- 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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- 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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- 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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- Four-Coordinate Copper Halonitrosyl {CuNO}10 Complexes
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While copper nitrosyl complexes are implicated in numerous biological systems, isolable examples remain limited. In this report, we show that [Cl3CuNO]?, with a {CuNO}10 electron configuration, can be generated by nitrite reduction at a copper(I) dichloride anion or by nitric oxide addition to a copper(II) trichloride precursor. The bromide analogue, [Br3CuNO]? was synthesized analogously, and both copper halonitrosyl complexes were characterized by X-ray diffraction and a variety of spectroscopic methods. Experimental data and multireference (CASSCF/NEVPT2) calculations provide strong evidence for a CuII–NO. ground state. Both [Cl3CuNO]? and [Br3CuNO]? release and recapture NO. reversibly, and exhibit nitrosative reactivities toward a wide range of biological nucleophiles, such as amines, alcohols, and thiols.
- Bower, Jamey K.,Sokolov, Alexander Yu.,Zhang, Shiyu
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- Effect of stirring devices on the intensification of gas-fluid processes
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A comparative analysis is made of the operation of apparatus of rotary-pulsation and ejector types with self-suction turbine agitator. The dependence of the efficiency of operation on the output capacity and energy-related characteristics determining power consumption for agitation of gas-fluid mixtures were determined experimentally.
- Ivanets,Al'brekht,Ivanets
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Read Online
- One-Pot Tandem ortho-Naphthoquinone-Catalyzed Aerobic Nitrosation of N-Alkylanilines and Rh(III)-Catalyzed C-H Functionalization Sequence to Indole and Aniline Derivatives
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The nitroso group served as a traceless directing group for the C-H functionalization of N-alkylanilines, ultimately removed after functioning either as an internal oxidant or under subsequent reducing conditions. The unique ability of o-NQ catalysts to aerobically oxidize the N-alkylanilines without using solvents and stoichiometric amounts of oxidants has rendered the new opportunity to develop the telescoped catalyst systems without a need for directly handling the hazardous N-nitroso compounds.
- Si, Tengda,Kim, Hun Young,Oh, Kyungsoo
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p. 1152 - 1163
(2021/01/14)
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- Access to Branched Allylarenes via Rhodium(III)-Catalyzed C-H Allylation of (Hetero)arenes with 2-Methylidenetrimethylene Carbonate
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A rhodium(III)-catalyzed C-H allylation of (hetero)arenes by using 2-methylidenetrimethylene carbonate as an efficient allylic source has been developed for the first time. Five different directing groups including oxime, N-nitroso, purine, pyridine, and pyrimidine were compatible, delivering various branched allylarenes bearing an allylic hydroxyl group in moderate to excellent yields.
- Zhang, Shang-Shi,Zheng, Yi-Chuan,Zhang, Zi-Wu,Chen, Shao-Yong,Xie, Hui,Shu, Bing,Song, Jia-Lin,Liu, Yan-Zhi,Zeng, Yao-Fu,Zhang, Luyong
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supporting information
p. 5719 - 5723
(2021/08/16)
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- Rh(iii)-catalyzed, hydrazine-directed C-H functionalization with 1-alkynylcyclobutanols: A new strategy for 1: H -indazoles
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Rh(iii)-catalyzed coupling of phenylhydrazines with 1-alkynylcyclobutanols was realized through a hydrazine-directed C-H functionalization pathway. This [4+1] annulation, based on the cleavage of a Csp-Csp triple bond in alkynylcyclobutanol, provides a new pathway to prepare diverse 1H-indazoles under mild reaction conditions. This journal is
- Zhang, Lei,Chen, Junyu,Chen, Xiahe,Zheng, Xiangyun,Zhou, Jian,Zhong, Tianshuo,Chen, Zhiwei,Yang, Yun-Fang,Jiang, Xinpeng,She, Yuan-Bin,Yu, Chuanming
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supporting information
p. 7415 - 7418
(2020/07/15)
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- Rhodium(iii)-catalyzed indole synthesis at room temperature using the transient oxidizing directing group strategy
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Rh-catalyzed reactions of N-alkyl anilines with internal alkynes at room temperature have been developed using an in situ generated N-nitroso group as a transient oxidizing directing group. Due to mild reaction conditions, this method enabled synthesis of a broad range of N-alkyl indoles, including even two indole-based medicinal compounds. Our work disclosed the feasibility of the transient oxidizing directing group strategy in C-H functionalization reactions, which possesses the potential to enhance overall step-economy and impart new reactivity patterns to substrates.
- Shang, Yaping,Jonnada, Krishna,Yedage, Subhash Laxman,Tu, Hua,Zhang, Xiaofeng,Lou, Xin,Huang, Shijun,Su, Weiping
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supporting information
p. 9547 - 9550
(2019/08/15)
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- 4-amino diphenylamine preparation method
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The invention discloses a 4-amino diphenylamine preparation method which includes the steps: slowly dropping concentrated hydrochloric acid into concentrated sulfuric acid, drying generated HCl gas bythe concentrated sulfuric acid and then leading the HCl gas into n-butyl alcohol for absorbing the gas; adding diphenylamine, sodium nitrite, water and methylbenzene, dissolving the diphenylamine bystirring, and then dropping hydrogen chloride for reaction with n-butyl alcohol solution; performing standing and liquid separation, removing water phase and organic phase vacuum desolvation agents, adding water, stirring the solution and performing suction filtration, washing and drying to obtain 4-nitroso diphenylamine; adding the 4-nitroso diphenylamine into an autoclave, adding solvents and catalysts, replacing air in the autoclave by hydrogen and performing hydrogenation reaction; filtering catalyzed hydrogenation liquid, decompressing the desolvation agents and finally performing rectification to obtain 4-amino diphenylamine. According to the preparation method, under the condition of low and medium pressure, composite skeleton nickel catalysts replace traditional noble metal catalysts for hydrogenation reduction of 4-amino diphenylamine, waste gas, waste water and industrial residues are fewer, environmental protection is benefited, and production cost is reduced.
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Paragraph 0024-0065
(2019/04/06)
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- Copper(II) activation of nitrite: Nitrosation of nucleophiles and generation of NO by thiols
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Nitrite (NO2-) and nitroso compounds (E-NO, E = RS, RO, and R2N) in mammalian plasma and cells serve important roles in nitric oxide (NO) dependent as well as NO independent signaling. Employing an electron deficient β-diketiminato copper(II) nitrito complex [C12NNf6]Cu(κ2-O2N)-THF, thiols mediate reduction of nitrite to NO. In contrast to NO generation upon reaction of thiols at iron nitrite species, at copper this conversion proceeds through nucleophilic attack of thiol RSH on the bound nitrite in [CuII](κ2-O2N) that leads to S-nitrosation to give the S-nitrosothiol RSNO and copper(Il) hydroxide [CuII]-OH. This nitrosation pathway is general and results in the nitrosation of the amine Ph2NH and alcohol tBuOH to give Ph2NNO and tBuONO, respectively. NO formation from thiols occurs from the reaction of RSNO and a copper(II) thiolate [CuII]-SR intermediate formed upon reaction of an additional equiv thiol with [CuII]-OH.
- Kundu, Subrata,Kim, William Y.,Bertke, Jeffery A.,Warren, Timothy H.
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supporting information
p. 1045 - 1048
(2017/05/15)
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- An efficient synthesis of: N -nitrosamines under solvent, metal and acid free conditions using tert -butyl nitrite
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Synthesis of various N-nitroso compounds from secondary amines is reported using tert-butyl nitrite (TBN) under solvent free conditions. Broad substrate scope, metal and acid free conditions, easy isolation procedure and excellent yields are few important features of this methodology. The acid labile protecting groups such as tert-butyldimethylsilyl (TBDMS) and tert-butyloxycarbonyl (Boc) as well as sensitive functional groups such as phenols, olefins and alkynes are found to be stable under the standard reaction conditions. Besides N-nitrosation, TBN is also found to be an efficient reagent in few other transformations including aryl hydrazines to aryl azides and primary amides to carboxylic acids under mild conditions.
- Chaudhary, Priyanka,Gupta, Surabhi,Muniyappan, Nalluchamy,Sabiah, Shahulhameed,Kandasamy, Jeyakumar
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supporting information
p. 2323 - 2330
(2016/05/19)
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- Palladium-catalyzed oxidative C-H bond acylation of N-nitrosoanilines with toluene derivatives: A traceless approach to synthesize N-alkyl-2-aminobenzophenones
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A palladium-catalyzed cascade cross-coupling of N-nitroso-anilines and toluene derivatives for the direct synthesis of N-alkyl-2-aminobenzophenones is described. N-nitroso groups in anilines can act as the traceless directing groups while toluene derivatives can serve as effective acyl precursors under mild reaction conditions.
- Wu, Yinuo,Feng, Ling-Jun,Lu, Xiao,Kwong, Fuk Yee,Luo, Hai-Bin
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supporting information
p. 15352 - 15354
(2015/01/08)
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- Rhodium(III)-catalyzed N-nitroso-directed C-H addition to ethyl 2-oxoacetate for cycloaddition/fragmentation synthesis of indazoles
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RhIII-catalyzed N-nitroso-directed C-H addition to ethyl 2-oxoacetate allows subsequent construction of indazoles, a privileged heterocycle scaffold in synthetic chemistry, through the exploitation of reactivity between the directing group and installed group. The formal [2+2] cycloaddition/fragmentation reaction pathway identified herein, a unique reactivity pattern hitherto elusive for the N-nitroso group, emphasizes the importance of forward reactivity analysis in the development of useful C-H functionalization-based synthetic tools. The synthetic utility of the protocol is demonstrated with the synthesis of a tri-cyclic-fused ring system. The diversity of covalent linkages available for the nitroso group should enable the extension of the genre of reactivity reported herein to the synthesis of other types of heterocycles.
- Chen, Jinsen,Chen, Pei,Song, Chao,Zhu, Jin
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supporting information
p. 14245 - 14249
(2015/02/05)
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- Rhodium(III)-catalyzed N-nitroso-directed C-H olefination of arenes. High-yield, versatile coupling under mild conditions
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N-Nitroso compounds are a versatile class of organic structures that allow expedient access to a diversity of synthetically useful architectures through demonstrated reactivities. We report herein the development of a Rh(III)-catalyzed N-nitroso-directed
- Liu, Baoqing,Fan, Yang,Gao, Yang,Sun, Chao,Xu, Cheng,Zhu, Jin
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supporting information
p. 468 - 473
(2013/02/23)
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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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- A three-coordinate copper(II) amide from reductive cleavage of a nitrosamine
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A NO-velty: A copper(1) β-diketiminate activates the nitrosamine Ph2NNO to give a rare, three-coordinate copper(II) amide, [(Me 2NN)Cu-NPh2]. Reaction of this amide with NOgas returns Ph2NNO as well as a mixed-valence species with NOfunctionalized β-diketiminate ligands (see scheme; Cu light blue, N dark blue, O red). Thus, both the cleavage and formation of R2N-NO bonds may take place at a common copper center. (Figure Presented)
- Melzer, Marie M.,Mossin, Susanne,Dai, Xuliang,Bartell, Ashley M.,Kapoor, Pooja,Meyer, Karsten,Warren, Timothy H.
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supporting information; experimental part
p. 904 - 907
(2010/06/11)
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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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- Reactions of nitrosoarenes with nitrogen monoxide (nitric oxide) and nitrogen dioxide: Formation of diarylnitroxides
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Nitrosoarenes react with nitrogen monoxide (nitric oxide) at room temperature and in aprotic media to afford the corresponding diarylnitroxides by the intermediate formation of N-nitrosoarylnitroxides. However, these latter spin adducts, in contrast with literature reports, have never been detected by us. N-nitrosophenylnitroxide is obtained only in the oxidation of the ammonium salt of N-nitrosophenylhydroxylamine (cupferron) with trace amounts of lead tetraacetate. However, it evolves with time to diphenylnitroxide, as demonstrated by following the reaction course in the ESR cavity. On a macroscale level, the reaction between nitrosobenzene and nitric oxide leads to the formation of N-nitrosodiphenylamine, 4-nitro-N-nitrosodiphenylamine, 4-nitrodiphenylamine and 4,4′-dinitrodiphenylamine, in addition to diphenylnitroxide. Diarylnitroxides are also obtained when nitrosoarenes react with small amounts of nitrogen dioxide; the mechanism of this reaction is proposed and discussed. The structure of 4-nitro-N-nitrosodiphenylamine was determined by X-ray analysis. Wiley-VCH Verlag GmbH & Co. KGaA, 2008.
- Astolfi, Paola,Carloni, Patricia,Damiani, Elisabetta,Greci, Lucedio,Marini, Milvia,Rizzoli, Corrado,Stipa, Pierluigi
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experimental part
p. 3279 - 3285
(2009/04/06)
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- PROCESS FOR PRODUCING HYDRAZONE COMPOUND
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The present invention provides a process for producing a hydrazone compound represented by the general formula (5): which comprises a step of condensing a hydrazine compound represented by the general formula (3): with a carbonyl compound represented by the general formula (4): without taking the hydrazine compound out of a reactor. According to the invention, the target hydrazone compound can be obtained in high quality and in a high yield without taking the hydrazine compound out of the reactor at all, the hydrazine compound being a reaction intermediate which is structurally unstable and has a fear of influencing safety of workers owing to its toxicity (mutagenicity).
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Page/Page column 7; 8
(2008/06/13)
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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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- 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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- 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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- 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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- 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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- 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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- 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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- 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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- 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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- 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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- New sulfonyl derivatives of 2,2-diphenyl-1-picrylhydrazyl and their supramolecular complexes with crown ethers or kryptands
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The synthesis of mono-and di-sulfonates 1 and 2 derived from DPPH was optimised (their notation is NaOSO2-DPPH and (NaOSO2)2-DPPH, respectively). The pKa values of the corresponding hydrazines 3 and 4 were determined. With crown ether 18-C-6, hydrophobic supramolecular complexes are formed by 3 and 4. The sodium monosulfonate 3 reacts with thionyl chloride yielding the sulfochloride ClSO2-DPPH-H (5). With alcohols or amines, 5 reacts readily leading to alkyl esters and sulfonamide derivatives, respectively: thus, valine afforded a well-characterized compound, and the corresponding free radical may be used as a spin label or as a colored redox indicator for peptide chemistry. Similarly, 4-aminoantipyrine forms a sulfonamide. The new compounds were characterised by elemental analysis, IR, UV-VIS, NMR and ESR spectroscopy, and by their complexation and transport data.
- Ioni?ǎ, Petre,Cǎproiu, Miron T.,Balaban, Alexandru T.
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p. 935 - 941
(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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- An improved synthesis of camphorquinone-3-oxime
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Camphorquinone 3-oxime is prepared in 77% yield in one step from camphor. The synthesis avoids the use of toxic selenium reagents, and provides the syn compound as the major stereoisomer.
- Love, Brian E.,Jones, Edward G.
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p. 2831 - 2840
(2007/10/03)
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- Reactions of Nitric Oxide with Amines in the Presence of Dioxygen
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Nitric oxide (NO), a multifaceted bioregulatory agent and an environmental pollutant, can effectively convert aromatic amines to the corresponding triazenes under aerobic conditions, but not under anaerobic conditions.Nucleic acid bases and nucleosides are also determinated via hydrolysis of the diazonium ion products with exposure to aerobic NO solution.A peroxynitrite radical or nitrogen dioxide is suggested to be the ultimate reactive species.
- Nagano, Tetsuo,Takizawa, Hiromasa,Hirobe, Masaaki
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p. 8239 - 8242
(2007/10/02)
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- Transnitrosation by N-aryl-N-nitrosoureas; NO-carrying O-nitrosoisourea
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Transfer of nitroso groups, so-called transnitrosation, from aromatic N-nitroso compounds such as N-nitrosoureas, N-nitrosamides and N-nitrosamines, to aromatic amines or ureas was observed under non-acidic conditions at room temperature. Sterically hindered 3,3-dibenzyl-1-(4-tolyl)-1-nitrosourea (1a) rapidly nitrosates indoline, N-alkylanilines or 3-methyl-1-(4-tolyl)urea to give their N-nitroso derivatives. In the case of N,N-dimethylanilines, nitrosative demethylation occurs to give N-methyl-N-nitrosanilines. The transnitrosation is accelerated by electron-releasing groups on the nitroso acceptors, N-alkylanilines. The transnitrosation mechanism is considered to be as follows: N-nitrosourea (1) thermally decomposes to nitric oxide and ureidyl radical followed by formation of an O-nitrosoisourea intermediate (10), which acts as an NO-carrying agent and nitrosates anilines or ureas.
- Tanno,Sueyoshi,Miyata
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p. 1760 - 1767
(2007/10/02)
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- Nitrosations with hydrazine derivatives. Novel synthesis of arylsulfonyltriazenes by nitrosation of N4-arylsulfonylsemicarbazides
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N1-disubstituted N4-arenesulfonylsemicarbazides 3 are prepared by hydrazinolysis of the arenesulfonylurethanes 2, which result from arenesulfonamides and chloroformic acid ester. Under nitrosating conditions 3 are mainly transformed into the sulfonyltriazenes 4.
- Hanefeld,Hartmann
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p. 672 - 675
(2007/10/02)
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- Nitrosamines and Hydrazones of Dinitroformaldehyde from N,N-Disubstituted Hydrazines, a Dialkyl Nitroxide, and Tetranitromethane
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N,N-Disubstituted hydrazines reacted with a mixture of a dialkylnitroxide and tetranitromethane to give nitrosamines and small amounts of hydrazones of dinitroformaldehyde.
- Krishnan, Ashwin M.,Wolford, Lionel T.,Boyer, Joseph H.
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p. 569 - 570
(2007/10/02)
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- Nitrosamines from N,N-Disubstituted Hydrazines Via Hydrazones of Dinitroformaldehyde and Ethyl Nitroglyoxylate
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N,N-Dialkyl, diaryl, and arylalkyl hydrazones of dinitroformaldehyde were obtained from hydrazines and either tetranitromethane (TNM) or iodotrinitromethane (ITM) and gave nitrosamines on irradiation at 350 nm in acetone for several days.Similar N,N-disubstituted hydrazones of ethyl nitroglyoxylate were obtained from the hydrazines and either ethyl dinitroiodoacetate (DNIA) or ethyl dinitrobromoacetate (DNBA) but were neither thermal nor photochemical precursors to nitrosamines, coproducts obtained in minor amounts.Explanations for the formations of the hydrazones and nitrosamines were offered.
- Boyer, Joseph H.,Krishnan, Ashwin M.
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p. 201 - 213
(2007/10/02)
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- Nitrosamines from N,N-Disubstituted Hydrazines
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Photolysis of nitro hydrazones (from N,N-disubstituted hydrazines and tetranitromethane) gave nitrosamines.
- Boyer, Joseph H.,Krishnan, Ashwin M.
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p. 715 - 716
(2007/10/02)
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- Unusual Rate-limiting Proton Transfer in the Acid-catalysed Reactions of N-Nitroso Compounds
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For both N-methyl-N-nitrosoaniline and N-nitrosodiphenylamine, the catalytic effect of halide ion, thiocyanate ion, and thiourea in the denitrosation reaction in acid solution disappears at high nucleophile concentrations.This suggests a change to an earlier rate-limiting step.The data, including the variation of rate constant with acidity, are quantitatively in accord with a reaction mechanism involving protonation of the nitosamine followed by nucleophilic attack, either stage being rate limiting, depending on the reactivity and concentration of the nucleophile.The kinetic solvent isotope effect kH2O/kD2O decreases from 1.59 at 0.43M-thiourea to 0.71 at 0.015M-thiourea, which is consistent with a change from general acid catalysis at high to specific hydrogen ion catalysis at low .Substituent effects at the amino-nitrogen atom and also in the 4-position of a phenyl substituent are very amall, the largest effect being a three-fold reduction in rate constant effected by a 4-NO2 group.These results are in accord with the known dipolar nature of nitrosamines.There is a close analogy between this system and the acid-catalysed cleavage reaction of carbamate derivatives.A similar mechanism is proposed involving a pre-association of the reactants forming a hydrogen-bonded intermediate.
- Al-Kaabi, Sharifa S.,Hallett, Geoffrey,Meyer, Thomas A.,Williams, D. Lyn H.
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p. 1803 - 1808
(2007/10/02)
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- A FACILE IN-SITU DIAZO COUPLING REACTIONS UNDER TWO-PHASE CONDITIONS CATALYZED BY TETRAKISBORATE ION
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In-situ diazo-coupling and N- and C-nitrosations under CH2Cl2-aq.H2SO4 two-phase systems have proved to be catalyzed by TFPB ion.
- Iwamoto, Hidetoshi,Sonoda, Takaaki,Kobayashi, Hiroshi
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p. 4703 - 4706
(2007/10/02)
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- Method for producing 4-nitrosodiphenylamine
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A method for producing 4-nitrosodiphenylamine, consisting in diphenylamine nitrozation with nitrites of alkali metals or ammonium nitrite in the presence of an acid and an organic solvent nonmiscible with water; said nitrozation being carried out under stirring with a speed determined by Reynolds number not below, 8-10×103 or in the presence of polymers of methacrylic acid esters in an amount of 0.01-0.02% of the reaction mixture weight under stirring with a speed determined by Reynolds number equal to 4-5×103 ; this is followed by rearrangement of the resultant N-nitrosodiphenylamine with anhydrous hydrogen chloride in an inert gas atmosphere in the presence of an alkyl 4-aminodiphenylamine in an amount of 0.5-1% of the N-nitrosodiphenylamine weight, with subsequent neutralization of the formed 4-nitrosodiphenylamine hydrochloride and isolation of the desired product. The method described above makes it possible to increase the product yield at the nitrozation stage by a factor of 5-6 and to raise the yield of the desired product up to 99% in terms of the converted N-nitrosodiphenylamine. 4-Nitrosodiphenylamine produced serves as an intermediate in the synthesis of antioxidants for rubbers and plastics, in the synthesis of dyestuffs, and is also used as a component in a number of antioxidant compositions.
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