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WO2018214039A1 - Procédé de purification d'hydroquinone de butyle tertiaire - Google Patents

Procédé de purification d'hydroquinone de butyle tertiaire Download PDF

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Publication number
WO2018214039A1
WO2018214039A1 PCT/CN2017/085612 CN2017085612W WO2018214039A1 WO 2018214039 A1 WO2018214039 A1 WO 2018214039A1 CN 2017085612 W CN2017085612 W CN 2017085612W WO 2018214039 A1 WO2018214039 A1 WO 2018214039A1
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WO
WIPO (PCT)
Prior art keywords
polar solvent
tbhq
composition
dtbhq
mixture
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Ceased
Application number
PCT/CN2017/085612
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English (en)
Inventor
Howard Hao
Ding Wang
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Rhodia Operations SAS
Original Assignee
Rhodia Operations SAS
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Rhodia Operations SAS filed Critical Rhodia Operations SAS
Priority to PCT/CN2017/085612 priority Critical patent/WO2018214039A1/fr
Publication of WO2018214039A1 publication Critical patent/WO2018214039A1/fr
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

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Classifications

    • 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
    • C07C37/68—Purification; separation; Use of additives, e.g. for stabilisation
    • C07C37/70—Purification; separation; Use of additives, e.g. for stabilisation by physical treatment
    • C07C37/74—Purification; separation; Use of additives, e.g. for stabilisation by physical treatment by distillation
    • C07C37/78—Purification; separation; Use of additives, e.g. for stabilisation by physical treatment by distillation by azeotropic distillation
    • 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
    • C07C37/68—Purification; separation; Use of additives, e.g. for stabilisation
    • C07C37/70—Purification; separation; Use of additives, e.g. for stabilisation by physical treatment
    • 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
    • C07C37/68—Purification; separation; Use of additives, e.g. for stabilisation
    • C07C37/70—Purification; separation; Use of additives, e.g. for stabilisation by physical treatment
    • C07C37/84—Purification; separation; Use of additives, e.g. for stabilisation by physical treatment by crystallisation
    • 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
    • C07C39/02—Compounds having at least one hydroxy or O-metal group bound to a carbon atom of a six-membered aromatic ring monocyclic with no unsaturation outside the aromatic ring
    • C07C39/08—Dihydroxy benzenes; Alkylated derivatives thereof

Definitions

  • the present invention relates to a method for the purification of a composition comprising at least tertiary butyl hydroquinone, 2, 5-ditertiary butyl hydroquinone, and a non-polar solvent.
  • Said method notably comprises addition of a polar solvent and distillation of the mixture.
  • TBHQ Tertiary butyl Hydroquinone
  • 2- (1, 1-Dimethylethyl) -1, 4-benzenediol is an aromatic organic compound and obtained by t-butylation of hydroquinone.
  • 2, 5-ditertiary butyl hydroquinone (DTBHQ, hereinafter) is usually formed as a by-product in this process.
  • TBHQ has antioxidant properties with a concomitant low toxicity.
  • the compound is utilized as an antioxidant in the food industry or as an intermediate in the preparation of other chemicals. It is notably used as preservative in foods especially for unsaturated vegetable oils as well as many other edible animal fats.
  • TBHQ is used as an antioxidant for fat, lards, oils and fat-containing food, either by incorporation into the food stuff itself or by being incorporated in the material which is used to encase or wrap the particular food stuff.
  • this compound is likely to increase in the future due to the low toxicity and higher solubility which the process relates to butylated hydroxyanisole (BHA) which heretofore has been widely used as an antioxidant in foods.
  • BHA butylated hydroxyanisole
  • An excellent quality of TBHQ is that it does change the color, flavor or odor of the food to which it is added.
  • TBHQ is evaluated by both the European Food Safety Authority (EFSA) and the United States Food and Drug Administration (FDA) and it is found that the concentration of TBHQ allowed in foods is safe to consume.
  • EFSA European Food Safety Authority
  • FDA United States Food and Drug Administration
  • concentration of TBHQ allowed in foods is safe to consume.
  • An upper limit of 0.02%of the fat or oil content in foods is set by FDA.
  • concentrations higher than this, TBHQ can cause adverse effect on health.
  • purification of TBHQ is quite important to the usage of food-grade additives.
  • the main impurity in TBHQ is the by-product of the alkylation of hydroquinone, namely DTBHQ.
  • the current practice for the preparation of food-grade TBHQ is by recrystallization. This recrystallization entails completely dissolving crude water wet TBHQ crystals in toluene, decanting the water and filtering the hot solution to a crystallizer.
  • the TBHQ is crystallized, and the majority of the DTBHQ remains in the toluene mother liquor.
  • the toluene is removed from the wet crystals by further processing steps.
  • the product is then isolated, dried and then pulverized prior to packaging for sale. This process is expensive and is very intensive in both labor and equipment requiring long batch cycle times and specialized equipment. Consequently, the cost to purify TBHQ to food-grade TBHQ by this process is high.
  • a method for purifying TBHQ is disclosed in patent JP62-081340.
  • the produced TBHQ by alkylation of hydroquinone in high productivity is purified by bringing crude crystals obtained through an extraction step with hot water and crystallization step into contact with toluene, draining the crystals and removing the solvent from the drained cake by an azeotropic method.
  • the method requires for a large amount of toluene that is two times as TBHQ preferably. Possible pollution effects and cost could be caused by the release of toluene in the environment.
  • the present invention therefore pertains to a method for purifying TBHQ (tertiary butyl hydroquinone) from a composition comprising at least TBHQ, DTBHQ (2, 5-ditertiary butyl hydroquinone) and a non-polar solvent, comprising at least the following steps:
  • step (b) distilling out the non-polar solvent from the mixture obtained in step (a) ;
  • the process of the present invention permits to purify TBHQ without the use of further non-polar solvent, which is a more environment-friendly and cost-saving for producing TBHQ with high purification.
  • An object of the invention is to provide a flexible process which makes it possible to control the purity of the TBHQ desired and to obtain a product which can meet high-purity requirements.
  • the articles “a” , “an” and “the” are used to refer to one or to more than one (i.e., to at least one) of the grammatical object of the article.
  • weight percent As used herein, “weight percent” , “wt%, ” , “percent by weight” , “%by weight, ” and variations thereof refer to the concentration of a substance as the weight of that substance divided by the total weight of the composition and multiplied by 100.
  • Ratios, concentrations, amounts, and other numerical data may be presented herein in a range format. It is to be understood that such range format is used merely for convenience and brevity and should be interpreted flexibly to include not only the numerical values explicitly recited as the limits of the range, but also to include all the individual numerical values or sub-ranges encompassed within that range as if each numerical value and sub-range is explicitly recited.
  • a temperature range of about 70°Cto about 85°C should be interpreted to include not only the explicitly recited limits of about 70°Cto about 85°C, but also to include sub-ranges, such as 75°Cto 80°C, 80°Cto 85°C, and so forth, as well as individual amounts, including fractional amounts, within the specified ranges, such as 72.20°C, 80.60°C, and 83.30°C, for example.
  • soluble in polar solvent is understood to mean a component has the property to dissolve in a polar solvent served as the medium for a mixture.
  • a chemical moiety that forms part of a larger compound may be described herein using a name commonly accorded it when it exists as a single molecule or a name commonly accorded its radical.
  • naphtha referred to flammable liquid hydrocarbon mixtures is derived from the refining of crude oil.
  • the terms "naphtha” , “naphta” and “naphth” are accorded the same meaning when used to describe a moiety attached to other chemical moieties.
  • the present invention concerns purifying TBHQ from a composition comprising at least TBHQ, DTBHQ and a non-polar solvent, comprising at least the following steps:
  • step (b) distilling out the non-polar solvent from the mixture obtained in step (a) ;
  • a separation step of DTBHQ may be preferably employed between step (b) and (c) .
  • Said separation step of DTBHQ could separate DTBHQ from TBHQ at a temperature comprised between 60 to 120°Cto obtain a liquid phase mixture.
  • the composition of the invention may comprise from 40 to 99 wt%of TBHQ, with respect to the total weight of the composition.
  • the invention may also comprise from 0.1 to 30 wt%of DTBHQ, with respect to the total weight of the composition.
  • the composition may also comprise from 0.1 to 60 wt%of non-polar solvent, with respect to the total weight of the composition.
  • the composition of the invention may comprise at least from 40 to 99 wt%of TBHQ, from 0.1 to 30 wt%of DTBHQ, from 0.1 to 60 wt%of non-polar solvent, with respect to the total weight of the composition. Total amount of the components in the composition is 100%by weight.
  • composition of present invention may further comprise other components.
  • Said composition may in solid or liquid form for instance.
  • the composition may be preferably obtained by a process for preparing TBHQ, in which TBHQ is synthesized via a reaction of hydroquinone with t-BuOH in the presence of a catalyst, such as H 3 PO 4 .
  • the solvent of this reaction could be a non-polar solvent, especially toluene. Therefore, the composition may include other materials such as hydroquinone (HQ) , t-BuOH, tert-butylquinone (TBQ) , isobutylene, water, acid, other non-polar solvent besides TBHQ, DTBHQ and toluene.
  • the non-polar solvent of present invention could be chosen in the group constituted by: toluene, xylene, n-heptane, octane, isooctane, cyclohexane, naphtha and mixtures thereof.
  • the non-polar solvent is preferably an aromatic solvent, more preferably toluene.
  • Step (a) then concerns the mixing of the composition with at least a polar solvent in order to obtain a solid-liquid two-phase mixture in which TBHQ is dissolved in the polar solvent and DTBHQ is solid.
  • An antioxidant may be further added in step (a) with a weight ratio comprised from 0.1%to 10%with respect to the total weight of the polar solvent and preferably from 0.5%to 5%, more preferably from 1%to 3%.
  • the antioxidant of present invention may be preferably soluble in the polar solvent as that which was added into the step (a) and may be chosen in the group constituted by: citric acid, Na 2 S 2 O 5 , and Na 2 S 2 O 4 .
  • the antioxidant is citric acid.
  • TBHQ is dissolved in the polar solvent by heating, more preferably TBHQ is substantially dissolved (i.e., preferably less than 10%, preferably less than 5%remains undissolved in the solvent) in the polar solvent, more preferably TBHQ is completely dissolved in the polar solvent.
  • the amount of the polar solvent to be added to the composition must be sufficient to completely dissolve TBHQ present in the composition without dissolving DTBHQ, more preferably without dissolving a significant amount of DTBHQ (i.e., preferably less than 5%, preferably less than 2%is dissolved in the solvent) .
  • the weight ratio between polar solvent and the composition may be comprised from 10: 1 to 40: 1, with respect to the total weight of the composition, preferably from 15: 1 to 35: 1, more preferably from 20: 1 to 30: 1. Notably said weight ratio is equal to 15: 1, 20: 1, 25: 1, 30: 1, 35: 1, 40: 1 or any range obtained between these values.
  • the polar solvent could be pre-heated before step (a) , notably before mixing with the composition of the invention. It is also possible to heat the mixture formed by mixing the composition with at least the polar solvent.
  • the temperature of solid-liquid two-phase mixture obtained in step (a) may be above the crystallization point of TBHQ in the solvent until TBHQ is all dissolved. It may be comprised from 50 to 100°Cand preferably from 70 to 85°C. For example, the temperature is preferably from 70 to 85°Cand more preferably 75 to 85°C, while DTBHQ is not dissolved when water is used as polar solvent.
  • the solid-liquid two-phase mixture at the end of step (a) may notably comprise: a liquid phase of polar solvent in which TBHQ is completely dissolved, aliquid phase of non polar solvent, a solid phase comprising DTBHQ.
  • Polar solvent is preferably apolar protic solvent.
  • Polar solvents maybe chosen in the group constituted by: water, formic acid, n-butanol, isopropanol, ethanol, methanol or mixture of any of them.
  • the polar solvent is preferably water.
  • the polar solvent and non-polar solvent combinations are chosen in order to obtain an azeotrope, also called a constant boiling mixture.
  • the polar solvent and non polar solvent may then form an azeotrope.
  • a person skilled in the art may consult appropriate azeotrope data tables for various binary and ternary mixtures of liquids, notably solvents. Those tables include the composition of a mixture by weight, the boiling point (b. p. ) of a component, and the boiling point of a mixture.
  • Generating azeotrope and its subsequent distillation notably permits to separate non-polar solvent wherein the non-polar solvent is residual in a little amount in the starting composition.
  • polar solvent and non-polar solvent combinations are as follows:
  • the azeotrope formed by the polar solvent and non-polar solvent has a boiling point comprised from 70 to 140°C, more preferably from 80 to 100°C.
  • the boiling point of the azeotrope is less than the boiling point temperatures of any of its constituents (ie. positive azeotrope) .
  • step (a) Preferably no non polar solvent is added to the composition of the invention in step (a) .
  • Step (b) concerns then distilling out the non-polar solvent from the mixture obtained in step (a) .
  • step (b) It is notably possible in step (b) to heating the solid-liquid two-phase mixture obtained at step (a) and distilling out the non-polar solvent.
  • the heating temperature of step (b) is not particularly limited and depends on the boiling point of solvent. Preferably, it may be comprised from 85 to 120°Cand more preferably from 90 to 115°C.
  • the distillation in step (b) may be carried out by a simple distillation, extractive distillation, fractional distillation, or azeotropic distillation.
  • the distillation in step (b) is carried out by an azeotropic distillation.
  • an azeotrope occurs when the composition of a vapor in equilibrium with a liquid mixture has the same composition as the liquid.
  • Azeotropic distillation takes advantage of azeotropes that form naturally between many components.
  • Azeotropic distillation involves the formation of an azeotrope, or the use of an existing azeotrope, to effect a desired separation.
  • azeotropic distillation usually occurs at a temperature around 85°Cfor a mixture of toluene and water.
  • the distillate herewith may be toluene and water in the present invention.
  • apart of polar solvent is distilled and the residue of polar solvent is remained to dissolve TBHQ.
  • the non-polar solvent and polar solvent are preferably distilled out from the solid-liquid two-phase mixture obtained at step (a) in a weight ratio comprised from 5 to 20%, preferably from 10 to 15%, with respect to the total weight of polar solvent. Notably said weight ratio is equal to 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20 or any range obtainedbetween these values.
  • distillation is done at atmospheric pressure, but with proper equipment it is possible to carry out distillation at a wide variety of pressures, both above and below atmospheric pressure.
  • the distillation is carried out at a pressure comprised from 0.05 to 0.12, more preferably from 0.08 to 0.11 Mpa.
  • polar solvent may be distilled out, notably to enhance removal of the non-polar solvent possibly existing in undissolved DTBHQ.
  • the medium may then comprise from 50 to 99 wt%, preferably 85 to 97 wt%, of water with respect to the total weight of the medium. With continued water removal, a very low amount of toluene is obtained in the final composition
  • Distillation column used in step (b) may comprise a pot, notably including a reboiler, acolumn, acondenser to condense the overheads products, and one or several product receivers.
  • the equipment may be completed with a decanter to separate the two liquid phases and a reflux with a pump.
  • a batch heteroazeotropic distillation is used in step (b) .
  • step separation step of DTBHQ several known separation techniques may be used to separate DTBHQ from TBHQ, such as for instance filtrating or centrifuging. Filtration may be made at positive pressure, such as comprised from 0.3 to 0.6 MPa, or under vacuum, such as comprised from 100 to 900 mbar.
  • DTBHQ may be for instance isolated by filtration at a temperature comprised from 60 to 120°C, preferably from 80 to 90°C.
  • Step (c) concerns then cooling liquid phase mixture obtained at step (b) to crystalize TBHQ.
  • the liquid phase mixture obtained at step (b) could be preferably cooled to a temperature from 10 to 40°C.
  • Step (d) concerns then filtrating and drying TBHQ obtained at step (c) .
  • Filtration and drying maybe carried out by several techniques known in the art.
  • composition after filtrating and before drying in step (d) may comprise:
  • non-polar solvent preferably 0-1 ppm
  • composition at the end of step (d) may comprise:
  • the purified TBHQ obtained by the process of the invention may be further purified by a process comprising at least the following steps:
  • composition at the end of step (h) may comprise:
  • the present invention also concerns a method for removing a non-polar solvent from a composition comprising TBHQ, DTBHQ, and a non-polar solvent, notably a composition at least 40-99 wt%of TBHQ, 0.1-30 wt%of DTBHQ, 0.1-60 wt%of non-polar solvent, with respect to the total weight of the composition; said method comprising distilling said composition in presence of an azeotrope forming agent to remove the non-polar solvent and polar solvent as overhead product, obtaining TBHQ and DTBHQ and the azeotrope forming agent as bottom products, wherein said azeotrope forming agent is a polar solvent, preferably water.
  • An azeotrope forming agent and non-polar solvent could combine to form an azeotrope.
  • Their mixture can have a lower boiling point than either of the components forming the azeotrope. Distilling said azeotrope permits to remove the non-polar solvent in gaseous phase from the mixture of the composition with a polar solvent as obtained in step (a) that usually comprises dissolved TBHQ in polar solvent and undissolved DTBHQ.
  • the present invention also concerns a composition
  • a composition comprising, preferably consisting of:
  • Said composition is preferably in a solid form and may be converted to other physical forms such as flakes or tablets or similar compressed forms.
  • TBHQ as purified by the method the present invention may be used in perfumery as a fixative to lower the evaporation rate and improve stability, as a stabilizer to inhibit autopolymerization of organic peroxides, as antioxidant in various applications such as food, beverage, cosmetics, biodiesel, varnishes, lacquers, resins, and oil-field additives.
  • TBHQ is tertiary butyl hydroquinone (Cas: 1948-33-0)
  • DTBHQ is 2, 5-ditertiary butyl hydroquinone (Cas: 88-58-4)
  • t-BuOH is tert-Butanol (Cas: 75-65-0)
  • HQ hydroquinone (Cas: 123-31-9)
  • Na 2 S 2 O 5 is sodium pyrosulfite (Cas: 7681-57-4)
  • TBHQ has been synthesized as follows:
  • step 1-4 Add the mixture prepared in step 1-3 to the reactor evenly in totally 6 hours
  • TBHQ has been purified as follows:
  • Citric acid aqueous mother liquor is recycled for next batch, by making up the mother liquor with some fresh water
  • Table 1 lists the experimental conditions. As can be seen, different quantities of water were removed in different experiments, in order to compare the toluene residue in TBHQ with different conditions.
  • Crude TBHQ indicates TBHQ obtained by the process of steps (a) – (d) and separation step of DTBHQ.
  • Final TBHQ indicates TBHQ obtained by recrystallization step using ethanol in steps 2-1 to 2-4.

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  • Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)

Abstract

L'invention concerne un procédé de purification d'une composition comprenant au moins de l'hydroquinone de butyle tertiaire, de l'hydroquinone de butyle 2,5-ditertiaire, et un solvant non polaire. Ledit procédé comprend notamment l'ajout d'un solvant polaire et la distillation du mélange.
PCT/CN2017/085612 2017-05-24 2017-05-24 Procédé de purification d'hydroquinone de butyle tertiaire Ceased WO2018214039A1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
PCT/CN2017/085612 WO2018214039A1 (fr) 2017-05-24 2017-05-24 Procédé de purification d'hydroquinone de butyle tertiaire

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/CN2017/085612 WO2018214039A1 (fr) 2017-05-24 2017-05-24 Procédé de purification d'hydroquinone de butyle tertiaire

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2020136678A1 (fr) * 2018-12-24 2020-07-02 Milestone Preservatives Pvt. Ltd. Procédé de préparation d'hydroquinone de butyle tertiaire

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6281340A (ja) * 1985-10-04 1987-04-14 Showa Denko Kk ２−ｔｅｒｔ−ブチルヒドロキノンの精製方法
WO2001098242A1 (fr) * 2000-06-16 2001-12-27 Eastman Chemical Company Procede de purification d'hydroquinone de monobutyle tertiaire
CN1583698A (zh) * 2004-06-11 2005-02-23 广州优宝工业有限公司 特丁基对苯二酚的制备方法
CN103864581A (zh) * 2014-04-04 2014-06-18 广州泰邦食品科技有限公司 一种tbhq精品的提纯工艺
CN105294403A (zh) * 2015-09-11 2016-02-03 东莞市感恩食品科技有限公司 一种特丁基对苯二酚的制备工艺

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6281340A (ja) * 1985-10-04 1987-04-14 Showa Denko Kk ２−ｔｅｒｔ−ブチルヒドロキノンの精製方法
WO2001098242A1 (fr) * 2000-06-16 2001-12-27 Eastman Chemical Company Procede de purification d'hydroquinone de monobutyle tertiaire
CN1583698A (zh) * 2004-06-11 2005-02-23 广州优宝工业有限公司 特丁基对苯二酚的制备方法
CN103864581A (zh) * 2014-04-04 2014-06-18 广州泰邦食品科技有限公司 一种tbhq精品的提纯工艺
CN105294403A (zh) * 2015-09-11 2016-02-03 东莞市感恩食品科技有限公司 一种特丁基对苯二酚的制备工艺

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2020136678A1 (fr) * 2018-12-24 2020-07-02 Milestone Preservatives Pvt. Ltd. Procédé de préparation d'hydroquinone de butyle tertiaire

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