EP1240131A1 - Neo-acid catalysts and their use in esterification reactions - Google Patents
Neo-acid catalysts and their use in esterification reactionsInfo
- Publication number
- EP1240131A1 EP1240131A1 EP99966236A EP99966236A EP1240131A1 EP 1240131 A1 EP1240131 A1 EP 1240131A1 EP 99966236 A EP99966236 A EP 99966236A EP 99966236 A EP99966236 A EP 99966236A EP 1240131 A1 EP1240131 A1 EP 1240131A1
- Authority
- EP
- European Patent Office
- Prior art keywords
- acid
- neo
- alcohol
- process according
- compound
- 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.)
- Withdrawn
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C67/00—Preparation of carboxylic acid esters
- C07C67/08—Preparation of carboxylic acid esters by reacting carboxylic acids or symmetrical anhydrides with the hydroxy or O-metal group of organic compounds
Definitions
- the present invention relates to neo-acid catalysts and to their use as non- reactive catalysts in esterification reactions.
- Reacting a carboxylic acid moiety with an alcohol to form an ester is a basic and well known chemical reaction used in a variety of different chemical synthesis schemes.
- the reaction is catalyzed by acid. Accordingly, the carboxylic acid reactant can serve as both reactant and catalyst.
- the acid reactant is consumed, the amount of acid available to serve as a catalyst steadily decreases.
- catalytic action is reduced. This causes the reaction rate to be slowed at higher conversion rates resulting in longer reaction times and/or less than complete conversion into the ester.
- esterification catalysts include acids such as p-toluene sulfonic acid, sulfuric acid, phosphorous acid and trichloroacetic acid as well as metal or metal oxides such as titanium tetra butoxide and aluminum powder. These catalysts can be effectively employed in a variety of esterification reactions. However, removing these types of catalysts from the ester product can be difficult, resulting in lower product quality and/or lower process efficiency. Accordingly, there is a need in the art for new, alternative types of esterification catalysts.
- the present invention relates to non-reactive catalytic neo-acids.
- one embodiment of the present invention relates to a process, which comprises reacting a carboxylic acid compound with a hydroxyl compound to form an ester, wherein the reaction is carried out in the presence of a catalytic amount of a non- reactive catalytic neo-acid compound.
- Another embodiment of the present invention relates to a process which comprises combining a polybasic acid compound or anhydride thereof, a polyhydric alcohol compound, optionally a mono-hydric alcohol, and a non-reactive catalytic neo-acid compound into a mixture; and reacting together carboxylic acid and hydroxyl groups present in the mixture to form esters.
- a further embodiment of the present invention relates to a process which comprises subjecting an isomeric mixture of neo-acids to an esterification reaction with an excess of alcohol to esterify all of the reactive neo-acid; isolating the non-reactive neo-acid from said composition; and adding said non-reactive neo-acid to a reaction medium containing a carboxylic acid compound and a hydroxyl compound, in an amount sufficient to catalyze an esterification reaction between said carboxylic acid compound and said hydroxyl compound.
- neo-acids can serve as non-reactive catalysts in esterification reactions. While not wishing to be bound by any theory, it is believed that the stearic hindrance in certain neo-acid isomers prevents the carboxylic acid moiety from being reacted. These carboxylic acid compounds, while essentially unreactive in the esterification reaction, can nonetheless function as a catalyst.
- the non- reactive neo-acid catalysts of the present invention are either non-objectionable in the ester product or easily separated from the ester product. Thus these catalysts will generally avoid the separation difficulty experienced by the aforementioned prior art catalysts.
- Figure 1 illustrates the reaction kinetics of esterifying a group of neo-decanoic acid isomers with iso-decyl alcohol in accordance with Example 1.
- Figure 2 illustrates a gas chromatogram of the neo-decanoic acid composition used in Example 1.
- Figure 3 illustrates the gas chromatogram for the recovered neo-decanoic acid and unreacted alcohol from Example 1.
- Figure 4 illustrates a comparison of the kinetics for catalyzed and uncatalyzed esterification as set forth in Example 2.
- Figure 5 illustrates the gas chromatogram for the uncatalyzed reaction product of Example 2.
- Figure 6 illustrates the gas chromatogram for the catalyzed reaction product of Example 2.
- Neo-acids also known as trialkyl acetic acids, are generally represented by the formula:
- R'-R 3 each represent an alkyl group.
- Neo-acids have been used, albeit with difficulty, to form a variety of ester products.
- the stearic hindrance of the trialkyl group reduces the reactivity of the carboxylic acid moiety.
- the present invention turns this normally troublesome propensity into an advantageous property. Namely, by selecting neo-acids that do not react with the hydroxyl groups in the reaction medium, the neo-acid can function as a non-reactive catalyst.
- non-reactive means that the neo-acid is essentially not consumed; i.e., less than 5 %, preferably less than 2 % and more preferably less than 1 % of the neo-acid is consumed in the given esterification reaction under the conditions employed. Because the neo-acid is non-reactive, its presence does not alter the molar ratio of the reactant carboxylic acid group to the hydroxyl group. This ability is particularly useful in esterification reactions where excess alcohol is required, such as in the production of complex alcohol esters.
- the neo-acid catalyst of the present invention can be added to such esterification reactions without adversely affecting the alcohol excess and thereby provide a catalytic effect without disrupting the desired ester product. Furthermore, because the neo-acid catalyst is an organic acid, it is relatively easy to separate from the ester product.
- each of three alkyl groups attached to the alpha carbon in the neo- acid has from 1 to 18 carbon atoms, which may be, independently, straight or branched chain.
- the total number of carbons in the neo-acid is typically at least 7, generally from 9 to 26, more usually 9 tol8, and conveniently 10 to 14.
- a non-reactive neo-acid having fewer than 7 carbon atoms in total is possible, but uncommon and would most likely be involved in a reaction where the hydroxyl group was stearically hindered or the reaction conditions otherwise do not favor esterification. Having more than 26 total carbon atoms tends to form a solid, waxy substance that is not easy to use in a liquid reaction environment and is thus not normally desired.
- Preferred neo-acid catalysts are C , Cio, and C 1 neo-acids.
- Ri - R 3 represent an alkyl group containing 3 to 18 carbon atoms, preferably with branching in at least one of the 3 to 18 carbon atom alkyl groups.
- one of the alkyl groups, such as R 2 is a methyl or ethyl group while the remaining alkyl groups, R 1 and R 3 , each have 3 to 18 carbon atoms.
- at least one of, and optionally both of, R 1 and 3 are branched.
- Preferred non-reactive neo-acid catalysts include branched isomers having a total of 10 or 13 carbon atoms, such as a neo- decanoic acid.
- the non-reactive neo-acids can be used to catalyze an esterification reaction between a carboxylic acid compound and a hydroxyl compound to form an ester.
- a “hydroxyl compound” means any compound having at least one hydroxyl group (OH) therein and includes mixtures of such compounds.
- the hydroxyl compound includes compounds represented by the formula R(OH) n wherein R is an aliphatic hydrocarbyl group, a cycloaliphatic hydrocarbyl group, an aryl group or an aralkyl group and n is 1-8.
- R is an aliphatic hydrocarbyl group, a cycloaliphatic hydrocarbyl group, an aryl group or an aralkyl group and n is 1-8.
- the hydroxyl compound generally contains 3 to 20 carbon atoms, but is not limited thereto.
- the "hydrocarbyl group” means a group containing 3 to 20 carbon atoms and which may also be substituted with chlorine, nitrogen and/or oxygen atoms.
- R is a branched aliphatic hydrocarbyl group containing 5 to 13 carbon atoms.
- suitable hydroxyl compounds including both mono-hydric and polyhydric compounds, are n-pentyl alcohol, iso-pentyl alcohol, n-heptyl alcohol, iso-heptyl alcohol, n-octyl alcohol, 2-efhylhexyl alcohol, n-octyl alcohol, iso-octyl alcohol, n-nonyl alcohol, iso-nonyl alcohol, n-decyl alcohol, iso-decyl alcohol, neopentyl glycol, trimethyolethane, trimethylolpropane, trimethylolbutane, pentaerythritol, di-pentaerythritol and
- a “carboxylic acid compound” is any compound that contains at least one carboxylic acid moiety (COOH) therein, and includes mixtures of such compounds.
- the carboxylic acid compound can be a straight or branched chain aliphatic carboxylic acid compound or an aromatic carboxylic acid compound. Typically the carboxylic acid compound contains 2 to 24 carbon atoms, but is not limited thereto.
- the carboxylic acid compound can be a polybasic acid (polycarboxylic acid) compound or anhydride thereof such as a dibasic acid.
- Suitable dibasic acids include oxalic acid, succinic acid, glutaric acid, adipic acid, azelaic acid, sebacic acid, dodecanedioic acid, phthalic acid, and anhydrides thereof.
- a convenient way to identify a suitable non-reactive catalytic neo-acid is to subject a neo-acid composition, generally a mixture of neo-acid isomers, to esterification with an excess of alcohol under conventional conditions. If non-reactive neo-acids are present, the conversion will reach a plateau where essentially no further conversion of the acid reactant into an ester is occurring. At this point all of the reactive neo-acids have been consumed in the reaction and the unreacted neo-acid remaining in the reaction medium is the non-reactive neo-acid catalyst.
- the non- reactive neo-acid(s) remaining can be isolated and used to catalyze an esterification reaction by adding it to a reaction medium containing a carboxylic acid compound and a hydroxyl compound, in an amount sufficient to catalyze an esterification reaction.
- the alcohol used to screen for the non-reactive neo-acid is the same as the hydroxyl compound used in the subsequent esterification reaction.
- the neo-acid isomers recovered from the first reaction should be non-reactive for purposes of the second reaction.
- the neo-acids are conveniently isolated from the first reaction as an alcohol solution that can be directly added to the subsequent esterification reaction.
- the carboxylic acid compound need not be similar to the neo-acid catalyst and usually the non-reactive catalytic neo-acid has a different number of carbon atoms than the acid reactant being esterified.
- a preferred non-reactive catalytic neo-acid is a neo-acid isomer or mixture thereof that is non- reactive with iso-decyl alcohol.
- Neo-acids are, in general, commercially available.
- Non-reactive neo-acids suitable for use as an esterification catalyst can be empirically determined by screening the commercially available neo-acid compositions in the manner described above.
- Neo-acids can also be synthesized by well known techniques. For example, small olefins such as propylene can be polymerized to yield larger olefins such as C 6 , C 9 , C12, etc.
- a carboxyl group (COOH) is added to the olefin at the point of unsaturation to make a corresponding C 7 , C10, C 13 , etc., acid.
- This synthesis scheme which is commonly employed commercially, leads to a product having a mixture of acids both in terms of carbon number (i.e. a small amount of the C9 and C ⁇ mixed with the intended C10 acid, for example) and structural isomers.
- the range of variation in neo- acid and the level of purity depends upon the synthesis scheme and the conditions used. While it is not necessary to reveal the exact structural formula for the non- reactive neo-acid catalyst, given the empirical screening methodology described above, it is generally desired when seeking to synthesize non-reactive catalytic neo-acids to use conditions that favor the formation of long chains in the neo structure.
- Such structural features will enhance the likelihood of producing and isolating a non-reactive catalytic neo-acid from the neo-acid population produced.
- targeted synthesis of a non-reactive catalytic neo-acid isomer could be performed.
- Non-reactive catalytic neo-acids can be used in any esterification reaction that would benefit from an acid catalyst.
- the non-reactive catalytic neo-acid can be used as a replacement catalyst.
- the non-reactive catalytic neo-acid is the only non- reactive catalyst present during the esterification reaction; i.e., no catalyst other than the reactant carboxylic acid compound, is added or present during the esterification reaction.
- the esterification reaction can produce a final product, such as a base stock oil or refrigerant lube, or an intermediary product.
- esterification is commonly used in organic synthesis schemes to protect a hydroxyl or carboxylic acid group, and such reactions are specifically contemplated as being within the scope of an esterification reaction of the present invention.
- the amount of catalyst added should be effective to catalyze the esterification reaction and is normally at least 1 mol %, generally 1 mol % to 50 mol %, especially 2 mol % to 30 mol %, taking the amount of reactant carboxylic acid compound initially charged as being 100%.
- 5 mol % to 15 mol % of the non-reactive neo-acid catalyst is added to the reaction medium, based on the amount of reactant carboxylic acid compound initially charged.
- the use of small amounts of catalyst may not provide sufficient catalytic effect.
- the use of large amounts of catalyst tends to dilute the concentration of reactants in the reaction vessel, thereby limiting total yield; i.e. less volume in the vessel for reactants means that less product is produced.
- the non-reactive catalytic neo-acid can be combined with the reactants in a variety of ways.
- the non-reactive catalytic neo-acid is added separately from the acid reactant.
- the non-reactive catalytic neo-acid can be supplied as a separate isolated neo-acid composition or as an alcohol solution, or it can be previously combined into the hydroxyl feed stream in either the isolated or alcohol solution form.
- This ability to have the neo-acid mixed with the hydroxyl compound represents another aspect of the present invention, specifically a composition consisting essentially of a non-reactive catalytic neo-acid and an alcohol.
- the neo-acid contained in the composition comprises 5 to 95 % by weight of the composition, more preferably 5 to 50 wt %.
- an esterification reaction proceeds as follows.
- a carboxylic acid compound and a hydroxyl compound are combined with a non-reactive catalytic neo- acid and reacted at an elevated temperature usually greater than 100°C and frequently within the range of about 180°C to 250°C. Lower temperatures can be used but generally at the cost of much longer reaction times and lower yields. Frequently, the reaction temperature and pressure are sufficient to allow the water produced by esterification to be boiled off. Hydroxyl compound that is vaporized with the water is preferably refluxed back into the reaction mixture.
- the non-reactive catalytic neo-acid can be present at the start of the reaction or it can be added during the reaction, such as after 10 %, or after at least 50 % or even after at least 90 % by mole of the limiting reagent in the esterification reaction has been reacted.
- esterification reactions are driven to completion or near completion, i.e. conversions of at least 99.8%, more preferably at least 99.9%, although lower conversion rates are also contemplated.
- the ester can be fully esterified (at least 96 % conversion of the limiting reagent (either hydroxyl group or carboxylic acid groups) or partially esterified (5% to less than 96% of the carboxylic acid groups are esterified).
- the ester can be simple or complex.
- the non-reactive catalytic neo-acid is used to produce esters that are complex and/or have branching.
- Patents 5,750,750, 4,661,662, 4,053,491, 4,263,159, 4,957,649, 5,164,122, 5,665,585, 5,698,502, and5,817,607 and in WO90/12849 are appropriate for using the non-reactive catalytic neo-acid of the present invention and each one is incorporated herein in its entirety.
- Neo-decanoic acid is reacted with excess iso-decyl alcohol.
- the reaction proceeds to approximately 70% conversion (see Figure 1) at which point no further appreciable progress is made. Having reached this plateau, the remaining unreacted neo-decanoic acid and the iso-decyl alcohol are recovered by vacuum stripping and condensation. Illustrative gas chromatograms of the original neo-decanoic acid feed and the recovered unreacted species are shown in Figures 2 and 3, respectively. While the amount of neo-decanoic acid is reduced by the esterification, a portion remains that corresponds to the unreacted/non-reactive neo-decanoic acid isomer.
- a complex ester is synthesized by reacting trimethylol propane (TMP), adipic acid (AA), and iso-decyl alcohol (IDA) at 220°C in an inert nitrogen atmosphere.
- TMP trimethylol propane
- AA adipic acid
- IDA iso-decyl alcohol
- Figure 4 illustrates the differences in conversion rate.
- the presence of the non-reactive neo-acid catalyst facilitates full conversion while the uncatalyzed reaction plateau's at approximately 99.6% conversion. Since the quantity of neo-acid is insignificant compared to the initial amount of AA, the catalyst has almost no effect on the reaction rates at low conversions. But, as the reaction proceeds and the AA is consumed, the neo-acid catalytic effect becomes significant and has a noticeable effect on conversion.
- Figures 5 and 6 illustrate the gas chromatograms for the products of reaction "A" and "B", respectively. Noticeably, Figure 6 shows the presence of the neo-acid peak, indicating that the neo-acid was non-reactive and hence not consumed. Once the reaction is completed, the neo-acid can be removed by stripping.
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
- Low-Molecular Organic Synthesis Reactions Using Catalysts (AREA)
Abstract
Description
Claims
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
PCT/US1999/029683 WO2001044156A1 (en) | 1999-12-15 | 1999-12-15 | Neo-acid catalysts and their use in esterification reactions |
Publications (1)
Publication Number | Publication Date |
---|---|
EP1240131A1 true EP1240131A1 (en) | 2002-09-18 |
Family
ID=22274302
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP99966236A Withdrawn EP1240131A1 (en) | 1999-12-15 | 1999-12-15 | Neo-acid catalysts and their use in esterification reactions |
Country Status (4)
Country | Link |
---|---|
EP (1) | EP1240131A1 (en) |
CN (1) | CN1398250A (en) |
AU (1) | AU2183100A (en) |
WO (1) | WO2001044156A1 (en) |
Families Citing this family (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
RU2409551C2 (en) | 2005-06-24 | 2011-01-20 | Хексион Спешелти Кемикалс Рисерч Белджиум С.А. | Method for esterification of polyatomic alcohols with acids substituted with tertiary alkyls |
Family Cites Families (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5532405A (en) * | 1994-04-29 | 1996-07-02 | Exxon Chemical Patents Inc. | Preparation of plasticizer or polyol esters by the staged addition of the lower boiling point reactant |
-
1999
- 1999-12-15 EP EP99966236A patent/EP1240131A1/en not_active Withdrawn
- 1999-12-15 CN CN99817074.7A patent/CN1398250A/en active Pending
- 1999-12-15 WO PCT/US1999/029683 patent/WO2001044156A1/en not_active Application Discontinuation
- 1999-12-15 AU AU21831/00A patent/AU2183100A/en not_active Abandoned
Non-Patent Citations (1)
Title |
---|
See references of WO0144156A1 * |
Also Published As
Publication number | Publication date |
---|---|
WO2001044156A1 (en) | 2001-06-21 |
CN1398250A (en) | 2003-02-19 |
AU2183100A (en) | 2001-06-25 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
HK1070911A1 (en) | Process for producing poly (ethylene-aromatic dicarboxylate ester) resin and resin product | |
US5210207A (en) | Transvinylation process by reactive distillation | |
KR19990076903A (en) | Process for the preparation of 1,2-bis (acyloxylate) | |
CN1061401A (en) | The preparation method of carboxylic acid anhydride | |
KR20100036301A (en) | Method for synthesizing allyl methacrylate | |
US5155253A (en) | Transvinylation process for the preparation of thermally labile vinyl compounds and for vinyl compounds prepared from thermally labile acids | |
JPH10511100A (en) | Production of amide ester compounds | |
JPH0747563B2 (en) | Synthesis of vinyl ester | |
WO2001044156A1 (en) | Neo-acid catalysts and their use in esterification reactions | |
JP4860830B2 (en) | Method for producing high purity (meth) acrylic acid ester | |
JP2003521478A (en) | How to perform an equilibrium limited reaction | |
CN1238324C (en) | 2-[4-2,2-dihalocyclopropyl)phenoxy]-alkanoic acids and exters thereof production process | |
US5648509A (en) | Process for the preparation of diesters of phosphonocarboxylic acid derivatives | |
JP3261730B2 (en) | Production of allyl esters | |
EP0943600B1 (en) | Processes for the preparation of dicarboxylic acid monoesters | |
JPH0525093A (en) | Production of allyl esters | |
CN111094231B (en) | Process for producing bishydroxyalkylene dicarboxylate | |
WO1998052903A1 (en) | Processes for conducting equilibrium-limited reactions | |
JP4125916B2 (en) | Method for producing high purity ester | |
US4457868A (en) | Method for esterification | |
JPS6121218B2 (en) | ||
EP0612711A1 (en) | Process for the hydroxycarbonylation of lactones | |
EP0333980B1 (en) | Propanone 1,3-disulfonic acid as an esterification catalyst | |
JPH10204026A (en) | Synthesis of phenol carboxylic acid derivative | |
EP0333373A2 (en) | Method for synthesizing acyloxycarboxylic acids |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
PUAI | Public reference made under article 153(3) epc to a published international application that has entered the european phase |
Free format text: ORIGINAL CODE: 0009012 |
|
17P | Request for examination filed |
Effective date: 20020711 |
|
AK | Designated contracting states |
Kind code of ref document: A1 Designated state(s): AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE |
|
AX | Request for extension of the european patent |
Free format text: AL;LT;LV;MK;RO;SI |
|
RIN1 | Information on inventor provided before grant (corrected) |
Inventor name: TURNER, DAVID, W. Inventor name: CLAUSI, DOMINIC, T. |
|
GRAP | Despatch of communication of intention to grant a patent |
Free format text: ORIGINAL CODE: EPIDOSNIGR1 |
|
STAA | Information on the status of an ep patent application or granted ep patent |
Free format text: STATUS: THE APPLICATION IS DEEMED TO BE WITHDRAWN |
|
18D | Application deemed to be withdrawn |
Effective date: 20031128 |
|
RIN1 | Information on inventor provided before grant (corrected) |
Inventor name: TURNER, DAVID, W. Inventor name: CLAUSI, DOMINIC, T. |