cas 3377-86-4, 2-BROMOHEXANE | Articles data

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An Unusually Mild and Selective Bromination of Some n-Alkanes with Barium Tetrafluorobromate
Abstract: Barium tetrafluorobromate Ba(BrF4)2 is a brominating agent for hexane, octane, and decane. The reaction occurs under very mild conditions at –25 to –20°C and results in preferential formation of 2-bromoalkanes.
Sobolev,Ostvald,Zherin,Shushpanova,Filimonov
p. 297 - 299
(2021/03/26)

Preparation method of alkane brominated material
The invention relates to a preparation method of an alkane brominated material. The preparation method comprises the following steps: adding alkane, a bromine-containing compound or elemental bromine,a catalyst and acid into a solvent; adding the solvent into a light-transmission reaction container under air or oxygen atmosphere; sealing; performing stirring reaction under constant pressure and light illumination conditions; then analyzing a nuclear magnetic yield, and performing extraction, drying, filtration, distillation under reduced pressure and column separation to obtain the alkane brominated material. Compared with the prior art, the preparation method disclosed by the invention has the advantages that by using low-cost and safe bromic salt as a bromine source, the air as an oxidizing agent and a nitrogen-containing reagent as the catalyst, reaction is carried out under the conditions of constant temperature and constant pressure, so that energy conservation and economy are realized, and the preparation method is convenient and safe to operate and is environmentally friendly.
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Paragraph 0070-0071

(2018/09/08)

Catalytic Bromination of Alkyl sp3C-H Bonds with KBr/Air under Visible Light
Alkyl sp3C-H bonds of cycloalkanes and functional branch/linear alkanes have been successfully brominated with KBr using air or O2 as an oxidant at room temperature to 40 °C. The reactions are carried out in the presence of catalytic NaNO2 in 37% HCl (aq)/solvent under visible light, combining aerobic oxidations and photochemical radical processes. For various alkane substrates, CF3CH2OH, CHCl3, or CH2Cl2 is employed as an organic solvent, respectively, to enhance the efficiency of bromination.
Zhao, Mengdi,Lu, Wenjun
supporting information
p. 5264 - 5267
(2018/09/12)

Preparation of manganese/Graphite oxide composite using permanganate and graphite: Application as catalyst in bromination of hydrocarbons
A highly efficient one-pot preparation of manganese/graphite oxide (MnOX/GO) composite from graphite and KMnO4 is described. Hummers preparation method of GO requires a stoichiometric amount of KMnO4, as a result, the method produces a large amount of reduced Mn species. The Mn residue generally is a waste, therefore, we envisioned converting it to value-Added materials. A MnOX/GO composite was prepared in one-pot by treating the unpurified GO with aqueous KOH. The composite was characterized by XRD, XAFS, SEM and TEM. Among various applications of the MnOX/GO composite, we applied it as a recyclable catalyst for bromination of saturated hydrocarbons, one of the most basic but important chemical transformations. The MnOX/GO composite is expected to be an efficient catalyst because of the high surface area and high accessibility of substrates derived from the 2- dimensional sheet structure. When the reaction of a saturated hydrocarbon and Br2 in the presence of catalytic MnOX/GO was performed under fluorescent light irradiation, a brominated product was formed in high yield in a short reaction time. GO could strongly bind with Mn to prevent elution to the liquid phase, enabling the high recyclability.
Suzuki, Hideyuki,Nishina, Yuta
p. 74 - 78
(2017/08/14)

Tetrabutylphosphonium Bromide Catalyzed Dehydration of Diols to Dienes and Its Application in the Biobased Production of Butadiene
We report the use of the ionic liquid tetrabutylphosphonium bromide as a solvent and catalyst for dehydration of diols to conjugated dienes. This system combines stability, high reaction rates, and easy product separation. A reaction mechanism for the model compound 1,2-hexanediol is proposed and experimentally corroborated. This particular mechanism allows for the selective formation of conjugated dienes, in contrast with purely acidic catalysis. Next, the reaction is also performed on various other diols. As a first application, we assessed the biobased production of 1,3-butadiene. With 1,4-butanediol as the starting material, a 94% yield of butadiene was reached at 100% conversion.
Stalpaert, Maxime,Cirujano, Francisco G.,De Vos, Dirk E.
p. 5802 - 5809
(2017/09/15)

PROCESS FOR THE PREPARATION OF ORGANIC BROMIDES
The present invention provides a process for the preparation of organic bromides, by a radical bromodecarboxylation of carboxylic acids with a bromoisocyanurate.
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Paragraph 00166

(2017/07/28)

Terminal-Selective Functionalization of Alkyl Chains by Regioconvergent Cross-Coupling
Hydrocarbons are still the most important precursors of functionalized organic molecules, which has stirred interest in the discovery of new C?H bond functionalization methods. We describe herein a new step-economical approach that enables C?C bonds to be constructed at the terminal position of linear alkanes. First, we show that secondary alkyl bromides can undergo in situ conversion into alkyl zinc bromides and regioconvergent Negishi coupling with aryl or alkenyl triflates. The use of a suitable phosphine ligand favoring Pd migration enabled the selective formation of the linear cross-coupling product. Subsequently, mixtures of secondary alkyl bromides were prepared from linear alkanes by standard bromination, and regioconvergent cross-coupling then provided access to the corresponding linear arylation product in only two steps.
Dupuy, Stéphanie,Zhang, Ke-Feng,Goutierre, Anne-Sophie,Baudoin, Olivier
supporting information
p. 14793 - 14797
(2016/11/23)

Site-selective aliphatic C-H bromination using N -bromoamides and visible light
Transformations that selectively functionalize aliphatic C-H bonds hold significant promise to streamline complex molecule synthesis. Despite the potential for site-selective C-H functionalization, few intermolecular processes of preparative value exist. Herein, we report an approach to unactivated, aliphatic C-H bromination using readily available N-bromoamide reagents and visible light. These halogenations proceed in useful chemical yields, with substrate as the limiting reagent. The site selectivities of these radical-mediated C-H functionalizations are comparable (or superior) to the most selective intermolecular C-H functionalizations known. With the broad utility of alkyl bromides as synthetic intermediates, this convenient approach will find general use in chemical synthesis.
Schmidt, Valerie A.,Quinn, Ryan K.,Brusoe, Andrew T.,Alexanian, Erik J.
supporting information
p. 14389 - 14392
(2014/12/10)

Direct bromination of hydrocarbons catalyzed by Li2MnO 3 under oxygen and photo-irradiation conditions
A method for the direct bromination of hydrocarbons with Br2 using a ubiquitous and inexpensive catalyst is highly desirable. Herein, we report the selective mono-bromination of hydrocarbons in good yield using Li2MnO3 as a catalyst under irradiation with a fluorescent room light. This new catalyst can be recycled. The effect of light was investigated using action spectra, which revealed that the reaction occurred on the surface of the catalyst.
Nishina, Yuta,Morita, Junya,Ohtani, Bunsho
p. 2158 - 2162
(2013/03/13)

Bromination of hydrocarbons with CBr4, initiated by light-emitting diode irradiation
The bromination of hydrocarbons with CBr4 as a bromine source, induced by light-emitting diode (LED) irradiation, has been developed. Monobromides were synthesized with high efficiency without the need for any additives, catalysts, heating, or inert conditions. Action and absorption spectra suggest that CBr4 absorbs light to give active species for the bromination. The generation of CHBr3 was confirmed by NMR spectroscopy and GC-MS spectrometry analysis, indicating that the present bromination involves the homolytic cleavage of a C-Br bond in CBr4 followed by radical abstraction of a hydrogen atom from a hydrocarbon.
Nishina, Yuta,Ohtani, Bunsho,Kikushima, Kotaro
p. 1663 - 1667
(2013/10/22)

Catalytic distillation process for primary haloalkanes
A process for making primary haloalkanes by catalytic distillation of internal haloalkanes which comprises a) introducing an internal haloalkane feed into a catalytic distillation column; b) isomerizing at least a portion of the internal haloalkane feed in the presence of an internal haloalkane isomerization catalyst at a temperature at or above the boiling point of the internal haloalkanes and below the temperature and pressure at which hydrogen halide is formed to form primary haloalkanes; and removing the primary haloalkanes from the catalytic distillation column.
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Page/Page column 9

(2012/02/17)

Highly efficient oxidative bromination of alkanes with the HBr-H 2O2 system in the presence of catalyst
Various cycloalkanes and straight-chain alkanes were efficiently brominated with an aqueous HBr-H2O2 system. This oxidative brominating process was promoted by catalysis and irradiation with light. The cycloalkanes were converted to the corresponding bromo-cycloalkanes in moderate yields and the straight-chain alkanes produced dominantly secondary bromides. This simple but effective bromination method of alkanes is characterized by high atom efficiency, inexpensive reagents and the absence of organic waste, which make it a good alternative to the existing method for Ci￡H activation through bromination. A simple, effective, environmentally friendly method was researched for bromination of alkanes in good yield with HBr as the origin of bromine.
Li, Yujin,Ju, Jie,Jia, Jianhong,Sheng, Weijian,Han, Liang,Gao, Jianrong
experimental part
p. 2428 - 2432
(2011/10/03)

Histamine H3 and H4 receptor affinity of branched 3-(1H-imidazol-4-yl)propyl N-alkylcarbamates
A series of imidazole-containing (non-)chiral carbamates were tested at human histamine H3 receptor (H3R). All compounds displayed Ki values below 100 nM. A trend for a stereoselectivity at human H3R was observed for the chiral α-branched ligands. Selected compounds were also tested at human histamine H4 receptor and showed moderate to weak affinities (118-1460 nM).
?azewska, Dorota,Wiecek, Ma?gorzata,Ligneau, Xavier,Kottke, Tim,Weizel, Lilia,Seifert, Roland,Schunack, Walter,Stark, Holger,Kie?-Kononowicz, Katarzyna
scheme or table
p. 6682 - 6685
(2010/06/16)

Ultrasound assisted synthesis of 5,9-dimethylpentadecane and 5,9-dimethylhexadecane - The sex pheromones of Leucoptera coffeella
Racemic 5,9-dimethylpentadecane and 5,9-dimethylhexadecane, the major and minor constituents, respectively, of the sex pheromone of Leucoptera coffeella, have been synthesized from citronellol in 56-58% overall yield through six steps. Ultrasound irradiation efficiently supported tosylation of alcohols (two steps) as well as the subsequent cross coupling reactions with the pertinent Grignard reagents (also two steps).
Doan, Nhuan Ngoc,Le, Thach Ngoc,Nguyen, Hao Cong,Hansen, Poul Erik,Duus, Fritz
p. 2080 - 2088
(2008/02/08)

FORMATION OF HETEROATOM CONTAINING DERIVATIVES OF PARAFFINS
A process by which alkyl halides may be reacted (coupled) with nucleophilic materials in the presence of a homogeneous catalyst system. The process comprises reacting (coupling) alkyl halides with a nucleophilic material in the presence of a homogeneous catalyst system to produce derivatives of alkyl halides, wherein the homogeneous catalyst system comprises at least one metal or metal compound which has the ability to form metal-halogen bonds.
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Page/Page column 9-10

(2008/06/13)

CONVERSION OF ALKYLHALIDES INTO ALCOHOL ALKOXYLATES
A process for converting alkyl halides to alkyl alcohol alkoxylates is described. This is a direct alkoxylation because the alkyl alcohol alkoxylates are made without going through an alkyl alcohol intermediate. The process comprises direct alkoxylation coupling of alkyl halides with a nucleophilic material in the presence of a homogeneous catalyst system to produce alkyl alcohol alkoxylates, wherein the homogeneous catalyst system comprises at least one metal or metal compound which has the ability to form metal-halogen bonds. A process for converting alkanes (paraffins) to alkyl alcohol alkoxylates is also described. This method comprises a) halogenation of at least one alkane to produce at least one alkyl halide; and b) direct alkoxylation coupling of at least a portion of the alkyl halide with a nucleophilic material in the presence of a homogeneous catalyst system to produce alkyl alcohol alkoxylates, wherein the homogeneous catalyst system comprises at least one metal or metal compound which has the ability to form metal-halogen bonds.
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Page/Page column 9-10

(2008/06/13)

Chemoselective monobromination of alkanes promoted by unactivated MnO 2
Reaction of alkanes with bromine promoted by unactivated MnO2 gave the corresponding alkylbromides in excellent yield with good chemoselectivity. The MnO2 could be easily recovered and reused.
Jiang, Xuefeng,Shen, Meihua,Tang, Yu,Li, Chaozhong
p. 487 - 489
(2007/10/03)

Direct bromination and iodination of non-activated alkanes by hypohalite reagents
The direct functionalisation of alkanes through bromination and iodination has been successfully achieved. The combination of stoichiometric mixtures of elemental halogen and sodium alkoxides leads to the formation of alkyl hypobromites and hypoiodites as reagents. The halogenation occurs without external photostimulation under thermal reaction conditions. Georg Thieme Verlag Stuttgart.
Montoro, Raul,Wirth, Thomas
p. 1473 - 1478
(2007/10/03)

BiX3 as an efficient and selective reagent for the halogen exchange reaction
Bismuth halides are efficient and selective reagents in the halogen exchange reactions carried out under mild conditions. This rapid, high yield reaction proceeds mainly with retention of configuration.
Boyer, Bernard,Keramane, El Mehdi,Arpin, Severine,Montero, Jean-Louis,Roque, Jean-Pierre
p. 1971 - 1976
(2007/10/03)

Development of chiral N-alkylcarbamates as new leads for potent and selective H3-receptor antagonists: Synthesis, capillary electrophoresis, and in vitro and oral in vivo activity
Novel carbamates as derivatives of 3-(1H-imidazol-4-yl)propanol with an N-alkyl chain were prepared as histamine H3-receptor antagonists. Branching of the N-alkyl side chain with methyl groups led to chiral compounds which were synthesized stereospecifically by a Mitsunobu protocol adapted Gabriel synthesis. The optical purity of some of the chiral compounds was determined (ee > 95%) by capillary electrophoresis (CE). The investigated compounds showed pronounced to high antagonist activity (K(i) values of 4.1-316 nM) in a functional test for histamine H3 receptors on rat cerebral cortex synaptosomes. Similar H3-receptor antagonist activities were observed in a peripheral model on guinea pig ileum. No stereoselective discrimination for the H3 receptor for the chiral antagonists was found with the in vitro assays. All compounds were also screened for central H3-receptor antagonist activity in vivo in mice after po administration. Most compounds were potent agents of the H3-receptor-mediated enhancement of brain N(τ)- methylhistamine levels. The enantiomers of the N-2-heptylcarbamate showed a stereoselective differentiation in their pharmacological effect in vivo (ED50 of 0.39 mg/kg for the (S)-derivative vs 1.5 mg/kg for the (R)- derivative) most probably caused by differences in pharmacokinetic parameters. H1- and H2-receptor activities were determined for some of the novel carbamates, demonstrating that they have a highly selective action at the histamine H3 receptor.
Sasse, Astrid,Kiec-Kononowicz, Katarzyna,Stark, Holger,Motyl, Malgorzata,Reidemeister, Sibylle,Ganellin, C. Robin,Ligneau, Xavier,Schwartz, Jean-Charles,Schunack, Walter
p. 593 - 600
(2007/10/03)

Aliphatic Propargylamines: Potent, Selective, Irreversible Monoamine Oxidase B Inhibitors
A series of aliphatic propargylamine derivatives has been synthesized.Some of them possess highly potent, irreversible, selective, inhibitory activity toward monoamine oxidase B (MAO-B).The potency of the inhibitors is related to chain length and substitution of a hydrogen on the terminal carbon of the aliphatic chain.MAO inhibitory activity as assessed in vitro increased as the aliphatic carbon chain length increased.Substitution of a hydrogen by hydroxyl, carboxyl, or carbethoxyl groups at the aliphatic chain terminal or replacement of the methyl group on thenitrogen atom by an ethyl group considerably reduced the inhibitory activity.Stereospecific effects were observed with the R-(-)-enantiomer being 20-fold more active than the S-(+)-enantiomer.Inhibitors with relatively short carbon chain lengths (i.e. four to six carbons) were found to be more potent than those with longer chains in inhibiting brain MAO-B activity in vivo especially after oral administration.Chronic administration of low doses of the aliphatic propargylamines caused a slight cumulative inhibition of MAO-A activity in the mouse brain.These MAO-B inhibitors appear to be nontoxic, and they do not possess an amphetamine-like moiety in their structure as is the case for deprenyl.We expect that these aliphatic propargylamines may be useful in the treatment in certain neuropsychiatric disorders.
Yu, Peter H.,Davis, Bruce A.,Boulton, Alan A.
p. 3705 - 3713
(2007/10/02)

A CONVENIENT AND EFFICIENT METHOD FOR THE CONVERSION OF ALKYL CHLORIDES TO THE CORRESPONDING BROMIDES
Reaction of representative alkyl chlorides (involving primary, secondary and tertiary substrates as also a dichloide) with stoechiometric amount of lithium bromide in the presence of a transfer agent (5percent Aliquat 336) without any added solvent, resulted in high conversions into the corresponding bromides under convenient and economical conditions.
Loupy, Andre,Pardo, Claude
p. 1275 - 1282
(2007/10/02)

ORGANOBORANES FOR SYNTHESIS. 10. THE BASE-INDUCED REACTION OF BROMINE WITH ORGANOBORNES. A CONVENIENT PROCEDURE FOR THE CONVERSION OF ALKENES INTO ALKYL BROMIDES VIA HYDROBORATION
The reaction of trialkylboranes with bromine is greatly accelerated by base.Bromination in the presence of sodium hydroxide provides alkyl bromide along with a large amount of the corresponding alcohol.The use of sodium methoxide as a base eliminates this undesirable side reaction and provides an improved yield of alkyl bromide.Consequently, hydroboration, followed by bromination in the presence of sodium methoxide, provides a convenient new procedure for the conversion of alkenes into alkyl bromides.The organoboranes, obtained via hydroboration of terminal alkenes, react with the utilization of all three alkyl groups attached to boron, providing nearly quantitative yields of alkyl bromides. This procedure also accommodates common organic functional groups, as demonstrated by the preparation of methyl 11-bromoundecanoate and 11-bromoundecyl acetate from the corresponding functionally substituted alkenes.Under these conditions, secondary and bulky primary alkyl groups react more sluggishly.However, a procedure involving simultaneous addition of bromine and methanolic sodium methoxide provides improved results for such derivatives.Surprisingly, the base-induced bromination of tri-exo-nobornylborane results in an inversion of configuration at the reaction center to give predominantly endo-2-bromonorbornane.A mechanism is proposed to account for this remarkable inversion.
Brown, Herbert C.,Lane, Clinton F.
p. 2763 - 2772
(2007/10/02)

2,5,6,7-tetranor-4,8-inter-m-phenylene PGI2 derivatives
Disclosed herein are novel prostaglandin I2 (PGI2) derivatives exhibiting excellent in vivo duration and activities, said derivatives being represented by the general formula: STR1 wherein R1, X, R2 and R3 are as defined herein.
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(2008/06/13)

C-H Activation on Platinum, a Mechanistic Study
C-H activation on heterogeneous Pt catalysts is found to be most facile at low Pt dispersion and surface structure intensive at dispersions above 10percent.Two distinct processes have been identified which lead to the formation of mono- and polydeuterated products, repectively.The ratio of mono-/polydeuteration processes increases with increasing dispertion.Evidence is provided for the formation of ?-intermediates as the initiator of polydeuteration.The most facile mechanism of exchange propagation in a single molecule is through a ?-allyl-type interconversion.The deuterium in monodeuterated n-hexane is located at the terminal position by high-resolution deuterium NMR.NMR spectroscopy also provides evidence for steric effects which prevent significant H/D exchange at positions close to quaternary centers.C-H activation appears to be steric hindrance, the C-H bond energy, and the partial pressure of the substrate.
Lebrilla, Carlito B.,Maier, Wilhelm F.
p. 1606 - 1616
(2007/10/02)

Selectivity in the Halogenation of Hexane by Tertiary Aminium Radicals from the Photodecomposition of N-Halogenoammonium Perchlorates
The photochlorination of hexane with tertiary N-chloroammonium perchlorates in trifluoroacetic acid gives monochlorohexanes in high yield and with a striking preference for the 2-isomer.It is shown that free-radical chains are involved in which hydrogen-atom abstraction is by tertiary aminium radicals.The marked preference for 2- compared with 3-chlorination is attributed mainly to the bulky aminium radical attacking the relatively more accessible 2-position; an alternative explanation involving a reversible hydrogen-atom abstraction is ruled out.The magnitude of the primary deuterium kinetic isotope effect in these photochlorinations gives information about the dependence of the extent of C-H bond breakage in the transition state on the structure of the abstracting aminium radical.
Fuller, Steven E.,Smith, John R. Lindsay,Norman, Richard O. C.,Higgins, Raymond
p. 545 - 552
(2007/10/02)

Addition of Hydrohalogenic Acids to Alkenes in Aqueous-Organic, Two-Phase Systems in the Presence of Catalytic Amounts of Onium Salts
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Landini, Dario,Rolla, Franco
p. 3527 - 3529
(2007/10/02)