cas 615-57-6, 2,4-Dibromoaniline | Articles data

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NOVEL TRICYCLIC COMPOUND AS IRAK4 INHIBITOR
The present invention relates to a pharmaceutical composition for preventing or treating autoimmune diseases or tumors, containing, as an active ingredient, a tricyclic compound represented by the following Chemical Formula 1 or a pharmaceutically acceptable salt thereof, and a health food composition for preventing or alleviating autoimmune diseases or tumors, containing the tricyclic compound as an active ingredient. The tricyclic compound represented by Chemical Formula 1 of the present invention has an excellent inhibitory activity against IRAK4, and thus can be usefully used for the prevention, treatment, or alleviation of autoimmune diseases or tumors.
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Paragraph 0046-0048

(2021/10/02)

A Practical Procedure for Regioselective Bromination of Anilines
A highly practical procedure for the preparation of bromoanilines by using copper-catalyzed oxidative bromination has been developed. Treatment of free anilines with readily available NaBr and Na 2S 2O 8in the presence of a catalytic amount of CuSO 4·5H 2O enabled regioselective bromination.
Takahashi, Yusuke,Seki, Masahiko
p. 1828 - 1832
(2021/04/15)

Selective Thiocyanation and Aromatic Amination to Achieve Organized Annulation of Enaminone with Thiocyanate
A tandem insertion of thiocyanate to enamine was performed for the regioselective synthesis of multisubstituted benzoimidazo[2,1-b]thiazoles. This method was shown to be effective in addressing the issue of isomerization encountered in common strategies. With a change made to the leading group on the aniline fragment of enamine, the reaction achieved different transformations, thus enabling multisubstituted benzo[4,5]imidazo[2,1-b]thiazoles and thiazoles in satisfactory yields.
Feng, Xukai,Leng, Xin,Li, Jianli,Li, Yao,Liu, Hua,Liu, Lang,Liu, Ping,She, Mengyao,Zhang, Jun,Zhang, Shengyong,Zheng, Tingting
supporting information
p. 8396 - 8401
(2021/11/17)

Visible-light-promoted oxidative halogenation of (hetero)arenes
Organic halides are critical building blocks that participate in various cross-coupling reactions. Furthermore, they widely exist as natural products and artificial molecules in drugs with important physiological activities. Although halogenation has been well studied, to the best of our knowledge, studies focussing on sensitive systems (e.g.aryl amines) have not been reported. Herein, we describe a compatible oxidative halogenation of (hetero)arenes with air as the oxidant and halide ions as halide sources under ambient conditions (visible light, air, aqueous system, room temperature, and normal pressure). Moreover, this protocol is practically feasible for gram-scale synthesis, showing potential for industrial application.
Jiang, Xuefeng,Li, Yiming,Lu, Lingling
supporting information
p. 5989 - 5994
(2020/10/18)

Aryl halide and synthesis method and application thereof
The invention discloses a synthesis method of aryl halides (including aryl bromide shown as a formula (2) and aryl iodide shown as a formula (3)). All the systems are carried out in an air atmosphere,visible light is utilized to excite a substrate or a photosensitizer to catalyze the reaction; and in a reaction solvent, when aromatic hydrocarbon shown in the formula (1) and sodium bromide serve as raw materials, aryl bromide shown in the formula (2) is obtained through a reaction under the auxiliary action of an additive (protonic acid); or when aromatic hydrocarbon shown in the formula (1) and sodium iodide are used as raw materials, under the auxiliary action of an additive (protonic acid), aryl iodide shown in the formula (3) is obtained through reaction. The synthesis method has the advantages of cheap and accessible raw materials, simple reaction operation and mild reaction conditions. The method is compatible with the arylamine which is liable to be oxidized. The invention provides a new method for the synthesis of aryl halides, realizes the amplification of basic chemicals aryl halides including aryl bromide shown in the formula (2) and aryl iodide shown in the formula (3),and has wide application prospect and practical value.
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Paragraph 0064-0066

(2020/06/02)

A metal-free aerobic oxidative bromination of anilines and aryl ketones with 2-methylpyridinium nitrate as a reusable ionic liquid
An aerobic oxidative bromination of anilines and aryl ketones catalyzed by recyclable 2-methylpyridinium nitrate ionic liquid is achieved in water using hydrobromic acid as the bromine source and molecular oxygen as the oxidant. The catalytic system shows good efficiency and atom economy.
Li, Ming-Fang,Wang, Jian,Ke, Yong-Xin,Pan, Song-Cheng,Yin, Hong,Du, Wenting,Li, Jing-Hua
p. 267 - 270
(2020/01/08)

AN IMPROVED ONE POT, ONE STEP PROCESS FOR THE HALOGENATION OF AROMATICS USING SOLID ACID CATALYSTS
The present invention disclosed an improved one pot, one step process for halogenation of compound of formula (II) to afford corresponding halogenated compound of formula (I) having improved yield and increased selectivity under very mild conditions.
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Page/Page column 0063

(2019/04/18)

Sustainable visible light assisted in situ hydrogenation via a magnesium-water system catalyzed by a Pd-g-C3N4 photocatalyst
A non-hazardous and relatively mild protocol was formulated for an effectual hydrogen generation process via a "magnesium-activated water" system with a Pd-g-C3N4 photocatalyst under visible light at room temperature. Water functions photochemically as a hydrogen donor without any external source with the Pd-g-C3N4 photocatalyst. The synthesized Pd-g-C3N4 photocatalyst is highly efficient under visible light for the selective reduction of a wide range of unsaturated derivatives and nitro compounds to afford excellent yields (>99%). The photocatalyst Pd-g-C3N4 could be easily recovered and reused for several runs without any deactivation during the photochemical hydrogen transfer reaction process.
Sharma, Priti,Sasson, Yoel
supporting information
p. 261 - 268
(2019/01/28)

Cu-mediated selective bromination of aniline derivatives and preliminary mechanism study
A simple and efficient bromination of aniline, aniline derivatives, and analogs have been developed. Forty three examples were given and the highest yield reached was 98%. Different substrates including substituted aniline, pyridin-amine, N-substituted aniline, N,N-disubstituted aniline, N-phenyl-amide, N-phenyl-sulfonamide, and nitrogen-containing heterocycles were all reactive and selectively generated desired bromo-products. The method can be applied to synthesize drug intermediate and quinoxaline derivatives.
Zhao, Hong-Yi,Yang, Xue-Yan,Lei, Hao,Xin, Minhang,Zhang, San-Qi
p. 1406 - 1415
(2019/05/01)

Unusual Chemistry in an Uncatalyzed Bromate-Aniline Oscillator: Ring-Contraction Oxidation of Aniline with Pulsative CO2 Production
The bromate-aniline oscillatory reaction was discovered 4 decades ago, but neither the detailed mechanism nor the key products or intermediates of the reaction were described. We report herein a detailed study of this reaction, which yielded new insights. We found that oscillatory oxidation of aniline by acidic bromate proceeds, to a significant extent, via a novel reaction pathway with the periodic release of carbon dioxide. Several products were isolated, and their structures, not described so far, were justified on the basis of MS and NMR. One of the main products of the reaction associated with the CO2 release route can be assigned to 2,2-dibromo-5-(phenylimino)cyclopent-3-en-1-one. A number of known compounds produced in the studied reaction, including unexpected brominated 1-phenylpyrroles and 1-phenylmaleimides, were identified by comparison with standards. A mechanism is suggested to explain the appearance of the detected compounds, based on coupling of the anilino radical with the produced 1,4-benzoquinone. We assume that the radical adduct reacts with bromine to form a cyclopropanone intermediate that undergoes a Favorskii-type rearrangement. Further oxidation and bromination steps including decarboxylation lead to the found brominated phenyliminocyclopentenones. The detected derivatives of 1-phenylpyrrole could be produced by a one-electron oxidation of a proposed intermediate 2-phenylamino-5-bromocyclopenta-1,3-dien-1-ol followed by β-scission with the abstraction of carbon monoxide. Such a mechanism is known from the combustion chemistry of cyclopentadiene. The proposed mechanism of this reaction provides a framework for understanding the observed oscillatory kinetics.
Valent, Ivan,Pribus, Marek,Novák, Filip,Plánková, Sylvia,Bla?ko, Jaroslav,Kubinec, Róbert,Almássy, Ambroz,Filo, Juraj,Sigmundová, Ivica,Sebechlebská, Táňa,Lawson, Thuy Bich,Noszticzius, Zoltán
p. 9669 - 9681
(2019/11/14)

Making endo-cyclizations favorable again: A conceptually new synthetic approach to benzotriazoles via azide group directed lithiation/cyclization of 2-azidoaryl bromides
Although benzotriazoles are important and ubiquitous, currently there is only one conceptual approach to their synthesis: bridging the two ortho-amino groups with an electrophilic nitrogen atom. Herein, we disclose a new practical alternative-the endo-cyclization of 2-azidoaryl lithiums obtained in situ from 2-azido-aryl bromides. The scope of the reaction is illustrated using twenty-four examples with a variety of alkyl, alkoxy, perfluoroalkyl, and halogen substituents. We found that the directing effect of the azide group allows selective metal-halogen exchange in aryl azides containing several bromine atoms. Furthermore, (2-bromophenyl)diazomethane undergoes similar cyclization to give an indazole. Thus, cyclizations of aryl lithiums containing an ortho-X = Y = Z group emerge as a new general approach for the synthesis of aromatic heterocycles. DFT computations suggested that the observed endo-selectivity applies to the anionic cyclizations of other functionalities that undergo "1,1-additions" (i.e., azides, diazo compounds, and isonitriles). In contrast, cyclizations with the heteroatomic functionalities that follow the "1,2-addition" pattern (cyanates, thiocyanates, isocyanates, isothiocyanates, and nitriles) prefer the exo-cyclization path. Hence, such reactions expand the current understanding of stereoelectronic factors in anionic cyclizations.
Ageshina, Alexandra A.,Chesnokov, Gleb A.,Topchiy, Maxim A.,Alabugin, Igor V.,Nechaev, Mikhail S.,Asachenko, Andrey F.
supporting information
p. 4523 - 4534
(2019/05/17)

Sodium sulfate-hydrogen peroxide-sodium chloride adduct: selective protocol for the oxidative bromination, iodination and temperature dependent oxidation of sulfides to sulfoxides and sulfones
The regioselective bromination and iodination of unprotected aromatic primary amines using enclathrated hydrogen peroxide as an oxidant under mild conditions has been developed, in which potassium bromide (KBr) and potassium iodide (KI) were used as brominating and iodinating agents, respectively. The adduct shows not only regioselectivity for para- or ortho-isomers but also a remarkable chemoselectivity for monobromination. Selective oxidation of sulfides to sulfoxides and sulfones has also been studied and good to excellent yields of the desired products were obtained. Acetic acid was found to be the solvent of choice for these reactions. This simple method represents an ecologically benign and alternative pathway for the oxidative halogenation of anilines and the oxidation of sulfides to sulfoxides and sulfones.
Gayakwad, Eknath M.,Patel, Khushbu P.,Shankarling, Ganapati S.
supporting information
p. 6001 - 6009
(2019/04/17)

Direct Synthesis of Structurally Divergent Indole Alkaloids from Simple Chemicals
A direct and structurally divergent synthesis of indole alkaloids from very simple 2-vinylanilines, alkynes and TBN via a novel substrate fragmentation/cycloaddition strategy has been developed, which provides an efficient noble-metal-free approach to access a library of highly valuable indole derivatives of tryptamines and tryptamine-related oximes, lactams, and lactones, as well as β-carbolines, spiroindolines, and hexa-hydropyrrolo[2,3-b]indoles.
Shen, Tao,Zhu, Bencong,Lin, Fengguirong,Pan, Jun,Wei, Jialiang,Luo, Xiao,Liu, Jianzhong,Jiao, Ning
supporting information
p. 815 - 818
(2018/07/31)

Complexes of cis-dioxomolybdenum(VI) with a chiral tetradentate tripodal-like ligand system: Syntheses, structures and catalytic activities
Racemic complexes with the general formula cis-[MoO2(bzacLn)] (1–4) (H2bzacLn?=?2-((4/5-R-2-hydroxyphenylamino)(pyridin-2-yl)methyl)-1-phenylbutane-1,3-dione, where n?=?1–4 for R?=?H, 5-Me, 5-Cl and 4-Me, respectively and 2Hs represent the dissociable phenolic proton and the active tertiary CH proton) have been synthesized in 75–82% yields by reacting [MoO2(bzac)2] (Hbzac?=?benzoylacetone) with the potentially N2O-donor 5,5-membered fused chelate rings forming Schiff bases 4/5-R-2-(2-pyridylaldimine)phenols (HLn; n?=?1–4 for R?=?H, 4-Me, 4-Cl and 5-Me, respectively) in hot methanol. The chiral ligand system (bzacLn)2?in 1–4 is formed via metal assisted Mannich-type addition of benzoylacetonate methine to the azomethine fragment of HLn. All four complexes have been characterized by elemental (CHN) analysis, solution conductivity, magnetic susceptibility, spectroscopic (IR, UV–Vis and NMR) and electrochemical measurements. The molecular structures of 1–3 have been established by single crystal X-ray crystallography. In each complex, the chiral (bzacLn)2?acts as a tetradentate, N2O2-donor, tripodal-like ligand system and along with the two mutually cis oxo groups forms a distorted octahedral N2O4coordination environment around the molybdenum(VI) center. All four complexes are diamagnetic and non-electrolytic. The infrared spectra are generally consistent with the structural formulas of 1–4. The electronic spectra of 1–4 in dimethylformamide display two strong absorption bands in the range 245–300?nm. The cyclic voltammograms of 1–4 in dimethylformamide exhibit a metal centered one-electron reduction response within ?0.64 to ?0.74?V. All these complexes (1–4) and the analogous cis-[MoO2(acacL1–4)] (5–8) synthesized from [MoO2(acac)2] (Hacac?=?acetylacetone) and HL1–4have been evaluated for their bromoperoxidase activities.
Ghosh, Sabari,Kurapati, Sathish Kumar,Pal, Samudranil
p. 26 - 33
(2017/03/07)

Highly active Ru-g-C3N4 photocatalyst for visible light assisted selective hydrogen transfer reaction using hydrazine at room temperature
The present study describes the highly efficient heterogeneous photoactive catalyst Ru-g-C3N4 screened for selective transfer hydrogenation of nitroarenes and olefins. Photoactive catalyst Ru-g-C3N4 exhibits excellent reactivity in visible light under very mild reaction conditions via using hydrazine hydrate as a source of hydrogen with high turnover number. The easily separable heterogeneous photoactive Ru-g-C3N4 catalyst is straightforward to handle in visible light (LED lamp), non-toxic, environmentally friendly and at the same time eliminates the use of high pressure hydrogenation reactors without the need for external sources of energy.
Sharma, Priti,Sasson, Yoel
p. 48 - 52
(2017/08/30)

Palladium-modified functionalized cyclodextrin as an efficient and recyclable catalyst for reduction of nitroarenes
A palladium-modified functionalized cyclodextrin (DACH-Pd-β-CD) catalytic system was synthesized and characterised. It showed high catalytic performance in the reduction of different nitroarenes to the corresponding anilines with the presence of sodium borohydride in water at room temperature. The yields of the desired products are up to 99%. Furthermore, the catalyst can be easily separated and still could maintain high catalytic activity after five cycles and no leaching of Pd into solution occurred.
Guo, Yafei,Li, Jiuling,Zhao, Fen,Lan, Guineng,Li, Liang,Liu, Yuqi,Si, Yunsen,Jiang, Yubo,Yang, Bo,Yang, Rui
p. 7950 - 7954
(2016/02/09)

Direct Tryptophols Synthesis from 2-Vinylanilines and Alkynes via C - C Triple Bond Cleavage and Dioxygen Activation
An unexpected metal-free C - C triple bond cleavage, dioxygen activation, and reassembly into tryptophol derivatives has been developed. This chemistry provides a novel, simple, and efficient approach to highly valuable tryptophol derivatives from simple substrates under mild conditions. The mechanistic studies may promote the discovery of new methodologies through C-C bond cleavage and dioxygen activation.
Shen, Tao,Zhang, Yiqun,Liang, Yu-Feng,Jiao, Ning
supporting information
p. 13147 - 13150
(2016/10/24)

Facile protocol for reduction of nitroarenes using magnetically recoverable CoM0.2Fe1.8O4 (M = Co, Ni, Cu and Zn) ferrite nanocatalysts
Transition metal doped cobalt ferrite (CoM0.2Fe1.8O4 (M = Co, Ni, Cu, Zn)) nanoparticles were fabricated using the sol-gel methodology. The obtained ferrite nanoparticles were annealed at 400 °C and characterized using Fourier transform infra-red spectroscopy (FT-IR), X-ray diffraction (XRD), high resolution transmission electron microscopy (HR-TEM), vibrating sample magnetometry (VSM) and energy dispersive X-ray (EDX) and scanning transmission electron microscopy (STEM). In the FT-IR spectra two bands in the range 1000-400 cm-1 were observed corresponding to the M-O bond in the tetrahedral and octahedral sites. XRD patterns confirmed the formation of a cubic spinel structure with a Fd3m space-group. HR-TEM analysis revealed a quasi-spherical shape with particle sizes in the range 20-30 nm for all the synthesized ferrite nanoparticles. The lattice inter-planar distances of 0.29, 0.25, 0.21 and 0.16 nm obtained from HR-TEM corresponding to the (2 2 0), (3 1 1), (4 0 0) and (5 1 1) lattice planes respectively were in complete agreement with the XRD data. The EDX-STEM confirmed the elemental composition as per the desired stoichiometric ratio. The catalytic efficiency of the synthesized ferrite samples was explored for the reduction of nitrophenols. Cu substituted cobalt ferrite nanoparticles (CoCu0.2Fe1.8O4) possessed excellent catalytic activity while CoM0.2Fe1.8O4 (M = Co, Ni and Zn) were inactive for the same. The substrate scope of the developed protocol was also evaluated for the reduction of various CH3-, NH2-, Br-, Cl- etc. substituted nitroaromatic compounds.
Goyal, Ankita,Kapoor, Surbhi,Samuel, Pankaj,Kumar, Vinod,Singhal, Sonal
p. 51347 - 51363
(2015/06/25)

Selective bromination of pyrrole derivatives, carbazole and aromatic amines with DMSO/HBr under mild conditions
Bromination of pyrrole derivatives, carbazole and aromatic amines using the DMSO/HBr system affords high yields of the corresponding bromo compounds. Temperature control used in the bromination of anilines helped to promote selective formation of mono- or di-brominated products. Simple operation, low toxicity and high selectivity make this a promising new procedure for the bromination of aromatic compounds.
Liu, Cong,Dai, Rongji,Yao, Guowei,Deng, Yulin
p. 593 - 596
(2015/01/09)

Green halogenation of aromatic heterocycles using ammonium halide and hydrogen peroxide in acetic acid solvent
The green generation of X+ (X = Br, I) using hydrogen peroxide in aqueous acetic acid allows access to aromatic heterocyclic halides in yields and purities comparable to syntheses employing N-bromosuccinimide. In activated and unsubstituted thiophene rings, regioselectivity is quantitative for positions α to the sulfur; pyrroles also give quantitative reactions, at least initially. Deactivated rings, including furans and thiazoles, as well as thiophenes with strongly electron-withdrawing groups showed little to no reactivity under the conditions investigated. The reaction shows remarkable functional group tolerance (to alcohol, nitro, alkyl, halo, and carbonyl groups), as shown through reaction with substituted phenols. In all bromination reactions, reaction yields and regiochemistry were very similar to reactions involving N-bromosuccinimide in tetrahydrofuran solvent.
D'Aleo, Danielle N.,Allard, Sheena R.,Foglia, Cassandra C.,Parent, Shawna L.M.,Rohr, David J.,Gottardo, Christine,MacKinnon, Craig D.
p. 679 - 683
(2013/08/23)

A facile, regioselective and controllable bromination of aromatic amines using a CuBr2/Oxone system
A combination of cupric bromide and Oxone serves as a facile, mild and effective reagent for the bromination of aromatic amines. Primary, secondary and tertiary aromatic amines are all suitable substrates. The reaction possesses high regioselectivity and functional group tolerance, and mono- and multi-brominated products can be obtained controllably in moderate to excellent yields. The Royal Society of Chemistry 2013.
Li, Xin-Le,Wu, Wei,Fan, Xin-Heng,Yang, Lian-Ming
p. 12091 - 12095
(2013/09/02)

Fast and efficient bromination of aromatic compounds with ammonium bromide and Oxone
A highly efficient, rapid and regioselective protocol was developed for the ring bromination of aromatic compounds under mild conditions with ammonium bromide as a source of bromine source and Oxone (potassium peroxysulfate) as an oxidant. No metal catalyst or acidic additive is required. A variety of aromatic compounds, including methoxy, hydroxy, amino, and alkyl arenes, reacted smoothly to give the corresponding monobrominated products in good to excellent yields in very short reaction times. Moreover, dibromination of deactivated anilines to give the corresponding dibromides proceeded in high yields. Interestingly, 1-(2-naphthyl)ethanone provided a ring-brominated product. Georg Thieme Verlag Stuttgart . New York.
Naresh, Mameda,Arun Kumar, Macharla,Mahender Reddy, Marri,Swamy, Peraka,Nanubolu, Jagadeesh Babu,Narender, Nama
p. 1497 - 1504
(2013/06/27)

Regioselective and high-yielding bromination of phenols and anilins using N-bromosaccharin and amberlyst-15
A regioselective and facile conversion method for bromination of anilines and phenols using N-bromosaccharine in the presence of a catalytic amount of Amberlyst-15 lead to enhancement of the reaction rate and yielded brominated products in good to excellent yields and short reaction times.
Baharfar,Alinezhad,Azimi,Salehian
experimental part
p. 863 - 865
(2012/04/23)

Efficient and regioselective bromination of aromatic compounds with ethylenebis(N-methylimidazolium) ditribromide (EBMIDTB)
A regioselective and highly efficient method for bromination of phenol and aniline derivatives using ethylenebis(N-methylimidazolium) ditribromide (EBMIDTB) as an efficient reagent in dichloromethane at ambient temperature is reported. The reagent can be recovered and reused several times.
Hosseinzadeh, Rahman,Tajbakhsh, Mahmood,Mohadjerani, Maryam,Lasemi, Zahra
experimental part
p. 868 - 876
(2010/05/18)

Regioselective bromination of organic substrates by LDH-CO3 2--Br- promoted by V2O5-H 2O2
An efficient, fast, simple, mild, and selective monobromination of aromatic compounds, with high para-selectivity, is reported. The catalytic system is readily prepared from a Mg-Al-layered double hydroxide-CO3 2--Br- (LDH-CO32--Br-) as the source of bromide, V2O5 as a promoter and hydrogen peroxide as the oxidant. The use of hydrogen peroxide as a synthetically useful oxidizing agent is reported for generating electrophilic bromine in situ from easily available KBr as a bromine source, to brominate electron rich aromatic compounds, employing LDH-CO32--Br3- as the phase-transfer catalyst. The phase-transfer catalyst leads to nearly complete bromination in 3 h at room temperature with high selectivity. The reaction rate of p-bromoanisole and p-bromotoluene formation by LDH-CO 32--Br3- in a triphasic system was studied. The heterogeneity of the reaction system facilitates the recovery and recycling of the catalyst, and the reagent components are environmentally acceptable. The catalyst, LDH-CO32--Br3 -, and its precursors, LDH-CO32--Br- and LDH-CO32-, were characterized by powder XRD, FT-IR and UV-vis spectroscopy.
Ghiaci,Sedaghat,Ranjbari,Gil
experimental part
p. 18 - 26
(2011/01/05)

Regiospecific oxyhalogenation of aromatics over SBA-15-supported nanoparticle group IV-VI metal oxides
TiOx, VOx, MoOx and WOx supported on SBA-15 exhibit efficient catalytic activity for oxyhalogenation of aromatics with the H2O2-halide ion system. Unlike the hitherto known solid catalysts, these reusable catalysts yield the para-halogenated product with 100% selectivity at 298 K and moderate acidic pH (3-5). The catalytic activity was enhanced by five orders of magnitude when supported on SBA-15. Springer Science+Business Media, LLC 2010.
Saikia,Rajesh,Srinivas,Ratnasamy
scheme or table
p. 190 - 201
(2010/11/05)

Efficient, rapid, and regioselective bromination of phenols and anilines with N-bromosaccharin using tungstophosphoric acid as a heterogeneous recyclable catalyst
A simple, efficient, and rapid method for high-yielding regioselective mono bromination of phenols and anilines has been achieved by treatment with N-bromasaccharin in the presence of a catalytic amount of tungstophosphoric acid. Copyright Taylor & Francis Group, LLC.
Alinezhad, Heshmatollah,Tavakkoli, Sahar Mohseni,Salehian, Fatemeh
experimental part
p. 3226 - 3232
(2010/12/24)

Effect of structural factors and solvent nature in bromination of anilines
Reaction of electrophilic bromination of aniline containing various ortho, meta, and para substituents in the aromatic ring was studied. The optimal conditions for synthesis of mono-, di-, tri-, and tetrabromo derivatives of aniline and brominated analog of Aniline Black were found.
Bagmanov
p. 1570 - 1576
(2011/06/20)

Copper-catalyzed oxybromination and oxychlorination of primary aromatic amines using LiBr or LiCl and molecular oxygen
Nuclear oxybromination of unprotected aromatic primary amines catalyzed by copper(II) acetate [Cu(OAc)2] under mild conditions has been developed, in which bromide ions are used as halogenating agents and dioxygen as a final oxidant. The catalyst shows not only high regioselectivity for para- or ortho-isomers but also a remarkable chemoselectivity for monobromination. Oxychlorination of aniline can also be performed under similar conditions, albeit with lower selectivities, with N-phenylacetamide being the main by-product. This simple catalytic method represents ecologically benign and economically attractive synthetic pathway to expensive low-volume aromatic haloamines.
Menini, Luciano,Da Cruz Santos, Joyce C.,Gusevskaya, Elena V.
experimental part
p. 2052 - 2058
(2009/08/07)

An efficient, rapid and regioselective nuclear bromination of aromatics and heteroaromatics with NBS using sulfonic-acid-functionalized silica as a heterogeneous recyclable catalyst
A simple, efficient and rapid method has been developed for high-yielding regioselective nuclear monobromination of aromatic and heteroaromatic compounds using NBS in the presence of sulfonic-acid-functionalized silica at room temperature. The catalyst works under heterogeneous conditions and can be recycled.
Das, Biswanath,Venkateswarlu, Katta,Krishnaiah, Maddeboina,Holla, Harish
p. 8693 - 8697
(2007/10/03)

Tetrameric DABCO-bromine: An efficient and versatile reagent for bromination of various organic compounds
Tetrameric DABCO-bromine is a powerful brominating agent but shows reasonable selectivity with certain substrates. The selective bromination for activated aromatic compounds and alkenes is reported. Synthesis of α-bromo ketones and nitriles has also been achieved by using this reagent and the results are also reported. All products reported were obtained in good to excellent yields.
Heravi, Majid M.,Derikvand, Fatemeh,Ghassemzadeh, Mitra
p. 125 - 128
(2007/10/03)

Polymer-supported organotin reagents for regioselective halogenation of aromatic amines
(Chemical Equation Presented) Polymer-supported triorganotin halides were used in the halogenation reaction of aromatic amines. Treatment of aromatic amines with n-butyllithium and polymer-supported organotin halides gave the corresponding polymer-bound N-triorganostannylamines, which by treatment with bromine or iodine monochloride gave the para-halogenated aromatic amines with high yields and high selectivities. The polymer-supported organotin halides reagents regenerated during the course of the halogenation reaction can be reused without loss of efficiency. The presence of tin residues in halogenated aromatic amines was also investigated and evaluated at under 20 ppm after three runs.
Chretien, Jean-Mathieu,Zammattio, Francoise,Le Grognec, Erwan,Paris, Michael,Cahingt, Blanche,Montavon, Gilles,Quintard, Jean-Paul
p. 2870 - 2873
(2007/10/03)

An intriguing effect of lithium perchlorate dispersed on silica gel in the bromination of aromatic compounds by N-bromosuccinimide
A convenient and efficient procedure for electrophilic aromatic bromination has been developed by mixing of N-bromosuccinimide and an aromatic compound at room temperature on the surface of silica gel mixed with solid anhydrous LiClO4. All of the substrates examined underwent clean electrophilic aromatic bromination in reaction times of a few minutes to afford the corresponding bromoarenes under neutral conditions in excellent yield. In the case of thiophenol, no substitution reaction occurred, and the corresponding disulfide was obtained in excellent yield.
Bagheri, Mojtaba,Azizi, Najmedin,Saidi, Mohammad R.
p. 146 - 149
(2007/10/03)

Regioselective and high-yielding bromination of aromatic compounds using hexamethylenetetramine-bromine
A regioselective and highly efficient method for bromination of aromatic compounds in the presence of a stoichiometric amount of hexamethylenetetramine- bromine (HMTAB) as an efficient reagent in dichloromethane is reported. The selectivity depends on the temperature and nature of the substituent on the substrate. The reactivity of this reagent was increased by supporting it to silica gel for bromination of less activated compounds.
Heravi, Majid M.,Abdolhosseini, Nafiseh,Oskooie, Hossein A.
p. 8959 - 8963
(2007/10/03)

Novel bromination method for anilines and anisoles using NH 4Br/H2O2 in CH3COOH
A simple, efficient, regioselective, environmentally safe, and economical method for the oxybromination of anilines and anisoles without catalyst is reported. The electrophilic substitution of bromine generated in situ from ammonium bromide as a bromine source and hydrogen peroxide as an oxidant for the first time.
Krishna Mohan,Narender,Srinivasu,Kulkarni,Raghavan
p. 2143 - 2152
(2007/10/03)

[bmim]Br3 as a new reagent for regioselective monobromination of arylamines under solvent-free conditions
Reaction of arylamines with 1-butyl-3-methylimidazolium tribromide ([bmim]Br3) under solvent-free conditions, gave selectively the corresponding monobromination products with excellent, yields.
Le, Zhang-Gao,Chen, Zhen-Chu,Hu, Yi,Zheng, Qin-Guo
p. 2809 - 2812
(2007/10/03)

Mild and regioselective oxidative bromination of anilines using potassium bromide and sodium perborate
The selective monobromination of various deactivated anilines using potassium bromide and sodium perborate as oxidant has been achieved. The use of ammonium molybdate as catalyst accelerates the rate of reaction but is not essential to obtain good yields and high selectivities. (C) 2000 Elsevier Science Ltd.
Roche, Didier,Prasad, Kapa,Repic, Oljan,Blacklock, Thomas J.
p. 2083 - 2085
(2007/10/03)

Liquid phase regioselective bromination of aromatic compounds over HZSM-5 catalyst
A simple, efficient, regioselective and environmentally safe method for oxybromination of activated aromatics catalyzed by HZSM-5 is reported. The electrophilic substitution of bromine generated from KBr using HZSM-5 as a catalyst and H2O2 as an oxidant.
Narender,Srinivasu,Kulkarni,Raghavan
p. 3669 - 3675
(2007/10/03)

Regioselective catalytic halogenation of aromatic substrates
Regioselective chlorination and bromination of some aromatic substances have been carried out using KCl and KBr in presence of sodium perborate as an oxidant and sodium metavanadate, sodium tungstate, ammonium metavanadate and ammonium molybdate as efficient catalysts. This environmentally friendly catalytic halogenation method gave good yields of products under mild conditions.
Bandgar,Nigal, Neeta J.
p. 3225 - 3229
(2007/10/03)

Electrophilic Aromatic Bromination Using Bromodimethylsulfoniuin Bromide Generated in Situ
It has been shown that bromodimethylsulfonium bromide, generated in situ by treating dimethyl sulfoxide with aqueous hydrobromic acid, is a milder and more selective reagent for electrophilic aromatic bromination than elemental bromine.
Majetich, George,Hicks, Rodgers,Reister, Steven
p. 4321 - 4326
(2007/10/03)

Selectivity in bromination of aniline and N-substituted anilines encapsulated in β-cyclodextrin
In contrast to the conventional bromination, aniline and N-methylaniline encapsulated in β-Cyclodextrin (β-CD) give ortho-bromoaniline and parabromo-N-methylaniline respectively in larger yield. The results are explained on the basis of mode of complexation between β-CD and anilines.
Velusamy, Ponnusamy,Pitchumani, Kasi,Srinivasan, Chockalingam
p. 3487 - 3496
(2007/10/03)

Novel site-specific one-step bromination of substituted benzenes
Regiospecific bromination of benzene derivatives has been carried out with Me2SO-HBr; this method gives excellent yields of 2-bromobenzaldehyde and 2-bromonitrobenzene; strong ortho- and para-directing monosubstituted benzenes give para-bromo derivatives; a general discussion of the mechanism of these reactions is given.
Srivastava, Sanjay K.,Chauhan, Prem Man Singh,Bhaduri, Amiya P.
p. 2679 - 2680
(2007/10/03)

Catalysts for the Oxidative Bromination of Aromatic Amines and their N-Acetyl Derivatives
In the nuclear bromination of aromatic amines by bromide and hydrogen peroxide in acetic acid, sodium tungstate has been compared with ammonium molybdate and ammonium vanadate, and found to be an effective catalyst.
Hanson, James R.,Opakunle, Alexander,Petit, Philippe
p. 457
(2007/10/03)

Bromation regioselective en serie aromatique. I: Monobromation en position para de phenols et d'amines aromatiques par le tribromure de tetrabutylammonium
The reaction of tetrabutylammonium tribromide (TBABr3) with phenols and aromatic amines in aprotic and non-basic solvents at 20 deg C gives exclusively the corresponding para-brominated compounds in high yields.A mechanism involving electrophilic substitution by the tribromide anion Br3- itself is suggested to account for the results, especially the regioselective para bromination.Key words: bromination, tetrabutylammonium tribromide, phenols, aromatic amines.
Berthelot, Jacques,Guette, Catherine,Desbene, Paul-Louis,Basselier, Jean-Jacques,Chaquin, Patrick,Masure, Daniel
p. 2061 - 2066
(2007/10/02)

REGIOSELECTIVE MONOBROMINATION OF AROMATIC AMINES WITH TETRABUTYLAMMONIUM TRIBROMIDE
A simple and efficient method for monobromination of aromatic amines predominantly in the para position is reported.Tetrabutylammonium tribromide is used at 20 deg C and yields of parabromoanilines are higher than 90percent.
Berthelot, J.,Guette, C.,Essayegh, M.,Desbene, P.L.,Basselier, J.J.
p. 1641 - 1646
(2007/10/02)

SELECTIVE MONOBROMINATION OF ANILINE DERIVATIVES BY USE OF BROMINE ADSORBED ON ZEOLITE 5A
Aniline is selectively brominated by use of molecular bromine adsorbed on zeolite 5A in carbon tetrachloride to give monobromoanilines.Coexistence of organic bases such as pyridine and 2,6-lutidine increases the yield and selectivity of 4-bromoaniline. o-, m-, and p-Toluidines are also monobrominated selectively according to the present procedure.
Onaka, Makoto,Izumi, Yusuke
p. 2007 - 2008
(2007/10/02)

1,3-DIARYL-2,2-DIHALOAZIRIDINES IN NITRATION AND BROMINATION REACTIONS
In the nitration of 3-(4-nitrophenyl)-1-phenyl-2,2-dichloroaziridine in acetic acid, 1-(o- and p-nitrophenyl)-derivatives are formed in a 35:65 ratio. 1,3-Diphenyl-2,2-dichloroaziridine undergoes opening of the three-membered ring under the same conditions, forming a mixture of o- and p-nitroanilides and 2-nitro-4-chloroanilides of 2-acetoxy (or 2-chloro)-2-phenylacetic acids.The bromination of 3-(4-nitrophenyl)-1-phenyl-2,2-dichloroaziridine in aqueous acetic acid leads to 1-(4-bromophenyl)-3-(4-nitrophenyl)-2,2-dichloroaziridine, while in a mixture of acetic acid and acetic anhydride it leads to the anilide of 2-bromo-2-phenylacetic acid and 2-bromo-N-(2,4-dibromophenyl)-1-(4-nitrophenyl)-2,2-dichloroethylamine.
Khlebnikov, A. F.,Kostikov, R. R.
p. 739 - 744
(2007/10/02)

Preparation of 3-Substituted Quinolines. I. Alkylation of Malonaldehyde Dianil Derivatives
2-Substituted 1-arylamino-3-arylimino-1-propenes (III) were prepared by the reaction of N-lithio derivatives of 1-arylamino-3-arylimino-1-propenes (malonaldehyde dianil derivatives) (II) and substituted benzyl bromides. 2-Allyl and 2-(2,4-dinitrophenyl) derivatives of II were prepared by the same method.However, the alkylation failed with less reactive alkyl halides such as ethyl iodide as alkylating agents.Hydrolysis of III afforded α-substituted β-(arylamino)acroleins (IV), which afforded 3-substiuted quinolines (V) on heating with aluminium chloride.Keywords -- 2-alkyl-1-arylamino-3-arylamino-1-propene; α-alkyl-β=(arylamino)acrolein; 3-alkylquinoline; alkylation; hydrolysis; cyclodehydration
Todoriki, Reiko,Ono, Machiko,Tamura, Shinzo
p. 4277 - 4285
(2007/10/02)

Synthetic Application of Aminosilanes: Selective Bromination of Anilines via Reaction of Anilinosilanes with N-Bromosuccinimide
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Ando, Wataru,Tsumaki, Hidetoshi
p. 263 - 264
(2007/10/02)

Pyrolysis of Aryl Azides. V. Characterization of Phenylazo, Benzoyl and Formyl as Neighbouring Groups
The enhancements of thermolysis rate of azidobenzene produced by ortho phenylazo, benzoyl and formyl substituents are 21180, 70.0 and 22.8 at 393.2 K (decalin solutions).The same ortho substituents produce much smaller enhancements (169, 8.56 and 10.7 respectively) in the pyrolysis rate of 1-azido-2,4-dibromobenzene.These results are interpreted as steric effects on an electrocyclic thermolysis mechanism, and are not consistent with the alternative pathway of intramolecular 1,3-dipolar addition which continues to be advocated by Hall and Dolan.
Dickson, Noel J.,Dyall, Leonard K.
p. 91 - 99
(2007/10/02)