3,381,047 United States Patent 0 ’ Patented Apr. 30, 1968

1 2 3,331,047 stituted with groups selected from the class consisting of CYCLODODECATRlENE-1,5,9 PROCESS alkyls having 1-6 carbon atoms, phenyl, and alkyl sub Herbert Sousa Eleuterio and Theodore Augur Koch, Wil stituted phenyl having 7-12 carbon atoms and wherein at mington, DeL, assignors to E. I. du Pont de Nernours least 1 alpha carbon atom in the main chain of said ali and Company, Wilmington, Del., a corporation of phatic and substituted aliphatic acids has at least one and Delaware preferably at least two hydrogen atoms attached thereto. No Drawing. Continuation-impart of application Ser. No. 485,090, Sept. 3, 1965. This application Dec. 7, 1965, Other substituents on the acid that do not adversely af Ser. No. 59?,721 feet the catalyst or the yield to the desired products are 8 laims. (Cl. 260-666) within the purview of this invention, e.g., acids having 10 halogen substituents sufficiently removed from the car boxyl groups are operable. Illustrations of the acids con ABSTRACT OF THE DTSCLGSURE templated by the above de?nition are saturated and un saturated, mono-, di-, and tricarboxylic acids such as Aliphatic carboxylic acids are employed to increase the formic; propionic; butyric; lauric; pentadecanoic; acrylic; rate and yield in the trimerization of butadiene to form crotonic; sorbic; nonanoic; 3-hexyl-; decanoic, 4-butyl-; cyclododecatriene—l,5,9 using organoaluminum sesqui crotonic, 3-methyl-; 2,5-heptadienedioic, 4-pentyl-; 1,2,4 chloride and titanium compounds as catalysts. hexanetricarboxylic; 3-hexynedioic; 4,6-decadiynedioic; pentyn-4-oic acid; capric; pelargonic; isobutyric; isovaler This application is a continuation-in-part of copending ic; oxalic; malonic; pimelic; sebacic; azelaic; isocaproic; 20 isoenanthic; succinic; glutaric; adipic; 1,12-dodecanedioic; application Ser. No. 485,090, ?led Sept. 3, 1965 by H. S. and u,5-dimethy'l-butyric acid. Formic and acetic acids Eleuterio and T. A. Koch, now abandoned. are preferred. The present invention relates to a process for the tri The ratio of organoaluminum sesquichloride to the merization of butadiene to cyclododecatriene-(1,5,9) titanium compound is not so critical. The molar ratio using a catalyst prepared from an organoaluminum ses of ethylaluminum sesquichloride to titanium tetrachloride quihalide, an aliphatic acid and a selected tetravalent titanium compound. may be varied from 3/1 to 30/1. Higher ratios may be used but are not desirable because of the expense of the The production of cyclododecatriene-(1,5,9) by sub ethylaluminum sesquichloride. jecting 'butadiene to the action of various catalysts is The catalyst may be made up by reacting the acid with known. Butadiene trimerization catalysts, based on alkyl 30 ethylalurninum sesquichloride followed by reaction of the aluminum chlorides and titanium halides, such as those product so formed with titanium tetrachloride. However, described in Schneider et al., United States Patent 3,076, for continuous operation, it is convenient to add all three 045, and Wilke, United States Patent 2,964,574 are catalyst components separately and simulaneously to the known. reaction vessel. The present invention is an improvement both in rate The butadiene trimerization reaction can be run in of reaction and in ultimate yield over these above-men any inert hydrocarbon solvent such as benzene, cyclo tioned prior processes involving the use of a certain hexane, toluene, xylene and hexane. Cyclododecatriene is catalyst system under certain reaction conditions. an excellent solvent and the preferred one for continuous The catalyst system is prepared from the hereinafter trimerization of butadiene. de?ned organoaluminum sesquichloride, an aliphatic acid The butadiene trimerization reaction temperature and titanium tetrachloride. Catalyst components are pref should be maintained at from 20° to 120° C., and pref— erably limited to these three. For convenience, the exact erably from 60° to 90° C. At lower temperatures, the composition of the organometallic compound may be reaction rates become unduly slow and at higher tempera varied and described as any composition having the fol tures, increasing yield losses to by-products occur. lowing ratio of materials Pressure is not a critical variable in the instant inven tion and may be varied from 1/2 atm. to 50 atm., prefer (Z) (2.5-3.5)A12C1(3.5-2.5) ably at from 1 to 5 atm. Increasing the pressure in many cases will improve the productivity of the catalyst. wherein Z is selected from the class consisting of alkyl By operating within the hereinabove set forth limits, radicals having 2-3 carbon atoms and the phenyl radical. 50 butadiene trimer is formed at above the average reaction When the process is conducted at about 1 p.s.i.g. pressure, rates in the absence of an acid and in yields usually the molar ratio of organoaluminum sesquichloride to the greater than 80 percent. The reaction can be conducted in aforesaid acid should be maintained at from 1/0.l mole multiple stages. to l/ 0.50 mole with from 1/0.3 to 1/ 0.4 being especially The following examples are illustrative of the inven the preferred range. As the pressure is increased above 1 tion. p.s.i.g., the above ranges can be expanded, e.g., from Examples 1-7 1/0.1 to 1/0.7 or greater. The tetravalent titanium compounds which are operable The apparatus employed for the trimerization con in the present process are soluble in the reaction medium sists of a 2 liter, 3-necked, creased, round-bottomed ?ask to the extent of at least 0.01 mole percent based upon 60 ?tted ‘with rubber stopper, condenser with outlet to mer cyclododecatriene at 20° C. and do not contain a sub cury bubbler, thermometer, high speed stirrer, and gas stituent which inactivates the catalyst. These titanium inlet. After the apparatus is well dried and flushed with compounds have the formula TiA, wherein A is selected inert gas, 150 ml. of benzene which is dried and rendered from the class consisting of chlorine, bromine, iodine and oxygen-free by distillation from sodium potassium alloy OR, wherein R is a hydrocarbon radical having 1-20 65 under nitrogen is added to the ?ask. The benzene is heated to 55° C.i-5° C. and acetic acid as a 0.4 M carbon atoms. The four A’s in a given titanium compound solution in benzene and a 1 M solution of ethyl alumi may be the same or different. num sesquichloride in benzene in the amounts indicated Acids which are operable in the present invention are in Table I is injected with moderate agitation followed selected from the class consisting of formic acid, oxalic 70 by 1 millimole of titanium tetrachloride as 10 ml. of a acid, and aliphatic acids having 2-15 carbon atoms, ali 0.1 M solution in benzene. The rate of stirring is then phatic acids having 2-15 carbon atoms which are sub increased to 2000 rpm. Butadiene, puri?ed by stirring 3,381,047 3 4 with and distillation from tn'isobutyl aluminum, is Temperature, °C. ______75 passed into the reactor slightly more rapidly than it is Pressure, p.s.i.g ______1 adsorbed to maintain a purge of a few cc./min. through Percent distribution in crude: the trapIThe reaction temperature is maintained at 70: Cyclododecatriene ______87.7 2° C. After the time shown in the table, the catalyst is Cyclooctadiene ______0.74 deactivated with a 10 ml. sample of a 1:1 mixture of Vinylcyclo-hexane ______._ 1.08 acetone and isopropyl ‘alcohol and a sample of the crude Polymer ______8.67 reaction mixture is analyzed immediately by gas chroma tography. The average rate of the reaction throughout Examples 9-27 a run is vgiven as the number of g./ min. of pure cyclo 10 dodecatriene actually produced. Example 7 illustrates the A 500 cc. reaction vessel is equipped with inlets for poor rate and yield obtained in the absence of the acid. the continuous introduction of the solution of the cata~ lyst and butadiene which is dried in the liquid phase with TABLE I a molecular sieve ‘and is introduced as a gas by vaporiz E1'3A12C132 Milliruoles Time Yield Rate ing in the presence of tri-n-butyl aluminum. The inlets Ex Acetic Acid of EtaAlzCla (1nin.) (Percent) (g./min.) Molar Ratio are arranged to permit the introduction of ethylalumi num sesquichloride (except Example 21 which uses 1:0. 4 S. 66 84 92 6. 65 1 :0. 5 8. 33 40 89. 5 2. 0 phenyl aluminum sesquicliloride), the titanium com 1:0. 39 8.71 75 91 6. 4 pound and the acid is separate streams. As in Example 8, 1:0. 40 8. 60 80 91 G. 9 1:0. 00 8.00 100 76. 5 2. 4 a liquid product is continuously removed such that a 1:0. 20 9. 32 (it) 89 6. 15 steady state condition prevails. The runs are started by 1:0. 00 6.00 28 60 0. 1 ?lling the reactor with dry cyclododecatriene and su?i cient catalyst for one hour of operation. Butadiene gas The optimum ratio of et-hylaluminum sesquichloride to is introduced in amounts su?icient to maintain 1 p.s.i.g. acetic acid as shown by the above data is about 1/0.4. during the run (except Examples 22-—27 which were Example 8 conducted at 5 p.s.i.g.). The reaction is conducted at 75° C. Except where indicated, the titanium compounds A 500 cc. reaction vessel is equipped with inlets for are added as a 10% solution in cyclohexane and at the continuous introduction of the solutions of the cataylst rate of 1.01 g. of titanium tetrachloride per gallon per components substantially as described in Paragraph 1 of hour or the equivalent thereof. The adipic and dodecane Examples 1-7 and dry butadiene. Liquid product is con dioic acids were prereacted with the sesquichloride in tinuously removed such that steady state conditions pre toluene while maintaining a local excess of the sesqui vail. The conditions and results ‘are reported in Table II. chloride in order to obtain a clear solution. The di carboxylic acids are insoluble initially but go into solu TABLE II Example 8: tion as their reaction with the sesquichloride progresses. Catalyst ratio moles Et3A12C13/T‘IC14/ For adipic, to 200 cc. of toluene was added 3.65 grams acetic acid ______10/ 1/4.0 of adipic acid and 31.67 grams of the sesquichloride; Steady state productivity pounds crude/ for dodecanedioic, to 200 cc. of toluene were added 5.76 gal of crude 1n reactor/hour ______7.17 grams of dodecanecnoic and 32.2 grams of the sesqui Feed rate T1C14 gm./gal./hour ______1.0 40 chloride. The prereaeted mixture was then added to the Steady state T1Cl4 conc. gram T1C14/ reactor. The composition of the product along with the tgal. ______1.0 other experimental results are shown 1.11 Table III. TAB LE III 9 10 11 12 13 14 15 16 17 18 19 Catalyst: Molar Ratio 10/1/5____ 10/1/4____ loll/3.-.- 10/1/2___._ 10/1/3 .. 10/1/4..._ 10/1/3.5 ______-_ loll/3.5.- 10/1/5____ 10/1/4__.._ 10/1/1.96 (CzH5)3AlzC13/TiA4/A0id. _ A 01- ______Cl" ______Cl- ______Cl- ______Cl- _ Isopropoxrdek I4 ______Cl- ______C-l- .... __ Cl Acid ______Acetic 1. Formic9_ Fo 9. Forrnic 7 ______Formir?. Formict‘. LauricL Adipic. Steady State Productltity. ______.___ 6.05_____ 5.80_____ 7.96---“ 7.81.--“ 7.73 ______- 5.2 .... -- 4.00-._-_ 5.34""- 4.06. (Pounds of crude/gal. of crude in reactor/hour). Product Distribution in Crude Product: Cyclododecatriene ______84.6“-.- __ 85.8 ...... __ 82.5"..- 73.9...“ 85.9_____ 82.8. Cyclooctadienc______1.17__ _ . .50_____ 1.00_____ 1.32____.. 0.63. Vinyl Cyclohexane __ 1.15.. __ . _ _ . _ . .68.-.“ .37.-." 0.99_.___ 3.87. Nonvolatile residue ______-_ 10.l._..___ 8.56""- 8.09"“- 7.99_____ .2___-. 26.7-__-- 10.7“--- 10.8.

20 21 22 11 23 11 24 11 25 11 26 "- 27 11 Catalyst: Molar Ratio loll/1.92 ...... __ 10/1/45____ 10/1/4.--.. 10/1/4---_____ 10/1/4 ______-- 10/1/4 ______-_ 10/1/4 .... __ 10/1/4.

_(CzHs)aAIzCh/TiAdacid. Cl- Br-___ 01*______01* CI- 01-. Acid ______Dodecanedioic.- For-mic __ Phenyl acetic 14.- 10-un' Acrylic 15.- Isobutyrie? decenoic 15. Steady State Productivity: 4.38 ...... -_ 6.78 ______8.28-"-.. 4.81 ______7.05 ______-_ 6.37 ...... __ 6.88 ..... __ 3.59. (Pounds of crude/gal. of crude in reactor/hour). Product Distribution in Crude Product: Cyclododeeatriene ______-_ 84.2 ______88.0 ______85.9-_____-__-. 85.0 ..... __ 82.3. Cyclooctadiene______0.54. - 1 0 Vinyl cycl0hexane_ __ 3.49 _ . Nonvolatile residue--.“ __._ 9.86 ______13.4______1 Added as 2.71 M in cyclohexane. 9 Added as 1.30 M in benzene. 1 vaporized and added with the dry butadiene. 1° Added as 1.86 M in benzene. 3 Added as 0.298 M in cyclohexane. ‘1 Operation at 5 p.s.i.g. 4 Added as 0.015 M in cyclohexane (somewhat unstable in solution). 12 Added as 1.99 M in cyclohexane. B The catalyst was phenylaluminum sesquichloride added as a 40% 13 Added as 0.458 M in cyclohexane. by weight solution in clilorobcnzone. 14 Added as 0.415 M in benzene. 6 Normalized. 15 Added as 1.05 M in cyclohexane. 7 Added as 1.59 Min benzene. 1'5 Added as 2.98 M in cyclohexanc. X Added as 0.681 M in benzene. 17 Added as 2.17 M in cycloliexane. 3,381,047 5 6 Cycloclodecatriene is a valuable chemical intermediate 3. The process of claim 2 conducted in the range 60 which can be readily oxidized to succinic acid which is to 90° C. useful in the production of plastics such as polyamides. 4. A process for the preparation of cyclododccatriene It also may be hydrogenated in a known manner. Thus, 1,5,9 which comprises contacting butadiene with a cata cyclododecene or cyclododecane is obtained from cyclo lyst consisting essentially of ethylaluminum sesquichlo dodecatriene. These hydrogenated products may, in turn, ride from 0.20 to 0.40 mole per mole of said sesquichlo be oxidized in known manner to form the corresponding ride of an aliphatic monocarboxylic acid having 1 to 10 dicarboxylic acids. carbon atoms and titanium tetrachloride in an amount We claim: such that the molar ratio of said sesquichloride to tita 1. A process for the production of cyclododecatriene nium tetrachloride is maintained at from 3~30/ 1 at a tem 1,5,9 which comprises contacting butadiene with a cata perature of 60 to 90° C. and at a pressure of 0.5-50 lyst system formed by mixing an organoaluminum com atmospheres. pound having the formula 5. The process of claim 1 wherein said acid is acetic acid. 6. The process of claim 1 wherein said acid is formic wherein Z is selected from the class consisting of alkyl acid. radicals having 2 to 3 carbon atoms and the phenyl radi 7. The process of claim 4 wherein said acid is acetic cal with from about 0.10 to about 0.70 mole of an ali acid. phatic carboxylic acid having 1 to 15 carbon atoms and 8. The process of claim 4 wherein said acid is formic a titanium compound having the formula TiA, where A acid. is selected from the class consisting of chlorine, bromine, References Cited iodine and OR, where R is a hydrocarbon radical having 1 to 20 carbon atoms, in an amount such that the molar UNITED STATES PATENTS ratio of said organoaluminum compound to said titanium 3,163,611 12/1964 Anderson et al ______252—429 compound is maintained at from 3-30/1 and at a tem 3,280,205 10/1966 Yosida et al. ______260-666 perature in the range of 20 to 120° C. and at a pressure DELBERT E. GANTZ, Primary Examiner. of 0.5—50 atmospheres. 2. The process of claim 1 wherein said orgauoalumi V. O’KEEFE, Assistant Examiner. num compound is ethylaluminum sesquichloride.