- Base-catalyzed aryl halide isomerization enables the 4-selective substitution of 3-bromopyridines
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The base-catalyzed isomerization of simple aryl halides is presented and utilized to achieve the 4-selective etherification, hydroxylation and amination of 3-bromopyridines. Mechanistic studies support isomerization of 3-bromopyridines to 4-bromopyridines proceedsviapyridyne intermediates and that 4-substitution selectivity is driven by a facile aromatic substitution reaction. Useful features of a tandem aryl halide isomerization/selective interception approach to aromatic functionalization are demonstrated. Example benefits include the use of readily available and stable 3-bromopyridines in place of less available and stable 4-halogenated congeners and the ability to converge mixtures of 3- and 5-bromopyridines to a single 4-substituted product.
- Bandar, Jeffrey S.,Puleo, Thomas R.
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p. 10517 - 10522
(2020/10/18)
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- Cathodic C-H Trifluoromethylation of Arenes and Heteroarenes Enabled by an in Situ-Generated Triflyltriethylammonium Complex
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While several trifluoromethylation reactions involving the electrochemical generation of CF3 radicals via anodic oxidation have been reported, the alternative cathodic, reductive radical generation has remained elusive. Herein, the first cathodic trifluoromethylation of arenes and heteroarenes is reported. The method is based on the electrochemical reduction of an unstable triflyltriethylammonium complex generated in situ from inexpensive triflyl chloride and triethylamine, which produces CF3 radicals that are trapped by the arenes on the cathode surface.
- Cantillo, David,Jud, Wolfgang,Kappe, C. Oliver,Maljuric, Snjezana
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supporting information
(2019/10/08)
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- Efficient and practical 3-bromobenzotrifluoride synthesis method
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The invention discloses an efficient and practical 3-bromobenzotrifluoride synthesis method, which comprises the following concrete steps that (1) acetic acid and water are added into a reaction container; then, 98-percent sulphuric acid is dropwise added; (2) benzotrifluoride is added; sodium bromide is added in batches; the temperature during the charging is controlled not to exceed 45 DEG C; (3) after the reaction is completed, the material temperature in the container is lowered to 30 DEG C or below; after the still standing, an organic layer A is separated out; meanwhile, a water layer Bis left; (4) an organic solvent is added into the water layer B; extraction is performed once; an organic layer C is separated out; (5) the organic layers A and C are merged; water is added into a mixed solution; after the stirring, still standing is performed in a liquid separating funnel; an upper layer water phase and a lower organic layer are separated; (6) the organic layer obtained in the step (5) is washed by a NaOH water solution; (7) the organic layer in the step (6) is subjected to operations such as separation and drying, 3-bromobenzotrifluoride can be obtained. The NaBrO3-H2SO4-CH3COOH system is adopted for reaction; three wastes (waste water, waste solid and waste gas) are few; high efficiency and practicability are realized.
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Paragraph 0023-0028
(2018/10/19)
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- Visible-Light photoredox decarboxylation of perfluoroarene iodine(III) Trifluoroacetates for C-H trifluoromethylation of (Hetero)arenes
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A scalable and operationally simple decarboxylative trifluoromethylation of (hetero)arenes with easily accessible C6F5I(OCOCF3)2 under photoredox catalysis has been developed. This method is tolerant of various (hetero)arenes and functional groups. Notably, C6F5I is recycled from the decarboxylation reaction and further used for the preparation of C6F5I(OCOCF3)2. The combination of photoredox catalysis and hypervalent iodine reagent provides a practical approach for the application of trifluoroacetic acid in trifluoromethylation reactions.
- Yang, Bin,Yu, Donghai,Xu, Xiu-Hua,Qing, Feng-Ling
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p. 2839 - 2843
(2018/04/14)
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- Copper-Promoted Conversion of Aromatic Amines into Trifluoromethylated Arenes: One-Pot Sandmeyer Trifluoromethylation
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A simple copper-promoted one-pot Sandmeyer trifluoromethylation of aromatic amines with Langlois’ reagent has been demonstrated. The reaction is performed in mild reaction conditions under an air atmosphere with good substrate scope and functional group compatibility. It provides an alternative and straightforward synthetic approach to access a variety of trifluoromethylated arenes.
- Hong, Jianquan,Wang, Guifu,Huo, Lianguang,Zheng, Changge
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supporting information
p. 1761 - 1767
(2017/09/06)
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- Synthesis method of trifluperidol drug intermediate m-bromobenzotrifluoride
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The invention relates to a synthesis method of a trifluperidol drug intermediate m-bromobenzotrifluoride, which comprises the following steps: (i) adding 300mL of 50-70 wt% potassium chloride solution into a reaction vessel which is provided with a stirrer, a thermometer and a dropping funnel, control the stirring rate at 300-500 rpm, adding 0.35mol of m-aminobromobenzotrifluoride (2), heating the solution to 60-65 DEG C until the solid is completely dissolved, cooling to 5-8 DEG C, dropwisely adding 0.35-0.39mol of sodium nitrate in 60ml of water to prepare a solution, controlling the reaction temperature at 15-20 DEG C, and determining the end point with potassium iodide test paper to obtain diazonium salt (3); and (ii) adding 0.12 mol of nickel dichloride into 300ml of sodium bromide solution, heating the solution to 85-90 DEG C, adding the diazonium salt (3) solution obtained in the step (i), carrying out steam distillation until no organic matters are distilled out, separating out the organic layer, washing with a solution, washing with a salt solution, washing with a neutralizing solution, dehydrating with a dehydrating agent, distilling under reduced pressure, and collecting the 80-85-DEG C fraction to obtain the m-bromobenzotrifluoride.
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-
Paragraph 0017; 0018; 0019
(2016/10/17)
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- Copper-Promoted Trifluoromethanesulfonylation and Trifluoromethylation of Arenediazonium Tetrafluoroborates with NaSO2CF3
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A tunable chemoselective trifluoromethanesulfonylation and trifluoromethylation of arenediazonium tetrafluoroborates with Langlois' reagent (NaSO2CF3) was developed. The Cu2O-catalyzed reaction in DMSO gave aryl trifluoromethanesulfones as the major products. On the other hand, the trifluoromethylated arenes were produced in the presence of oxidant tert-butyl hydroperoxide, CuBF4(MeCN)4, and 2,2′;6′,2 terpyridine (tpy). Both of these transformations proceed under mild conditions and tolerate functional groups.
- Zhang, Ke,Xu, Xiu-Hua,Qing, Feng-Ling
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p. 7658 - 7665
(2015/08/18)
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- Introducing a new radical trifluoromethylation reagent
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Perfluoro-3-ethyl-2,4-dimethyl-3-pentyl radical (PPFR) is a persistent radical stable at room temperature, but easily decomposes at 90 °C to produce a CF3 radical which is able to react with a variety of aromatic compounds to afford the corresponding trifluoromethyl derivatives, usually as mixtures of regioisomers in good to excellent overall yields.
- Sato, Azusa,Han, Jianlin,Ono, Taizo,Wzorek, Alicja,Ace?a, José Luis,Soloshonok, Vadim A.
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supporting information
p. 5967 - 5970
(2015/03/30)
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- Tribromoisocyanuric acid in trifluoroacetic acid: An efficient system for smooth brominating of moderately deactivated arenes
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Moderately deactivated arenes are efficiently brominated by the reaction with tribromoisocyanuric acid (0.34 mol equiv) in trifluoroacetic acid at room temperature in 48-85% isolated yield. This medium avoids the polybromination of the substrate, observed in the same reaction performed in 98% H 2SO4. Georg Thieme Verlag Stuttgart · New York.
- De Almeida, Leonardo S.,De Mattos, Marcioc. S.,Esteves, Pierre M.
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p. 603 - 606
(2013/04/10)
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- Silver catalyzed bromination of aromatics with N-bromosuccinimide
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A heterogeneous silver catalyst was prepared and applied efficiently for the selective bromination of aromatics with NBS. The silver nanoparticles combined with the acidic support HMB can activate both the aromatic ring and NBS, and the synergistic effects between the silver nanoparticles and the HMB highly enhanced the efficiency of the bromination reaction.
- Zhang, Rui,Huang, Lei,Zhang, Yanfang,Chen, Xiaorong,Xing, Weihong,Huang, Jun
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experimental part
p. 378 - 383
(2012/06/18)
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- From carboxylic acids to the trifluoromethyl group using BrF3
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Organic trifluoromethyl derivatives were made from aromatic and aliphatic carboxylic acids by transforming them first into the corresponding dithioesters followed by reaction with bromine trifluoride under mild conditions (0 °C, 2 min).
- Cohen, Or,Mishani, Eyal,Rozen, Shlomo
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experimental part
p. 3579 - 3582
(2010/07/04)
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- PROCESS FOR THE PREPARATION OF FLIBANSERIN INVOLVING NOVEL INTERMEDIATES
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The present invention related to process for the preparation of flibanserin involving novel intermediates. 1,3-dihydro-1-(2-bromoethyl)- 3-isopropenyl-2H-benzimidazol-2-one reacts with diethanolamine and converting the obtained dihydroxy compound to 1,3-dihydro- 1-[2-[N-[bis-(2-chloroethyl)amino]ethyl]-3-isopropenyl-2H-benzimidazol-2-one followed by depotection to obtain 1,3-dihydro- 1-[2-[N-bis-(2-chloroethyl)amino]ethyl]-1,2-H-benzimidazol-2-one. This on condensing with m-trifluoromethyl aniline gives flibanserin hydrochloride.
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Page/Page column 16; 17
(2010/11/18)
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- Relative basicities of ortho-, meta-, and para-substituted aryllithiums
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(Chemical Equation Presented) The relative basicities of aryllithiums bearing methoxy, chlorine, fluorine, trifluoromethyl and trifluoromethoxy substituents at the ortho, meta, and para positions have been assessed. To this end, two aryllithiums of compar
- Gorecka-Kobylinska, Joanna,Schlosser, Manfred
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experimental part
p. 222 - 229
(2009/04/11)
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- Bromination by means of sodium monobromoisocyanurate (SMBI)
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A variety of aromatic compounds with both activating and deactivating substituents were brominated with sodium monobromoisocyanurate (SMBI) 1, diethyl ether, diethyl ether-methanesulfonic acid, trifluoroacetic acid, or sulfuric acid were employed as solvents. Thus nitrobenzene was conveniently brominated in sulfuric acid, benzene was readily monobrominated in diethyl ether-methanesulfonic acid, and phenol was selectively brominated at the ortho position under mild conditions in refluxing diethyl ether. With substituents that are easily protonated, trifluoroacetic acid may be employed as solvent in the reaction with 1, in contrast NBS was ineffective in trifluoroacetic acid. This renders 1 a superior reagent relative to NBS. In addition to aromatics, alkenes, ketones and esters were also brominated with 1. Diethyl malonate was brominated with 1 and then subjected to a Bingel reaction with NaH to afford the desired methanofullerene in reasonable yield.
- Okada, Yukihiro,Yokozawa, Masanori,Akiba, Miwa,Oishi, Kazuhiko,O-Kawa, Kyoji,Akeboshi, Tomohiro,Kawamura, Yasuo,Inokuma, Seiichi,Nakamura, Yosuke,Nishimura, Jun
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p. 2506 - 2511
(2007/10/03)
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- Process for the preparation of trifluoromethyl acetophenone
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A process for the preparation of a compound of formula I wherein Y is a group that is inert during preparation of the compound and m is from 0 to 4 is described. The process broadly involves the steps of a) reacting a compound of formula II wherein X is chlorine, bromine or iodine, and Y and m are as defined above, with a vinylether or an enamide in a solvent, a base and a catalytic amount of a palladium compound and a phosphine ligand. The resulting intermediate is then hydrolyzed to the compound of formula I.
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- A convenient new method for the bromination of deactivated aromatic compounds
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Treatment of deactivated aromatic compounds with N-bromosuccinimide in trifluoroacetic acid solvent in the presence of sulfuric acid gave the corresponding monobromoaromatic compounds in good to excellent yields.
- Duan, Jianxin,Zhang, Lian Hao,Dolbier Jr., William R.
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p. 1245 - 1246
(2007/10/03)
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- Benzopyridazinone and pyridopyridazinone compounds
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Benzo or pyridopyridazinones and pyridazinthiones of the formula STR1 wherein: X and Y are nitrogen or carbon, provided that at least one is carbon, and Z is oxygen or sulfur; R1 is hydrogen, lower alkyl, aryl, aralkyl, heterocyclo, heterocyclo lower-alkyl, heteroaryl, or heteroaralkyl; R2, R3, R4, R5 and R6 are independently selected from hydrogen, lower alkyl, halo, carboxy, alkoxycarbonyl, carbamoyl, lower-alkyl carbonyl, halocarbonyl, thiomethyl, trifluoromethyl, cyano or nitro; or a pharmaceutically acceptable ester, ether or salt thereof, have been found to be useful as an anti-inflammatory, antasthmatic, immunosuppressive, anti-allograft rejection, anti-graft-vs-host rejection, autoimmune disease or analgetic agent(s).
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- A Novel Method for Converting Aromatic Acids into Trifluoromethyl Derivatives using BrF3
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Aryltrifluoromethyl derivatives are obtained in good yields from the corresponding aryl carboxylic acids by reacting their dithionic esters with BrF3 under very mild conditions.
- Rozen, Shlomo,Mishani, Eyal
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p. 2081 - 2082
(2007/10/02)
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- Halogenation Using N-Halogenocompounds. II. Acid Catalyzed Bromination of Aromatic Compounds with 1,3-Dibromo-5,5-dimethylhydantoin
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Ring bromination of aromatic compounds using 1,3-dibromo-5,5-dimethylhydantoin in dichloromethane is promoted by the addition of strong acids.Both organic and inorganic acids whose pKa values are lower than -2 showed the promoting effect.This acid-catalyzed bromination is both practical and effective, even for aromatics having electron-withdrawing substituents.
- Eguchi, Hisao,Kawaguchi, Hideichiro,Yoshinaga, Sachiyo,Nishida, Akiko,Nishiguchi, Takeshi,Fujisaki, Shizuo
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p. 1918 - 1921
(2007/10/02)
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- REACTIONS OF ORGANIC COMPOUNDS WITH SF4-HF-HALOGENATING AGENT SYSTEMS VI. REACTIONS OF BENZENE AND ITS DERIVATIVES WITH SF4-HF-Cl2(Br2)
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In the reactions of benzene-carboxylic and -dicarboxylic acids with SF4-HF-Cl2(Br2), apart from the conversion of carboxyls into trifluoromethyl groups, there occurs the halogenation of the benzene ring with the formation of the corresponding chloro- and bromo-containing (trifluoromethyl)- and bis(trifluoromethyl)-benzenes.
- Kunshenko, B. V.,Omarov, V. O.,Muratov, N. N.,Mikhailevskii, S. M.,Yagupol'skii, L. M.
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p. 108 - 112
(2007/10/02)
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- TRIFLUORMETHYLIERUNGSREAKTIONEN VON Te(CF3)2 MIT HALOGENBENZOLEN UND METHYLBENZOLEN
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Substituent effects on yields and regioselectivity of photochemical and thermal trifluoromethylation reactions of Te(CF3)2 with halogen benzenes and methyl benzenes are investigated under comparable conditions.All reactions lead to trifluoromethylated products.The yields of the thermal are always higher than those of the corresponding photochemical reactions.The reactivity of the halobenzenes increases in the series C6H5-F a sidereaction, but H-substitution is the primary reaction pathway.During the reactions with iodobenzene tellurium containing compounds are also formed.The reactions with methyl benzenes show an increase in reactivity in the series hexamethylbenzene mesitylene toluene p-xylene.In all cases only ring substituted products are detected.Reactions with toluene and p-xylene yield tellurium containing compounds as well as addition products.The 19F-n.m.r spectra of the products are given.
- Naumann, Dieter,Kischkewitz, Jurgen
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p. 283 - 299
(2007/10/02)
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- Electrophilic cleavage reactions of carbon-silicon bonds in neutral hexacoordinate silicon compounds: diorgano(phtalocyaninato)silicon
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Preparations of diorgano(phtalocyaninato)silicon 1)(R2)> and their reactions with N-bromosuccinimide (NBS), halogens, copper(II) halides, and 3-chloroperbenzoic acid (MCPBA) are reported.The alkyl-silicon bonds are readily cleaved by NBS, halogens, and CuX2 to give the corresponding alkyl halides.The reactivity of aryl-silicon bonds toward NBS and halogen depends greatly on the electronic effect of the substituent on the benzene ring, but these bonds are almost inert to CuX2.The reactivity of the carbon-silicon bond towards NBS cleavage decreases in the order 4-MeOC6H4 > n-C8H17 > 4-MeC6H4 > Ph >> 3-CF3C6H4.Cleavage of alkyl-silicon bonds may involv one-electron transfer from substrate to reagent and alkyl radical intermediates, while the electrophilic aromatic substitution mechanism may operate in the cleavage of aryl-silicon bonds. are stable to MCPBA.
- Tamao, Kohei,Akita, Munetaka,Kato, Hidehito,Kumada, Makoto
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p. 165 - 180
(2007/10/02)
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- CATALYTIC AND STOICHIOMETRIC BROMINATION OF AROMATIC COMPOUNDS IN AQUEOUS TRIFLUOROACETIC ACID IN THE PRESENCE OF NITROGEN-CONTAINING OXIDIZING AGENTS
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The mono- and polybromination of benzene, halogenobenzenes, toluene, p-xylene, anisole, biphenyl, benzotrifluoride, benzoic acid, p-nitro- and p-carboxytoluene, p-methoxybenzonitrile, tetralin, and naphtalene were studied in trifluoroacetic acid and its aqueous solutions in systems containing stoichiometric amounts of bromine or alkali-metal bromide and stoichiometric or catalytic (in the presence of oxygen or air) amounts of nitrogen-containing oxidizing agent (nitrogen(IV) oxide, alkali-metal nitrate or nitrite).It is suggested that the brominating agent under the investigated conditions is nitryl bromide NO2Br.Under the conditions of catalytic bromination anthracene is oxidized to anthraquinone with a preparative yield.
- Cheprakov, A. V.,Makhon'kov, D. I.,Rodkin, M. A.,Beletskaya, I. P.
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p. 217 - 223
(2007/10/02)
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- Photochemical Bromination of Simple Arenes
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Photochemical bromination of benzene, fluorobenzene, chlorobenzene, t-butylbenzene, α,α,α-trifluorotoluene, and (in tetrachloromethane) biphenyl and naphthalene gives substitution products and adducts such as 1,2,3,4,5,6-hexabromocyclohexane (1).The decomposition of (1) and of the analogous chlorobenzene adduct (3) under photochemical conditions gives the parent arene, the monobrominated halogenobenzene, and bromine which may be scavenged by toluene to give benzyl bromide or by benzene to give bromobenzene and dibromobenzenes.Addition is a kinetically controlled process, so that the mechanism of formation of these aryl bromides must be largely through the reversible formation of these adducts.This is consistent with the unusual orientation of apparent attack by bromine upon the arene substrates, since the relative amounts of the isomeric aryl bromides is a consequence of the relative stabilities and ease of elimination of HBr and Br2 from a family of adducts. The range of isomer distribution found within the reaction of each arene with bromine is consistent with two competing processes involved in the formation of the aryl bromides; one of these might by the direct homolytic substitution by bromine atoms upon the arene.
- Bolton, Roger,Bhangar, Muhammad Iqbal,Williams, Gareth H.
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p. 893 - 896
(2007/10/02)
-
- Nucleophilic Displacement in Polyhalogenoaromatic Compounds. Part 11. Kinetics of Protiodeiodination of Iodoarenes in Dimethyl Sulphoxide-Methanol
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The rates of methoxide-ion induced protiodeiodination of a number of polychloroiodobenzenes and their derivatives have been measured in dimethyl sulphoxide-methanol (9:1 v/v; 323.2 K).The true reagent under these conditions appears to be the dimethyl sulphoxide anion, and the rates of reaction in some cases appear to approach that expected of a diffusion controlled process.This corresponds to a major decrease in the efficacy of further activating substituents in the aromatic system, altough deactivating groups such as p-OMe still show large effects.Chlorine promotes protiodeiodination in the order of efficiency o-Cl > m-Cl > p-Cl; the trifluoromethyl group activates displacement in the order o-CF3 > p-CF3 > m-CF3, although with much less difference between isomeric sites. o-Nitro-groups promote protiodeiodination whereas the p-nitro-group encourages methoxydeiodination.No evidence of methoxydeiodination was found in attack of the polychloroiodobenzenes, although the rates of methoxydechlorination of the corresponding polychlorobenzenes suggest that in some cases this might occur.Evidence rejecting the possible SRN1 mechanism and supporting nucleophilic attack by a carbanionic species upon iodine is presented.
- Bolton, Roger,Moore, Clive,Sandall, John P.B.
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p. 1593 - 1598
(2007/10/02)
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- FLUOROALKYLATION OF AROMATIC COMPOUNDS
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Perfluoroalkylation of benzene, halobenzenes, pyridine, furan and thiophene has been accomplished through thermolysis of perfluoroalkyl iodides (CF3I, n-C10F21I and RfORfI) in the presence of the appropriate aromatic compound.Yields of alkylated products vary depending on temperature, presence of an HI acceptor and reactants ratio.Isomeric mixtures are obtained with halobenzenes, pyridine and thiophene.Furan however yields only the alpha substituted product.
- Cowell, Allan B.,Tamborski, Christ
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p. 345 - 356
(2007/10/02)
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- M-Bromo-benzotrifluorides
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A process for preparing an m-bromo-benzotrifluoride by brominating an unsubstituted, halo or alkyl substituted benzotrichloride in the presence of a catalyst and thereafter fluorinating the brominated product at elevated temperature and pressure. Also disclosed are new m-bromo-benzotrifluorides including 4-fluoro-3-bromo-benzotrifluoride and 4-methyl-3-bromobenzotrifluoride.
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