Patented Mar. 9, 1954 2,671,815

UNITED STATES PATENT ‘ OFFICE 2,671,815 MANUFACTURE OF DIARYLALKANES Herman Pines and Vladimir N. Ipatieff, Chicago, 111., assignors to Universal Oil Products Com pany, Chicago, 111., a corporation of Delaware No Drawing. Application June 21, 1950, Serial No. 169,525 16 Claims. (Cl. 260-668) 1 2 This application is a continuation-in-part of contacted alone with a branched-chain ole?n in our co-pending application Serial Number the presence of an acid-acting catalyst. ‘788,645 (now Patent No. 2,526,896, October 24, The essential feature of this process is illus 1950) which was ?led November 28, 1947, as a trated by the following equation which shows the continuation-impart of application Serial Num reaction of paracymene, cumene and methyl cy ber 619,430 ?led September 29, 1945, now aban clohexene in the presence of an alkylating cata cloned. lyst to form 2-para-tolyl-2-(4-isopropylphenyl) This invention relates to a process for manu propane and methylcyclohexane. In this reac facturing diarylalkanes and particularly for tion hydrogen transfer appears to occur between manufacturing alkylated diphenylalkanes. 10 para-cymene and methylcyclohexene and the re An object of this invention is the production of sultant unsaturated product may then be re a diarylalkane. garded as alkylating cumene to form the alkylated Another object of this invention is the produc di(alkylphenyl)propane mentioned above. tion of an alkylated diphenylalkane hydrocarbon. A further object of this invention is the pro 15 CH3 CH3 duction of an alkylated diphenylmethane hydro carbon. One embodiment of this invention relates to a process for producing an unsymmetrical diaryl alkane hydrocarbon which comprises reacting at hydrogen transfer conditions in the presence of an acid-acting catalyst a branched-chain ole?n, an aromatic hydrocarbon having two hydrocar bon radical substituents in para positions to each other and in which at least one of these radicals has only two hydrogen atoms combined with the carbon atom that is joined to the aromatic ring, and an aromatic hydrocarbon which does not undergo hydrogen transfer when contacted alone with a branched-chain ole?n in the presence of an The dialkylated aromatic hydrocarbons used as acid-acting catalyst. one of the groups of starting materials for this Another embodiment of this invention relates to process contained at least one para-arrangement a process for producing an unsymmetrical diaryl of hydrocarbon radical substituents in order to alkane hydrocarbon which comprises reacting at give the hydrogen transfer reaction. Also one of hydrogen transfer conditions in the presence of 35 the substituents in para-arrangement must con an acid-acting catalyst a branched-chain ole?n, tain either one but not more than two hydrogen an aromatic hydrocarbon having two alkyl group atoms combined with the carbon atom that is substituents in para positions to each other and. joined to the aromatic ring. Benzene hydrocar in which one of these alkyl group substituents has bons suitable for the process are represented by at least one and not more than two hydrogen 40 the following formula: . atoms combined with the carbon atom that is joined to the aromatic ring, and. an aromatic hy 1 | drocarbon which does not undergo hydrogen transfer when contacted alone with a branched chain ole?n in the presence of an acid-acting 45 catalyst. We have developed a method for manufactur 11-0411 H—(:i-R2 ing an unsymmetrical diarylalkane hydrocar in H bon by effecting a reaction between a branched chain ole?nic hydrocarbon, a para-dialkylated 50 wherein each of R1, R2 and R3 is selected from the aromatic hydrocarbon in which one alkyl group group consisting of an alkyl radical, a cycloalkyl contains at least one replaceable hydrogen atom radical, a cycloalkalkyl radical, and a bicyclo bound to the carbon atom that is combined with alkyl radical. By the term “cycloalkalkyl radi the aromatic ring, and an aromatic hydrocarbon cal” is meant a hydrocarbon radical in which a which does not undergo hydrogen transfer when 56 cycloalkyl group replaces a hydrogen atom of an 2,671,815 3 4 alkyl group. A cycloalkalkyl radical is thus a Phosphoric acid catalyst comprises orthophos; cycloalkyl derivative of an alkyl radical. phoric acid and also polyphosphoric acids such Such aromatic hydrocarbon starting materials as pyrophosphoric acid, triphosphoric acid, and. include para-cymene, 1,2-di-methyl-4-isopropyl tetraphosphoric acid. Under certain conditions benzene, 2,4-di-isopropyltoluene, 4-iso-propyl-2 of operation various acid-acting, oxide-type cat cyclohexyltoluene, and also l-methyl-ll-ethyl alysts may be used. which include activated clays, benzene, 1-n1ethyle4-normal-propylbenzene, 1,4 silica-alumina composites, and other silica-con di-ethylbenzene, 1,4-di-normal-propylbenzene, taining materials which are generally utilizable etc. There are some other aromatic hydrocarbon as catalysts for hydrocarbon cracking, starting materials for this process which do not 10 The operating conditions used in this process undergo hydrogen transfer reactions with ole are dependent upon the nature of the hydrocar ?ns in the presence of acid-acting catalysts but bons being treated and also upon the catalysts do undergo alkylation reactions. Such aromatic employed. When utilizing strong mineral acids, hydrocarbons include benzene and monoalkyl or such as hydrogen ?uoride, sulfuric acid, ?uoro monoalkylated aromatic hydrocarbons having a sulfonic acid, chlorosulfonic acid and the like, single hydrocarbon group bound to an aromatic and also Friedel-Crafts metal halides promoted ring, this single hydrocarbon group being selected by a hydrogen halide such as hydrogen chloride, from the members of the group consistingyof an the process is carried out at; temperature of from alkyl group, a cycloalkyl group, a cycloalkalk'yl about ~30° to about 100° C. and at a pressure up group, and a bicycloalkyl group, thus including to about 100 atmospheres. However, in the pres such hydrocarbons as benzene, toluene, ethyl ence of hydrogen fluoride, sulfuric acid, and alu benzene, 'p'ro'pyl benzene, cumene, butyl benzenes minum chloride catalysts the preferred operating and other alkyl benzenes in which the alkyl group temperature is preferably from about 0° to about contains‘, for example, from 5 to 10 carbon atoms, 50° C. while in contact with ferric chloride cata etc. lyst the preferred operating temperature is from Not only the above-indicated monalkylaro~ about 50° to about 100° C. Silica-alumina and matic hydrocarbonsare used as starting mate other synthetic oxide catalysts and clays are rials ‘in this process but also polyalkyl aromatics generally used’ at a temperature of from about which do not undergo a hydrogen transfer re 200° to about 400° C. and at a superatmospheric action when contacted alone with a branched 30 pressure generally not in excess of about 100 at ‘chain olefin in the presence of an alkylation cat mospheres. alyst. _ Such polyalkyl aromatics include poly Our process is carried out in either batch or methylbenzenes and o-di'ethylbenzene. continuous type of operation. In batchetype op Ole?nic starting materials suitable for use in eration the usual procedure consists in placing a this process for manufacturing diarylalkanes mineral acid or Friedel-Crafts catalyst and a have branched-chains and include such hydro portion, generally ‘about 50%, of the aromatic carbons as trimethylethylene, dihydrolimonene, hydrocarbons in a reactor provided with a me methylcyclohexene, 1,1,3 - trimethylcyclohexene, chanically driven stirrer, cooling these materials menthene, and bicycloole?ns, such as camphene, to a temperature of from about 0° to about 10° C. etc. The exact type of ole?ns to be used is ‘de and adding thereto with stirring, a solution of pendent on the catalyst and on the aromatic hy the branched-chain ole?n in the remainder of drocarbons with which the hydrogen transfer the aromatic hydrocarbons. The reaction mix and condensation reaction is to be effected. Thus ture is then separated and the product is washed, normal octene and cyclohexene which are ole?ns dried, and distilled to recover therefrom the not possessing branched-chain structures, when diarylalkane hydrocarbons. Unconverted arc reacted with a para-di-alkyl-aromatic hydrocar matic hydrocarbons recovered in this distillation boil and another alkylatable aromatic hydrocar are utili'zable in the further operation of the bon at operating conditions similar to those used process. It is preferred that the aromatic hy with the branched-chain ole?ns e?'ect alkylation 'dr'ocarbons acting as a hydrogen donor be in ex ‘rather than hydrogen transfer. cess of the aromatic hydrocarbons which are sub In addition to the branched-chain mono-ole mitted to alkylation. nus mentioned above, other ole?n-acting com“ The process is also carried out in a continuous pounds which are also utilizable in this process manner by passing the aromatic and branched comprise conjugated di-olefins containing a ter chain Ole?nic hydrocarbons through a suitable tiary carbon atom, alcohols, ethers, esters of . reactor in which they are contacted in the pres carboii'ylic acids, and alkyl halides which may be ence of the catalyst, the latter either as a liquid regarded as capable of forming branched-chain or as a solid, depending upon the catalyst em bl'e?hs in situ in the reaction mixture. ployed in the process. When using mineral acid The process as herein described is carried out catalysts such as sulfuric acid, fluorosulfonic in the presence of an acideacting catalyst at con acid, or hydrogen fluoride, this catalytic material ditions necessary for the hydrogen transfer re action. Suitable acid-acting catalysts include is introduced continuously to the reactor which mineral acids, such as sulfuric acid, chlorosul~ is provided with suitable mixing means and the fonic acid, fluorosulfonic acid, hydrogen ?uoride, resultant product is then separated into a hy hydroxyboro?uoric acid, ?uorosulfonic acids, ‘ drocarbon layer and ‘a ‘catalyst layer, the latter phosphoric acids and Friedel-Crafts halide cata being returned to further use in the process while lysts, particularly aluminum chloride, aluminum the hydrocarbon layer is washed, dried, vand dis bromide, ferric chloride, zirconium chloride, and tilled as hereinabove set forth. When a solid cat boron trifluoride. Since in some cases Friedel alyst such as silica-alumina, clay, ‘or a supported ‘Crafts catalysts may cause an alkyl migration Friedel-Crafts type catalyst is used as 'a ?xed bed ‘within the aromatic ring before the hydrogen in the reactor and the aromatic and 'ole?nic hy transfer reaction occurs, it is sometimes ‘advan drocarbons are passed thercthrough, the result tageous to use Friedel-Crafts complexes, such as ant hydrocarbon product requires no washing etherate, alcoholate, etc. as catalysts for this and ‘drying treatment and may be distilled to reaction. 75 separate therefrom unconverted ‘aromatic and 2,671,815 5 6 ole?nic hydrocarbons and to recover the desired arylalkane containing a long-chain alkyl, cyclo diarylalkane hydrocarbons. alkyl or cycloalkalkyl group is neutralized by a Thus cymene and cumene and related alkylben basic substance such as sodium hydroxide, sodi zene hydrocarbons react readily with branched um carbonate, etc., to form a surface-active agent chain ole?ns to form a diphenylalkane and a such as a wetting agent or detergent. Some of saturated hydrocarbon, the latter having sub the unsymmetrical diarylalkane hydrocarbons stantially the same carbon skeleton as that of formed in this process are useful as additives to the ole?nic hydrocarbon charged to the process. lubricating oils to improve the viscosity and/or An aromatic hydrocarbon which does not contain cold test properties thereof. , the aforementioned hydrocarbon radical substit 10 The following example is given to illustrate uents in para positions to each other does not this process but with no intention of limiting un react with a branched-chain ole?n to give the duly the generally broad scope of the invention. desired hydrogen transfer reaction. Also an ole An agitated mixture consisting of 60 grams of ?n which does not have a branched-chain struc hydrogen ?uoride, 0.75 M. of p-ethyltoluene, and ture such as is present in trimethylethylene, di 0.15 M. of cumene is placed in a copper vessel hydrolimonene, methylcyclopentene, methylcy and maintained at a temperature of 05° C. while clohexene, etc., acts as an alkylating agent for a solution consisting of 0.50 M. of p-ethyltoluene, the aromatic hydrocarbon also charged to the 0.10 M. of cumene and 0.20 M. of 4-methylcyclo process. Accordingly, in order to obtain hydro hexene is added slowly thereto. After the addi gen transfer and condensation reactions rather 20 tion is completed the mixture is agitated for an than alkylation, it is necessary to use a branched additional time of 15 minutes and then poured chain ole?nic hydrocarbon together with a di upon ice, precooled to —50° C. The hydrocarbon substituted benzene hydrocarbon or other di layer is washed and distilled giving about 8 grams substituted benzene hydrocarbon or other di-sub of product corresponding to 1-p-toly1-1-(4-iso stituted aryl hydrocarbon in which substituents 4) propylphenyl) -ethane. are in para positions to each other and one of We claim as our invention: said substituents comprises an ethyl group, a 1. A process for producing an unsymmetrical normal propyl group, or other hydrocarbon group diarylalkane hydrocarbon which comprises re in which at least one and not more than two acting at hydrogen transfer conditions in the hydrogen atoms are combined with the carbon presence of an acid-acting catalyst an alkylcyclo atom adjacent to the aromatic nucleus, that ole?n, an aromatic hydrocarbon having two sat is, the carbon atom in alpha position to the arc urated hydrocarbon radical substituents in para matic ring, and another aromatic hydrocarbon positions to each other and in which one of these which does not undergo hydrogen transfer. hydrocarbon radical substituents has at least one In applicants’ related application Serial Num = and not more than two hydrogen atoms combined ber 788,644 (now Patent No. 2,526,897, October with the carbon atom that is joined to the arc 26, 1950), and in parent application Serial Num matic ring, and an aromatic hydrocarbon hav ber 788,645 (Patent 2,526,896), which were ?led ing not more than one saturated hydrocarbon November 28, 1947, and in Serial Number 36,274, group bound to the aromatic ring. ?led June 30, 1948 (now Patent 2,519,577, Au 40 2. A process for producing an unsymmetrical gust 22, 1950), it was disclosed that the reaction diarylalkane hydrocarbon which comprises re products, namely, arylindan hydrocarbons and acting at hydrogen transfer conditions in the diarylalkane hydrocarbons are useful as start presence of an acid-acting catalyst an alkylcyolo ing materials for the preparation of oxidation ole?n, an aromatic hydrocarbon having two sat inhibitors, detergents, and additives for lubricat urated hydrocarbon radical substituents in para ing oils. Thus it was stated that the arylindan positions to each other and in which at least one and diarylalkane hydrocarbons may be sulfon of these hydrocarbon radical substituents has ated and hydrolyzed to form phenols or they only two hydrogen atoms combined with the car may be nitrated and reduced to the correspond bon atom that is joined to the aromatic ring, and ing amines which may then be diazotized and an aromatic hydrocarbon having not more than converted into phenols that are useful as inhibi one saturated hydrocarbon group bound to the tors to retard oxidation of hydrocarbons, fats, aromatic ring. vegetable oils, foods, etc. Furthermore, these 3. A process for producing an unsymmetrical arylindan and diarylalkane hydrocarbons may diarylalkane hydrocarbon which comprises react also be sulfonated and the resultant sulfona 55 ing at hydrogen transfer conditions in the pres tion products which contain a long-chain alkyl, ence of an acid-acting catalyst an alkylcyclo cycloalkyl, or cycloalkalkyl group may be con ole?n, an aromatic hydrocarbon having two sat verted into a surface-active agent such as a wet urated hydrocarbon radical substituents in para ting agent or detergent. Also some of the indan positions to each other and in which at least one and diarylalkane hydrocarbons formed by those of these hydrocarbon radical substituents has processes are useful as additives in lubricating only one hydrogen atom combined with the car oils. bon atom that is joined to the aromatic ring, In respect to their utility, the diarylalkane hy and an aromatic hydrocarbon having not more drocarbons formed by the present process are than one saturated hydrocarbon group bound to similar to the indan and diarylalkane hydrocar 65 the aromatic ring. bons formed by the processes of our aforemen 4. A process for producing an unsymmetrical tioned Patents 2,519,577, 2,526,896 and 2,526,897. diarylalkane hydrocarbon which comprises re Thus the unsymmetrical diarylalkanes which are acting in the presence of a mineral acid catalyst formed by the present process are sulfonated at a temperature of from about -30° to about and hydrolyzed to form phenols or they are ni 100° C. an alkylcycloole?n, an aromatic hydro trated and reduced to the corresponding amines carbon having two alkyl group substituents in which are then diazotized and converted into para positions to each other and in which one phenols that are useful to retard oxidation of hy— of these alkyl groups has at least one and not drocarbons, fats, vegetable oils, foods, etc. Also more than two hydrogen atoms combined with the sulfonation product of an unsymmetrical di 75 the carbon atom that is joined to the aromatic 2,871,816 7 8 ring, and an aromatic hydrocarbon having not ole?n in the presence of a mineral acid catalyst more than one saturated hydrocarbon group at a temperature of from about —30° to about bound to the aromatic ring. 100° C. 5. A process for producing an unsymmetrical 11. A process for producing 2-para-tolyl-2 diphenylalkane hydrocarbon which comprises re~ (5-isopropylphenyl)propane which comprises re acting in the presence of a mineral acid catalyst acting cymene, cumene, and a branched-chain at a temperature of from about --30° to about ole?n in the presence of a hydrogen ?uoride cata 100° C. an alkyl cycloole?n, a benzene hydrocar lyst at a temperature of from about —30° to about bon having two alkyl group substituents in para 100° C. positions to each other and in which one of these 10 12. A process for producing 2-para-tolyl-2 alkyl groups has at least one and not more than (5-isopropy1phenyl) propane which comprises re two hydrogen atoms combined with the carbon acting cymene, cumene, and a branched-chain atom that is joined to the benzene ring, and a ole?n in the presence of a hydrogen ?uoride cata benzene hydrocarbon having not more than one lyst at a temperature of from about 0° to about saturated hydrocarbon group bound to the arc- 50° C. matic ring. 13. A process for producing 2-para-tolyl-2 6. A process for producing an unsymmetrical (5-isopropylphenyl)propane which comprises re diphenylalizane hydrocarbon which comprises re acting cymene, cumene, and a branched-chain acting in the presence of a sulfuric acid catalyst ole?n in the presence of a sulfuric acid catalyst at a temperature of from about 0° to about 50° C. at a temperature of from about 0° to about 50° C. an alkylcycloole?n, a benzene hydrocarbon hav 14. A process for producing an unsymmetrical ing two alkyl group substituents in para positions diarylalkane hydrocarbon which comprises react to each other and in which one of these alkyl ing at hydrogen transfer conditions in the pres groups has at least one and not more than two ence of an acid-acting catalyst a branched-chain hydrogen atoms combined vwith the carbon atom 25 cyclohexene hydrocarbon, an aromatic hydro that is joined to the benzene ring, and a ben carbon having two saturated hydrocarbon radical zene hydrocarbon having not more than one satu substituents in para positions to each other and rated hydrocarbon group bound to the aromatic in which one of these hydrocarbon radical sub ring. stituents has at least one end not more than two '7. A process for producing an unsymmetrical hydrogen atoms combined with the carbon atom diphenylalkane hydrocarbon which comprises re that is joined to the aromatic ring, and an acting in the presence of a hydrogen ?uoride aromatic hydrocarbon having not more than one catalyst at a temperature of from about -30° to saturated hydrocarbon group bound to the about 100° C. an alkylcycloole?n, a benzene hy aromatic ring. drocarbon having two alkyl group substituents in 1*5. A process for producing a diarylalkane para positions to each other and in which one which comprises reacting para-cymene, cumene of these alkyl groups has at least one and not and a branched-chain ole?n at hydrogen transfer more than two hydrogen atoms combined with conditions and in the presence of an acid-acting the carbon atom that is joined to the benzene catalyst. ring, and a benzene hydrocarbon having not more 40 16. A process for producing a diarylalkane than one saturated hydrocarbon group bound to > which comprises reacting para-cymene, cumene the aromatic ring. and methylcyclohexene vat hydrogen transfer con 8. A process for producing an unsymmetrical ditions and in the presence of an acid-acting diarylalkane hydrocarbon which comprises react catalyst. ing in the presence of a mineral acid catalyst at HERMAN PINES. a temperature of from about —30° to about 100° VLADIMIR N. IPATIEFF. C. an alkylcycloole?n, a monalkylated aromatic hydrocarbon, and an aromatic hydrocarbon hav References Cited in the file of this patent ing two alkyl group substituents in para positions UNITED STATES PATENTS to each other and in which one of these alkyl groups has at least one and not more than two Number Name Date hydrogen atoms combined with the carbon atom 2,010,949 Eglo? ______Aug. 13, 1935 that is joined to the aromatic ring. OTHER REFERENCES 9. A process for producing an unsymmetrical diphenylalkane hydrocarbon which comprises re- r Ipatie? et al., “Influence of Sulfuric Acid Con~ acting in the presence of a hydrogen ?uoride centration . . .,” Jour. Amer. Chem. Soc, 58,. catalyst at a temperature of from about -—30° to pages 919-922 (June ‘1936) 4 pages. about 100° C. an alkylcycloole?n, a monoalkyl Simons, “Potential Use of Hydrogen Fluoride benzene hydrocarbon and a benzene hydrocarbon . . .,” IndJEng. Cher/n32, pages 178-183 (6 pages), having two alkyl group substituents in para 60 February 1940. positions to each other and in which one of these Scahanen, “Conversion of Petroleum,” page alkyl groups has at vleast one and not more than 373 (1 page), published by Reinhold Pub. Corp., two hydrogen atoms combined with the carbon New York (1940). atom that is joined to the benzene ring. Thomas, “Anhydrous Aluminum Chloride in 10. A process for producing 2-para-tolyl-2 65 .Organic Chemistry,” page 430 (1 page only), (S-isopropylphenyl)propane which comprises re published by Reinhold Pub. Corp., New York acting cymene, cumene, and a branched-chain (1941).