WO2005023739A1 - Selective catalytic oxybromination of hydroxyaromatic compounds - Google Patents
Selective catalytic oxybromination of hydroxyaromatic compounds Download PDFInfo
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- WO2005023739A1 WO2005023739A1 PCT/US2004/021999 US2004021999W WO2005023739A1 WO 2005023739 A1 WO2005023739 A1 WO 2005023739A1 US 2004021999 W US2004021999 W US 2004021999W WO 2005023739 A1 WO2005023739 A1 WO 2005023739A1
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- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07B—GENERAL METHODS OF ORGANIC CHEMISTRY; APPARATUS THEREFOR
- C07B39/00—Halogenation
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- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C37/00—Preparation of compounds having hydroxy or O-metal groups bound to a carbon atom of a six-membered aromatic ring
- C07C37/62—Preparation of compounds having hydroxy or O-metal groups bound to a carbon atom of a six-membered aromatic ring by introduction of halogen; by substitution of halogen atoms by other halogen atoms
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C39/00—Compounds having at least one hydroxy or O-metal group bound to a carbon atom of a six-membered aromatic ring
- C07C39/24—Halogenated derivatives
- C07C39/26—Halogenated derivatives monocyclic monohydroxylic containing halogen bound to ring carbon atoms
- C07C39/27—Halogenated derivatives monocyclic monohydroxylic containing halogen bound to ring carbon atoms all halogen atoms being bound to ring carbon atoms
Definitions
- This invention relates to the catalyzed bromination of hydroxyaromatic compounds, and more particularly to the use of transition metal compound catalysts for improved para- and mono-selectivity of the reaction products.
- Monocyclic dihydroxyaromatic compounds such as hydroquinone and dihydroxybiphenyls such as 4,4'-dihydroxybiphenyl (hereinafter sometimes simply "biphenol") have numerous uses in the chemical industry.
- both compounds can be used in polymer preparation, notably in the preparation of polycarbonates, polysulfones and polyimides, especially polyetherimides.
- each compound can be prepared from p-bromophenol: hydroquinone by hydrolysis: and biphenol by reductive coupling in the presence of a noble metal catalyst, a base and a reducing agent.
- Brominated hydroxyaromatic compounds as exemplified by p-bromophenol, can be prepared by reaction of the precursor hydroxyaromatic compound with HBr, elemental bromine, or with various kinds of bromides.
- Commonly assigned, co- pending US Application No. 10/342,475 discloses an efficient means of preparing brominated hydroxyaromatic compounds including p- bromophenol. The method comprises contacting a hydroxyaromatic compound with oxygen and a bromide source in an acidic medium, in the presence of elemental copper or a copper compound as catalyst.
- the present invention provides an efficient method for selectively brominating hydroxyaromatic compounds to form mono-substituted products while minimizing the formation of dibromo-phenols and more highly brominated by-products.
- the method provides high selectivity for producing para-brominated hydroxyaromatic compounds relative to ortho-brominated products.
- the method provides overall high process yields, as well as high selectivity, using transition metal compounds of Groups rV-VIII to catalyze the oxybromination reaction. Furthermore, corrosive copper catalysts need not be employed.
- the present invention relates to a method for preparing a brominated hydroxyaromatic compound.
- the method comprises contacting a hydroxyaromatic compound with oxygen and a bromine compound selected from the group consisting of hydrogen bromide, elemental bromine, ionic bromide salts, and mixtures thereof, 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 invention in another aspect, relates to a method for preparing 4-bromophenol, 4- bromo-o-cresol or 4-bromo-m-cresol, which comprises contacting phenol, o-cresol or m-cresol, respectively, with air and hydrogen bromide 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 present invention relates to the novel use of compounds and complexes of Group rV-VIII transition metals to catalyze the selective oxybromination of hydroxyaromatic compounds.
- the products are mostly mono-brominated compounds, predominantly the p-bromo compound, with minor amounts of o-bromo compound being present. Formation of multi-brominated by-products is substantially reduced in comparison to prior methods, through the use of these catalysts.
- the common initial reactant for all products obtained according to the method of this invention is a hydroxyaromatic compound, such as a monocyclic monohydroxyaromatic compound.
- the hydroxyaromatic compound is contacted with oxygen and a bromine compound in the presence of a catalyst, which is a compound or mixture of compounds of Group IV- VIII transition metals of the Periodic Table.
- the bromination reaction may be conducted at a temperature in the range of about 20- 150°C, but generally about 60-100°C.
- selectivity to brominated products means moles of specific brominated products as a percentage of moles of hydroxyaromatic compound consumed. Furthermore, “monoselectivity” is defined herein as moles of para- brominated and ortho-brominated product formed as a percentage of moles of para- brominated products, ortho- brominated products, dibrominated products, and more highly brominated products formed. Selectivity to the p-brominated products, i.e. "paraselectivity” is defined as the percentage of mono-brominated products which are brominated in the para-position, the remainder of which are ortho-brominated compounds.
- the hydroxyaromatic reactant may be an unsubstituted hydroxyaromatic compound such as phenol, or a substituted compound provided that the 4-position is unsubstituted and thus available for bromination.
- the 2-, 3-, and 4- positions relative to the carbon attached to the hydroxy group are also known as and referred to herein as ortho-, meta-, and para, respectively.
- a substituent may be located at any position of the aryl ring other than the 1- or 4- carbons.
- Exemplary substituents are alkyl groups, particularly C 1-4 alkyl.
- Illustrative compounds are those having the formula
- each R is independently hydrogen or a substituent, preferably C 1-4 alkyl.
- phenol Particularly preferred in most instances is phenol, and specific reference will frequently be made to phenol hereinafter.
- homologous compounds such as o- and m-cresol may be substituted for phenol as desired.
- the oxygen is employed in stoichiometric excess and may be pure oxygen or may be employed in the form of air or oxygen-enriched air. Contact may be made with flowing oxygen or air or under pressure, typically up to about 100 arm.
- Suitable bromine compounds include hydrogen bromide, elemental bromine (Br 2 ), and bromide salts. Mixtures of the bromine compounds may also be used. Hydrogen bromide may be employed in any form; examples are gaseous HBr, aqueous HBr (hydrobromic acid) and HBr in solution in a polar organic solvent, typically one of the solvents described hereinafter. Often the starting reaction medium will be anhydrous.
- Bromide salts include alkali metal bromides such as sodium bromide and potassium bromide and alkaline earth metal bromides such as calcium bromide and magnesium bromide.
- the contact is in an acidic medium.
- Aqueous acidic media including Br ⁇ nsted acids generally, and particularly including sulfuric acid, phosphoric acid and triflic acid, may be employed; or, if hydrobromic acid is the bromine compound employed, it may also serve as the acidic medium.
- Polar solvents may also be present. These may include polar aprotic solvents such as acetonitrile, dimethyl sulfoxide, chloroform, ethyl acetate, and o-dichlorobenzene, as well as protic solvents such as water, acetic acid, propionic acid, and excess hydroxyaromatic compound. Acetic acid is frequently preferred. Mixtures of the foregoing solvents may also be employed.
- reaction medium is frequently anhydrous.
- Hydrogen bromide in acetic acid under anhydrous conditions or hydrobromic acid are generally preferred as bromine sources/acidic mediums.
- Hydrobromic acid may be employed at any concentration, including the commercially available 48% or 62% (by volume) aqueous solution.
- Acetic acid is also frequently added when hydrobromic acid is employed.
- the molar ratio of ionic bromide to hydroxyaromatic compound is preferably less than 1 :1, to minimize conversion to dibromo and more highly brominated compounds; ratios in the range of about 0.2-0.9:1 are typical.
- the molar ratio of Br 2 to hydroxyaromatic compound is preferably less than 1:2, typically in the range of about 0.2-0.9:2, again to minimize the formation of by-products.
- one mole of bromine reacts with one mole phenol to generate 1 mole of p-bromophenol and 1 mole of HBr, which then reacts with a second mole of phenol in the presence of oxygen and the catalyst to yield a second mole of p-bromophenol.
- use of the catalysts described herein allows consumption of all the bromine employed in the bromination reaction using inexpensive oxygen, such as in air, as an oxidant.
- the oxybromination reaction of the present invention occurs in the presence of a catalyst comprising one of more compounds or complexes of Group IV-VIII transition metals.
- a molar ratio of hydroxyaromatic compound to the catalyst ranging from about 1:1 to about 500:1 minimizes conversion of the products to dibromo and more highly brominated compounds.
- a molar ratio of 200:1 provides a high product yield with excellent mono-selectivity.
- suitable Group IV-VIII transition metals include vanadium, titanium, molybdenum, tungsten, and iron, for example.
- vanadium any vanadium source including cationic, anionic salts and neutral complexes may be used as the catalyst for selective oxybromination of phenolics.
- Vanadate salts such as sodium metavanadate having the chemical formula NaVO 3 , are preferentially used.
- catalysts which have proven useful for these bromination reactions include, for example, bis(acetylacetonate)oxovanadium, bis(acetylacetonate)oxotitanium, sodium molybdenum oxide dihydrate (NaMoO 4 '2H O) , iron bromide (FeBr 2 ), and tungstic acid (H 2 WO "xH 2 O).
- Bis(acetylacetonate)oxo vanadium has the chemical formula VO(CH 3 COCHCOCH 3 ) 2 , which is often abbreviated as VO(acac) 2 .
- bis(acetylacetonate)oxotitanium has formula TiO(CH 3 COCHCOCH 3 ) 2 , which is also referred to as TiO(acac) 2 .
- the invention is not limited to use of these catalysts, and other ligands and salts will be obvious to those of skill.
- the Group IV-VIII transition metal catalyst compounds may be used alone or in combination.
- a mixture of any of the aforementioned catalysts may be employed.
- a compound of vanadium mixed with a compound of molybdenum is employed as the catalyst.
- the catalyst is a compound of vanadium mixed with a compound of tungsten.
- a mixture of Group IV-VIII transition metal compounds often improves the selectivity of the reaction to brominated products and the paraselectivity. Furthermore, the yield of brominated products generally increases significantly, as does the rate of the reaction.
- the molar ratio of the vanadium compound to the other metal compound is in the range of about 1 :0.5 to about 1 :6. Examples of such combinations include mixtures of sodium metavanadate (NaVO 3 ) with either sodium molybdenum oxide dihydrate (NaMoO 4 2H 2 O) or tungstic acid (H 2 WO 4 xH 2 O).
- a nitrate salt such as sodium nitrate
- Addition of a nitrate salt increases the yield of the mono-brominated product and the rate of the reaction, and in some embodiments the selectivity to brominated products and para-selectivity also improves.
- the molar ratio of the nitrate salt to the Group IV- VIII transition metal catalyst compound(s) preferably ranges from about 1:1 to about 1 :4. However a ratio of about 1 :2 is typical.
- Sodium nitrate in combination with a compound of vanadium will often be used to catalyze the reaction.
- the products of the catalytic bromination reaction are mostly mono-brominated compounds, predominantly in the para position, with minor amounts of compounds brominated in the ortho position being present. Formation of dibrominated and more highly brominated by-products is reduced using the Group IV-VIII transition metal catalysts described herein.
- Selectivity to brominated phenol products is generally greater than 79%, but typically ranges from 94-100% when a vanadium catalyst is employed.
- a monoselectivity of 100% is often observed, but frequently ranges from 96-100% depending on the reactants, catalyst(s), and reaction conditions used. However, a monoselectivity greater than 70% is acceptable.
- selectivity to the p-brominated products i.e. "paraselectivity" is usually at least 80% and often greater than 90%.
- Examples 1-6 illustrate the catalytic bromination of phenol with HBr aq/O 2 in a solvent using compounds of Group IV-VIII transition metals as the catalyst.
- a 3-dram vial equipped with a stirring bar was charged with 1.5 g (15.9 mmol) phenol, 2.95 g of aqueous HBr (48 wt %) (17.5 mmol), 1.5 g of acetic acid, and 0.250 g (1.0 mmol) of VO(acac) 2 .
- the vial was sealed with a cap containing a hole to allow for air flow during the reaction and placed in an aluminum block.
- the block was placed in a standard one gallon Autoclave Engineers autoclave reactor, pressurized to 34.0 atm with air and heated at 100° C for 2 hours. It was then cooled to room temperature and depressurized. The resulting mixture was analyzed by vapor phase chromatographic analysis. The results are shown in Table I.
- Example 1 The procedure of Example 1 was followed except that the vial was charged with 1.5 g (15.9 mmol) phenol, 1.47 g of aqueous HBr (48 wt %) (8.72 mmol), 2.5 g of acetic acid, and 0.250 g (1.0 mmol) of VO(acac) 2 .
- the results are shown in Table I.
- Example 1 The procedure of Example 1 was followed except that the vial was charged with 1.5 g (15.9 mmol) phenol, 2.0 g of aqueous HBr (48 wt %) (11.9 mmol), 1.5 g of acetic acid, and 0.175 g (0.7 mmol) of VO(acac) 2 .
- the results are shown in Table I.
- Example 1 The procedure of Example 1 was followed except that the vial was charged with 1.5 g (15.9 mmol) phenol, 2.0 g of aqueous HBr (48 wt %) (11.9 mmol), 1.35 g of ethyl acetate, and 0.175 g (0.7 mmol) of VO(acac) .
- the results are shown in Table I.
- Example 1 The procedure of Example 1 was followed except that the vial was charged with 1.5 g (15.9 mmol) phenol, 2.0 g of aqueous HBr (48 wt %) (11.9 mmol), 1.35 g of ethyl acetate, and 0.107 g (0.5 mmol) of FeBr 2 .
- the results are shown in Table I.
- Example 1 The procedure of Example 1 was followed except that the vial was charged with 1.5 g (15.9 mmol) phenol, 2.5 g of aqueous HBr (48 wt %) (14.8 mmol), 2.5 g of acetic acid, and 0.155 g (0.7 mmol) of NaMoO '2H 2 O. Also, the vial was pressurized to 6.8 atm with air instead of 34.0 atm. The results are shown in Table I. Table I
- Example 2 The procedure of Example 1 was followed except that the vial was charged with 1.5 g (15.9 mmol) phenol, 4 g of 30 % solution of HBr (14.8 mmol) in acetic acid, and 0.174 g (0.7 mmol) of VO(acac) 2 . Furthermore, the reaction was conducted for 1 hour at 100° C instead of 2 hours. The results are found in Table II.
- Example 7 The procedure of Example 7 was followed except that 0.108 g (0.5 mmol) of FeBr 2 was added as the catalyst. The results are found in Table II.
- Example 7 The procedure of Example 7 was followed except that 0.131 g (0.5 mmol) of TiO(acac) 2 was added as the catalyst. The results are found in Table II.
- Example 7 The procedure of Example 7 was followed except that 0.155 g (0.7 mmol) of NaMoO 4 '2H 2 O was added as the catalyst. Also, the vial was pressurized to 6.8 atm with air instead of 34.0 atm. The results are found in Table II.
- Example 11 The procedure of Example 7 was followed except that 0.188 g (0.7 mmol) of H 2 WO 4 xH 2 O was added as the catalyst. Also, the vial was pressurized to 6.8 atm with air instead of 34.0 atm. The results are found in Table II.
- Example 7 The procedure of Example 7 was followed except that 0.155 g (0.7 mmol) of NaMoO ' 2H 2 O was added as the catalyst. Also, the reaction was conducted for 2 hours at 65° C instead of 1 hour at 100° C. The results are found in Table II.
- Example 12 The procedure of Example 12 was followed except that 0.188 g (0.7 mmol) of H 2 WO 4 xH 2 O was added as the catalyst. The results are found in Table II.
- Example 12 The procedure of Example 12 was followed except 0.174 g (0.7 mmol) of VO(acac) 2 was added as the catalyst. The results are found in Table II.
- Example 12 The procedure of Example 12 was followed except 0.026 g (0.1 mmol) of VO(acac) 2 was added as the catalyst. The results are found in Table II.
- Examples 16-17 illustrate the use of a mixture of bis(acetylacetonate)oxovanadium (VO(acac) 2 ) and sodium molybdenum oxide dihydrate (NaMoO 4 2H 2 0) or a mixture of bis(acetylacetonate)oxovanadium (VO(acac) 2 ) and tungstic acid (H 2 WO xH 2 O) to catalyze the oxybromination of phenol with anhydrous HBr/O 2 in a solvent.
- the invention is not limited to mixtures of these particular catalysts, as one of skill would know.
- Example 12 The procedure of Example 12 was followed except that 0.026 g (0.1 mmol) of VO(acac) 2 and 0.155 g (0.7 mmol) of NaMoO 4 '2H 2 O were added as catalysts. The results are found in Table III.
- Example 12 The procedure of Example 12 was followed except 0.026 g (0.1 mmol) of VO(acac) 2 and 0.188 g (0.7 mmol) of H 2 W0 4 'xH 2 O were added as catalysts. The results are found in Table III.
- Example 18 shown in Table III show that the addition of the vanadium compound catalyst to the molybdenum compound catalyst significantly increased the paraselectivity of the reaction by about 7%. Furthermore, the selectivity to brominated products increased to 99.2 %, and the yield of brominated products more than doubled, as did the rate of the reaction. Comparing the results of Example 13 shown in Table II with those of Example 19 in Table III, one can see that addition of the vanadium compound catalyst to the tuncstic acid catalyst increased the paraselectivity of the reaction by about 8% and the selectivity to brominated products by more than 30% (i.e., 99.4%). Furthermore, the yield of brominated products more than tripled, as did the rate of the reaction.
- Example 18 The procedure of Example 18 was followed except that 0.045 g (0.5 mmol) of NaNO 3 was added with the catalyst. The results are shown in Table IV.
- a 3-dram vial equipped with a stirring bar was charged with 1.5 g (15.9 mmol) phenol, 4 g of 30 % solution of HBr (14.8 mmol) in acetic acid, and 0.104 g (0.9 mmol) of NaVO .
- the vial was sealed with a cap containing a hole to allow for air flow during the reaction and placed in an aluminum block.
- the block was placed in a standard one gallon Autoclave Engineers autoclave reactor, pressurized to 34.0 atm with air and heated at 65° C for 1 hour. It was then cooled to room temperature and depressurized. The resulting mixture was analyzed by vapor phase chromatographic analysis. The results are shown in Table V.
- Example 20 The procedure of Example 20 was followed except that the catalyst was 0.074 g (0.6 mmol) NaVO 3; and 0.044 g (0.5 mmol) of NaNO 3 was added to the reaction mixture. The results are shown in Table V.
- Example 20 The procedure of Example 20 was followed except that the catalyst was 0.089 g (0.35 mmol) of VO(acac) 2> and 0.047 g (0.55 mmol) of NaNO 3 was added to the reaction mixture. The results are shown in Table V.
- Example 20 The procedure of Example 20 was followed except that the catalyst was 0.050 g (0.2 mmol) of FeBr 2> and 0.044 g (0.5 mmol) of NaNO 3 was added to the reaction mixture. The results are shown in Table V.
- EXAMPLE 24 The procedure of Example 20 was followed except that the catalyst was 0.067 g (0.25 mmol) of TiO(acac) 2> and 0.043 g (0.5 mmol) of NaNO 3 was added to the reaction mixture. The results are shown in Table V.
- Examples 25-27 illustrate that a small amount of water added to the oxybromination reaction mixture when anhydrous HBr is used as the brominating agent in the presence of a Group IV-VIII transition metal compound catalyst results in high monoselectivity and paraselectivity of the products. However, the reaction rate and bromophenol yield decreases.
- Example 25 The procedure of Example 25 was followed except that water was added in the ratio of 1 mole H 2 O to 1 mole HBr. The results are found in Table VI.
- Example 25 The procedure of Example 25 was followed except that water was added in the ratio of 2 moles H O to 1 mole HBr. The results are found in Table VI.
- Examples 28-30 illustrate the oxybromination of o-cresol with aqueous HBr in acetic acid and air in the presence of a compound of a Group IV-VIII transition metal as the catalyst.
- the monoselectivity was 100% and the paraselectivity was greater than 90%.
- EXAMPLE 28 A 3-dram vial equipped with a stirring bar was charged with 1.75 g (16.2 mmol) o- cresol, 2 g of aqueous HBr (48 wt %) (11.8 mmol), 1.25 g of acetic acid, and 0.1 g (0.4 mmol) of VO(acac) 2 .
- the vial was sealed with a cap containing a hole to allow for air flow during the reaction and placed in an aluminum block.
- the block was placed in a standard one gallon Autoclave Engineers autoclave reactor, pressurized to 34.0 atm with air and heated at 100° C for 1 hour. It was then cooled to room temperature and depressurized. The resulting mixture was analyzed by vapor phase chromatographic analysis. The results are shown in Table VII.
- Example 28 The procedure of Example 28 was followed except that 0.225g (0.9 mmol) of VO(acac) 2 was added as the catalyst. The results are shown in Table VII.
- Example 28 The procedure of Example 28 was followed except that 0.35g (1.4 mmol) of VO(acac) 2 was added as the catalyst. The results are shown in Table VII.
Abstract
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Priority Applications (2)
Application Number | Priority Date | Filing Date | Title |
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EP04756818A EP1660424A1 (en) | 2003-08-28 | 2004-07-09 | Selective catalytic oxybromination of hydroxyaromatic compounds |
JP2006524643A JP2007521319A (en) | 2003-08-28 | 2004-07-09 | Catalytic selective oxybromination of hydroxyaromatic compounds |
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US10/650,567 US7022886B2 (en) | 2003-08-28 | 2003-08-28 | Selective catalytic oxybromination of hydroxyaromatic compounds |
US10/650,567 | 2003-08-28 |
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PCT/US2004/021999 WO2005023739A1 (en) | 2003-08-28 | 2004-07-09 | Selective catalytic oxybromination of hydroxyaromatic compounds |
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US (1) | US7022886B2 (en) |
EP (1) | EP1660424A1 (en) |
JP (1) | JP2007521319A (en) |
KR (1) | KR20060127842A (en) |
CN (1) | CN1874982A (en) |
WO (1) | WO2005023739A1 (en) |
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KR20110041561A (en) * | 2008-08-05 | 2011-04-21 | 바스프 에스이 | Process for the preparation of 4-bromophenyl derivatives |
CN102766028A (en) * | 2012-08-15 | 2012-11-07 | 山东默锐科技有限公司 | Method for preparing 2-bromine-4-methylphenol |
CN104098449B (en) * | 2013-04-02 | 2016-01-20 | 江苏英力科技发展有限公司 | A kind of preparation method of 2,6-dimethoxy-3-bromo-4-methylphenol |
CN108250060B (en) * | 2018-01-26 | 2021-10-15 | 江苏尚莱特医药化工材料有限公司 | Synthesis method of 5-bromo-2-chlorobenzoic acid |
CA3142008A1 (en) * | 2019-05-31 | 2020-12-03 | Purisys Llc | Processes for the preparation of halogenated dihydroxybenzene compounds |
CN110143852A (en) * | 2019-06-28 | 2019-08-20 | 福建医科大学 | A method of photocatalytic synthesis is at more bromophenol compounds in water phase |
Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2779785A (en) * | 1952-12-22 | 1957-01-29 | Dow Chemical Co | Halogenated phenyl-salicylic acids |
US2802029A (en) * | 1951-10-17 | 1957-08-06 | Knoll Ag | Bromsalicyloyl-chloranilide |
Family Cites Families (3)
Publication number | Priority date | Publication date | Assignee | Title |
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US3987068A (en) * | 1975-07-28 | 1976-10-19 | E. I. Du Pont De Nemours And Company | Oxidation of monohydroxy aryl compounds to 1,4-quinones |
US7045666B2 (en) * | 2003-01-16 | 2006-05-16 | General Electric Company | Bromination of hydroxyaromatic compounds and further conversion to dihydroxyaromatic compounds |
US6815565B2 (en) * | 2003-04-04 | 2004-11-09 | General Electric Company | Method for preparing hydroquinones and dihydroxybiphenyl compounds from mixtures of bromophenols and benzoquinones |
-
2003
- 2003-08-28 US US10/650,567 patent/US7022886B2/en not_active Expired - Lifetime
-
2004
- 2004-07-09 CN CNA2004800320979A patent/CN1874982A/en active Pending
- 2004-07-09 EP EP04756818A patent/EP1660424A1/en not_active Withdrawn
- 2004-07-09 JP JP2006524643A patent/JP2007521319A/en not_active Withdrawn
- 2004-07-09 WO PCT/US2004/021999 patent/WO2005023739A1/en active Application Filing
- 2004-07-09 KR KR1020067004257A patent/KR20060127842A/en not_active Application Discontinuation
Patent Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2802029A (en) * | 1951-10-17 | 1957-08-06 | Knoll Ag | Bromsalicyloyl-chloranilide |
US2779785A (en) * | 1952-12-22 | 1957-01-29 | Dow Chemical Co | Halogenated phenyl-salicylic acids |
Non-Patent Citations (4)
Title |
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B.P.BANDGAR ET AL.: "Regioselective catalytic halogenation of aromatic substrates", SYNTHETIC COMMUNICATIONS, vol. 28, no. 17, 1998, pages 3225 - 3229, XP009041370 * |
J.H. ESPENSON ET AL.: "Bromide ions and methyltrioxorhenium as cocatalysts for hydrogen peroxide oxidations and brominations", JOURNAL OF ORGANIC CHEMISTRY, vol. 64, 1999, pages 1191 - 1196, XP002310159 * |
NEUMANN R ET AL: "OXYBROMINATION CATALYSED BY THE HETEROPOLYANION COMPOUND H5PMO10V2O40 IN AN ORGANIC MEDIUM: SELECTIVE PARA-BROMINATION OF PHENOL", JOURNAL OF THE CHEMICAL SOCIETY, CHEMICAL COMMUNICATIONS, CHEMICAL SOCIETY. LETCHWORTH, GB, vol. 19, 1988, pages 1285 - 1287, XP009031632, ISSN: 0022-4936 * |
R. HEDGE VISNUMURTHY ET AL.: "Regioselective catalytic halogenation of arenes, mimicking vanadium haloperoxidase reactions", J.CHEM.RESEARCH, 1996, pages 62 - 63, XP009041368 * |
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EP1660424A1 (en) | 2006-05-31 |
CN1874982A (en) | 2006-12-06 |
US7022886B2 (en) | 2006-04-04 |
JP2007521319A (en) | 2007-08-02 |
KR20060127842A (en) | 2006-12-13 |
US20050049441A1 (en) | 2005-03-03 |
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