Preparing By Halogenation Patents (Class 568/779)
  • Publication number: 20130144071
    Abstract: A method of the present invention, for producing an iodizing agent, includes the step of electrolyzing iodine molecules in a solution by using an acid as a supporting electrolyte. This realizes (i) a method of producing an iodine cation suitable for use as an iodizing agent that does not require a sophisticated separation operation after iodizing reaction is completed, and (ii) an electrolyte used in the method. Further, a method of the present invention, for producing an aromatic iodine compound, includes the step of causing an iodizing agent, and an aromatic compound whose nucleus has one or more substituent groups and two or more hydrogen atoms, to react with each other under the presence of a certain ether compound. This realizes such a method of producing an aromatic iodine compound that position selectivity in iodizing reaction of an aromatic compound is improved.
    Type: Application
    Filed: January 30, 2013
    Publication date: June 6, 2013
    Applicants: NIPPOH CHEMICALS CO., LTD., JAPAN SCIENCE AND TECHNOLOGY AGENCY
    Inventors: Japan Science and Technology Agency, Nippoh Chemicals Co., Ltd.
  • Patent number: 7834221
    Abstract: A process for preparing tetrabromobisphenol A, which comprises: i) reacting bisphenol A and bromine in dichloromethane in the presence of aqueous hydrogen peroxide at a temperature in the range of room temperature to the reflux temperature, wherein said dichloromethane is present in an amount sufficient for substantially dissolving brominated derivatives of said bisphenol A formed thereby, ii) separating the substantially solid-free reaction mixture obtained in step i) into aqueous and organic phases, precipitating tetrabromobisphenol A from the organic phase and isolating said precipitated tetrabromobisphenol A from said organic phase.
    Type: Grant
    Filed: July 3, 2006
    Date of Patent: November 16, 2010
    Assignee: Bromine Compounds Ltd.
    Inventor: Joseph Zilberman
  • Publication number: 20080275253
    Abstract: A practical and efficient method for halogenation of activated carbon atoms using readily available N-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.
    Type: Application
    Filed: February 29, 2008
    Publication date: November 6, 2008
    Inventors: Yanhua Zhang, Hisashi Yamamoto, Kazutaka Shibatomi
  • Patent number: 7399890
    Abstract: The present process serves for the hydrodehalogenation of halogenated meta-cresols of the formula (I) in which the R1 to R4 radicals are each as defined in the description, and is characterized in that halogenated meta-cresols of the formula (I) are contacted with a catalyst which has been prepared by applying one or more salts of palladium and/or platinum and optionally copper salts to an aluminum oxide or titanium oxide support material, together with hydrogen, at temperatures between 100 and 250° C.
    Type: Grant
    Filed: December 7, 2004
    Date of Patent: July 15, 2008
    Assignee: Lanxess Deutschland GmbH
    Inventors: Michael Pies, Klaus Schönauer, Volker Hassmann, Hermann Uhr
  • Patent number: 7053251
    Abstract: A method for brominating hydroxyaromatic compounds to form products, such as p-bromophenol, is disclosed. The method uses elemental bromine as the brominating agent and comprises contacting a hydroxyaromatic compound with bromine and oxygen in the presence of metal catalyst. Suitable catalysts include elemental copper, copper compounds, and compounds of Group IV–VIII transition metals.
    Type: Grant
    Filed: August 28, 2003
    Date of Patent: May 30, 2006
    Assignee: General Electric Company
    Inventors: Ryan Christopher Mills, John Yaw Ofori
  • Patent number: 7045666
    Abstract: Brominated hydroxyaromatic compounds such as p-bromophenol are prepared by contacting a hydroxyaromatic compound with oxygen and a bromine source such as hydrogen bromide or an alkali metal or alkaline earth metal bromide in an acidic medium, in the presence of elemental copper or a copper compound as catalyst. The brominated product of this reaction may be converted alternately to a dihydroxyaromatic compound such as hydroquinone by hydrolyses, or a dihydroxybiphenyl compound such as 4,4?-dihydroxybiphenyl by reductive coupling.
    Type: Grant
    Filed: January 16, 2003
    Date of Patent: May 16, 2006
    Assignee: General Electric Company
    Inventors: Eric James Pressman, John Yaw Ofori, Grigorii Lev Soloveichik, Ryan Christopher Mills, Jonathan Lloyd Male
  • Patent number: 7022886
    Abstract: A method for selectively brominating hydroxyaromatic compounds is disclosed. Hydroxyaromatic compounds are contacted with oxygen and a bromine source, in an acidic medium, in the presence of a catalyst selected from the group of compounds and mixtures of compounds of Group IV–VIII transition metals of the Periodic Table of Elements. The selectivity of mono-brominated products produced, predominantly in the para-position, from the method using transition metal compounds as catalysts is significantly higher than that of known methods using other catalysts. Thus, there is a significant reduction in the production of undesirable dibrominated and more highly brominated by-products.
    Type: Grant
    Filed: August 28, 2003
    Date of Patent: April 4, 2006
    Assignee: General Electric Company
    Inventor: Grigorii Lev Soloveichik
  • Patent number: 6982356
    Abstract: A method for preparing hydroxyaromatic compounds brominated in the para-position, such as p-bromophenol, is disclosed. The method yields overall high process selectivity through isomeric equilibration and separation of the brominated products, thereby eliminating the need for high para selectivity in the products of catalytic oxybromination reactions of hydroxyaromatic compounds using oxygen, a bromine source, and an acidic medium in the presence of a metal catalyst. Furthermore, the invention provides an efficient method for recycling the metal catalyst, as well as reagents used in the bromination, to further reactions.
    Type: Grant
    Filed: September 17, 2003
    Date of Patent: January 3, 2006
    Assignee: General Electric Company
    Inventors: Eric James Pressman, Jonathan Lloyd Male, Ryan Christopher Mills, John Yaw Ofori
  • Patent number: 6815565
    Abstract: A method is described for the simultaneous preparation of p-bromophenols and p-benzoquinones, intermediates useful in the preparation of hydroquinones and 4,4′-dihydroxybiphenyls, respectively. Hydroquinones and 4,4′-dihydroxybiphenyls are useful monomers for the preparation of a variety of polymers. The method also comprises reducing the p-benzoquinone to its corresponding hydroquinone in the presence of the p-bromophenol. Limiting the amount of HBr present in the reaction mixture was shown to control the amount of benzoquinone produced. The method also allows for the recycling of many of the reagents used, thereby reducing the cost of producing each monomer.
    Type: Grant
    Filed: November 7, 2003
    Date of Patent: November 9, 2004
    Assignee: General Electric Company
    Inventors: Ryan Christopher Mills, Eric James Pressman, Timothy Leigh Chuck, John Yaw Ofori
  • Publication number: 20040199027
    Abstract: A method is described for the simultaneous preparation of p-bromophenols and p-benzoquinones, intermediates useful in the preparation of hydroquinones and 4,4′-dihydroxybiphenyls, respectively. Hydroquinones and 4,4′-dihydroxybiphenyls are useful monomers for the preparation of a variety of polymers. The method also comprises reducing the p-benzoquinone to its corresponding hydroquinone in the presence of the p-bromophenol. Limiting the amount of HBr present in the reaction mixture was shown to control the amount of benzoquinone produced. The method also allows for the recycling of many of the reagents used, thereby reducing the cost of producing each monomer.
    Type: Application
    Filed: November 7, 2003
    Publication date: October 7, 2004
    Applicant: General Electric Company
    Inventors: Ryan Christopher Mills, Eric James Pressman, Timothy Leigh Chuck, John Yaw Ofori
  • Patent number: 6740253
    Abstract: The present invention relates to a non-hazardous brominating reagent from an aqueous alkaline bromine byproduct solution obtained from bromine recovery plant and containing 25 to 35% bromine dissolved in aqueous lime or sodium hydroxide containing alkali bromide and alkali bromate mixture having bromide to bromate stoichiometric ratio in the range of 5:1 to 5.1:1 or 2:1 to 2.1:1 and a pH ranging between 8-12 and also relates to a method for borminating aromatic compounds by using the above brominating agent.
    Type: Grant
    Filed: January 23, 2002
    Date of Patent: May 25, 2004
    Assignee: Council of Scientific and Industrial Research
    Inventors: Rajinder Nath Vohra, Pushpito Kumar Ghosh, Maheshkumar Ramniklal Gandhi, Himanshu Labhshanker Joshi, Hasina Hajibhai Deraiya, Rohit Harshadray Dave, Koushik Halder, Kishorkumar Manmohandas Majeethia, Sohan Lal Daga, Vadakke Puthoor Mohandas, Rahul Jasvantrai Sanghavi
  • Patent number: 6693221
    Abstract: A method is described for the simultaneous preparation of 4-bromophenols and p-benzoquinones, intermediates useful in the preparation of hydroquinones and 4,4′-dihydroxybiphenyls respectively. Hydroquinones and 4,4′-dihydroxybiphenyls are useful monomers for the preparation of a variety of polymers. In one example phenol is reacted with in the presence of HBr, a catalytic amount of cupric bromide and a stoichiometric excess of oxygen under relatively mild conditions to provide a mixture of the phenol, 4-bromophenol, and 1,4-benzoquinone. Phenol conversion was 54 percent and selectivities for bromophenol and benzoquinone were 23% and 37% respectively. Limiting the amount of HBr present in the reaction mixture was shown to control the amount of benzoquinone produced.
    Type: Grant
    Filed: April 4, 2003
    Date of Patent: February 17, 2004
    Assignee: General Electric Company
    Inventors: Ryan Christopher Mills, Timothy Leigh Chuck
  • Patent number: 6313355
    Abstract: Tetrabromobisphenol-A is produced in a bromination process where no bromine or only a very small proportion of bromine is fed to the reactor. In the process aqueous hydrobromic acid, is the sole source or a major source of the bromine. In the process there are at least three concurrent continuous feeds to the reactor. One is composed of bisphenol-A and/or underbrominated bisphenol-A and a water-miscible organic solvent. The second is gaseous hydrogen bromide or preferably, aqueous hydrobromic acid, and the third is aqueous hydrogen peroxide. Optionally a small additional continuous feed of bromine can be employed. The feeds are proportioned to maintain a liquid phase containing (i) from above about 15 to about 85 wt % water, based upon the amount of water and water-miscible organic solvent in such liquid phase, and (ii) an amount of unreacted bromine that is in excess over the stoichiometric amount theoretically required to convert the bisphenol-A and/or underbrominated bisphenol-A to tetrabromobisphenol-A.
    Type: Grant
    Filed: July 12, 2000
    Date of Patent: November 6, 2001
    Inventors: Thanikavelu Manimaran, Richard A. Holub, Randall S. Barton
  • Patent number: 6300527
    Abstract: This invention relates, inter alia, to a process for the production of tetrabromobisphenol-A by the bromination of bisphenol-A and/or underbrominated bisphenol-A, which process features: a water and water-miscible organic solvent reaction medium; a relatively high reaction temperature; and the presence, in the reaction medium, of both (i) excess unreacted Br2 during the feed of bisphenol-A to the reactor, and (ii) sufficient HBr to protect the tetrabromobisphenol-A produced against undesirable color formation. Tetrabromobisphenol-A precipitates from the reaction mass and is easily recovered. Product of high purity (97% or more) and very low color (APHA of 50 or less) can be produced, even when using large excesses of bromine in the reaction.
    Type: Grant
    Filed: July 12, 2000
    Date of Patent: October 9, 2001
    Assignee: Albemarle Corporation
    Inventors: Thanikavelu Manimaran, Hassan Y. Elnagar, Richard A. Holub, Alvin E. Harkins, Jr., Bonnie G. McKinnie
  • Patent number: 6265621
    Abstract: The present invention provides a process for producing a halogenated phenol compound represented by the general formula [II]: wherein Q is a monovalent organic residue, A is, the same or different, a hydrogen atom, halogen atom, —SO3H or —SO3Na group, or A at the ortho-position relative to Q may be combined with Q to form a divalent organic residue and X is a halogen atom including each isotope thereof, which comprises the step of reacting in a solvent a phenol compound represented by the general formula [I]: wherein X, Q and A have the same meanings as defined above, with a halide ion represented by the general formula X− wherein X has the same meanings as defined above, in the presence of a semiconductor catalyst with a photocatalytic activity under light irradiation conditions. According to the present invention, the halogenated phenol compound can be produced under moderate conditions.
    Type: Grant
    Filed: August 15, 2000
    Date of Patent: July 24, 2001
    Assignee: Sumitomo Chemical Company, Limited
    Inventors: Hiroshi Komori, Kazuhiko Nishioka
  • Patent number: 6235946
    Abstract: Tetrabromobisphenol-A is produced in a bromination process where no bromine or only a very small proportion of bromine is fed to the reactor. In the process aqueous hydrobromic acid, is the sole source or a major source of the bromine. In the process there are at least three concurrent continuous feeds to the reactor. One is composed of bisphenol-A and/or underbrominated bisphenol-A and a water-miscible organic solvent. The second is gaseous hydrogen bromide or preferably, aqueous hydrobromic acid, and the third is aqueous hydrogen peroxide. Optionally a small additional continuous feed of bromine can be employed. The feeds are proportioned to maintain a liquid phase containing (i) from above about 15 to about 85 wt % water, based upon the amount of water and water-miscible organic solvent in such liquid phase, and (ii) an amount of unreacted bromine that is in excess over the stoichiometric amount theoretically required to convert the bisphenol-A and/or underbrominated bisphenol-A to tetrabromobisphenol-A.
    Type: Grant
    Filed: October 12, 1999
    Date of Patent: May 22, 2001
    Assignee: Albemarle Corporation
    Inventors: Thanikavelu Manimaran, Richard A. Holub, Randall S. Barton
  • Patent number: 6218584
    Abstract: This invention relates, inter alia, to a process for the production of tetrabromobisphenol-A by the bromination of bisphenol-A and/or underbrominated bisphenol-A, which process features: a water and water-miscible organic solvent reaction medium; a relatively high reaction temperature; and the presence, in the reaction medium, of both (i) excess unreacted Br2 during the feed of bis-phenol-A to the reactor, and (ii) sufficient HBr to protect the tetrabromobisphenol-A produced against undesirable color formation. Tetrabromobisphenol-A precipitates from the reaction mass and is easily recovered. Product of high purity (97% or more) and very low color (APHA of 50 or less) can be produced, even when using large excesses of bromine in the reaction.
    Type: Grant
    Filed: June 10, 1999
    Date of Patent: April 17, 2001
    Assignee: Albemarle Corporation
    Inventors: Thanikavelu Manimaran, Hassan Y. Elnagar, Richard A. Holub, Alvin E. Harkins, Jr., Bonnie G. McKinnie
  • Patent number: 6162953
    Abstract: This invention relates to a process for the production of tetrabromobisphenol-A by the bromination of bisphenol-A, which process features the addition of bisphenol-A to a reaction mass containing unreacted Br.sub.2 and 30 to 85 wt % water and an alcohol solvent, the reaction mass being at a relatively high temperature.
    Type: Grant
    Filed: September 28, 1999
    Date of Patent: December 19, 2000
    Assignee: Albemarle Corporation
    Inventors: Bonnie G. McKinnie, Richard A. Holub, Hassan Y. Elnagar
  • Patent number: 6084137
    Abstract: This invention relates to a process for the production of tetrabromobisphenol-A by the bromination of bisphenol-A, which process features the addition of bisphenol-A to a reaction mass containing unreacted Br.sub.2 and 30 to 85 wt. % water and an alcohol solvent, the reaction mass being at a relatively high temperature.
    Type: Grant
    Filed: October 21, 1997
    Date of Patent: July 4, 2000
    Assignee: Albemarle Corporation
    Inventors: Bonnie G. McKinnie, Richard A. Holub, Hassan Y. Elnagar
  • Patent number: 6084136
    Abstract: This invention relates to a process for the production of tetrabromobisphenol-A by the bromination of bisphenol-A, which process features: (a) feeding to a reaction mass (i) bisphenol-A and (ii) a stream of gaseous bromine, the gaseous stream having a Reynold's No. .gtoreq.40,000; (b) the reaction mass containing from about 50 to about 20,000 ppm unreacted bromine and less than 20 wt % HBr; and (c) the reaction mass having precipitated therefrom tetrabromobisphenol-A, all of (a)(ii), (b) and (c) occurring during the bisphenol-A feed.
    Type: Grant
    Filed: June 11, 1998
    Date of Patent: July 4, 2000
    Assignee: Albmarle Corporation
    Inventors: Richard A. Holub, Steven R. Alferi, Bonnie G. McKinnie, Hassan Y. Elnagar
  • Patent number: 6002050
    Abstract: This invention relates to a process for the production of tetrabromobisphenol-A, which process features: a water and water miscible solvent reaction medium; a relatively high reaction temperature; and the presence, in the reaction medium, of unreacted Br.sub.2 during the feed of bisphenol-A to the reactor.
    Type: Grant
    Filed: September 8, 1998
    Date of Patent: December 14, 1999
    Assignee: Albemarle Corporation
    Inventor: Bonnie G. McKinnie
  • Patent number: 5907063
    Abstract: Activated aromatic compounds are more economically ring brominated by reacting the compounds with a sulfoxide/HBr brominating agent while removing water from the reaction mixture. The water removal provides high conversions and yields when employing stoichiometric quantities of reactants.
    Type: Grant
    Filed: March 24, 1998
    Date of Patent: May 25, 1999
    Assignee: Albemarle Corporation
    Inventor: Kevin J. Theriot
  • Patent number: 5847236
    Abstract: 2-Chloro-4-methylphenol is prepared by reacting 4-methylphenol with a chlorinating agent in the presence of a catalyst system of one or more Lewis acids in a total amount of 0.1-10% by weight and one or more diaryl sulphides in a total amount of 0.1-10% by weight, all based on the amount of 4-methylphenol. The reaction temperature is 0.degree.-100.degree. C. The chlorinating agent is used in an amount of 0.5-1.5 mol per mole of 4-methylphenol. The reaction can be carried out until virtually complete consumption of the 4-methylphenol, high isomeric selectivity and high stage selectivity being observed.
    Type: Grant
    Filed: September 25, 1996
    Date of Patent: December 8, 1998
    Assignee: Bayer Aktiengesellschaft
    Inventors: Franz-Josef Mais, Helmut Fiege
  • Patent number: 5817890
    Abstract: The present invention relates to new fluorinated hexane compounds corresponding to the following general formula (II): ##STR1## in which X'.sub.2, X'.sub.3, and X'.sub.4 are the same or different, and denote a halogen or a pseudohalogen, preferably a halogen, more preferably chlorine and fluorine, with the condition that, when R.sub.1 is hydroxyl, cyano, amido, imido, ethoxy, benzyloxy, cyclohexyloxy and tert-butoxy, not all the halogens can simultaneously be chlorine and R.sub.4, R.sub.3 and R.sub.5 are simultaneously equal to H;R.sub.1 denotes a hydrogen, a hydrocarbon chain such as an alkyl chain, alkoxy, cycloalkyl ether, an aromatic group, aromatic ether or an alkoxy, carbonyl, carboxyl or acyloxy, cyano, amido, imido or hydroxyl group;R.sub.
    Type: Grant
    Filed: March 9, 1995
    Date of Patent: October 6, 1998
    Assignee: Rhone-Poulenc Chimie
    Inventors: Lucette Duhamel, Pierre Duhamel, Bertrand Leblond, Jean-Marie Poirier
  • Patent number: 5723690
    Abstract: This invention relates to a process for the production of tetrabromobisphenol-A by the bromination of bisphenol-A, which process features: a water and water miscible solvent reaction medium; a relatively high reaction temperature; the presence, in the reaction medium, of unreacted Br.sub.2 during the feed of bisphenol-A to the reactor; and the oxidation of co-produced HBr to yield Br.sub.2.
    Type: Grant
    Filed: October 30, 1995
    Date of Patent: March 3, 1998
    Assignee: Albemarle Corporation
    Inventor: Bonnie G. McKinnie
  • Patent number: 5696302
    Abstract: A highly concentrated aqueous tribromophenolate solution containing a non-hydrophillic solvent and a reducing agent is prepared by dissolving an alkali and a reducing agent in water, adding a non-hydropillic solvent and adding tribromophenol.
    Type: Grant
    Filed: December 27, 1995
    Date of Patent: December 9, 1997
    Assignee: Dai-Ichi Kogyo Seiyaku Co., Ltd.
    Inventors: Setsuo Nishibori, Hideto Kondo
  • Patent number: 5484932
    Abstract: Compounds such as ##STR1## wherein R is F, CF.sub.3, CF.sub.2 H, CHF CF.sub.3 or CF.sub.2 CF.sub.3, as well as related compounds containing chlorine, are used as solvents in halogenation processes.
    Type: Grant
    Filed: June 2, 1994
    Date of Patent: January 16, 1996
    Assignee: Bayer Aktiengesellschaft
    Inventor: Albrecht Marhold
  • Patent number: 5475153
    Abstract: A process for the preparation of 4,4'-isopropylidene bis(2,6-dibromophenol), also known as tetrabrombisphenol A, that dramatically reduces the formation of alkyl bromide by-products. Bisphenol A is brominated with a C.sub.3 to C.sub.5 n-alcohol in a water mixture to suppress the formation of alkyl bromides. The bisphenol A is brominated between 15.degree. C. and 25.degree. C. and then heated at a 55.degree. C. to 70.degree. C. to insure bromination is complete. The tetrabrombisphenol A is then filtered from the reaction mixture and dried. Tetrabromobisphenol A produced from this process typically has a melting point of 180.degree. C. or higher, and is typically greater than 98% pure. Hydrogen peroxide is optionally combined with the reactants to reduce the amount of added bromine necessary for the bromination of the tetrabromobisphenol A.
    Type: Grant
    Filed: January 4, 1995
    Date of Patent: December 12, 1995
    Assignee: Great Lakes Chemical Corp.
    Inventor: Stuart Armstrong
  • Patent number: 5446212
    Abstract: A reduced methyl bromide process for making tetrabromobisphenol A in methanol, including: dissolving bisphenol-A in a methanol solvent to form a bisphenol-A methanol solution, adding bromine to the bisphenol-A methanol solution to brominate bisphenol-A and form tetrabromobisphenol A and hydrogen bromide, exposing the bisphenol-A methanol solution to an amount of a hydrogen peroxide agent to reduce the amount of methyl bromide co-product resulting from the bromination of bisphenol-A in methanol by reducing the amount of hydrogen bromide co-product available to react with the methanol, and collecting the resulting tetrabromobisphenol A product thus formed after the bromination is substantially complete.
    Type: Grant
    Filed: September 8, 1994
    Date of Patent: August 29, 1995
    Assignee: Great Lakes Chemical Corp.
    Inventors: Dave C. Sanders, Arthur G. Mack, Larry D. Timberlake
  • Patent number: 5426243
    Abstract: An improved process for the preparation of 1,6-dibromo-2 -naphthol is disclosed. The improvement is accomplished by carrying out the reaction in an organic solvent at a temperature of from about 40.degree. to about 60.degree. C. in the presence of a catalytically-effective amount of a compound of the formula: ##STR1## where R.sub.1, R.sub.2, R.sub.3 and R.sub.4 are the same or different and are alkyl, cycloalkyl, phenyl, substituted phenyl, naphthyl, substituted naphthyl heteroaryl, substituted heteroaryl or R.sub.1 taken together with R.sub.2 and the nitrogen atom form a heteroaryl or substituted heteroaryl group in which the heteroatom is nitrogen and X is an inorganic anion.
    Type: Grant
    Filed: August 17, 1994
    Date of Patent: June 20, 1995
    Assignee: Albemarle Corporation
    Inventor: Jean-Pierre Lecouve
  • Patent number: 5387725
    Abstract: Compounds having acidic protons and a molecular structure which can delocalize the electron density of the conjugate base (target compounds) are chlorinated by contacting such compounds with a perchloroalkane and aqueous base in the presence of a phase transfer catalyst which is an tetraalkylammonium hydroxide. Chlorinated products, preferably gem-dichloro compounds, are produced. The gem-dichloro compounds are useful for alkylation of aromatic compounds. For instance fluorene is chlorinated to form 9,9-dichlorofluorene which is reacted with such compounds as phenol or aniline to form such compounds as 9,9-bis(hydroxyphenyl)fluorene, 9,9-bis(aminophenyl)fluorene, or 9-aminophenyl-9-chlorofluorene.
    Type: Grant
    Filed: July 12, 1993
    Date of Patent: February 7, 1995
    Assignee: The Dow Chemical Company
    Inventors: Marlin E. Walters, W. Frank Richey, Katherine S. Clement, Steven L. Brewster, Emmett L. Tasset, Paul M. Puckett, V. Rao Durvasula, Hong A. Nguyen
  • Patent number: 5283375
    Abstract: This invention relates to a process for preparing a flame retardant product predominant in tetrabromobisphenol-A. The process comprises: (a) dissolving bisphenol-A in a methanol solvent containing up to about 5 weight percent water, wherein the ratio of methanol to bisphenol-A ranges from about 25 to about 43 moles of methanol per mole of bisphenol-A based on the total amount of methanol used and the total amount of bisphenol-A to be brominated; (b) adding to the solution in (a) from about 3.9 to about 4.2 moles of bromine per mole of bisphenol-A to be brominated while maintaining a reaction temperature in the range of from about 0.degree. to about 40.degree. C.; (c) after the bromination is substantially complete, adding water to precipitate the tetrabromobisphenol-A thus formed; and (d) purifying the precipitated tetrabromobisphenol-A so as to obtain a product predominant in tetrabromobisphenol-A containing less than about 20 ppm total ionic impurity.
    Type: Grant
    Filed: December 15, 1992
    Date of Patent: February 1, 1994
    Assignee: Ethyl Corporation
    Inventors: Bonnie G. McKinnie, Gary L. Sharp, Robert E. Williams
  • Patent number: 5149858
    Abstract: Phenolic compounds, notably admixtures of 2,4-dichlorophenol and 2,6-dichlorophenol, are selectively chlorinated at the ortho positions thereof, with gaseous chlorine and in a molten medium, in the presence of a selectivity-enhancing effective amount of an organic cation.
    Type: Grant
    Filed: July 18, 1988
    Date of Patent: September 22, 1992
    Assignee: Rhone-Poulenc Chimie
    Inventors: Jean-Roger Desmurs, Bernard Besson, Isabelle Jouve
  • Patent number: 5118874
    Abstract: Compounds of the formula ##STR1## in which, independently of one another, each R is OH or lower alkyl having 1-4 carbon atoms and each R' is hydrogen or lower alkyl having 1-4 carbon atoms, are prepared by the condensation of partially fluorinated aromatic hydrocarbons in the presence of hydrogen fluoride or by the reductive coupling of partially fluorinated aromatic compounds. The compounds are used as a starting material for the preparation of partially fluorinated polycondensates.
    Type: Grant
    Filed: June 20, 1991
    Date of Patent: June 2, 1992
    Assignee: Hoechst Aktiengesellschaft
    Inventors: Wolfgang Appel, Gunter Siegemund
  • Patent number: 5059722
    Abstract: Tetrabromobisphenol-A is made in high purity by adding a methanol-bromine solution to a methanol-bisphenol-A solution with vigorous agitation. Use of the bromine-methanol solution reduces the amount of by-products compared to the use of liquid bromine feed to a methanol-bisphenol-A solution. The process is readily adapted to large scale equipment by circulating the reaction mixture from the reaction vessel through an external closed loop which includes an impingement mixer. The bromine-methanol feed is pumped at the proper rate and ratio into the impingement mixture whereby it impinges with the circulating reaction mixture. The resultant bromination mixture is then returned to the reaction vessel.
    Type: Grant
    Filed: December 22, 1989
    Date of Patent: October 22, 1991
    Assignee: Ethyl Corporation
    Inventors: Olan W. Mitchell, Bonnie G. McKinnie
  • Patent number: 5053557
    Abstract: A process is disclosed for preparing 2-chloro-4-fluorophenol which comprises chlorinating 4-fluorophenol with a chlorinating agent in the presence of water. The process according to the present invention has advantages in that the chlorination can be carried out using inexpensive reagents without requiring the use of particular apparatus and under mild conditions, and the desired product can be obtained in good yields and with high selectivity. 2-Chloro-4-fluorophenol obtained in the present invention is useful as a starting material for producing various pharmaceutical agents and agricultural agents.
    Type: Grant
    Filed: September 6, 1990
    Date of Patent: October 1, 1991
    Assignee: Sagami Chemical Research Center
    Inventors: Kenji Hirai, Mitsuo Yamashita
  • Patent number: 5026926
    Abstract: The polychlorophenols, e.g., 2,6-dichlorophenol (a known agrochemical intermediate), are effectively prepared by chlorinating ortho-chlorophenol with gaseous chlorine, optionally in the presence of other chlorophenols, characteristically in the molten state, and in the presence of a catalytically effective amount of a primary, secondary or tertiary amine.
    Type: Grant
    Filed: March 7, 1988
    Date of Patent: June 25, 1991
    Assignee: Rhone-Poulenc Chimie
    Inventors: Jean-Claude Leblanc, Serge Ratton, Bernard Besson, Jean-Roger Desmurs
  • Patent number: 5017728
    Abstract: Tetrabromobisphenol-A is made in high purity and increased yield by adding a methanol-bromine solution to a methanol bisphenol-A solution with vigorous agitation. The amount of methanol in the reaction vessel is adjusted to yield a ratio of tetrabromobisphenol-A to methanol when the reaction is substantially complete that provides a lower amount of Hbr impurity in the tetrabromobisphenol-A product. An increased recovery of tetrabromobisphenol-A product is achieved by adjusting the water added to the reaction vessel when the bromination reaction is essentially complete.
    Type: Grant
    Filed: August 20, 1990
    Date of Patent: May 21, 1991
    Assignee: Ethyl Corporation
    Inventors: Bonnie G. McKinnie, Daniel A. Wood
  • Patent number: 4997946
    Abstract: A method of iodinating hydroxyaromatic and aminoaromatic compounds is disclosed, comprising reacting the hydroxyaromatic or aminoaromatic compound with an aqueous solution of a metal iodide and a metal hypochlorite at a temperature about -100.degree. to 100.degree. C. in the presence of an alcohol having 1-10 carbon atoms.
    Type: Grant
    Filed: August 18, 1987
    Date of Patent: March 5, 1991
    Assignee: Eastman Kodak Company
    Inventors: Kevin J. Edgar, Guy R. Steinmetz
  • Patent number: 4954662
    Abstract: Ortho-substituted phenolic compounds, e.g., 2,6-dichlorophenol, are selectively chlorinated, e.g., into 2,4,6-trichlorophenol, with gaseous chlorine in either the molten state or in a solvent medium, in the presence of a selectivity-enhancing effective amount of an organic cation.
    Type: Grant
    Filed: July 18, 1988
    Date of Patent: September 4, 1990
    Assignee: Rhone-Poulenc Chimie
    Inventors: Jean-Roger Desmurs, Bernard Besson, Isabelle Jouve
  • Patent number: 4940807
    Abstract: Electron-rich aromatic compounds are selectively brominated in good yield in the presence of water using potassium tribromide as the brominating agent. In this way monobromination is favored and dibromination is suppressed as compared to the use of elemental bromine as the brominating agent.
    Type: Grant
    Filed: June 12, 1989
    Date of Patent: July 10, 1990
    Assignee: Ethyl Corporation
    Inventor: Robert N. DePriest
  • Patent number: 4885408
    Abstract: The ortho-substituted phenols, e.g., 2,6-dichlorophenol, are reacted with gaseous chlorine, in the presence of a catalytically effective amount of a strong or Lewis acid, to produce, e.g., a more pure 2,4,6-trichlorophenol in good yield.
    Type: Grant
    Filed: July 2, 1987
    Date of Patent: December 5, 1989
    Assignee: Rhone-Poulenc Chimie
    Inventors: Serge Ratton, Jean-Roger Desmurs
  • Patent number: 4876396
    Abstract: Phenolic compounds and mixtures thereof, e.g., admixture of 2,4-dichlorophenol and 2,6-dichlorophenol, are selectively chlorinated at a position ortho to a hydroxyl function thereof, by reacting such phenolic compound with gaseous chlorine, in a molten reaction medium, in the presence of a catalytically effective amount of a primary, secondary or tertiary amine.
    Type: Grant
    Filed: July 28, 1987
    Date of Patent: October 24, 1989
    Assignee: Rhone-Poulenc Specialites Chimiques
    Inventors: Jean-Claude LeBlanc, Serge Ratton
  • Patent number: 4855514
    Abstract: A process for producing iodophenols which comprises contacting phenol, a source of iodine and molecular oxygen in an aqueous medium to produce an iodophenol.
    Type: Grant
    Filed: August 17, 1988
    Date of Patent: August 8, 1989
    Assignee: Eastman Kodak Company
    Inventors: Mark Rule, Regina M. Moncier
  • Patent number: 4855513
    Abstract: The chlorophenols, e.g., 2,4,6-trichlorophenol, are efficiently prepared by chlorinating an ortho-/para-substituted phenolic compound with gaseous chlorine, whether in molten state or in a solvent reaction medium, in the presence of a catalytically effective amount of a primary, secondary or tertiary amine.
    Type: Grant
    Filed: March 7, 1988
    Date of Patent: August 8, 1989
    Assignee: Rhone-Poulenc Chimie
    Inventors: Bernard Besson, Jean-Roger Desmurs, Isabelle Jouve
  • Patent number: 4827047
    Abstract: The chloronitrophenols, e.g., 2,6-dichloro-4-nitrophenol (a known agrochemical/pharmaceutical intermediate), are efficiently prepared by chlorinating ortho- or para-nitrophenol with gaseous chlorine, characteristically in the molten state, and in the presence of a catalytically effective amount of a primary, secondary or tertiary amine.
    Type: Grant
    Filed: March 7, 1988
    Date of Patent: May 2, 1989
    Assignee: Rhone-Poulenc Chimie
    Inventors: Jean-Roger Desmurs, Isabelle Jouve
  • Patent number: 4783556
    Abstract: Tetrabromobisphenol-A is made in high purity by adding a methanol-bromine solution to a methanol-bisphenol-A solution with vigorous agitation. Use of the bromine-methanol solution reduces the amount of by-products compared to the use of liquid bromine feed to a methanol-bisphenol-A solution. The process is readily adapted to large scale equipment by circulating the reaction mixture from the reaction vessel through an external closed loop which includes an impingement mixer. The bromine-methanol feed is pumped at the proper rate and ratio into the impingement mixture whereby it impinges with the circulating reaction mixture. The resultant bromination mixture is then returned to the reaction vessel.
    Type: Grant
    Filed: November 27, 1987
    Date of Patent: November 8, 1988
    Assignee: Ethyl Corporation
    Inventors: Olan W. Mitchell, Bonnie G. McKinnie
  • Patent number: 4754080
    Abstract: This invention relates to novel compositions comprising a N-halodialkylamine as defined in the specification and an inorganic oxide. The compositions are useful as halogenating agents for phenolic compounds. The compositions have the advantage that they are milder halogenating agents than halogens or hydrogen halides.
    Type: Grant
    Filed: April 6, 1987
    Date of Patent: June 28, 1988
    Assignee: British Petroleum Company p.l.c.
    Inventors: Michael Butters, Barry Nay, Keith Smith
  • Patent number: 4740636
    Abstract: Included is a process to prepare a 4-HALOmethyl-3,5-dihalo-2,6-disubstitutedphenol from a 4-methyl(substituted)phenol and a HALOgenating agent, in an aprotic organic diluent. The process is highly selective and efficient. For example, high purity 4-bromomethyl-3,5-dibromo-2,6-dimethylphenol can be prepared from 2,4,6-trimethylphenol and bromine, in bromochloromethane at high conversion.
    Type: Grant
    Filed: May 15, 1987
    Date of Patent: April 26, 1988
    Assignee: The Dow Chemical Company
    Inventor: Abel Mendoza
  • Patent number: RE32606
    Abstract: There is disclosed a process for the preparation of completely brominated derivatives of aromatic compounds comprising one or more phenyl groups which may contain substituents, side chains or be partially-brominated. The complete bromination is effected by utilizing liquid bromine as a reaction solvent whereby the starting aromatic material is reacted with an excess of bromine which contains a bromination catalyst and the mixture is refluxed for a sufficient time. Use of these brominated derivatives as fire retarding agents is nylon and polyester is also disclosed.
    Type: Grant
    Filed: April 29, 1986
    Date of Patent: February 16, 1988
    Assignee: Great Lakes Chemical Corporation
    Inventor: Heinrich Stepniczka