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