- Decarbonylative halogenation by a vanadium complex
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Metal-catalyzed halogenation of the C-H bond and decarbonylation of aldehyde are conventionally done in nature. However, metal-mediated decarbonylative halogenation is unknown. We have developed the first metal-mediated decarbonylative halogenation reaction starting from the divanadium oxoperoxo complex K3V5+2(O 22-)4(O2-)2(μ-OH) (1). A concerted decarbonylative halogenation reaction was proposed based on experimental observations.
- Rana, Sujoy,Haque, Rameezul,Santosh, Ganji,Maiti, Debabrata
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Read Online
- Cobalt-Catalyzed Enantioselective C–H Arylation of Indoles
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Atropoisomeric (hetero)biaryls are scaffolds with increasing importance in the pharmaceutical and agrochemical industries. Although it is the most obvious disconnection to construct such compounds, the direct enantioselective C–H arylation through the concomitant induction of the chiral information remains extremely challenging and uncommon. Herein, the unprecedented earth-abundant 3d-metal-catalyzed atroposelective direct arylation is reported, furnishing rare atropoisomeric C2-arylated indoles. Kinetic studies and DFT computation revealed an uncommon mechanism for this asymmetric transformation, with the oxidative addition being the rate- and enantio-determining step. Excellent stereoselectivities were reached (up to 96% ee), while using an unusual N-heterocyclic carbene ligand bearing an essential remote substituent. Attractive dispersion interactions along with positive C–H-π interactions exerted by the ligand were identified as key factors to guarantee the excellent enantioselection.
- Ackermann, Lutz,Jacob, Nicolas,Oliveira, Jo?o C. A.,Wencel-Delord, Joanna,Zaid, Yassir
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supporting information
p. 798 - 806
(2022/02/03)
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- Efficient halogenation synthesis method of aryl halide
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The invention discloses an efficient halogenation synthesis method of aryl halide. The method comprises the following step: in the presence of a catalyst (sulfoxide or oxynitride), a halogenation reagent and a solvent, carrying out a halogenation reaction on an aromatic ring compound to obtain the aryl halide. According to the present invention, in the presence of a catalyst (sulfoxide or nitrogenoxide), a halogenation reagent and a solvent, the aromatic ring is subjected to an efficient halogenation reaction, such that the very useful aryl halide can be obtained with high activity and high selectivity; and by adopting the method disclosed by the invention, aryl halides can be efficiently synthesized, and the method has a wide application prospect in actual production.
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Paragraph 0159-0163
(2021/03/31)
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- Sulfoxide-Promoted Chlorination of Indoles and Electron-Rich Arenes with Chlorine as Nucleophile
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An efficient chlorination of indoles and electron-rich arenes with chlorine anion as nucleophile is described. With the use of ethyl phenyl sulfoxide as the promoter, the reaction went smoothly under metal-free and mild conditions. Various indoles and electron-rich arenes are converted into the corresponding chlorinated compounds in moderate to excellent yields. A plausible interrupted Pummerer reaction mechanism was proposed without the oxidation of chloride anion. In addition, the byproduct thioether could be easily converted to the starting material sulfoxide just by a simple oxidation reaction. (Figure presented.).
- Ji, Yuan-Zhao,Li, Hui-Jing,Wang, Yi-Ruo,Wu, Yan-Chao,Zhang, Zheng-Yan
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supporting information
(2020/02/05)
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- Oxidative Photochlorination of Electron-Rich Arenes via in situ Bromination
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Electron-rich arenes are oxidatively photochlorinated in the presence of catalytic amounts of bromide ions, visible light, and 4CzIPN as organic photoredox catalyst. The substrates are brominated in situ in a first photoredox-catalyzed oxidation step, followed by a photocatalyzed ipso-chlorination, yielding the target compounds in high ortho/para regioselectivity. Dioxygen serves as a green and convenient terminal oxidant. The use of aqueous hydrochloric acid as the chloride source reduces the amount of saline by-products.
- Düsel, Simon Josef Siegfried,K?nig, Burkhard
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supporting information
p. 1491 - 1495
(2019/04/30)
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- Regioselective Halogenation of Arenes and Heterocycles in Hexafluoroisopropanol
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Regioselective halogenation of arenes and heterocycles with N-halosuccinimides in fluorinated alcohols is disclosed. Under mild condition reactions, a wide diversity of halogenated arenes are obtained in good yields with high regioselectivity. Additionally, the versatility of the method is demonstrated by the development of one-pot sequential halogenation and halogenation-Suzuki cross-coupling reactions.
- Tang, Ren-Jin,Milcent, Thierry,Crousse, Benoit
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p. 930 - 938
(2018/01/28)
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- In Situ Formed IIII-Based Reagent for the Electrophilic ortho-Chlorination of Phenols and Phenol Ethers: The Use of PIFA-AlCl3 System
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A new and in situ formed reagent generated by mixing PIFA {bis[(trifluoroacetoxy)iodobenzene]} and AlCl3 was introduced in the organic synthesis for the direct and highly regioselective ortho-chlorination of phenols and phenol ethers. An efficient electrophilic chlorination for these electron-rich arenes as well as the scope of the reaction are described herein. An easy, practical, and open-flask reaction allowed us to introduce a chlorine atom, which is a highly important functional group in organic synthesis. The reproducibility of our method has been demonstrated on gram-scale by carrying out the reaction in 6-bromo-2-naphthol. This halogenation reaction also proceeds in excellent conditions by first preparing the iodine(III)-based chlorinating reagent. Our new chlorinating reagent can be stored at least for two weeks at 4 °C without losing its reactivity.
- Nahide, Pradip D.,Ramadoss, Velayudham,Juárez-Ornelas, Kevin A.,Satkar, Yuvraj,Ortiz-Alvarado, Rafel,Cervera-Villanueva, Juan M. J.,Alonso-Castro, ángel J.,Zapata-Morales, Juan R.,Ramírez-Morales, Marco A.,Ruiz-Padilla, Alan J.,Deveze-álvarez, Martha A.,Solorio-Alvarado, César R.
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p. 485 - 493
(2018/02/09)
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- Iron(III)-Catalyzed Chlorination of Activated Arenes
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A general and regioselective method for the chlorination of activated arenes has been developed. The transformation uses iron(III) triflimide as a powerful Lewis acid for the activation of N-chlorosuccinimide and the subsequent chlorination of a wide range of anisole, aniline, acetanilide, and phenol derivatives. The reaction was utilized for the late-stage mono- and dichlorination of a range of target compounds such as the natural product nitrofungin, the antibacterial agent chloroxylenol, and the herbicide chloroxynil. The facile nature of this transformation was demonstrated with the development of one-pot, tandem, iron-catalyzed dihalogenation processes allowing highly regioselective formation of different carbon-halogen bonds. The synthetic utility of the resulting dihalogenated aryl compounds as building blocks was established with the synthesis of natural products and pharmaceutically relevant targets.
- Mostafa, Mohamed A. B.,Bowley, Rosalind M.,Racys, Daugirdas T.,Henry, Martyn C.,Sutherland, Andrew
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p. 7529 - 7537
(2017/07/26)
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- Aromatic Monochlorination Photosensitized by DDQ with Hydrogen Chloride under Visible-Light Irradiation
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Photochlorination of aromatic substrates by hydrogen chloride with 2,3-dichloro-5,6-cyano-p-benzoquinone (DDQ) occurs efficiently to produce the corresponding monochlorinated products selectively under visible-light irradiation. The yields for the chlorination of phenol were 70 % and 18 % for p- and o-chlorophenol, respectively, without formation of further chlorinated products. The photoinduced chlorination is initiated by electron transfer from Cl- to the triplet excited state of DDQ. The radical intermediates involved in the photochemical reaction have been detected by time-resolved transient absorption measurements.
- Ohkubo, Kei,Fujimoto, Atsushi,Fukuzumi, Shunichi
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p. 996 - 999
(2016/04/20)
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- A Doubly Biomimetic Synthetic Transformation: Catalytic Decarbonylation and Halogenation at Room Temperature by Vanadium Pentoxide
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The halogenation of the C?H bond by metal-oxo-peroxo species and the decarbonylation of aldehydes by metal-peroxo species are performed routinely in biological systems. However, metal-mediated decarbonylative halogenation is unknown in nature. In this work, we have shown that widely available V2O5 and VO(acac)2 (acac=acetylacetonate) can catalyze decarbonylative halogenation through the generation of an intermediate vanadium-oxo-peroxo species, which was characterized by using 51 V NMR, UV/Vis, and resonance Raman spectroscopy. Further detection of formic acid from the reaction mixture confirmed the biomimetic aspects of decarbonylative halogenation. A detailed experimental and DFT study indicated a concerted mechanism for this decarbonylative halogenation performed under simple and mild reaction conditions.
- Rana, Sujoy,Pandey, Bhawana,Dey, Aniruddha,Haque, Rameezul,Rajaraman, Gopalan,Maiti, Debabrata
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p. 3367 - 3374
(2016/11/16)
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- Catalytic electrophilic halogenations and haloalkoxylations by non-heme iron halides
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Synthetic non-heme iron halides promote sub-stoichiometric aliphatic halogenation reactions via a radical mechanism. Complementary to such activity, we have developed an electrophilic halogenation of arenes employing non-heme iron halides. A catalytic version of these reactions has also been developed using potassium halide as the source of halogen atom for arenes at room temperature. Efforts towards understanding the mechanism of these catalytic halogenation reactions led to the discovery of the haloalkoxylation of olefins by a non-heme iron complex. Implications of these findings with respect to natural transformations are also discussed.
- Rana, Sujoy,Bag, Sukdev,Patra, Tuhin,Maiti, Debabrata
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supporting information
p. 2453 - 2458
(2014/09/30)
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- Room-temperature synthesis of tetra-ortho-substituted biaryls by NHC-catalyzed Suzuki-Miyaura couplings
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Into the groove: The introduction of a C2-symmetric N-heterocyclic carbene ligand with appropriately substituted naphthyl side chains enables the efficient Suzuki-Miyaura coupling to form bulky tetra-ortho-substituted biaryls from aryl bromides and chlorides at room temperature. DFT calculations uncover the subtle steric phenomena at play that lead to the superior catalytic performance. Cyoct=cyclooctyl. Copyright
- Wu, Linglin,Drinkel, Emma,Gaggia, Fiona,Capolicchio, Samanta,Linden, Anthony,Falivene, Laura,Cavallo, Luigi,Dorta, Reto
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supporting information; experimental part
p. 12886 - 12890
(2011/12/15)
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- Catalysis of the oxidative chlorination of aromatic compounds with substituted iron phthalocyanines
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Iron phthalocyanine-catalyzed oxidative chlorination of aromatic hydrocarbons using the H2O2-HCl system led to the formation of the corresponding chlorine derivatives.
- Fedorova,Kaliya,Luk'yanets,Negrimovskii
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experimental part
p. 1611 - 1613
(2009/06/28)
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- LEWIS ACID CATALYZED HALOGENATION OF ACTIVATED CARBON ATOMS
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A practical and efficient method for halogenation of activated carbon atoms using readily available /V-haloimides and a Lewis acid catalyst has been disclosed. This methodology is applicable to a range of compounds and any halogen atom can be directly introduced to the substrate. The mild reaction conditions, easy workup procedure and simple operation make this method valuable from both an environmental and preparative point of view.
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Page/Page column 25
(2008/06/13)
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- Grindstone chemistry: (Diacetoxyiodo)benzene-mediated oxidative nuclear halogenation of arenes using NaCl, NaBr or I2
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A technique of "Grindstone chemistry" is applied to the solvent-free halogenation of arenes with NaCl, NaBr or I2 using (diacetoxyiodo)benzene as the oxidant. Improved yields and higher purities of the products are observed compared with those from established methods.
- Karade,Tiwari,Huple,Siddiqui
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p. 366 - 368
(2007/10/03)
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- Lewis acid catalyzed highly selective halogenation of aromatic compounds
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A simple and efficient procedure for the halogenation of aromatic compounds with NCS, NBS, NIS and NFSI in the presence of catalytic amount of ZrCl 4 is described. Chlorination, bromination, iodination and fluorination of various aromatic compounds are performed with high selectivity under mild reaction conditions. Georg Thieme Verlag Stuttgart.
- Zhang, Yanhua,Shibatomi, Kazutaka,Yamamoto, Hisashi
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p. 2837 - 2842
(2007/10/03)
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- Efficient halogenation of aromatic systems using N-halosuccinimides in ionic liquids
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A simple, rapid and highly regioselective green protocol has been developed for the halogenation of aromatic systems with N-halosuccinimides using room temperature ionic liquids (ILs) as novel and recyclable reaction media to produce the corresponding halogenated aromatic compounds in high to quantitative yields. N-Halosuccinimides show enhanced reactivity in ionic liquids thereby reducing the reaction times dramatically and improving the yields substantially.
- Yadav,Reddy,Reddy,Basak,Narsaiah
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- A simple, efficient and regioselective oxychlorination of aromatic compounds using ammonium chloride and oxone
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A simple, efficient, mild and regioselective method for oxychlorination of aromatic compounds is reported. The electrophilic substitution of chlorine generated in situ from NH4Cl as a chlorine source and oxone as an oxidant is reported for the first time.
- Narender,Mohan, K.V.V. Krishna,Srinivasu,Kulkarni,Raghavan
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p. 1335 - 1338
(2007/10/03)
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- A novel and efficient ceric ammonium nitrate catalyzed oxidative nuclear chlorination of activated aromatic compounds by acetyl chloride
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A mild and efficient oxidative chlorination of activated aromatic compounds have been achieved in excellent yields using acetyl chloride in the presence of a catalytic amount of ceric ammonium nitrate at room temperature. However, chlorination failed to occur with deactivated aromatic rings.
- Roy, Subhas Chandra,Rana, Kalyan Kumar,Guin, Chandrani,Banerjee, Biplab
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p. 221 - 222
(2007/10/03)
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- Regioselective Halogenation and Dimerization of Alkoxynaphathalenes with Alumina- or Kieselguhr-supported Copper(II) Halides
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The reaction of 1-alkoxynaphathalenes 1 with alumina-supported copper(II) bromide or copper(II) chloride gave dimers, 4,4'-dialkoxy-1,1'-binaphthyls 3, as major products, and with Kieselguhr-supported copper(II) bromide afforded 1-bromo-4-alkoxynaphthalenes 2, while the reaction of 2-alkoxynaphathalenes 4 with alumina- or Kieselguhr-supported copper(II) bromide gave preferentially 1-bromo-2-alkoxynaphthalenes 5.
- Suzuki, Yoshitada,Takeuchi, Kiyoshi,Kodomari, Mitsuo
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p. 426 - 427
(2007/10/03)
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- Electrophilic Aromatic Bromination Using Bromodimethylsulfoniuin Bromide Generated in Situ
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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
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p. 4321 - 4326
(2007/10/03)
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- Regioselective Catalytic Halogenation of Arenes, mimicking Vanadium Haloperoxidase Reactions
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Ammonium metavanadate, mimicking vanadate dependent metalloenzymes, efficiently catalyses the halogenation of arenes in moderate to good yields using dilute hydrogen peroxide (30%) as an oxidizing agent, exhibiting remarkable regioselectivity.
- Hegde, Vishnumurthy R.,Pais, Godwin C. G.,Kumar, Rajiv,Kumar, Pradeep,Pandey, Bipin
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- RING CHLORINATION OF BENZENOID COMPOUNDS USING CALCIUM HYPOCHLORITE
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Chlorination of activated benzenoid rings is efficiently effected at 0 deg C in aqueous acetone/HOAc using calcium hypochlorite as the chlorinating agent.Good to excellent yields of the chlorinated products are obtained.
- Nwaukwa, Stephen O.,Keehn, Philip M.
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p. 799 - 804
(2007/10/02)
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- Zinc Salt Catalyzed Rearrangement of Acetals of Optically Active Aryl 1-Chloroethyl Ketones: Synthesis of Optically Active 2-Arylpropionic Acids and Esters
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The preparation of (S)-2-(4'-isobutylphenyl)propionic acid ((S)-Ibuprofen) (82percent optical purity) and (S)-2-(6'-methoxy-2'-naphthyl)propionic acid (Naproxen) (96percent optical purity) has been accomplished by starting from optically pure (S)-2-chloropropionyl chloride.The investigation for finding the best experimental conditions and minimizing racemization phenomena is presented.
- Piccolo, Oreste,Spreafico, Franca,Visentin, Giuseppina,Valoti, Ermanno
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- Nouvelles donnees sur la reaction entre le chlorure de pyridinium et les nitroalcanes. Cas du nitro-2 propane
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We have previously established that a refluxing mixture of a pyridinium halide and a primary nitroalcane gives rise to unexpected electrophilic halogenation of activated aromatic compounds with good yield (1).We confirm here that such unusual halogenation can be performed by means of pyridinium chloride and 2-nitropropane.Thus, when refluxing these two latter reagents in the presence of 2-methoxynaphtalene 1, 60percent of 1-chloro-2-methoxynaphtalene 2 is formed.However, the other products of the reaction (nitrogen oxides, 2-chloro-2-nitrosopropane 3, anetone and acetone oxime) are different from those formed with nitroethane (1-acetylpyridinium chloride oxime, acetohydroxamic acid, acetonitrile, acetamide, acetic acid and ammonium chloride).Although their results are notably different, both transformations induced respectively by the primary or the secondary nitroalcane start with the formation of a protonated nitronic acid and proceed according to similar mechanisms, as a consequence of the nucleophilic attack of the aci-nitro intermediate, among others, by the chloride anion.
- Dauzonne, Daniel,Demerseman, Pierre,Royer, Rene
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p. 204 - 206
(2007/10/02)
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- SUR LA REACTION ENTRE LE CHLORURE DE PYRIDINIUM ET LES NITROALCANES PRIMAIRES
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The lack of homogeneity in the dealkylation of phenol ethers by pyridinium halides had been overcome in a few cases by the use of solvents such as quinoline.The high dissolving power of nitrohydrocarbons led us to study their behaviour in the presence of pyridinium chloride and of 2-methoxynaphthalene 1, taken as the reference ether.On one hand, nitrobenzene is a good solvent which homogenizes the reaction mixture but slows down the reaction; on the other hand, it is not so with nitroalkanes which quickly interact.Thus, a mixture of 2-methoxynaphthalene 1, nitroethane and pyridinium chloride yields, after refluxing, 1-chloro-2-methoxynaphthalene 2, 1-acetylpyridinium chloride oxime 3, acetic acid, acetohydroxamic acid 5, acetonitrile, acetamide and ammonium chloride, in various proportions according to the relative amounts of reagents or the heating duration.The unusual chlorination of 1 can be carried out with primary nitro-alkanes other than nitroethane.Methyl phenol ethers other than 1 can be halogenated if they have a sufficiently electrophilic position.With this method, we were able to synthesize a few mono- or dichlorinated compounds starting from 1,6- or 1,7-dimethoxynaphthalenes and 5-methoxybenzofuran.The study of the experiments run with varying proportions of reactants or with overaddition of one or the other of the resulting products suggests a few mechanisms.Pyridinium bromide induces the same type of reaction, but with lower yields.
- Dauzonne, Daniel,Demerseman, Pierre,Royer, Rene
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p. 601 - 608
(2007/10/02)
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- CONDENSATION OF PHENOLS AND THEIR DERIVATIVES WITH AROMATIC COMPOUNDS IN THE PRESENCE OF ACIDIC AGENTS. V. REACTIONS OF CHLORINE-SUBSTITUTED NAPHTHOLS WITH BENZENE
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Substitution of the chlorine at position 1 by a phenyl residue occurs readily in the reaction of 1-chloro- and 1,4-dichloro-2-naphthols with benzene in the presence of aluminum chloride and hydrogen chloride. 4-Chloro-2-naphthol reacts with considerably great difficulty, giving a small yield of 4-phenyl-2-naphthol.The possibility of using a mixture of 4- and 2-chloro-1-naphthols for the production of 3-phenyl-1-naphthol was demonstrated.The possible reaction paths are discussed.
- Repinskaya, I. B.,Savel'ev, V. A.,Makarova, Z. S.,Koptyug, V. A.
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p. 1463 - 1466
(2007/10/02)
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- 2-(6'-methoxynaphth-2'yl) propionaldoxime and 5'-halo derivatives thereof
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New compounds, 2-(6'-methoxynaphth-2'-yl)propylene oxide, 2-(6'-methoxynaphth-2'-yl)propionaldoxime, 2-hydroxy-2-(6'-methoxynaphth-2'-yl)-propionitrile, 2-(6'methoxynaphth-2'-yl)acrylonitrile, 2-(6'-methoxynaphth-2'-yl)acrylic acid, the corresponding 5'-halo compounds and 2-(5'-halo-6'-methoxynaphth-2'-yl)propionaldehyde are useful intermediates in producing 2-(6'-methoxynaphth-2'-yl)propionic acid and the corresponding 5'-halo acids from 6-methoxy-2-acetylnaphthalene and the corresponding 5-halo compounds. The 2-propionic acids are anti-inflammatory, analgesic, anti-pyretic and anti-pruritic agents. The 2-propionaldehydes, obtained from the 2-acetyl compounds by way of the 2-propylene oxide, can be converted directly to the 2-propionic acids by way of the 2-propionaldoximes and the 2-propionitriles or more directly by Jones oxidation. Alternatively the 2-acrylonitriles, obtained from the 2-acetyl compounds by way of the 2-hydroxy-2-propionitrile, can be converted to the 2-propionic acid by way of the 2-acrylic acid or 2-propionitrile.
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