PRODUCTION OF TRIALKYLACETIC ACIDS USING A SOLID CATIONIC RESIN CATALYST SYSTEM

Abstract: This invention relates to a process for the production of trialkylacetic acids from branched olefins and carbon monoxide in a non-aqueous reaction system using a solid acid resin catalyst comprising a cationic resin having sufficient acid groups to provide requisite protons for reactant conversion to trialkylacetic acids.

Description: PRODUCTION OF TRIALKYLACETIC ACIDS USING A SOLID CATIONIC RESIN CATALYST SYSTEM HELD OF THE INVENTION This invention deals with the production of trialkylacetic acids from branched olefins, particularly isononene, by reacting said branched olefins with carbon monoxide using a solid cationic resin capable of providing a proton acid as catalyst. BACKGROUND OF THE INVENTION Trialkylacetic acids have found a variety of uses in the chemical industry. By way of example, neodecanoic acid is converted to metal salts and acts as a paint thinner. It is derivatized to vinyl esters and glycidyl esters for use in coating applications. Similarly, neopentanoic (pivalic) acid has found wide use in the production of agrichemicals, specialty chemicals and pharmaceuticals. Trialkylacetic acids have been produced by various processes using liquid catalysts, such as BF 3 » 2H 2 O, HF, H 3 PO 4 , BF 3 »H 2 O; H 2 SO 4 ; mixtures of BF 3 »2H : O with H : SO 4 or H 3 PO 4 . Such technology is described in U.S. Patent No. 3,068,256 to Roming and in other patent literature. Such processes, however, have disadvantages. A large inventory of corrosive acid is used. These processes require expensive materials of construction and relatively difficult catalyst separation and recovery steps. A variety of other processes are described in the patent literature. BASF European Patent Application 87108759.9 describes an aqueous system for reacting olefins with carbon monoxide and H 2 0 in the presence of acidic zeolites as catalysts. Zeolites of the pentasil type are preferred. Olefin conversion is preferably conducted in the gas phase. In one embodiment its zeolitic material is treated with acids. In contrast to the BASF patent which uses in organic metallic oxide zeolites having relatively low acid strength, the present process employs organic resins having an acidity equivalent to or greater than a 65 % sulfuric acid solution and uses a non-aqueous reaction system. Mitsubishi Chemical Japanese Patent 62187424 describes a process for the carboxylation of olefins by reacting the olefins with a hydroxyl compound selected from water, alcohol and carboxylic acid in the presence of a palladium catalyst and organic phosphine. A sulfonic acid ion-exchange resin is used as an accelerator. Two recent patents to Catalytica, Inc. are also noted. U.S. 5.227,521 discloses a process for producing trialkylacetic acids from branched olefins by reaction with carbon monoxide and water in the presence of Lewis acids. U.S. 5,241.112 similarly reacts branched olefins with carbon monoxide and water but utilizes a solid acid catalyst referred to as Molecular Engineered Layered Structures (MELS). It preferably is a compound comprising sulfonic acid and phosphonic acid groups where the phosphonic acid groups are covalently bonded to a polymeric chain. It is noted that essentially all the foregoing processes employ aqueous reaction conditions. Aqueous systems in general have the disadvantage of presenting a corrosive reaction environment and acting as a catalyst poison by weakening the acidity of the catalyst. Non- aqueous system are more selective in permitting alternative products, such as esters, to be directly produced. BRIEF DESCRIPTION OF THE INVENTION The present invention relates to a non-aqueous process for producing trialkylacetic acids from corresponding branched olefins by reacting said olefins with carbon monoxide in the presence of a solid cation exchange resin catalyst capable of forming a cation with the feed olefm and which typically is a cationic resin having sulfuric acid on its surface. The reaction takes place in a non-aqueous environment. The cation exchange resin has a 65 wt. percent, preferably 70 % , or greater sulfuric acid strength equivalent. The present process finds application for converting branched olefins to trialkylacetic acids represented by the following formula. Where each R group is an alkyl group has 1 to 10 carbons. Typically, the total number of carbon atoms in the molecule is 5 to 19, preferably 5 to 13. The branched or unbranched olefins used as feed reactant have the general formula: C=C / \ Where each R is an alkyl group having 1 to 15 carbons, or alternatively R, and/or R 5 can be hydrogen. Typically the total number of carbon atoms in the olefin is 4 to 18, preferably 4 to 12. The foregoing branched or unbranched olefins are reacted with CO in the presence of the instant catalyst system in a non-aqueous reaction system. The reaction conditions are summarized in the following table. CONDITIONS BROAD RANGE PREFERRED RANGE Reaction temperature 'C 25 - 120 50 - 120 Carbon Monoxide Pressure, 500 - 3,000 1,000 - 1,500 psig Resin acid strength, 65 wt. percent or greater 70 wt. percent or greater equivalent to sulfuric acid Sulfuric acid Sulfuric acid Sufficient catalyst is used to provide at least a molar equivalent of acidic (proton) group to the olefm. The catalyst of the present invention is a solid resin showing strong-acid behavior. It is preferably selected from the group consisting of sulfonated copolymers of styrene and DVB (divinylbenzene) and phenol or phenolic based resins. In either case, the resin is treated to give a sulfonic acid cation - exchange resin capable of providing sufficient protons (resin having an acid strength equivalent to at least 65 weight percent sulfuric acid) for the reaction to proceed to yield trialkylacetic acids. EXAMPLES The following examples illustrate the synthesis of trialkylacetic acids, particularly neodecanoic acid, from branched olefins such as isononene, by the present catalyst system as well as the need to maintain non-aqueous conditions during the synthesis reaction. In each example a cation exchange styrene divinylbenzene resin bead produced by Rohm and Haas Corporation, Philadelphia, PA, and sold under the name Amberlyst 15 was used. It is a well-known strongly acidic cation exchange resin having sulfonic groups attached to its backbone and sold in bead form. Amberlyst 15 is treated by the manufacturer with sulfuric acid to convert it into the acid form. The presence of inorganic acid residue on the ion exchange beads could serve as a catalyst for the production of trialkylacetic acids (neo acids). In order not to give a false positive result by the possible presence of free sulfuric acid, the resin was carefully extracted with water (50ml of water per lOOg of received resin) to ensure there was no measurable inorganic residue present. The resin was then separated and dried. The feed olefm in each case was isononene, a commercially available (Exxon Chemical Company) branched C 9 olefin made by the acid catalyzed oligomerization of propylene. It contains a large number of branched internal olefin isomers. A two liter rocking autoclave was used in each example with carbon monoxide serving to pressurize the reaction mixture. Heptane was used as solvent and other than Example 2 the reaction was conducted under substantially aqueous free conditions. EXAMPLE 1 A 289.9 g sample of isononene dissolved in 246.0 g n-heptane solvent was charged to the two liter rocking autoclave with 163.9 g of dry Amberlyst 15 resin beads obtained from Rohm and Hass Corp. The autoclave was pressurized to 1000 psig with carbon monoxide, heated with rocking to 155 ° C and the pressure then adjusted to 1500 psig with carbon monoxide. These reaction conditions were maintained for six hours. The autoclave was then cooled to room temperature and vented. The recovered product mixture was stirred with 500 ml water for three hours to separate reaction product. The organic phase was then separated from the aqueous phase and resin beads and analyzed by gas chromatography using known standards and calculated response factors. In all examples a gas chromatographic system using a Hewlett/Packard 5890 series 11 with an FID, HP-7673 autoinjector and HP plotter integrator or equivalent was used together with a column injection system. A CIS/CALS integrating computer system was used. A 30 meter x.53 mm ID FFAP column with about a 1 micron film was employed. Typically, an initial injector temperature of 123° and detection temperature of 280 °C was used. The oven temperature ran from 120 to 240 "C at increases of lO'C/min. The organic phase was found to consist of the following: 29 weight % unreacted isononene 42 weight % neodecanoic acid (mixed isomers) 26 weight % isooctadecenes (mixed isomers) 3 weight % C 27 olefins (mixed isomers) The amount of neodecanoic acid produced corresponded, on a molar basis, to 92 % of the theoretical active acid sites available on the resin beads as reported by the manufacturer. EXAMPLE 2 Example 1 was repeated with water present during the reaction. The following feeds were charged to the same two liter autoclave: 286.2 g isononene, 247.6 g n-heptane, 143.0 g Amberlyst 15 resin beads, and 12.3 g water. The reaction conditions were the same as Example 1 with the exception that a reaction temperature of 115 ' C was used. The recovered product was treated as above. Gas chromatographic analysis gave no evidence of trialkylacetic acid product formation. This illustrates that the present process must be conducted with these resin catalysts in a non-aqueous system. EXAMPLE 3 Example 1 was repeated at a lower reaction temperature. The following feed materials were charged to the two liter autoclave: 290.0 g isononene, 249.0 g n-heptane, and 137.2 g Amberlyst 15 resin beads. The reaction conditions were the same as Example 1 with the exception that a reaction temperature of 100°C was used. The recovered product mixture was filtered to separate the organic phase from the resin beads. The latter were rinsed with 100 cc n-heptane and returned to the autoclave for use in Example 4. The n-heptane rinse was combined with the organic phase and analyzed as per Example 1. The following results were obtained: 38 weight % unreacted isononene 26 weight % neodecanoic acid (mixed isomers) 35 weight % isooctadecene (mixed isomers) 1 weight % C 27 olefins (mixed isomers) The higher temperature of Example 1 gave somewhat better trialkylacetic acid product formation. EXAMPLE 4 Example 3 was repeated using the Amberlyst 15 resin beads recovered from Example 3 and the following feeds: 290.0 g isononene and 249.0 g n-heptane. The reaction conditions and product recovery were the same as given in Example 3. Analysis of the product gave the following results: 78 weight % unreacted isononene 5 weight % neodecanoic acid (mixed isomers) 17 weight % isooctadecene (mixed isomers) a trace of C 27 olefins (mixed isomers) This example illustrates the depletion of the active sites of the cation exchange resin and its ability to serve as a catalyst for converting branched olefins to trialkylacetic acids. Various modifications may be made to the present invention. While the specific examples described previously show the addition of water after the end of the reaction to convert the intermediate formed into the final trialkylacetic acid product, it is also possible to add alcohols, such as methanol, ethanol, isopropanol, etc. to form esters directly. Other terminating groups, such as phenols and amines can also to reacted with the intermediates produced by the present invention to form phenol esters and amines, respectively.

Claims: WE CLAIM: 1. A process for the production of trialkylacetic acids comprising the steps of contacting under non-aqueous conditions a branched or unbranched olefin having the general formula: R, R, \ / C=C / \ R. R 7 wherein each R is an alkyl group of 1 to 15 carbons, or alternatively R 4 and/or R 5 is hydrogen with carbon monoxide and a cationic resin having sufficient acid groups to provide requisite protons for conversion of said olefin and carbon monoxide to trialkylacetic acids. 2. The process of claim 1 wherein said cationic resin catalyst has an acidity at least equivalent to that of a 65 wt. percent sulfuric acid. 3. The process of claim 1 wherein said cationic resin catalyst has an acidity at least equivalent to that of 70 wt. percent sulfuric acid. 4. The process of claim 1 wherein said reaction is conducted at a temperature in the range of 25-120 * C. 5. The process of claim 1 wherein a carbon monoxide pressure of 500-3000 psig is used during the reaction. 6. The process of claim 1 which produces a trialkylacetic acid represented by the following formula: R, O I II R- C C OH where each R group has 1 to 10 carbon atoms. 7. The process of claim 6 where the total number of carbon atoms in the trialkylacetic acid ranges from 5 to 19. 8. The process of claim 1 where said cationic resin is selected from the group consisting of sulfonated copolymers of styrene and divinylbenzene; phenol and phenolic based resins. 9. The process of claim 1 where said feed olefin is isononene and the trialkylacetic acid product is neodecanoic acid. 10. A process for producing trialkylacetic acids which comprises the steps of contacting at 25 to 120° C under non-aqueous conditions a branched or unbranched olefin having the general formula: c=c / \ e. R 7 where each R is an alkyl group of 1 to 15 carbon atoms or alternatively R* and/or R 5 is hydrogen, with carbon monoxide and a cationic resin selected from the group consisting of sulfonated copolymers of styrene and divinylbenzene; phenol and phenolic based resins, wherein said resin has at least a 65 wt. percent sulfuric acid strength equivalent to produce a trialkylacetic acid. 11. The process of claim 10 wherein said trialkylacetic acid product is represented by the following formula: R, O I II R, C C OH R 3 where R is a alkyl group having 1 to 10 carbon atoms, and the total number of carbon atoms in the molecule is 5 to 19. 12. The process of claim 10 where said feed olefin is isononene and said trialkylacetic acid product is neodecanoic acid.

Inventors: CONNOR THOMAS H, CUSUMANO JOSEPH VICTOR, DIANA WILLIAM DANIEL, EMERT JACOB, GORDA KEITH R, SCHLOSBERG RICHARD HENRY, YOUNG DAVID ALEXANDER, CONNOR, THOMAS, H., CUSUMANO, JOSEPH, VICTOR, DIANA, WILLIAM, DANIEL, EMERT, JACOB, GORDA, KEITH, R., SCHLOSBERG, RICHARD, HENRY, YOUNG, DAVID, ALEXANDER
Applicants: EXXON CHEMICAL PATENTS INC, EXXON CHEMICAL PATENTS INC.
Application year: 1995
Main classification: C07C51
IPC codes: B01J31, C07B61, C07C51, C07C53