1
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Schlingemann J, Burns MJ, Ponting DJ, Avila CM, Romero NE, Jaywant MA, Smith GF, Ashworth IW, Simon S, Saal C, Wilk A. The Landscape of Potential Small and Drug Substance Related Nitrosamines in Pharmaceuticals. J Pharm Sci 2022; 112:1287-1304. [PMID: 36402198 DOI: 10.1016/j.xphs.2022.11.013] [Citation(s) in RCA: 28] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2022] [Revised: 11/11/2022] [Accepted: 11/11/2022] [Indexed: 11/18/2022]
Abstract
This article reports the outcome of an in silico analysis of more than 12,000 small molecule drugs and drug impurities, identifying the nitrosatable structures, assessing their potential to form nitrosamines under relevant conditions and the challenges to determine compound-specific AIs based on data available or read-across approaches for these nitrosamines and their acceptance by health authorities. Our data indicate that the presence of nitrosamines in pharmaceuticals is likely more prevalent than originally expected. In total, 40.4 % of the analyzed APIs and 29.6 % of the API impurities are potential nitrosamine precursors. Most structures identified through our workflow could form complex API-related nitrosamines, so-called nitrosamine drug substance related impurities (NDSRIs), although we also found structures that could release the well-known small and potent nitrosamines NDMA, NDEA, and others. Due to common structural motifs including secondary or tertiary amine moieties, whole essential drug classes such as beta blockers and ACE inhibitors are at risk. To avoid the risk of drug shortages or even the complete loss of therapeutic options, it will be essential that the well-established ICH M7 principles remain applicable for nitrosamines and that that the industry and regulatory authorities keep an open communication not only about the science but also to make sure there is a good balance between risk and benefit to patients.
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2
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Fang Y, Sun Q, Chen X, Qiu Y, Chen C, Wang L, Zhao Y, Su Y, Li T, Zhang L, Wang X. Rational design and syntheses of aniline-based diradical dications: isolable congeners of quinodimethane diradicals. Org Chem Front 2021. [DOI: 10.1039/d0qo01265c] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Two-electron oxidation of five aniline-based compounds 4,4′′-p/m-terphenyldiamines afforded the first isolable aniline-based diradical dications 12+–52+.
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3
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Grimm ML, Suleman NK, Hancock AN, Spencer JN, Dudding T, Rowshanpour R, Castagnoli N, Tanko JM. Stereoelectronic and Resonance Effects on the Rate of Ring Opening of N-Cyclopropyl-Based Single Electron Transfer Probes. J Am Chem Soc 2020; 142:2640-2652. [PMID: 31913031 DOI: 10.1021/jacs.9b12617] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
N-Cyclopropyl-N-methylaniline (5) is a poor probe for single electron transfer (SET) because the corresponding radical cation undergoes cyclopropane ring opening with a rate constant of only 4.1 × 104 s-1, too slow to compete with other processes such as radical cation deprotonation. The sluggish rate of ring opening can be attributed to either (i) a resonance effect in which the spin and charge of the radical cation in the ring-closed form is delocalized into the phenyl ring, and/or (ii) the lowest energy conformation of the SET product (5•+) does not meet the stereoelectronic requirements for cyclopropane ring opening. To resolve this issue, a new series of N-cyclopropylanilines were designed to lock the cyclopropyl group into the required bisected conformation for ring opening. The results reveal that the rate constant for ring opening of radical cations derived from 1'-methyl-3',4'-dihydro-1'H-spiro[cyclopropane-1,2'-quinoline] (6) and 6'-chloro-1'-methyl-3',4'-dihydro-1'H-spiro[cyclopropane-1,2'-quinoline] (7) are 3.5 × 102 s-1 and 4.1 × 102 s-1, effectively ruling out the stereoelectronic argument. In contrast, the radical cation derived from 4-chloro-N-methyl-N-(2-phenylcyclopropyl)aniline (8) undergoes cyclopropane ring opening with a rate constant of 1.7 × 108 s-1, demonstrating that loss of the resonance energy associated with the ring-closed form of these N-cyclopropylanilines can be amply compensated by incorporation of a radical-stabilizing phenyl substituent on the cyclopropyl group. Product studies were performed, including a unique application of EC-ESI/MS (Electrochemistry/ElectroSpray Ionization Mass Spectrometry) in the presence of 18O2 and H218O to elucidate the mechanism of ring opening of 7•+ and trapping of the resulting distonic radical cation.
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Affiliation(s)
- Michelle L Grimm
- Department of Chemistry , Virginia Tech , Blacksburg , Virginia 24060 , United States
| | - N Kamrudin Suleman
- Department of Chemistry , Virginia Tech , Blacksburg , Virginia 24060 , United States
| | - Amber N Hancock
- Department of Chemistry , Virginia Tech , Blacksburg , Virginia 24060 , United States
| | - Jared N Spencer
- Department of Chemistry , Virginia Tech , Blacksburg , Virginia 24060 , United States
| | - Travis Dudding
- Department of Chemistry , Virginia Tech , Blacksburg , Virginia 24060 , United States
| | - Rozhin Rowshanpour
- Department of Chemistry , Virginia Tech , Blacksburg , Virginia 24060 , United States
| | - Neal Castagnoli
- Department of Chemistry , Virginia Tech , Blacksburg , Virginia 24060 , United States
| | - James M Tanko
- Department of Chemistry , Virginia Tech , Blacksburg , Virginia 24060 , United States
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4
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Qiu S, Guo C, Wang M, Sun Z, Li H, Qian X, Yang Y. Mild dealkylative N-nitrosation of N,N-dialkylaniline derivatives for convenient preparation of photo-triggered and photo-calibrated NO donors. Org Chem Front 2018. [DOI: 10.1039/c8qo00818c] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Direct N-nitrosation of N,N-dialkylanilines under mild, non-acidic and non-oxidative conditions.
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Affiliation(s)
- Shaobing Qiu
- Shanghai Key Laboratory of Chemical Biology
- School of Pharmacy
- East China University of Science and Technology
- Shanghai
- China
| | - Chunlei Guo
- Shanghai Key Laboratory of Chemical Biology
- School of Pharmacy
- East China University of Science and Technology
- Shanghai
- China
| | - Mingkang Wang
- Shanghai Key Laboratory of Chemical Biology
- School of Pharmacy
- East China University of Science and Technology
- Shanghai
- China
| | - Zhenglong Sun
- Suzhou Institute of Biomedical Engineering and Technology (SIBET)
- Chinese Academy of Sciences
- Suzhou
- China
| | - Hui Li
- Suzhou Institute of Biomedical Engineering and Technology (SIBET)
- Chinese Academy of Sciences
- Suzhou
- China
| | - Xuhong Qian
- State Key Laboratory of Bioreactor Engineering
- East China University of Science and Technology
- Shanghai
- China
- Shanghai Key Laboratory of Chemical Biology
| | - Youjun Yang
- State Key Laboratory of Bioreactor Engineering
- East China University of Science and Technology
- Shanghai
- China
- Shanghai Key Laboratory of Chemical Biology
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5
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Yu K, Mitch WA, Dai N. Nitrosamines and Nitramines in Amine-Based Carbon Dioxide Capture Systems: Fundamentals, Engineering Implications, and Knowledge Gaps. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2017; 51:11522-11536. [PMID: 28946738 DOI: 10.1021/acs.est.7b02597] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Amine-based absorption is the primary contender for postcombustion CO2 capture from fossil fuel-fired power plants. However, significant concerns have arisen regarding the formation and emission of toxic nitrosamine and nitramine byproducts from amine-based systems. This paper reviews the current knowledge regarding these byproducts in CO2 capture systems. In the absorber, flue gas NOx drives nitrosamine and nitramine formation after its dissolution into the amine solvent. The reaction mechanisms are reviewed based on CO2 capture literature as well as biological and atmospheric chemistry studies. In the desorber, nitrosamines are formed under high temperatures by amines reacting with nitrite (a hydrolysis product of NOx), but they can also thermally decompose following pseudo-first order kinetics. The effects of amine structure, primarily amine order, on nitrosamine formation and the corresponding mechanisms are discussed. Washwater units, although intended to control emissions from the absorber, can contribute to additional nitrosamine formation when accumulated amines react with residual NOx. Nitramines are much less studied than nitrosamines in CO2 capture systems. Mitigation strategies based on the reaction mechanisms in each unit of the CO2 capture systems are reviewed. Lastly, we highlight research needs in clarifying reaction mechanisms, developing analytical methods for both liquid and gas phases, and integrating different units to quantitatively predict the accumulation and emission of nitrosamines and nitramines.
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Affiliation(s)
- Kun Yu
- Department of Chemical and Biological Engineering University at Buffalo, The State University of New York , Buffalo, New York 14260, United States
| | - William A Mitch
- Department of Civil and Environmental Engineering, Stanford University , Stanford, California 94305, United States
| | - Ning Dai
- Department of Civil, Structural and Environmental Engineering, University at Buffalo, The State University of New York , Buffalo, New York 14260, United States
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6
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Zhang S, Wang W, Liu S, Sui Y, Zhang Z, Tan G, Sun Q, Wang X. Putting aniline radical cations in a bottle. Sci China Chem 2017. [DOI: 10.1007/s11426-017-9096-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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7
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Tassone JP, MacQueen PM, Lavoie CM, Ferguson MJ, McDonald R, Stradiotto M. Nickel-Catalyzed N-Arylation of Cyclopropylamine and Related Ammonium Salts with (Hetero)aryl (Pseudo)halides at Room Temperature. ACS Catal 2017. [DOI: 10.1021/acscatal.7b02014] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Affiliation(s)
- Joseph P. Tassone
- Department
of Chemistry, Dalhousie University, 6274 Coburg Road, PO Box 15000, Halifax, Nova Scotia, Canada B3H 4R2
| | - Preston M. MacQueen
- Department
of Chemistry, Dalhousie University, 6274 Coburg Road, PO Box 15000, Halifax, Nova Scotia, Canada B3H 4R2
| | - Christopher M. Lavoie
- Department
of Chemistry, Dalhousie University, 6274 Coburg Road, PO Box 15000, Halifax, Nova Scotia, Canada B3H 4R2
| | - Michael J. Ferguson
- X-Ray
Crystallography Laboratory, Department of Chemistry, University of Alberta, Edmonton, Alberta, Canada T6G 2G2
| | - Robert McDonald
- X-Ray
Crystallography Laboratory, Department of Chemistry, University of Alberta, Edmonton, Alberta, Canada T6G 2G2
| | - Mark Stradiotto
- Department
of Chemistry, Dalhousie University, 6274 Coburg Road, PO Box 15000, Halifax, Nova Scotia, Canada B3H 4R2
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8
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Yu K, Reichard MC, Dai N. Nitrosamine Formation in the Desorber of Tertiary Alkanolamine-Based Carbon Dioxide Capture Systems. Ind Eng Chem Res 2016. [DOI: 10.1021/acs.iecr.5b04858] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Kun Yu
- Department of Chemical and
Biological Engineering, University at Buffalo, The State University of New York, Buffalo, New York 14260, United States
| | - Mikayla C. Reichard
- Department of Environmental
Sciences, Rutgers University, New Brunswick, New Jersey 08901, United States
| | - Ning Dai
- Department of Civil, Structural,
and Environmental Engineering, University at Buffalo, The State University of New York, Buffalo, New York 14260, United States
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9
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Sakai N, Sasaki M, Ogiwara Y. Copper(ii)-catalyzed oxidative N-nitrosation of secondary and tertiary amines with nitromethane under an oxygen atmosphere. Chem Commun (Camb) 2015; 51:11638-41. [DOI: 10.1039/c5cc03675e] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
The combination of Cu(OTf)2 and DBU under an O2 atmosphere effectively promoted the N-nitrosation of both secondary aromatic/aliphatic amines and tertiary aromatic amines with nitromethane (CH3NO2).
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Affiliation(s)
- Norio Sakai
- Department of Pure and Applied Chemistry
- Faculty of Science and Technology
- Tokyo University of Science (RIKADAI)
- Noda
- Japan
| | - Minoru Sasaki
- Department of Pure and Applied Chemistry
- Faculty of Science and Technology
- Tokyo University of Science (RIKADAI)
- Noda
- Japan
| | - Yohei Ogiwara
- Department of Pure and Applied Chemistry
- Faculty of Science and Technology
- Tokyo University of Science (RIKADAI)
- Noda
- Japan
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10
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Chen X, Wang X, Sui Y, Li Y, Ma J, Zuo J, Wang X. Synthesis, Characterization, and Structures of a Persistent Aniline Radical Cation. Angew Chem Int Ed Engl 2012. [DOI: 10.1002/ange.201205478] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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11
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Chen X, Wang X, Sui Y, Li Y, Ma J, Zuo J, Wang X. Synthesis, Characterization, and Structures of a Persistent Aniline Radical Cation. Angew Chem Int Ed Engl 2012; 51:11878-81. [DOI: 10.1002/anie.201205478] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2012] [Indexed: 11/12/2022]
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12
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Potturi HK, Gurung RK, Hou Y. Nitromethane with IBX/TBAF as a Nitrosating Agent: Synthesis of Nitrosamines from Secondary or Tertiary Amines under Mild Conditions. J Org Chem 2011; 77:626-31. [DOI: 10.1021/jo202276x] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Affiliation(s)
- Hima K. Potturi
- Meyers Institute for Interdisciplinary Research in
Organic and Medicinal Chemistry and Department of Chemistry and Biochemistry, Southern Illinois University, Carbondale, Illinois
62901, United States
| | - Ras K. Gurung
- Meyers Institute for Interdisciplinary Research in
Organic and Medicinal Chemistry and Department of Chemistry and Biochemistry, Southern Illinois University, Carbondale, Illinois
62901, United States
| | - Yuqing Hou
- Meyers Institute for Interdisciplinary Research in
Organic and Medicinal Chemistry and Department of Chemistry and Biochemistry, Southern Illinois University, Carbondale, Illinois
62901, United States
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13
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d’Ischia M, Napolitano A, Manini P, Panzella L. Secondary Targets of Nitrite-Derived Reactive Nitrogen Species: Nitrosation/Nitration Pathways, Antioxidant Defense Mechanisms and Toxicological Implications. Chem Res Toxicol 2011; 24:2071-92. [DOI: 10.1021/tx2003118] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Affiliation(s)
- Marco d’Ischia
- Department of Organic Chemistry and Biochemistry, University of Naples Federico II, Complesso Universitario Monte S. Angelo, via Cinthia 4, I-80126 Naples, Italy
| | - Alessandra Napolitano
- Department of Organic Chemistry and Biochemistry, University of Naples Federico II, Complesso Universitario Monte S. Angelo, via Cinthia 4, I-80126 Naples, Italy
| | - Paola Manini
- Department of Organic Chemistry and Biochemistry, University of Naples Federico II, Complesso Universitario Monte S. Angelo, via Cinthia 4, I-80126 Naples, Italy
| | - Lucia Panzella
- Department of Organic Chemistry and Biochemistry, University of Naples Federico II, Complesso Universitario Monte S. Angelo, via Cinthia 4, I-80126 Naples, Italy
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14
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Affiliation(s)
- Xianghua Yang
- a Key Laboratory for Bioorganic Phosphorus Chemistry and Chemical Biology (Ministry of Education), Department of Chemistry , Tsinghua University , Beijing, China
| | - Chanjuan Xi
- a Key Laboratory for Bioorganic Phosphorus Chemistry and Chemical Biology (Ministry of Education), Department of Chemistry , Tsinghua University , Beijing, China
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15
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Teuten EL, Loeppky RN. The mechanistic origin of regiochemical changes in the nitrosative N-dealkylation of N,N-dialkyl aromatic amines. Org Biomol Chem 2005; 3:1097-108. [PMID: 15750654 DOI: 10.1039/b418457b] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The regioselectivity of the nitrous acid mediated dealkylation of 4-substituted-N-ethyl-N-methylanilines is a function of the acidity of the reaction mixture. At high acidity deethylation predominates, whereas demethylation is the predominant reaction in nitrosamine formation at pH 2 and above. In some cases the regioselectivity of nitrosative dealkylation changes as the run proceeds. Through the use of the corresponding 4-nitroaniline as the primary substrate, CIDNP, kinetics, kinetic deuterium isotope effects and other transformations involving nitrosations with NO2 or NOBF4 in aprotic solvents, a new mechanism of tertiary amine nitrosation has been deduced and proposed to explain regioselective deethylation. The mechanism involves the oxidation of the substrate to the amine radical cation by NO+. This is followed by the abstraction of a hydrogen atom from the carbon adjacent to the amine nitrogen by NO2 to produce an iminium ion which reacts further to produce the corresponding aldehyde and the nitrosamine. Depending upon the acidity, this process competes with three other mechanistic pathways, two of which give the nitrosamine through the iminium ion, and one leads to the formation of C-nitro compounds. The competing pathways to nitrosamine formation involve NOH elimination from a nitrosammonium ion and deprotonation of the radical cation to give an alpha-amino radical which rapidly oxidized to the iminium ion. Predominant, but not highly regioselective demethylation occurs by these pathways. Nitro compound formation principally arises from the reaction of NO2 with the radical cation followed by deprotonation, but also occurs by para C-nitrosation followed by oxidation.
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Affiliation(s)
- Emma L Teuten
- Department of Chemistry, University of Missouri, Columbia, MO 65211, USA
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16
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Gissot A, N'Gouela S, Matt C, Wagner A, Mioskowski C. NaNO2-Mediated Transformation of Aliphatic Secondary Nitroalkanes into Ketones or Oximes under Neutral, Aqueous Conditions: How the Nitro Derivative Catalyzes Its Own Transformation. J Org Chem 2004; 69:8997-9001. [PMID: 15609931 DOI: 10.1021/jo0489824] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The nitrosation of secondary nitro derivatives into ketones or oximes depending on the nitro substituents has been reinvestigated. The reaction efficiently takes place under neutral conditions, thus allowing acid-sensitive substrates to be converted in very good yields. The generation of nitrosating species under such mild conditions is unprecedented. Mechanistic investigations strongly suggest that they result from the nucleophilic attack of the nitrite anion on the aci-nitro(nate) form of the secondary nitroalkane. The latter acts in turn as an autocatalyst for its own transformation by means of the nitrosating species generated in situ from it.
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Affiliation(s)
- Arnaud Gissot
- Laboratoire de Synthèse bioorganique, Université Louis Pasteur de Strasbourg, Unité associée au CNRS, UMR 7514, Faculté de Pharmacie, 74 route du Rhin-BP 24-F-67401 Illkirch-Graffenstaden, France
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17
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Wu H, Glaser R. The Heterolytic Dissociation of Neutral and Protonated Nitrous Acid. J Phys Chem A 2003. [DOI: 10.1021/jp035149m] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Hong Wu
- Department of Chemistry, University of Missouri-Columbia, Columbia, Missouri 65211
| | - Rainer Glaser
- Department of Chemistry, University of Missouri-Columbia, Columbia, Missouri 65211
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18
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Nonoyama N, Oshima H, Shoda C, Suzuki H. The Reaction of Peroxynitrite with Organic Molecules Bearing a Biologically Important Functionality. The Multiplicity of Reaction Modes as Exemplified by Hydroxylation, Nitration, Nitrosation, Dealkylation, Oxygenation, and Oxidative Dimerization and Cleavage. BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 2001. [DOI: 10.1246/bcsj.74.2385] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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19
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Cui W, Loeppky RN. The synthesis of N -arylcyclopropylamines via palladium-catalyzed C–N bond formation. Tetrahedron 2001. [DOI: 10.1016/s0040-4020(01)00118-1] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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20
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López-Cortés JG, Penieres-Carrillo G, Ortega-Alfaro MC, Gutiérrez-Pérez R, Toscano RA, Alvarez-Toledano C. Oxidative coupling-type mechanism of N, N-dialkylanilines in solvent-free conditions forming crystal violet derivatives. A clay-mediated and microwave-promoted approach. CAN J CHEM 2000. [DOI: 10.1139/v00-133] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
In the clay-mediated reaction of N,N-disubstituted anilines using microwave radiation as an energy source in the absence of solvent, crystal violet and derivatives, diphenylmethanes, and biphenyls were isolated along with intermediates supporting an oxidative coupling-type mechanism.Key words: clay, dyes, microwave radiation, solvent-free reactions.
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21
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Cho BP, Blankenship LR, Moody JD, Doerge DR, Beland FA, Culp SJ. Synthesis and Characterization of 4′-Amino and 4′-Nitro Derivatives of 4-N,N-Dimethylaminotriphenylmethane as Precursors for a Proximate Malachite Green Metabolite. Tetrahedron 2000. [DOI: 10.1016/s0040-4020(00)00649-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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22
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Loeppky RN, Elomari S. N-Alkyl-N-cyclopropylanilines as mechanistic probes in the nitrosation of N,N-dialkyl aromatic amines. J Org Chem 2000; 65:96-103. [PMID: 10813901 DOI: 10.1021/jo991104z] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A group of N-cyclopropyl-N-alkylanilines has been synthesized, and their reaction with nitrous acid in aqueous acetic acid at 0 degrees C was examined. All compounds reacted rapidly to produce the corresponding N-alkyl-N-nitrosoaniline by specific cleavage of the cyclopropyl group from the nitrogen. The transformations were unaffected by the nature of the alkyl substituent (Me, Et, (i)()Pr, Bn). The reaction of 4-chloro-N-2-phenylcyclopropyl-N-methylaniline with nitrous acid gave 4-chloro-N-methyl-N-nitrosoaniline (76%), cinnamaldehyde (55%), 3-phenyl-5-hydroxyisoxazoline (26%), and 5-(N-4-chlorophenylmethylamino)-3-phenylisoxazoline (8%). Both the selective cleavage of the cyclopropyl group from the aromatic amine nitrogen and nature of the products derived from the cyclopropane ring support a mechanism involving the formation of an amine radical cation. This step is followed by rapid cyclopropyl ring opening to produce an iminium ion with a C-centered radical which either combines with NO or is oxidized.
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Affiliation(s)
- R N Loeppky
- Department of Chemistry, University of Missouri, Columbia, Missouri 65211, USA.
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23
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Nitration and hydroxylation of substituted phenols by peroxynitrite. Kinetic feature and an alternative mechanistic view. Tetrahedron Lett 1999. [DOI: 10.1016/s0040-4039(99)01238-1] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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24
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Reactions of peroxynitrite with N,N-dimethyl-p-toluidine and 1,4-naphthoquinone. Evidence for heterolytic cleavage of a nitrogenoxygen bond in peroxynitrous acid. Tetrahedron Lett 1999. [DOI: 10.1016/s0040-4039(99)01239-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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25
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González-Mancebo S, García-Santos MP, Hernández-Benito J, Calle E, Casado J. Nitrosation of phenolic compounds: inhibition and enhancement. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 1999; 47:2235-2240. [PMID: 10794616 DOI: 10.1021/jf981094n] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The nitrosation of phenol, m-, o-, and p-cresol, 2,3-, 3,5-, and 2, 6-dimethylphenol, 3,5-di-tert-butylphenol, 2,4,6-trimethylphenol, o-chlorophenol, and o-bromophenol was studied. Kinetic monitoring of the reactions was accomplished by spectrophotometric analysis of the products at 345 nm. At pH > 3, the dominant reaction was C-nitrosation through a mechanism that appears to consist of an attack on the nitrosatable substrate by NO(+)/NO(2)H(2)(+), followed by a slow proton transfer. The finding of an isokinetic relationship supports the idea that the same mechanism operates throughout the series. The observed sequence of nitrosatable substrate reactivities is explained by (i) the preferred para-orientation of the hydroxyl group for the electrophilic attack of nitrosating agents, (ii) steric hindrance of alkyl substituents, which reduces or prevents attack by nitrosating agents, and (iii) the hyperconjugative effect of the methyl substituent, which causes electronic charge to flow into the aromatic nucleus, as well as the opposite electronic withdrawing effect induced by halogen substituents. The results show that potential nitrosation of widespread environmental species such as chlorophenols is negligible, but more attention should be paid to polyphenols with strongly nucleophilic carbon atoms.
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