3,231,621 United States Patent O? ice Patented Jan. 25, 1966

1 2 oxide, , and a carbon compound containing 7 3,231,621 ole?nic linkage with a catalyst com REACTION RATES IN CATALYTIC HY DROFORMYLATION prising a complex between a metal, preferably , Lynn H. Slaugh, Pleasant l, Cali?, assignor to Shell , and a nitrogen-containing com Oil Company, New York, N.Y., a corporation of Cl prising a substituted , to be described hereinafter, Delaware under conditions sufficient to produce and alco N0 Drawing. Filed June 26, 1961, Ser. No. 119,313 hols containing one more carbon atom than present in the

7 Claims. (Cl. 260-604) ole?nic reactant. - . . _ _ . As used herein, the term “complex” indicates a co The present invention relates to the preparation of ordination compound which is a combination of a metal oxygenated organic compounds, particularly aldehydes 10 atom with one or more electronically-rich or and alcohols, by the reaction of carbon monoxide and atoms capable of ‘independent existence. hydrogen with ole?nic organic compounds in the presence The ,metal is held in complex combination with the of an improved hydroformyla-tion catalyst. More spe particular nitrogen-containing ligand found most desir ci?cally, the present invention relates to hydroformyla 15 able for the particular process wherein it is to be used. tion using certain metal complex catalysts having as The ratio of the molar amount of ligand in the complex sociated therewith certain to be described ‘in detail is determined by the coordination number ‘of the par hereinafter. ticulartransition ‘metal involved. By “ligand” is meant Hydroformylati-on is well known in the art and com a having an element with a pair of electrons prises converting an ole?n by reaction with carbon mon capable of bondingwith a metal atom whereby .a complex oxide and hydrogen to a corresponding or alco is formed. The carbon monoxide molecule is an example hol, the aldehyde or alcohol group being substituted on of such a ligand and may serve as at least a port- of the one of the carbon atoms previously involved in the ole?nic complexes suitable in the present invention. However, linkage. Isomerization of the original double bond leads the, catalyst must also contain a nitrogen-containing to several different ole?ns, in which case the hydro 25 ligand comprising a substituted pyridine molecule, which formyla-tion product is varied accordingly. The ole?nic will be described now in greater detail. a linkage ‘is simultaneously saturated with the addition of In order to fully realize the advantages of the present hydrogen and carbon monoxide to form the aldehyde invention, the pyridine must be substituted by at least one or alcohol. Thus, hydroformylation may be shown in non-hydrocarbon electro-negative substituent. Examples the general case by the following equation: 30 vof. appropriate substituents are middle halides such .as "chloride and. bromide, , carboxylic acid, car boxylic ester, carboxylic acid anhydride, sulfonic acid and phosphoric acid. While ‘more than ‘one electro-negative " substituent may be present in the substituted pyridine 35 ligand with certain appreciable advantageous results, it has been found that for optimum effectiveness the use of but one such substituent in the pyridine molecule is pre ' ferred. The substituted pyridine compounds which may be In the above equation, each R represents an organic “used as ligands in the rnetal“ complex catalysts are rela radical or a suitable atom such as hydrogen or a halogen. tively well known organic materials themselves. The above reaction is similarly applicable to an ole?nic In the catalytic complexes useful herein, acarbon linkage in a cycloaliphatic ring, as, for example, when ‘monoxide molecule can replace any nitrogen-containing R2 and R3 are joined into a divalent radical, such as ligand provided that at least one ligand molecule of sub tetramethylene, or the like. i stituted pyridine is present in each complex. ' i In the past, dicobalt octacarbonyl has been widely used The catalysts for use in the process of this invention as a catalyst for the hydroformylation of \ole?ns. This may beprepared by a diversity of methods. A conven catalyst may be prepared ‘from many forms of cobalt by ient method is to combine a salt of the desire-d transition reduction with hydrogen in the ‘presence of carbon mon metal with the desired nitrogen-containing ligand in liquid oxide under pressure. However, this catalytic material phase. The valence state of the transition metal may then suffers from several rather serious shortcomings. One be reduced ‘by hydrogenating the solution. The reduc disadvantage is a relatively low reaction rate. While tion may be performed prior to the use of the catalyst or dicobalt octacarbonyl is Widely used industrially in Oxo it may be accomplished simultaneously with the hydro processes, there still exists a real need for improvement formylation process of this invention. Alternatively, the .in catalyst performance, particularly increased reac catalyst may be prepared from a carbon monoxide com tion rates. plex of the metal. For example, it is possible to start with The present invention now provides an improved hydro dicobalt oc'tacarbonyl, and by simply heating this sub formylation process for compounds having ole?nic link stance with a suit-able nitrogen-containing ligand of the age wherein the rates of reaction are signi?cantly in type previously described, replace one or more of the creased over those obtainable from known catalytic mate carbon monoxide molecules by nitrogen-containing li rials including, among others, dicobalt octacarbonyl. This gand, producing the desired catalyst. This latter method increase in reaction rate of catalytic hydroformylation of ‘was utilized in the preparation of most of the catalysts carbon compounds containing ole?nic linkage constitutes used in the examples hereinafter described. This latter a primary object of this invention. ‘method is very convenient for regulating the number of In brief, the invention comprises reacting carbon mon carbon monoxide molecules and other types of ligand 3,231,621 3 molecules present in the catalyst. Thus, by increasing the catalyst amount of ligand added to the dicobalt loctacarbonyl, CHSCOO CH1CH=CH3 + C0 + H, —-----> A more of the carbon monoxide molecules may be replaced. allyl acetate The hydroformylation reaction is carried out by in— CHsCOO CHrCHsCHzCHO timately contacting a carbon compound containing ole 'y-acetoxybutyraldehyde ?nic linkage such as an aliphatic ole?n hydrocarbon, gen erally in liquid phase, with carbon monoxide and hydro and/or 01150 0 O CHzCHQCHgCH?OH + isomeric products gen in the presence of the catalytic material at hydro 7-acetoxybutan0l

formylation temperature and pressure and under condi ’ catalyst tions sufficient to produce the desired reaction product. 1O + C0 + H2 ————-—-> CHO The reaction may be carried out at pressures of from about A 500 to 5000 psi. of hydrogen and canbon monoxide, cyclopentene formylcyclopentane with from about 1000 to 3000 psi. being preferred. and/0r If desired, even higher pressures, say about 6500 p.s.i., may often be advantageously used. The temperature 15 cyclopentylcarbinol may, in a large degree, depend upon the selected pres catalyst sure as well as upon the desired reaction product. While ———> it may ordinarily be in the range of from about 75° to diethyl tumarate 300° C., it has been found that a temperature of from O HO about 120° to 150° C. is suitable and often preferred. 20 C2H5O C 0 611011100 0 C211‘ The process of this invention is generally applicable diethyl a-i'ormylsuccinate to the hydroformylation of any aliphatic (cyclic or acylic) compound having at least one ethylenic carbon-to-carbon 01120 H bond. The invention is used to advantage in the hydro and/or 011150 0 O CHCHgC 0 0 0,11 formylat-ion of carbon-to-carbon ethylenically unsaturated 25 dicthyl a-methylolsuccinate linkages in hydrocarbons, preferably of from 2 to 12 carbons. Monoole?ns such as ethylene, propylene, and ornoH=cH2 catalyst butylene are a few examples of suitable lower ; by 'lower is meant an of 2 to about 8 carbon atoms. Feed hydrocarbons may include both branched allyl beezcne and straight-chain compounds having one or more of these ethylenic or ole?nic sites. These sites may be CHzCHzCHzCHO conjugated, as in 1,3~butadiene, or non-conjugated, as vin 1,5-he'xadiene. In the case of polyole?ns, i.e., poly enes, one or more of the oleiinic sites may be hydro-for 35 mylated. The unsaturated carbon-to-carbon linkages may 'y-phenylbutyral dehyde be between terminal and their adjacent carbon atoms, as in l-pentene, or between internal chain carbon atoms, ~CHzCHz CHzCHzO H as in 4-.octene, or as ‘in cyclohexene. and/0r + isomeric products Macromolecular materials involving acyclic units of the above types such as polydiole?ns like polybutadiene, as 'y-phenylbutanol well as copolymers of ole?ns and diole?ins such as styrene butadiene copolymer, are also within the scope of ap As will be seen from the general equation given for the plicability of this invention. hydroforrnylation reaction when producing alcohols, at Hydrocarbon cyclic compounds are equally suitable for lease one mole of carbon monoxide and two moles of hy use in this invention, especially ?ve- and six-ring carbon drogen are required for each mole of ole?n. If condi atom hydrocarbons. This group includes the unsatura tions are selected that will result primarily in an aldehyde ted alicyclic hydrocarbons such as the cylic ole?ns con product, only one mole of hydrogen is required for each taining carbon-to-carbon unsaturation such as the cyclo mole of ole?n. Highest yields, therefore, requirev at least alkenes like cyolopentene, cyclo-hexene, and cycloheptene. these stoichiometric amounts of carbon monoxide and hy Also included in this category are the terpenes and fused drogen reactants. Preferably, however, these reactants ring polycyclic ole?ns, such as 2,5-bicyclo(2.2.1)-hepta are present in an excess of the ole?n. diene, 1,4,4a,5,8,8a-hexahydro-1,4,5,8 - dimethanonapth The ratio of hydrogen to carbon monoxide at any given thalene and the like. time may be varied according to the particular ole?n The process of this invention may also be used to _hydroformylate ethylem'c carbon-to-carbon link-ages of undergoing hydroformylation. Generally, the ratio will non-hydrocarbons. Thus, it is possible to hydroformylate be at least 1. It has been found that in many cases, the ole?nically unsaturated alcohols, aldehydes, and acids rate of reaction as well as the yield of desired product whereby the formyl or carb-inol group is introduced into may be increased by increasing the HZ/CO ratio to about 2, although higher ratios up to about 10 or more may be the molecule at a site of unsaturation. The following are a few speci?c examples of di?’erent types of Iole?nic com used. pounds that may be hydroformylated in accordance with Ratios of catalyst to the ole?n to be hydroformylated the invention and the products obtained thereby: are not particularly critical and may be varied in order to achieve a homogeneous solution. Solvents are therefore not required, although inert solvents such as suitable satu catalyst 65 CH3(CH2)3CH=CH2 + C0 + H: ———--—-—> OH3(CH2)5CHO and/or rated hydrocarbons, ketones, alcohols, etc., may be used l-hexane A l-heptanal if desired. In general, larger quantities of catalyst will produce a faster reaction rate. Ratios of catalyst to ole?n CH3(CH¢)§CH¢OH + isomeric products between 1: 1000 and 1:1 will normally accomplish the de l-heptanol 70 sired eifect. catalyst When the reaction has preceeded to completion, the hydroformylation product may be removed from the re 3-chloropropanol action mixture by suitable means. Normally, distillation, ClCHzCHzCHO + isomeric products ?ltration or extraction with a solvent will be employed, a-chloropropanal 75 although other methods may be adapted when required. 3,231,621 5 6 The catalyst may then be recycled ‘for further hydro I claim as my invention: formylation of additional ole?n. 1. In a catalytic hydroformylation process wherein a The following example will best explain the details and monoole?nic hydrocarbon is reacted with carbon mon illustrate the advantageous results of the process of this oxide and hydrogen in the presence of a cobalt catalyst at invention. It is to be understood that the example is given a temperature of from about 75 to about 300° C., and a only for illustration and is not to be construed as limiting pressure of frOm about 500 to about 5000 lbs. per square scope or spirit of the invention except as delineated in the inch, thereby reacting said monoole?nic hydrocarbon with appended claims. carbon monoxide and hydrogen with the formation of re EXAMPLE action products consisting essentially of saturated ali 10 phated aldehydes and alcohols having one more carbon l-pentene (0.064 mole), n-octane (20 ml.), dicobalt atom to the molecule than said monoole?nic hydrocarbon, octacarbonyl (0.001 mole) and a nitrogen-containing the improvement which consists of using as said cobalt ligand (0.010 mole) were placed into an 80 ml. magneti catalyst a complex consisting essentially of cobalt in com mally stirred autoclave. After sealing the autoclave, it plex combination with both carbon monoxide and a non was ?ushed with an inert gas and then pressured with H2 15 hydrooarbon electro-negative substituted pyridine mole and CO. The autoclave was heated to the temperature cule selected from the group consisting of 2-chloropyri speci?ed in the accompanying Table. The resulting dine, Z-bromopyridine, 3-bromopyridine, 3-cyanopyridine maximum pressure generally was 1200-1700 psig. and ethyl nicotinate, said complex containing at least one After gas consumption had ceased or nearly ceased, the molecule of said non-hydrocarbon electro-negative sub autoclave was cooled and vented. The recovered prod 20 stituted pyridine for each molecule of cobalt. uct was analyzed by gas chromatographic techniques. 2. The process in accordance with claim 1 wherein The major products were n-hexyl, 2-methylpentyl and said complex contains about ?ve moles of said non-hydro 2-ethylbutyl aldehydes and alcohols. The relative carbon electro-negative substituted pyridine for each atom amounts of these materials produced are listed in the of cobalt. Table. A comparison of the rates of reaction for the 25 3. Catalytic process as in claim 2 wherein the non various catalysts are also given. hydrocarbon electro-negative substituted pyridine mole It was possible to show by infrared analyses that new cule is 2-chloropyridine. complexes were formed by reaction of the nitrogen-con 4. Catalytic process as in claim 2 wherein the non taining ligands with dicobalt octacarbonyl. hydrocarbon electro-negative substitiuted pyridine mole These novel catalysts were formed as well from cobalt 30 cule is 2-bromopyridine. chloride as from dicobalt octacarbonyl. 5. Catalytic process as in claim 2 wherein the non The accompanying Table is illustrative of the changes hydrocarbon electro~negative substitiuted pyridine mole in reaction rates available from the use of the substituted cule is 3-bromopyridine. pyridine ligands in a cobalt complex hydroformylation 6. Catalytic process as in claim 2 wherein the non catalyst as contrasted with the standard cobalt octacar hydrocarbon electro~negative substit'uted pyridine mole bonyl Oxo catalyst, as Well as such catalyst having a non cule is 3-cyanopyridine. substituted pyridine ligand, neither of which catalytically 7. Catalytic process as in claim 2 wherein the non active materials constitutes a part of the present invention hydrocarbon electro-negative substituted pyridine mole but are presented solely for purposes of comparison. 40 cule is ethyl nicotinate.

Table l-pentene = 0.64 mole n~octane = 20 ml. Hg/CO = 2.2 C02(CO)§ = 0.001 mole Nitrogen-containing ligand = 0.010 mole

_ 2,3-pyridine Ligand None (0x0 Pyridine 2-chloro- 2-bromo- 3-bromo- 3-cy_ano- Ethyl 3,5-dichloro- diearboxyl catalyst) pyridine pyridine pyridine pyridine nicotinate pyridine 1c acid anhydride

Temperature, ° C ______100 100 100 100 100 100 100 100 100 Pressure, max. p.s.i.g__ _ l, 700 1, 620 1, 500 1, 450 l, 260 l, 300 1, 540 1, 460 1, 300 Length of Experiment, hr 0.30 1. 4 0.5 O. 5 0.5 0.5 0.5 1 0.67 Conversion, percent ______76. 7 85. 3 ~l00 91. 6 74. 9 96. 3 ~l00 100 59.8 Material Balance, percent ______-. 80 88 96. 4 . 103. 6 87. 5 84.4 89.8 94. 8 106.6 Initial Gas Consumption, mmoles/ hr ______. 276:|:11 116 564 327 902. 4 459 744 186 323 Initial Rate? ______1. 69;l=0. 07 0.71 3. 45 2. 0 5. 53 2. 73 4. 56 1, 14 1. 97 Selectivity, percent (no-loss basis) to: Aldehydes ______94. 9 96 98. 2 97. 4 98. 5 96. 9 97. 9 9G. 7 95. 3 Alcohols ______3. 8 4 1. 8 2. 6 . l5 3. 1 2. 1 3. 3 4. 7 Product Distribution, per centH(ald(i.hydes plus alcohols): 1" “y 75 6 55 s 74 6 7s 2 54 1 51 7 62 s 68.9 67.6 2-methylpentyL2_ethylbutyl‘ _ _ _ _ 24.' 4 44.' 4 25.' 4 26.' 8 45.' 9 48.' 3 37.' 4 31. 1 32. 4

. . initial "as consumed mols/hi'. (i ) = a , 1 Imtml rate (initial ole?n conc., mols/l.) (initial cat. c0110., mols/l.) References Cited by the Examiner UNITED STATES PATENTS 2,576,113 11/1951 Hagemeyer ______260—604 2,820,059 1/ 1958 Hasek et al ______260—604 2,834,812 5/1958 Hughes et al. ______260—604 LEON ZITVER, Primary Examiner. CHARLES B. PARKER, Examiner.