Classifications

• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C49/00—Ketones; Ketenes; Dimeric ketenes; Ketonic chelates
  • C07C49/587—Unsaturated compounds containing a keto groups being part of a ring
  • C07C49/657—Unsaturated compounds containing a keto groups being part of a ring containing six-membered aromatic rings
  • C07C49/665—Unsaturated compounds containing a keto groups being part of a ring containing six-membered aromatic rings a keto group being part of a condensed ring system
  • C07C49/675—Unsaturated compounds containing a keto groups being part of a ring containing six-membered aromatic rings a keto group being part of a condensed ring system having three rings
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C46/00—Preparation of quinones

Definitions

• the present invention relates to a process for the synthesis of 2-ethyl-anthraquinone (EAQ) from ethylbenzene (EB) and phthalic anhydride (AP) reacted in a liquid mixture of HF and BF3 to form a complex of l 2- (4 '-ethylbenzoyl) benzoic acid (EBB) of molar formula EBB.nHF.mBF3 with n and m of between approximately 1 and approximately 3.
• EBB 2-ethyl-anthraquinone
• JP SCHIRMANN and SY recall DELAVARENNE in "Hydrogen Peroxide in Organic Chemistry" page 9, 1979, Edition and industrial documentation, Paris.
• European patent 0102297 B1 describes in its example 4, the formation of the EBB, nHF, mBF3 complex.
• European patent 0055951 B1 describes in its example 5 the reaction of phthalic anhydride and ethylbenzene in a mixture of HF and BF3. After degassing under reduced pressure to recover the HF / BF3 catalyst, a residue is obtained. The latter is washed with cold water and dried to give acid 2-
• Example 10 of this same patent also describes the production of 2- (4 '-ethylbenzoyl) benzoic acid after its purification in 10% sodium hydroxide, filtration of the basic solution obtained and precipitation of the EBB by addition of concentrated HCl. This purified acid is cyclized by heating in sulfuric acid.
• European patent 0 121 466 B1 describes a process for decomposing the 2-benzoylbenzoic acid (BB) complex with HF or BF3 of formula
• This decomposition is accompanied by a simultaneous cyclization of the BB part of the complex to give anthraquinone.
• This decomposition / cyclization takes place at a temperature between 100 ° C and 180 ° C in 1 to 3 parts by weight of sulfuric acid per part of BB in the complex or in 0.5 to 2 parts by weight of oleum per part of BB in the complex.
• the aim of the present invention is to develop a method for synthesizing EAQ of a quality which can be used directly in the synthesis of hydrogen peroxide and which does not have the drawbacks of an intermediate acid purification step.
• EBB either by washing with water or by dissolving in a basic solution followed by precipitation with an acid.
• this process also aims to avoid the significant release of HF and BF3 at temperatures of the order of 100 to 180 ° C and thus to avoid any problem of corrosion of these very aggressive products brought to high temperatures.
• EAQ 2-ethyl-anthraquinone
• EB ethylbenzene
• AP phthalic anhydride
• EBB 2- (4 '-ethylbenzoyl) benzoic acid
• the decomposition temperature of the EBB, nHF, m BF3 complex is advantageously from 0 ° C to 60 ° C and preferably between 20 and 40 ° C.
• This decomposition takes place advantageously under a pressure of 0.001 to 1 bar absolute.
• the duration of this step can be between 1 and 30 minutes.
• This decomposition can be done under a stream of gases, in particular air, nitrogen or BF3 _
• step B) the cyclization takes place at a temperature t ⁇ generally from 60 to 100 ° C and preferably between 80 and 90 ° C.
• the prevailing pressure is 0.01 to 1 bar absolute.
• the duration of this cyclization step is generally between 1 and 5 hours and preferably between 3 and 4 hours.
• the cyclization agent is pure concentrated sulfuric acid or oleum titrating from 0 to 20% by weight of SO3.
• the title oleum from 4 to 8% of SO3 by weight.
• the ratio q ranges from 10 to 25 and preferably from 15 to 20. Consequently, in these conditions, sulfuric acid or oleum is in an unusual excess, for this type of cyclization.
• step C) advantageously the dilute sulfuric acid obtained as 40 to 80% of pure H2SO4 by weight.
• this titer ranges from 60 to 80%.
• the dilution of the reaction medium is preferably carried out by very slow addition, with stirring, of water to the acid medium. This dilution generally lasts from 30 minutes to 2 hours.
• the maximum temperature of the acid medium, during this dilution, is advantageously from 60 to 90 ° C.
• the sulfuric acid thus diluted can, after filtration of the solid precipitate, be collected then recycled by known methods in concentrated sulfuric acid or in oleum.
• the cyclization stage B) can advantageously be replaced by two successive stages B ') and B' ').
• Step B ') consists in introducing 1 solid EBB containing only traces of HF and BF3 in a quantity q ⁇ _ of sulfuric acid or oleum to obtain a liquid medium at a temperature 3 and optionally passing it through a current of gas in order to entrain traces of HF.
• This gas can advantageously be chosen from air, nitrogen or BF3.
• the temperature 3 is from 20 to
• the prevailing pressure above the acid reaction medium is advantageously from 0.001 to 1 bar absolute.
• the duration is advantageously from 1 to 30 minutes and preferably 10 to 15 minutes.
• the amount of acid used q ⁇ is from 1 to 5 parts by weight per part by weight of AP used to obtain the initial complex EBB, nF, mBF3.
• boric acid H3BO3 or boric anhydride B2O3 can be added to the acid medium to transform the residual HF into BF3.
• the amount of boric acid is then from 1 to 20% by weight relative to the weight of AP used. Preferably this amount is 5 to 10%.
• Step B 1 ') consists in adding to the agitated and optionally degassed liquid medium a quantity q2 of concentrated sulfuric acid or of oleum so that
• the duration of this step B '') is generally between 1 and 5 hours and preferably between 3 and 4 hours.
• Stage D) consists in extracting the solid precipitate obtained in stage C) with a basic aqueous solution, which has the result of eliminating in the aqueous phase practically all the impurities and the unreacted products, without eliminating EAQ.
• the pH of the basic aqueous solution is from 10 to 14 and preferably around 12.
• the basic aqueous solution can be sodium hydroxide or an aqueous ammonia solution.
• the quantity by weight of this basic solution is from 5 to 30 times the weight of initial AP put into reaction and preferably from 10 to 20 times.
• the temperature t2 is generally from 60 to 100 ° C and preferably between 95 and 100 ° C.
• the basic aqueous solution of step D) also contains a metal complexing agent, for example the sodium salt of diethylenetriaminepentacetic acid (DTPA).
• DTPA diethylenetriaminepentacetic acid
• the basic aqueous solution contains hydrogen peroxide (H 2 C> 2).
• the hydrogen peroxide is present in an amount of 0.1 to 1% by weight relative to the weight of initial AP put into reaction.
• H2O2 makes it possible to oxidize certain impurities in the solid precipitate and to dissolve them in the aqueous phase and thus to obtain wet purified EAQ of better quality.
• Step E) allows the wet purified EAQ obtained at the end of step D to be dried.
• the wet purified EAQ is brought to a temperature higher than its melting point and preferably from 120 to 160 ° C. which allows the vaporization of the residual moisture under atmospheric pressure. This transition to the liquid phase facilitates the transfer of the EAQ into the "sublimator". In fact, liquid EAQ is vaporized and condenses as a solid. It is therefore a pseudo-sublimation because there is no transition from a solid phase to another solid phase via a vapor phase.
• this pseudo-sublimation is carried out at a temperature of 150 to 300 ° C under a pressure of 13 to 400 pascals.
• Example 1
• HF is adjusted so that the medium temperature does not exceed -40 ° C during charging.
• the average duration of introduction is 14 min. for HF and 8 min. for BF3.
• the dry solid is then melted in a rotary evaporator at 190 ° -200 ° C and "sublimated" under a vacuum of 266 pascals. 22.66 g of purified 2-ethyl-anthraquinone and 0.2 g of residue are obtained.
• the total chemical yield of the synthesis calculated on phthalic anhydride or 1 ethylbenzene is 64%.
• step D 0.15 g of a commercial solution of DTPA at 40% by weight is added to the basic aqueous solution and
• step B) This example is identical to Example 1, except that steps B ') and B 1 ') are replaced by a single step B) in which an amount q of 8% oleum is used equal to 393 g in the presence of 2g of H3BO3.
• the medium is heated for 30 minutes at 60 ° C. and then 4 hours at 85 ° C.
• the total chemical yield of the synthesis of EAQ purified by "sublimation" is 70%.

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• Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)

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Citations (4)

• 1995
  • 1995-03-15 FR FR9502988A patent/FR2731705B1/fr not_active Expired - Fee Related
• 1996
  • 1996-03-12 BR BR9607208A patent/BR9607208A/pt not_active Application Discontinuation
  • 1996-03-12 HU HU9801205A patent/HUP9801205A2/hu unknown
  • 1996-03-12 EP EP96906818A patent/EP0815069A1/fr not_active Withdrawn
  • 1996-03-12 WO PCT/FR1996/000383 patent/WO1996028410A1/fr not_active Application Discontinuation
  • 1996-03-12 CA CA002214017A patent/CA2214017A1/fr not_active Abandoned
  • 1996-03-12 CZ CZ972699A patent/CZ269997A3/cs unknown
  • 1996-03-12 KR KR1019970704539A patent/KR980700950A/ko not_active Application Discontinuation
  • 1996-03-12 JP JP8527334A patent/JPH11501650A/ja active Pending
  • 1996-03-12 AU AU50083/96A patent/AU5008396A/en not_active Abandoned
  • 1996-03-12 PL PL96322204A patent/PL322204A1/xx unknown
• 1997
  • 1997-08-05 NO NO973604A patent/NO973604L/no unknown

Patent Citations (4)

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