Process for the Preparation of Dodecanedioic Acid

Europaisches Patentamt J European Patent Office 6\) Publication number: 0 438 143 A1 Office europeen des brevets

EUROPEAN PATENT APPLICATION

@ Application number: 91100493.5 int. CIA C07C 55/21, C07C 51/31

© Designated Contracting States: @ Inventor: Davis, Darwin Darrell BE DE FR GB IT NL 105 Tampa Drive Victoria, Texas 77904(US) Inventor: Sullivan, David Lee 103 Hollywood Boulevard Victoria, Texas 77904(US)

© A process for the production of dodecanedioic phase, an aqueous phase containing cerium ions in acid by oxidation of cyclododecene using a two the plus 4 state. The cerium plus 4 ions may be phase system in which ruthenium tetroxide serves as regenerated by electrolytic oxidation in a separate the oxidizing agent in the organic phase, and step. ruthenium tetroxide is regenerated in the second

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Xerox Copy Centre EP 0 438 143 A1

PROCESS FOR THE PREPARATION OF DODECANEDIOIC ACID

Field of the Invention 1 - preferably greater than 5. Cyclododecene and ruthenium tetroxide are soluble in the organic This invention relates to the production of phase. In the organic phase cyclododecene is ox- dodecanedioic acid by the oxidation of idized to dodecanedioic acid and ruthenium tetrox- cyclododecene. The oxidizing agent is ruthenium 5 ide is reduced to one or more suboxides including tetroxide. Ruthenium tetroxide is regenerated in the ruthenium dioxide, and its complexes. Ruthenium reaction mixture by cerium in the plus 4 oxidation in its reduced state has limited solubility in the state. organic phase, and it tends to form a precipitate which is extracted or dissolved into the aqueous Background of the Invention w phase where it is oxidized by cerium + 4 ions to ruthenium tetroxide, and the reformed ruthenium Dodecanedioic acid is conventionally prepared tetroxide is again dissolved in the organic phase by the air oxidation of cyclododecane thus forming where it reacts with additional cyclododecene. In cyclododecanol or cyclododecanone. These com- order to assure that the cyclododecene is con- pounds are then oxidized to the acid by nitric acid. 75 verted to the desired acid in high yield, and not Such a process is disclosed in U.S. Patent aldehyde or other intermediate products, it is pref- 3,637,832. erable that the mole ratio of ruthenium tetroxide to The oxidation of olefins to aldehydes, ketones cyclododecene in the mixture should be greater and carboxylic acids by the use of ruthenium and than 1 during the oxidation part of the reaction. cerium salt is disclosed in U.S. Patent 3,459,644 to 20 Finally, the Ce*4- /ruthenium ratio is allowed to fall Mac Lean et al. below 1 at the end of the reaction in order to leave The oxidation of saturated cyclohydrocarbons ruthenium in the reduced state and largely in the to dioic acids using ruthenium tetroxide with a two- aqueous phase. The reaction mixture should be phase system in which the oxidation takes place in maintained at a temperature in the range of about the organic phase and the ruthenium dioxide 25 25 to 85° C in order to assure efficient reaction with formed in the organic phase is oxidized to minimum undesired byproducts. The organic phase ruthenium tetroxide by sodium hypochlorite in the is then separated from the aqueous phase, and the aqueous phase is disclosed in J. Org. Chem., Vol. dodecanedioic acid is separated from the organic 40, No. 17, 1975 on pp. 2539-40~by~Spitzer et al. phase by crystallization. The aqueous phase may The oxidation of alcohols to carbonyl com- 30 be subjected to electrolytic oxidation to convert the pounds using a two-phase system employing cerium +3 ions to cerium + 4 ions. The reduced ruthenium tetroxide as the oxidising agent in the ruthenium contained in the aqueous phase will at organic phase, and in which the ruthenium dioxide the same time be oxidized to ruthenium tetroxide. formed is oxidized indirectly by electrolysis in the An important advantage of this invention is that aqueous phase back to the tetroxide is disclosed in 35 dodecanedioic acid produced in the oxidation is J. Org. Chem., Vol. 51 , pp. 1 55-1 61 , (1 986). easily recovered from the organic phase with very The electrolytic oxidation of cerium + 3 ions to little loss of ruthenium. Most of reduced ruthenium cerium + 4 ions, and the use of cerium + 4 ions as at the finish of the cyclododecene oxidation is the oxidizing agent in the oxidation of aromatic present in the aqueous phase when the compounds to carbonyl containing compounds in 40 Ce+4/ruthenium is less than 1, with only very small methanesulfonic acid is disclosed in U.S. Patent quantities of ruthenium in the organic phase. 4,639,298 to Kreh. The concentration of the ruthenium tetroxide in the two-phase mixture at the start of the reaction Summary of the Invention can vary from about 5 to 1300 parts by weight per 45 million parts of the mixture. The present invention is a process for the The ratio of aqueous phase to organic acid oxidation of cyclododecene to dodecanedioic acid phase in the reaction mixture is preferably in the and comprises the steps of forming a two-phase range of 0.5 to 1 to 10 to 1 . mixture comprising an aqueous phase containing The mole ratio of cerium + 4 ion to ruthenium cerium + 4 ions, ruthenium tetroxide and at least so tetroxide in the two-phase reaction mixture can one acid selected from the group consisting of vary from 5 to 1 to 10,000 to 1 preferably 2,000 to methanesulfonic acid and sulfuric acid, and an or- 1. ganic phase containing ruthenium tetroxide and The aqueous phase also contains methanesul- cyclododecene. In the mixture the mole ratio of fonic acid or sulfuric acid. Methanesulfonic acid or cerium + 4 ion to ruthenium tetroxide is greater than sulfuric acid is present in a concentration sufficient EP0 438 143 A1 to keep the cerium ions soluble in the aqueous reducing agent employed should be sufficient to phase. Cerium salts, both +4 and +3 of reduce the concentration of cerium in the plus 4 methanesulfonic acid are more soluble than salts of state in the reaction mixture to about zero, and the other common acids. Preferably, the acid is amount of ruthenium tetroxide to about zero. methanesulfonic acid and the concentration in the 5 The organic phase that serves as the solvent two-phase mixture is about 1 .5 to 9 molar. for the cyclododecene, the ruthenium tetroxide, and the dodecanedioic acid, must be insoluble or only Description of the Drawings slightly soluble in the aqueous phase, must be liquid under the conditions at which the process is The drawing is a flow diagram of the process to practiced, must not be readily oxidized under the for oxidizing cyclododecene to dodecanedioic acid. reaction conditions, and must be a poor or non- solvent for the lower oxides of ruthenium. Suitable Detailed Description of the Invention materials for the organic phase include acids such as valeric acid, isovaleric acid, pivalic acid, The overall process of converting 75 isobutyric acid, 2-ethylbutyric acid, butyric acid, cyclododecene to dodecanedioic acid is readily heptanoic acid, octanoic acid, and mixtures of such understood by reference to the Figure. An aqueous acids. Other classes of solvents have some of solution containing ruthenium tetroxide, cerium + 4 these properties and may be suitable to varying ions and methanesulfonic acid, designated 1 in the degrees. These include saturated hydrocarbons Figure, is fed to stirred reactor 2. A solution of 20 such as cyclohexane and hexane and the like and organic solvent, e.g. valeric acid and halogenated saturated hydrocarbons such as chloro cyclododecene, 3, is also slowly fed to the reactor. and fluoro ethane, propane, etc. The reactor is stirred so as to obtain a well-mixed two-phase system. After the reaction is complete, Examples the contents of the reactor are passed via conduit 4 25 to decanter 5, where the organic phase is sepa- Example 1 rated from the aqueous phase. The organic phase is passed via conduit 6 to crystallizer 7 and separa- To a creased flask fitted with a paddle stirrer tor 8. The organic phase, e.g. valeric acid is then was added 70 ml of 0.33 N Ce(OSO2CH3)+ in recycled via conduit 9 to where additional 30 35.6% aqueous CH3SO3H. This solution was heat- cyclododecene is added via conduit 10. The aque- ed to 60° C and 0.05g ruthenium acetyacetonate ous phase that is separated at decanter 5 plus plus 10 ml valeric acid was added while paddle make up water are passed via conduit 11 through stirring. After the reaction mixture turned yellow (ca pump 12 and conduit 13 to the anode compartment 30 seconds), 0.086 g of cyclododecene was added of electrolytic cell 14. The cathode compartment of 35 dropwise over 3 minutes. The mixture was stirred cell 14 contains aqueous methanesulfonic acid an additional 5 minutes after completion of olefin which is recycled via conduit 15, pump 16, and addition, then decanted to yield a clear yellow conduit 17 with H2 gas removed via conduit 20. valeric acid phase (5.0 g) and an aqueous phase The regenerated anolyte, now containing cerium in (92 g). Analyses indicated cyclododecene was con- the +4 state as well as ruthenium tetroxide is 40 verted to dodecanedioic acid with 88% selectivity. recycled via conduit 18 to reactor 2. The crude dodecanedioic acid obtained at separator 8 is Example 2 passed to a refining step via conduit 19. with If the process is operated in a continuous man- To a 2-liter creased flask equipped paddle Ce+4 ner, the Ce+4 to ruthenium ratio in the reactor is 45 stirring was added 1250 ml of 0.75N present maintained at greater than 1 and a plug flow "clean as cerium methanesulfonate (CE[SO3CH3]4-) in up" reactor is added between reactor 2 and de- 50% (wt/wt) aqueous methanesulfonic acid. This canter 5, where the effluent from reactor 2 contin- solution was heated to 60 *C and powdered ues to react while the ratio of cerium + 4 ion to ruthenium acetylacetonate (1.2231 g = 3.07 ml) ruthenium tetroxide is lowered to 1 or less. As an 50 was added while stirring at about 500 rpm. During alternative to a clean up reactor, a reducing agent this addition, the green color associated with the such as oxalic acid, or an aliphatic alkanol, e.g. reduced ruthenium disappeared and the yellow col- * methanol or an aldehyde may be added to the or of FtuCU appeared as oxidation by Ce oc- mixture to reduce Ce^ and any ruthenium tetrox- curred. After the yellow color persisted, 225 ml of ide to suboxides and thus assure that the amount 55 valeric acid was added to the flask. of ruthenium in the organic phase is very small. Holding the reactor at 60 °C with 500 rpm Reducing agent can also be added if needed when stirring, a solution containing 12.1 g of 4% the process is operated batchwise. The amount of cyclododecene (96% cyclododecene, EP0 438 143 A1 cyclododecane) in 25 ml valeric acid was added to less. the RuCVCe** solution over 24 minutes. A 5 minute clean up time at 60 °C followed this, at 5. The process of claim 3 which is followed by a which time the clear yellow valeric acid phase was separate step of adding a reducing agent to removed and cooled to room temperature to yield the mixture to lower the Ce 4 ion concentration 7.0 g of crude dodecanodioic acid. and the ruthenium tetraoxide concentrations. Analyses of samples of the aqueous and organic phases from the reactor indicate about an 6. The process of claim 1 which includes the 87% selectivity (95% conversion) from additional steps of separating the organic cyclododecene to product dodecanediooic acid or 10 phase from the aqueous phase, and separating a 94% selectivity to the combined C10, Cn, and dodecanedioic acid from the organic phase. C12 dibasic acids present in both phases. Lower dibasic acids (C+ through Cg) were the remaining 7. The process of claim 6 in which after separa- cyclododecene oxidation products found. The tion of the organic phase from the aqueous aqueous mother liquor from the previously de- 75 phase, the aqueous phase is subjected to elec- scribed RuO+/Ce+* oxidation of cyclododecene trolytic oxidation to regenerate the Ce + 4 ions. was added to the anode reservoir of an electrolytic cell. An aqueous solution containing 50% (wt/wt) 8. The process of claim 1 in which the concentra- CH3SO3H was added to the cathode reservoir of tion of the ruthenium tetroxide in the mixture is this electrolytic cell. After circulation (7.5 cm/sec 20 in the range of about 5 to about 1300 parts per velocity) to the anode and cathode for 15 minutes million. while maintaining an anode reservoir temperature of 50 °C, a voltage of 2.1 ~» 2.2 was set between 9. The process of claim 1 in which the ratio of anode of platinum coated niobium and a stainless aqueous phase to organic phase is in the steel cathode while passing 5.0 amps between the 25 range of 0.5 to 1 to 10 to 1 . 100 cm2 electrodes. Periodically removing the anolyte and titrating for Ce*A' indicated the current 10. The process of claim 1 in which the organic efficiency (coulombs equivalent"1 Ce+4 phase contains valeric acid. theory/coulombs equivalent"1 Ce+4- actual x 100) was 75-85% when the Ce*3 > 0.1 N. 30 11. The process of claim 1 in which the organic phase contains an acid selected from the class Claims consisting of valeric acid, isovaleric acid, pivalic acid, isobutyric acid, 2-ethylbutyric acid, 1. A process for the oxidation of cyclododecene butyric acid, heptanoic acid, octanoic acid, and to dodecanedioic acid which comprises for- 35 mixtures of such acids. ming a mixture having an aqueous phase comprising an aqueous solution containing (a) 12. The process of claim 1 in which the aqueous Ce + 4 ions, (b) ruthenium tetroxide and (c) one phase contains methanesulfonic acid. or more acids selected from the class consisting of methanesulfonic acid and sulfuric acid, 40 and an organic phase containing cyclododecene, in which the overall mole ratio of Ce + 4 to ruthenium tetroxide in the mixture is greater than 1 , and oxidizing cyclododecene in the mixture at a temperature in the range of 45 about 25 to 85 degrees C.

2. The process of claim 1 in which the ratio of ruthenium tetroxide to cyclododecene in the reaction mixture is greater than 1 . 50

3. The process of claim 1 in which the concentration of Ce+4 ion diminishes during the oxidation of the cyclododecene. 55 4. The process of claim 3 in which the concentration of the Ce * ion diminishes to a level where the ratio of Ce 4 to ruthenium is 1 or

Application Number J European Patent EUROPEAN SEARCH REPORT Office

DOCUMENTS CONSIDERED TO BE RELEVANT F!P 91.100493 .5 Relevant CLASSIFICATION OF THE Citation of document with indication, where appropriate, APPLICATION (In«- CI.S) Category of relevant passages to claim

EP - Al - 0 021 118 C 07 C 55/21 (MITSUI) C 07 C 51/31 * Claims *

US - A - 3 461 160 (E.D. WILHOIT) * Totality *

CHEMICAL ABSTRACTS, vol. 104, no. 15, April 14, 1986, Columbus , Ohio , USA S. TORII et al. "Indirect electrooxidation of alcohols and aldehydes by using a double mediatory system consisting of ruthenium tetraoxide/ruthenium dioxide and chlorine cation/ chlorine anion redoxes in an aqueous -organic two-phase TECHNICAL FIELDS system" SEARCHED (Int. C1.5) page 637, abstract-No. 129 122m C 07 C 51/00 D C 07 C 55/00 & J. Org. Chem. 1986, 51(2) 155-61

The present search report has been drawn up for all claims Place of search Dale of completion of the scare VIENNA 12-04-1991 HOFBAUER the invention CITED DOCUMENTS T : theory or principle underlying CATEGORY OF E : earlier patent document, but published on, or alone after the filing date X : particularly relevant if taken D : document cited in the application Y : particularly relevant if combined with another cited for other reasons document of the same category L : document A : technological background & 7 member of the same patent family, corresponding () : non-written disclosure document [' : intermediate document