- Synthesis of N,N-diethylhydrazine and its reactions with carboxylic acids and alkyl halides
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N,N-Diethylhydrazine was synthesized by a modified procedure via nitrosation of diethylamine, followed by reduction of the resulting N-nitrosodiethylamine with zinc amalgam in a hydrochloric acid medium. Reactions of N, N-diethylhydrazine with carboxylic acids and alkyl halides resulted in formation of the corresponding hydrazinium salts.
- Akhmedov,Tadzhimukhamedov,Akhmedov
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Read Online
- Formation of nitrosamines in organic solvents and aqueous systems containing organic solvents
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Formation of N-nitrosodimethylamine and N-nitrosodiethylamine in organic solvents such as chloroform, benzene, ethyl acetate, n-hexane, acetonitrile and dioxane was much faster than that in the control citrate buffer at pH 3. This effect of the organic solvents may be due to their ability to suppress ionization of nitrous acid. Formation of the nitrosamines in acetone was faster, but the yield was less than in other organic solvents, probably due to reaction of the solvent with nitrous acid. Ethyl alcohol was not useful as the control buffer, since it consumed nitrous acid to produce nitrite ester. The use of pH-controlled aqueous systems containing acetonitrile and dioxane accelerated the formation of the nitrosamines by increasing the concentration of nitrous acid; the 25% acetonitrile-containing system produced 3 times as much N-nitrosodimethylamine and 6 times as much N-nitrosodiethylamine as compared to the control citrate buffer at pH 4. Formation of the nitrosamines in citrate was accelerated or inhibited by addition of acetone and ethyl alcohol depending upon the pH conditions. It is concluded that most organic solvents suppressed the ionization of nitrous acid and accelerated the nitrosation of the secondary amines.
- Iitsuka,Hoshino,Kato,Kikugawa
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Read Online
- Visible-Light-Induced Photoaddition of N-Nitrosoalkylamines to Alkenes: One-Pot Tandem Approach to 1,2-Diamination of Alkenes from Secondary Amines
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The generation of aminium radical cation species from N-nitrosoamines is disclosed for the first time through visible-light excitation at 453 nm. The developed visible-light-promoted photoaddition reaction of N-nitrosoamines to alkenes was combined with the o-NQ-catalyzed aerobic oxidation protocol of amines to telescope the direct handling of harmful N-nitroso compounds, where the desired α-amino oxime derivatives were obtained in a one-pot tandem N-nitrosation and photoaddition sequence.
- Patil, Dilip V.,Si, Tengda,Kim, Hun Young,Oh, Kyungsoo
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supporting information
p. 3105 - 3109
(2021/05/05)
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- Kinetic and Theoretical Study of the Nitrate (NO3) Radical Gas Phase Reactions with N-Nitrosodimethylamine and N-Nitrosodiethylamine
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The reaction rates of (CH3)2NNO and (CH3CH2)2NNO with NO3 radicals were determined relative to formaldehyde (CH2O) and ethene (CH2CH2) at 298 ± 2 K and 1013 ± 10 hPa in purified air by long path FTIR spectroscopy. The reactions are too slow to be of importance at atmospheric conditions: k NO3+(CH3)2NNO = (1.47 ± 0.23) × 10-16 and k NO3+(CH3CH2)2NNO = (5.1 ± 0.4) × 10-16 cm3 molecule-1 s-1 (1σ error limits). Theoretical calculations, based on CCSD(T?)-F12a/aug-cc-pVTZ//M06-2X/aug-cc-pVTZ results, predict the corresponding imines as the sole primary products in nitrosamine reactions with NO3 and OH radicals.
- Maguta, Mihayo Musabila,Stenstr?m, Yngve,Nielsen, Claus J.
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p. 6970 - 6977
(2016/10/12)
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- Facile N-nitrosation of secondary amines using poly(N,N'-dibromo-Nethylene- benzene-1,3-disulfonamide) and N,N,N′,N′-tetrabromobenzene-1,3- disulfonamide/NaNO2 under mild conditions
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In this research project, a combination of poly(N,N′-dibromo-N- ethylene-benzene-1,3-disulfonamide) [PBBS] and/or (N,N,N′,N′- tetrabromobenzene-1,3-disulfonamide) [TBBDA] with sodium nitrite in the presence of wet SiO2 (50% w/w) was used as an efficient nitrosating agent for the conversion of secondary amines to their corresponding nitroso compounds. N-Nitrosation reaction has been performed in dichloromethane at room temperature under mild and heterogeneous conditions. The reaction is operationally simple and corresponding products were achieved in good to excellent yields.
- Ghorbani-Vaghei, Ramin,Shiri, Lotfi,Ghorbani-Choghamarani, Arash
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p. 204 - 208
(2013/07/26)
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- Ionic liquid 1-(4-nitritobutyl)-3-methylimidazolium chloride as a new reagent for the efficient N-nitrosation of secondary amines under mild conditions
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1-(4-Nitritobutyl)-3-methylimidazolium chloride has been developed as a new reagent for efficient nitrosation of secondary amines at 0 °C to room temperature. A variety of N-nitrosamines were prepared in excellent yields by use of this task-specific ionic liquid under mild and heterogeneous conditions.
- Valizadeh, Hassan,Gholipour, Hamid,Shomali, Ashkan
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experimental part
p. 467 - 470
(2012/06/15)
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- 1-butyl-3-methylimidazolium nitrite as a reagent for the efficient n-nitrosation of secondary amines
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1-Butyl-3-methylimidazolium nitrite, [bmim]NO2 was used as a new effective reagent for the preparation of N-nitrosamines from the corresponding secondary amines at 0 °C to room temperature, under mild conditions in good to excellent yields.
- Valizadeh,Gholipour
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experimental part
p. 857 - 861
(2012/06/18)
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- N-nitrosation of secondary amines using p-TSA-NaNO2 as a novel nitrosating agent under mild conditions
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A combination of p-toluenesulfonic acid (p-TSA) and sodium nitrite was used as a novel effective nitrosating agent for the N-nitrosation of secondary amines to their corresponding nitroso derivatives under mild and heterogeneous conditions in moderate to excellent yields.
- Borikar, Sanjay P.,Paul, Vincent
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experimental part
p. 654 - 660
(2011/02/27)
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- Synthesis of N,N-dialkylnitramines from secondary ammonium nitrates in liquid or supercritical carbon dioxide
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An efficient explosion-proof method was developed for the preparation of N,N-dialkylnitramines by treatment of dialkylammonium nitrates with a mixture of nitric acid and acetic anhydride in the presence of ZnCl2 in liduid or supercritical carbon dioxide.
- Kuchurov,Fomenkov,Zlotin
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experimental part
p. 2058 - 2062
(2011/01/08)
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- Mechanistic studies on the reaction between R2N-NONOates and aquacobalamin: evidence for direct transfer of a nitroxyl group from R 2N-NONOates to cobalt(III) centers
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Tales of the unexpected: Transfer of a nitroxyl group from R2N-NONOates to aquacobalamin to form nitroxylcobaiamin does not proceed via H+-catalyzed R2NNONOate decomposition, but instead occurs via a probable NONOate-cobalamin intermediate (see scheme; r.
- Hassanin, Hanaa A.,Hannibal, Luciana,Jacobsen, Donald W.,El-Shahat, Mohamed F.,Hamza, Mohamed S. A.,Brasch, Nicola E.
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supporting information; experimental part
p. 8909 - 8913
(2010/03/01)
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- Bismuth chloride-sodium nitrite: A novel reagent for chemoselective N-nitrosation
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Bismuth(III) chloride-sodium nitrite was used as a mild and efficient reagent for N-nitrosation of various tetrazoles, secondary amines, and amides under ambient conditions. Nitrosation took place chemoselectively at the nitrogen atom, giving corresponding N-nitroso derivatives in good to excellent yield. Copyright Taylor & Francis Group, LLC.
- Chaskar, Atul C.,Langi, Bhushan P.,Deorukhkar, Amol,Deokar, Hrushikesh
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experimental part
p. 604 - 612
(2009/07/04)
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- Ph3P/Br2/n-Bu4NNO2 as an efficient system for the preparation of N-nitrosamines and azides
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The combination PPh3/Br2/n-Bu4NNO2 was developed as a new reagent system for the efficient preparation of N-nitrosamines and azides from the corresponding amines and hydrazine derivatives, respectively, at 0 °C to room temperature, in excellent yields.
- Iranpoor, Nasser,Firouzabadi, Habib,Nowrouzi, Najmeh
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p. 4242 - 4244
(2008/09/20)
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- Efficient procedure for chemoselective N-nitrosation of secondary amines with trichloromelamine-NaNO2
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A combination of trichloromelamine and sodium nitrite in the presence of wet silica gel was used as an effective nitrosating agent for the transformation of secondary amines into the corresponding N-nitroso derivatives under mild and heterogeneous conditions in good to excellent yields.
- Bamoniri,Zolfigol,Mirjalili,Fallah
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p. 1393 - 1396
(2008/03/27)
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- Tin(IV) chloride-sodium nitrite as a new nitrosating agent for N-nitrosation of amines, amides and ureas under mild and heterogeneous conditions
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We have developed a new method of N-nitrosation of various secondary and tertiary amines, amides and ureas using a mixture of tin(IV) chloride and sodium nitrate. This method leads to a selective, high-yielding and mild heterogeneous N-nitrosation by in situ generation of nitrosyl chloride (NOCl). The reaction can be carried out in several different solvents such as chloroform, dichloromethane, ethers, ethyl acetate and alcohols, at room temperature. Georg Thieme Verlag Stuttgart.
- Celaries, Benoit,Parkanyi, Cyril
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p. 2371 - 2375
(2008/02/03)
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- Alumina-methanesulfonic acid (AMA)/NaNO2 as an efficient procedure for the chemoselectivite N-nitrosation of secondary amines
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A combination of alumina/methanesulfonic acid (AMA) and sodium nitrite was used as an effective nitrosating agent for the nitrosation of secondary amines under mild and heterogeneous conditions in good to excellent yields. Copyright Taylor & Francis Group, LLC.
- Niknam, Khodabakhsh,Zolfigol, Mohammad Ali
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p. 2311 - 2319
(2007/10/03)
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- Molybdate sulfuric acid/NaNO2: A novel heterogeneous system for the N-nitrosation of secondary amines under mild conditions
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Wet molybdate sulfuric acid (=dioxo[bis(sulfato-κO)]molybdenum; MSA), a new solid acid, can be used in combination with sodium nitrite (NaNO 2) to transform a variety of secondary amines to the corresponding N-nitroso compounds under mild, heterogeneous conditions (Table). The process has several advantages: the reagents are inexpensive and non-hazardous, the reaction is clean, fast, and high-yielding, and MSA can be readily removed by filtration and re-used (after treatment with HCl) without loss of activity. Further, only N-nitrosation was observed, but no C- or O-nitrosation.
- Montazerozohori, Morteza,Karami, Bahador
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p. 2922 - 2926
(2007/10/03)
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- Dinitrogen tetroxide-impregnated charcoal (N2O 4/charcoal): Selective nitrosation of amines, amides, ureas, and thiols
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Efficient N-nitrosation of amines, amides, and ureas, and also S-nitrosation of thiols were performed with dinitrogen tetroxide impregnated on activated charcoal (N2O4/charcoal) in CH 2Cl2 at room temperature. High selectivity was observed for N-nitrosation of dialkyl amines, N-alkylamides and N-alkylureas. Dealkylation and N-nitrosation of trialkylamines were also performed by this reagent. Copyright Taylor & Francis, Inc.
- Iranpoor, Nasser,Firouzabadi, Habib,Pourali, Ali Reza
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p. 1517 - 1526
(2007/10/03)
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- Efficient degradation of organic pollutants by using dioxygen activated by resin-exchanged iron(II) bipyridine under visible irradiation
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Excellent response to visible light is shown by the [FeII(bpy)3]-amberlite photocatalyst, which can effectively activate molecular oxygen in such a way as to put us one giant step nearer to our goal - the development of the ultimate green technology for decontamination [Eq. (1)].
- Ma, Wanhong,Li, Jing,Tao, Xia,He, Ju,Xu, Yiming,Yu, Jimmy C.,Zhao, Jincai
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p. 1029 - 1032
(2007/10/03)
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- Selective N-nitrosation of amines, N-alkylamides and N-alkylureas by N2O4 supported on cross-linked polyvinylpyrrolidone (PVP-N2O4)
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N2O4 was supported on the cross-linked polyvinylpyrrolidone (PVP) to afford a solid, stable and recyclable nitrosating agent. This reagent shows excellent selectivity for N-nitrosation of dialkyl amines in the presence of diaryl-, arylalkyl-, trialkylamines and also for secondary amides in dichloromethane at room temperature under mild and heterogeneous conditions. Also N-nitroso-N-alkyl amides can be selectively prepared in the presence of primary amides and N-phenylamides under similar reaction conditions. Selective N-nitrosation or dealkylation and N-nitrosation of tertiary amines can also be performed by this reagent.
- Iranpoor, Nasser,Firouzabadi, Habib,Pourali, Ali-Reza
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p. 1591 - 1597
(2007/10/03)
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- A simple and efficient method for the N-nitrosation of secondary amines with NaNO2-Ac2O under mild conditions
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Secondary amines can be easily converted into their corresponding nitroso derivations using NaNO2-Ac2O as a nitrosating agent in dichloromethane at room temperature with high yields.
- Hou, Jian-Ye,Wang, Yu-Lu,Wang, Jin-Ye
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p. 626 - 627
(2007/10/03)
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- The use of Nafion-H/NaNO2 as an efficient procedure for the chemoselective N-nitrosation of secondary amines under mild and heterogeneous conditions
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A combination of Nafion-H and sodium nitrite in the presence of wet SiO2 was used as an effective agent for the N-nitrosation of secondary amines under mild and heterogeneous conditions in good to excellent yields.
- Zolfigol, Mohammad Ali,Habibi, Davood,Mirjalili, BiBi Fatemeh,Bamoniri, Abdolhamid
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p. 3345 - 3349
(2007/10/03)
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- Controlled photochemical release of nitric oxide from O2-naphthylmethyl- and O2-naphthylallyl-substituted diazeniumdiolates
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The photochemistry of O2-naphthylmethyl- and O2-naphthylallyl-substituted diazeniumdiolates has been investigated. Electron-donating methoxy group substitution is shown to have a significant effect on the observed photochemistry, with the appropriate substitution pattern resulting in efficient diazeniumdiolate photorelease. Observed nitric oxide release rates from these photoprecursors are consistent with those expected for normal thermal dissociation of the diazeniumdiolate in aqueous solutions and show the same pH dependence. Copyright
- Bushan, K. Mani,Xu, Hua,Ruane, Patrick H.,D'Sa, Raechelle A.,Pavlos, Christopher M.,Smith, Joseph A.,Celius, Tevye C.,Toscano, John P.
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p. 12640 - 12641
(2007/10/03)
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- Controlled photochemical release of nitric oxide from O2-benzyl-substituted diazeniumdiolates
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An investigation of potential photosensitive protecting groups for diazeniumdiolates (R2N-N(O)=NO-) has been initiated, and here the effect of meta electron-donating groups on the photochemistry of O2-benzyl-substituted diazeniumdiolates (R2N-N(O)=NOCH2Ar) is reported. Photolysis of the parent benzyl derivative (Ar = Ph) results almost exclusively in undesired photochemistry-the formation of nitrosamine and an oxynitrene intermediate with very little, if any, photorelease of the diazeniumdiolate. We have been able to use meta substitution to tune the photochemistry of these benzylic systems. The desired diazeniumdiolate photorelease has been shown to become more substantial with stronger π-donating meta substituents. This effect has been verified by direct observation of the photoreleased diazeniumdiolate with 1H NMR spectroscopy and by NO quantification measurements conducted in high- and low-ph solutions. In addition, the observed rates of NO release are consistent with that expected for normal thermal decomposition of the diazeniumdiolate in aqueous solutions and also show the same pH dependence.
- Ruane, Patrick H.,Bushan, K. Mani,Pavlos, Christopher M.,D'Sa, Raechelle A.,Toscano, John P.
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p. 9806 - 9811
(2007/10/03)
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- Silica sulfuric acid/NaNO2 as a novel heterogeneous system for the chemoselective N-nitrosation of secondary amines under mild conditions
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Neat chlorosulfonic acid reacts with silica gel to give silica sulfuric acid in which sulfuric acid is immobilized on the surface of silica gel via a covalent bond. A combination of silica sulfuric acid and sodium nitrite in the presence of wet SiO2 was used as an effective nitrosating agent for the nitrosation of secondary amines to their corresponding nitroso derivatives under mild and heterogeneous conditions in excellent yields.
- Zolfigol, Mohammad Ali,Bamoniri, Abdolhamid
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p. 1621 - 1624
(2007/10/03)
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- Trichloroisocyanuric acid/NaNo2 as a novel heterogeneous system for the N-nitrosation of N,N-dialkylamines under mild conditions
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A combination of trichloroisocyanuric acid and sodium nitrite in the presence of wet SiO2 was used as an effective nitrosating agent for the nitrosation of N,N-dialkyl amines to their corresponding nitroso derivatives under mild and heterogeneous conditions in moderate to excellent yields.
- Zolfigol, Mohammad Ali,Choghamarani, Arash Ghorbani,Hazarkhani, Hassan
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p. 1002 - 1004
(2007/10/03)
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- Silica chloride/NaNO2 as a novel heterogeneous system for the nitrosation of secondary amines under mild conditions
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Secondary amines can be readily converted to their corresponding nitroso derivatives with a combination of silica chloride (I), wet SiO2 and sodium nitrite in dichloromethane at room temperature with moderate to excellent yields.
- Zolfigol, Mohammad Ali,Shirini, Farhad,Ghorbani Choghamarani, Arash
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p. 1809 - 1813
(2007/10/03)
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- Chemistry of the diazeniumdiolates. 3. Photoreactivity
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We have found O2-substituted diazeniumdiolates, compounds of structure R2N - N(O)=NOR′ that are under development for various possible pharmaceutical uses, to be rather photosensitive. With R = ethyl and R′ = methyl, benzyl, or 2-nit
- Srinivasan,Kebede,Saavedra,Nikolaitchik,Brady,Yourd,Davies,Keefer,Toscano
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p. 5465 - 5472
(2007/10/03)
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- Chemoselective N-nitrosation of secondary amines under mild and heterogeneous conditions
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A combination of iodic or periodic acids and sodium nitrite in the presence of wet SiO2 was used as an effective nitrosating agent for the nitrosation of secondary amines to their corresponding nitroso derivatives under mild and heterogeneous conditions in excellent yields.
- Zolfigol,Choghamarani,Shirini,Keypour,Salehzadeh
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p. 359 - 365
(2007/10/03)
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- N-nitrosation of secondary amines under mild and heterogeneous conditions
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A combination of potassium monopersulfate and sodium nitrite in the presence of wet SiO2 was used as an effective nitrosating agent for the nitrosation of secondary amines to their corresponding nitroso derivatives under mild and heterogeneous conditions in excellent yields.
- Zolfigol,Bagherzadeh,Choghamarani,Keypour,Salehzadeh
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p. 1161 - 1166
(2007/10/03)
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- Formation of N-nitrosamines and N-nitramines by the reaction of secondary amines peroxynitrite and other reactive nitrogen species: Comparison with nitrotyrosine formation
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Reactive nitrogen species, including nitrogen oxides (N2O3 and N2O4), peroxynitrite (ONOO-), and nitryl chloride (NO2Cl), have been implicated as causes of inflammation and cancer. We studied reactions of secondary amines with peroxynitrite and found that both N-nitrosamines and N- nitramines were formed. Morpholine was more easily nitrosated by peroxynitrite at alkaline pH than at neutral pH, whereas its nitration by peroxynitrite was optimal at pH 8.5. The yield of nitrosomorpholine in this reaction was 3 times higher than that of nitromorpholine at alkaline pH, whereas 2 times more nitromorpholine than nitrosomorpholine was formed at pH 2N·), which react with nitric oxide (·NO) or nitrogen dioxide (·NO2) to yield nitroso and nitro secondary amines, respectively. Reaction of morpholine with NO· and superoxide anion (O2·-), which were concomitantly produced from spermine NONOate and by the xanthine oxidase systems, respectively, also yielded nitromorpholine, but its yield was 2·- inhibited its formation. Reactions of morpholine with nitrite plus HOCl or nitrite plus H2O2, with or without addition of myeloperoxidase or horseradish peroxidase, also yielded nitration and nitrosation products, in yields that depended on the reactants. Tyrosine was nitrated easily by synthetic peroxynitrite, by NaNO2 plus H2O2 with myeloperoxidase, and by NaNO2 plus H2O2 under acidic conditions. Nitrated secondary amines, e.g., N-nitroproline, could be identified as specific markers for endogenous nitration mediated by reactive nitrogen species.
- Masuda, Mitsuharu,Mower, Howard F.,Pignatelli, Brigitte,Celan, Irena,Friesen, Marlin D.,Nishino, Hoyoku,Ohshima, Hiroshi
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p. 301 - 308
(2007/10/03)
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- An efficient method for N-nitrosation of secondary amines under mild and, heterogeneous conditions
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A combination of inorganic acidic salts or silica gel supported inorganic acids and sodium nitrite in the presence of wet SiO2 was used as an effective nitrosating agent for the nitrosation of secondary amines to their corresponding nitroso derivatives under mild and heterogeneous conditions in moderate to excellent yields. Mg(HSO4)2 and NaHSO4 are superior to all the aforementioned reagents in convenience, yield and purity of the isolated nitrosoamines.
- Zolfigol, Mohammad Ali,Ghaemi, Ezat,Madrakian, Elahe,Kiany-Borazjani, Maryam
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p. 2057 - 2060
(2007/10/03)
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- Chemoselective N-nitrosation of secondary amines under mild and heterogeneous conditions via in situ generation of NOCI
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A combination of inorganic chloride salts [e.g. WCl6, AlCl3 and ZnCl2] and sodium nitrite in the presence of wet SiO2 were used as an effective nitrosating agent for the nitrosation of secondary amines to their corresponding nitroso derivatives under mild and heterogeneous conditions in moderate to excellent yields.
- Zolfigol,Shirini,Choghamarani,Taqian-Nasab,Keypour,Salehzadeh
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p. 420 - 422
(2007/10/03)
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- Efficient and chemoselective N-nitrosation of secondary amines under mild and heterogeneous conditions with sodium nitrite and oxalic acid two hydrate
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Secondary amines can be quantitatively converted to their corresponding nitroso derivatives with a combination of oxalic acid and sodium nitrite in dichloromethane at room temperature.
- Zolfigol, Mohammad Ali
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p. 905 - 910
(2007/10/03)
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- Nitrosation of Amines in Nonaqueous Solvents, 1. Evidence of a Stepwise Mechanism
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We studied the nitrosation of piperidine, morpholine, pyrrolidine, N-methylpiperazine, N,N′-dimethylethylenediamine and diethylamine by 2-bromoethyl nitrite, 2,2-dichloroethyl nitrite, 2,2,2-trichloroethyl nitrite, or N-methyl-N-nitroso-p-toluenesulfonamide (MNTS) in cyclohexane, isooctane, dichloromethane, 1,4-dioxane, or tetrahydrofuran. The dependence of the first-order pseudoconstant k0 on the amine concentration (always in excess) was sigmoid for nitrosation by alkyl nitrites and linear or quadratic for nitrosation by MNTS. The effects on k0 of isotopic substitution, temperature, and base catalysis by a less reactive amine were also determined. The experimental data are in keeping with a reaction mechanism involving a zwitterionic tetrahedral intermediate T± analogous to intermediates postulated for the aminolysis of carboxylic esters in similar solvents: according to this mechanism, T± is formed either directly from the amine and nitrosating agent (in the case of MNTS) or indirectly via a hydrogen-bonded complex between the amine and nitrosating agent (in the case of alkyl nitrites) and decomposes either spontaneously or with the catalytic assistance of a second amine molecule. For alkyl nitrites, the rate-controlling step is the formation of T± at high amine concentrations and its decomposition at low amine concentrations; for MNTS, the rate-controlling step is the formation of T± in more polar solvents and its decomposition in less polar solvents. An alternative mechanism, involving the formation of T± from both monomers and dimers of the amine, is ruled out.
- Garcia Rio,Leis,Iglesias
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p. 4701 - 4711
(2007/10/03)
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- Nitrosation of Amines in Nonaqueous Solvents. 2. Solvent-Induced Mechanistic Changes
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We studied the nitrosation of amines (pyrrolidine, piperidine, diethylamine, N-methylpiperazine, N,N′-dimethylethylenediamine, and morpholine) by alkyl nitrites (2-bromoethyl nitrite or 2,2- dichloroethyl nitrite) or by N-methyl-N-nitroso-p-toluenesulfonamide (MNTS) in the solvents chloroform, acetonitrile, and dimethyl sulfoxide (DMSO). The mechanism of nitrosation by alkyl nitrites depends on the solvent: in chloroform, all the results were in keeping with formation of a hydrogen-bonded complex between the amine and alkyl nitrite being followed by rate-controlling formation of a tetrahedral intermediate T± that rapidly decomposes to afford the final products; in acetonitrile, a situation intermediate between those obtaining in chloroform and cyclohexane results in the [amine] dependence of the first-order pseudoconstant k0 being qualitatively influenced by temperature and by the identities of both the amine and the alkyl nitrite; in DMSO, the results suggest a mechanism close to the mechanism acting in water. For nitrosation by MNTS, k0 depended linearly on [amine] in all three solvents. The Grunwald-Winstein coefficients correlating the rate constants k for nitrosation by MNTS in the chloroform, acetonitrile, DMSO, dioxane, dichloromethane, and water were l = 0.12 and m = 0.29. Correlation with the Kamlet-Abboud-Taft equation confirmed that k depends largely on the dipolarity of the solvent and, to a lesser extent, its capacity for hydrogen bonding.
- Garcia-Rio,Leis,Iglesias
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p. 4712 - 4720
(2007/10/03)
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- Mechanisms of Nitramine Thermolysis
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The thermal decomposition of a number of nitramines was studied in dilute solution and in the melt.The nitramines included acyclic mononitramines , cyclic mononitramines , cyclic dinitramines , and 1,3,5-trinitro-1,3,5-triazocyclohexane (RDX), octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX), hexanitrohexaazaisowurtzitane (HNIW), and 1,3,3-trinitroazetidine (TNAZ).For the acyclic and cyclic mono- and dinitramines, the corresponding nitrosamines were the only or major condensed-phase product.Kinetics and activation parameters were determined for the thermolysis of dilute solutions (0.01-1.0 wtpercent) over the range 200-300 deg C.The thermolyses were found to be first-order with the rate constants unaffected by the use of deuterated solvent.As the nitramines became more complex than dimethylnitramine (DMN), the rate of decomposition increased and the product distribution became more complex.As the length of the aliphatic chain increased (DMN DEN DPN), the rate of thermolysis increased, yet nitrosamine remained the only observed condensed-phase product.When a secondary carbon was attached to the N-nitramine (DIPN) rather than the primary (DPN), the rate of decomposition increased and a new condensed-phase product was observed.Among the cyclic nitramines, the rate of decomposition increased as the number of NNO2 groups increased (NPIP pDNP; NPyr DNI; mDMP RDX).The position of the nitramine groups affected the decomposition: meta NNO2 groups (mDNP) decomposed faster than para (pDNP).Ring strain decreased stability: mDNP DNI; HMX RDX.In complex nitramines, the increase in decomposition rate, the appearance of new products, and the change in the relative importance of nitrosamine and of N2 and N2O are attributed to new decomposition routes available to them.However, since complex nitramines (e.g.RDX) maintain first-order kinetics and since most have activation energies in the range of 40-50 kcal/mol, it is belived that the triggering mechanism remains N-NO2 homolysis.Intramolecular hydrogen transfer is also considered an important mode of nitramine decomposition.
- Oxley, J. C.,Kooh, A. B.,Szekeres, R.,Zheng, W.
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p. 7004 - 7008
(2007/10/02)
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- Reactivity of Nucleophilic Nitrogen Compounds towards the Nitroso Group
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We discuss the reactivity of 43 nucleophilic nitrogen compounds towards the nitroso group of N-methyl-N-nitrosotoluene-p-sulfonamide (MNTS), and in some cases with alkyl nitrites.The series of nucleophiles considered is structurally very varied, includes members exhibiting the alpha effect, and covers 8 pKa units and a range of reactivities of almost five orders of magnitude.The values of solvent isotope effects and activation parameters have been measured and throw light on the structure of the transition states involved.Reactivities do not correlate well with thebasicity of the nucleophile, largely owing to the behaviour of primary amines, ammonia and nucleophiles with an alpha effect.Application of the curve crossing model suggests a relationship with vertical ionization potentials.The relationship with Ritchie's N+ scale is discussed, and interesting correlations with the reactivities of the same nucleophiles in various other chemical processes are noted.
- Garcia-Rio, Luis,Iglesias, Emilia,Leis, J. Ramon,Pena, M. Elena,Rios, Ana
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- Formation of Nitrosamines in Alkaline Conditions: a Kinetic Study of the Nitrosation of Linear and Cyclic Secondary Amines by Nitroalkanes
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A study has been made of the nitrosation of sixteen secondary amines, six alkylamines (dimethylamine, diethylamine, dipropylamine, diisopropylamine, dibutylamine, diisobutylamine) and ten cyclic secondary amines (2-methylaziridine, azetidine, pyrrolidine, piperidine, 2-methylpiperidine, homopiperidine, heptamethyleneimine, piperazine, 1-methylpiperazine and morpholine) by nitropropane and nitrobutane in a strongly basic medium (-> = 0.1 mol dm-3).The nitrites were not formed in situ (i.e. in the actual bulk of the reaction medium) but rather were isolated,purified and used in pure form.The rate equation (i) was found v = k2obs (i).The fitting of the experimental results to the Taft correlation points to a nucleophilic attack on nitrite esters by the amines.Analysis of the log k2/pKa and log k2/Ei(v) correlations indicates orbital control of the reactions studied.These results, together with the fact that the reactivity of the different amines diminishes ostensibly when the values of the 13C-H nuclear spin coupling constant in the series of corresponding cycloalkanes increase, show that the overall hybridization of the nitrogen atom in the cycle changes from sp2 in the triangular nucleophile methylaziridine to sp3 in larger cycles.The results obtained at different temperatures and with water-tetrahydrofuran media, together with a study of isotope effects suggest that these reactions occur through a highly ordered transition state and that the role of solvation should not be overlooked.
- Calle, Emilio,Casado, Julio,Cinos, Jose L.,Mateos, Francisco J. Garcia,Tostado, Manuel
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p. 987 - 991
(2007/10/02)
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- Infrared Multiphoton Decomposition of Diethylnitramine
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Irradiation of gaseous diethylnitramine with infrared radiation from a pulsed CO2 laser under collision-free and collisional conditions resulted in the formation of diethylnitrosamine as the main product along with nitrogen dioxide, nitric oxide, formaldoxime, and diethyl nitroxide.Scavenging experiments with Cl2, NO, and (CD3)2NNO2 molecules have shown that the primary channel of unimolecular dissociation of diethylnitramine molecules is the scission of the N-NO2 bond, with a steady-state rate constant of 105.2 +/- 0.1(I/MW cm-2) s-1 for laser intensities in the range 3-15 MW cm-2 at an irradiation frequency of 1075.9 cm-1.A qualitative analysis of the chemical mechanism leading to the formation of final products as well as the importance of the diethylamino radical oxidation reactions is presented.
- Lazarou, Yannis G.,King, Keith D.,Papagiannakopoulos, Panos
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p. 7351 - 7355
(2007/10/02)
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- The mild N-nitrosation of secondary amines with trichloro nitromethane
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Reaction of trichloronitromethane with secondary amine leads to the formation of corresponding carcinogeneous N-nitrosamines under mild conditions.
- Demir,Mahasneh,Aksoy,Gercek
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p. 2607 - 2611
(2007/10/02)
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- Reactions of trifluoroamine oxide: A route to acyclic and cyclic fluoroamines and N-nitrosoamines
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Acyclic secondary fluoroamines and N-nitrosoamines R2NF and R2NNO (R = CH3, C2H5, n-C3H7, i-C3H7, n-C4H9, i-C4H9, c-C6H11) and saturated nonaromatic heterocyclic fluoroamines and N-nitrosoamines R NF and R NNO [R = c-C4H8, c-C5H10, 2,6-(CH3)2-c-C5H8, 2,2,6,6-(CH3)4-c-C5H6] were prepared by reacting trifluoroamine oxide (NF3O) with the respective amine at ≤0 °C in a 1:2 molar ratio. The amine hydrofluoride salts are also formed. Trifluoroamine oxide is a very effective fluorinating and nitrosating reagent and provides an excellent route to >NF- and >NNO-containing compounds. With PF5, 2,2,6,6-(CH3)4-c-C5H6NFgave [CH2CH2CH2C(CH3)2N +=C(CH3)2]PF6-.
- Gupta, Om Dutt,Kirchmeier, Robert L.,Shreeve, Jean'ne M.
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p. 2383 - 2386
(2007/10/02)
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- Structure-reactivity correlations in nitrosation reactions of secondary amines by alkyl nitrites in basic media
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A study was conducted on the influence of the basic character of different secondary amines on the rate of their nitrosation reactions by propyl and 2-hydroxyethyl nitrites in basic medium (pH = 9-12).For the series of the five structurally similar amines studied (morpholine, piperazine, N-methylpiperazine, piperidine, and pyrrolidine) an excellent linear correlation was observed between the values of the logarithm of the second order rate constant - corresponding to the attack of the alkyl nitrites on the unprotonated amines - and the pKa of these amines.These results, together with the scattering of linearity when including non structurally similar substrates, confirm that the reactions studied are mainly orbital-controlled and have permitted us a rough estimation of the vertical Ionization Potentials, vIP, of piperazine, N-methylpiperazine and morpholine.The kinetic study of nitrosation reaction of N-methylaniline has led to results from which, when compared with those obtained referring to the five above-mentioned substrates, it is possible to infer again that the reactivity of the nitrosatable substrates studied does not depend exclusively on their pKa.
- Casado, Julio,Castro, Albino,Lopez-Quintela, M. Arturo,Lorenzo-Barral, M. Francisco
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p. 401 - 404
(2007/10/02)
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- Inhibition of Nitrosamine Formation by Nondialyzable Melanoidins
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The degradation of nitrite and the inhibition towards formation of carcinogenic nitrosamines by melanoidins produced from the glucose-glycine system were investigated at various conditions.The degradation of nitrite was highest at pH 1.2 (29percent), when the ratio of melanoidins to nitrite was 1:3.The inhibition towards formation of nitrosamines by melanoidins had the same tendency as the degradation of nitrite, the inhibition also being highest at pH 1.2 (99percent).In addition, melanoidins after nitrite treatment exhibited a little higher mutagenicity and much stronger desmutagenicity than those of the original melanoidins.The change of the structure of melanoidins after treating with nitrite was also investigated by HPLC and CP-MAS NMR.
- Kato, Hiromichi,Lee, In Eui,Chuyen, Nguyen Van,Kim, Seon Bong,Hayase, Fumitaka
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p. 1333 - 1338
(2007/10/02)
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- Nitrosamines from Tertiary Amines and Dinitrogen Tetraoxide
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A preparative nitrosolysis of aliphatic acyclic and cyclic tertiary monoamines to nitrosoamines was brought about by treatment with dinitrogen tetraoxide in carbon tetrachloride at 0-40 deg C.Dealkylation was restricted, where applicable, to demethylation.Competitive oxidation to an amide was observed in the formation of dibutylformamide from tributylamine.Diamine dinitrate salts, without nitrosamine formation, were obtained from 1,4-dimethylpiperazine and 1,4-diazabicyclo-octane; however, each dinitrate salt thermolysed at 180-200 deg C to give a small amount of 1,4-dinitrosopiperazine.In acetic anhydride dinitrogen tetraoxide converted amines less efficiently, gave lower yield of nitrosoamines, was less selective in dealkylation, and introduced the formation of by-products.
- Boyer, Joseph H.,Pillai, T. Perumal
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p. 1661 - 1664
(2007/10/02)
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- Reaction of N-Nitroso- and N-Nitro-N-alkylamides with Amines
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Several N-nitroso- and N-nitrocarboxamides have been characterized by 1H and 13C NMR spectroscopy.These compounds react with ammonia and aliphatic amines to afford mainly carboxamides of general formula RCONH2, RCONHR', or RCONR'R''.N-Nitrosocarboxamides and aromatic amines give poor yields of RCONHAr; by contrast, N-nitrocarboxamides and aromatic amines lead to RCONHAr in good yields.The higher thermal stability of the N-nitroamides as compared to N-nitrosoamides is advantageous in this connection; nevertheless, the principal advantage of the NNO2 group appears to be that it activates the nucleophilic attack to the carbonyl of the amide function more than the NNO group, as has been demonstrated by competitive experiments.The reaction of N-nitroso- and N-nitro-N-methylsulfonamides with ammonia and diethylamine has been studied as well; whereas N-methyl-N-nitro-p-toluenesulfonamide reacts as N-nitrocarboxamides, transnitration is predominant with N-methyl-N-nitroso-p-toluenesulfonamide.
- Garcia, Jordi,Gonzalez, Javier,Segura, Ramon,Urpi, Felix,Vilarrasa, Jaume
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p. 3322 - 3327
(2007/10/02)
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