroxylamine catalyzed by the redox active transition metal ions. The favorable effect of H2SO4 on the amination is due mostly to the greater stability of hydroxylamine in the strongly acidic medium. Mixed oxides containing V(V) and Mo(VI) are active amination catalysts when suspended in 5 M solution of H2SO4 in acetic acid. Introduction of metallic Pd into these oxide catalysts improves performance increasing the yield and selectivity of amination with respect to the aromatic substrate. Toluene exhibited a close to benzene reactivity in amination giving approximately equal yields of o-, m-, p-toluidines. Mechanistic considerations based on literature data and results of ab initio quantum mechanics calculations suggest that the aminating species is the protonated amino radical ⋅NH3+, which in the rate-determining step reacts with benzene and toluene to yield the corresponding aminocyclohexadienyl and aminomethylcyclohexadienyl radical intermediates. These are then oxidatively aromatized to give, respectively, aniline and a non-regiospecific mixture of toluidines.
Cite: Kuznetsova N.I. , Kuznetsova L.I. , Detusheva L.G. , Likholobov V.A. , Pez G. , Cheng H.
Amination of Benzene and Toluene with Hydroxylamine in the Presence of Transition Metal Redox Catalysts
Journal of Molecular Catalysis A: Chemical. 2000. V.161. N1-2. P.1-9. DOI: 10.1016/S1381-1169(00)00206-5 WOS Scopus РИНЦ ANCAN OpenAlex
Dates:
Submitted: Feb 2, 1999
Accepted: Feb 28, 2000
Published online: Sep 7, 2000
Published print: Nov 6, 2000
Identifiers:
Web of science: WOS:000089923200001
Scopus: 2-s2.0-0034613883
Elibrary: 13342478
Chemical Abstracts: 2000:619609
Chemical Abstracts (print): 134:71327
OpenAlex: W2093157324
Citing:
DB Citing
Web of science 50
Scopus 56
Elibrary 56
OpenAlex 46
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