r 2,737,536 United States Patent Office Patented Mar. 6, 1956. 2 standard methods of synthesis. In many instances, for 2,737,536 example, the tert-alkyl-substituted aromatic compound METHOD OF SYNTHESEZING TERTALKYL cannot be conveniently prepared simply by direct alkyla SUBSTITUTED AROMATIC COMPOUNDS tion of the aromatic compound utilized as the starting material with an olefin to provide a product in which the Herman S. Bloch, Chicago, and George L. Hervert, aryl nucleus is directly attached to a tertiary carbon atom. Downers Grove, Ill., assignors to Universal Oil Prod. The latter is particularly true, for example, when a suit ucts Company, Des Plaines, I., a corporation of able olefinic alkylating agent having the requisite tertiary Delaware structure is unavailable or is too difficult or too expen No Drawing. Application December 31, 1952, 0 sive to prepare, and when the corresponding isoparaffin Serial No. 329,122 is available, as is frequently the case by virtue of the greater availability of paraffins of different structures from 11 Claims. (C. 260-671) natural Sources than the corresponding olefins which gen erally do not occur naturally. This invention relates to a process for the manufacture Thus, when utilizing a tertiary olefin as the alkylating of aromatic compounds having a tert-alkyl nuclear sub agent in a condensation reaction between the aromatic stituent. More specifically, the invention concerns a compound and the tertiary olefin, the product usually process for reacting an aromatic hydrocarbon having a comprises a mixture of various isomers of the desired nuclearly replaceable hydrogen atom with an iso alkyl aromatic compound and in some instances the paraffinic hydrocarbon to form a nuclearly tert-alkyl alkylation does not yield an alkylate product in which substituted aromatic hydrocarbon, the tert-alkyl group the alkyl group is attached to the aromatic nucleus being derived from the isoparaffin charging stocks as a through the tertiary carbon atom of the olefinic hydro result of hydrogen transfer between olefinic and paraf carbon alkylating agent. By means of the present proc finic hydrocarbon feed stocks in the presence of an acidic ess, the tertiary olefin is formed during the reaction in alkylation catalyst. situ via a hydrogen transfer reaction between the olefinic In accordance with one of its embodiments the present hydrocarbon charging stock and the isoparaffin reactant; invention relates to a process for the production of a tert in consequence, a major proportion of the product con alkyl-substituted aromatic compound which comprises sists of the tert-alkyl-substituted aromatic compound hav reacting an aromatic compound containing a nuclearly ing an alkyl group which is attached to the aromatic replaceable hydrogen atom with a paraffinic hydrocarbon 30 ring at the tertiary carbon atom of the isoparaffin re having in its structure a tertiary carbon atom, said re actant. It has been found that hydrogen transfer occurs action being effected in the presence of an olefinic hydro between the paraffinic and the olefinic hydrocarbon re carbon and an acidic alkylation catalyst capable of ef actants at the alkylating conditions maintained in the re fecting hydrogen transfer between the paraffinic and action mixture, and as a consequence of the presence of olefinic hydrocarbon reactants. 35 the acidic alkylation catalyst in the reaction mixture. A more specific embodiment of the invention concerns The products of the present invention are useful for all an alkylation process for the production of tert-amylben processes for which tert-alkyl-substituted aromatic com Zene which comprises reacting benzene with isopentane pounds may be employed. Thus, for example, the ef in the presence of dodecylene and an alkylation catalyst fectiveness of many alkylphenol and alkylaryl amine oxi comprising concentrated sulfuric acid, utilizing not over 40 dation inhibitors depends upon the character of the alkyl 1 molar proportion of dodecylene per mole of isopentane, substituent on the aromatic ring and in many cases, the said process being effected at alkylation and hydrogen tert-alkyl-substituted phenol and aryl amines are substan transfer reaction conditions. tially more effective than their corresponding normal and Many special aromatic organic compounds useful for secondary alkyl-substituted analogs. It is known that particular purposes require the presence of a tert-alkyl the physical properties and detergent qualities of alkyl substitutent on the aryl nucleus to be effective or to aryl sulfonates also vary considerably as the structure of exhibit optimum activity for the particular purpose to the alkyl substituent attached to the nucleus is varied, which the aromatic compound is put. Thus, for exam the alkylaryl sulfonates in which one of the alkyl sub ple, alkyl phenols, alkylaryl amines, alkylaryl amino stituents is a tertiary alkyl group generally having a lower phenols and many other types of aromatic compounds 50 melting point and in some cases greater solubility in water are used as food oxidation inhibitors and food preserva than the secondary and normal alkylaryl sulfonates hav tives and the maximum effectiveness of these compounds ing an alkyl group containing the same number of carbon for their intended purpose are realized when one or more atoms per group as the tertiary alkyl group. Similarly, of the alkyl substitutents on the aromatic ring is a tert tert-alkylphenols are advantageously used in the prepara alkyl group. In the paper entitled "Alkyl phenols as 55 tion of oil-soluble phenol-formaldehyde resins, the t-alkyl anti-oxidants' by R. H. Rosenwald et al., Industrial En (e.g. t-butyl or t-amyl) group imparting enhanced solu gineering Chemistry 42, page 162, the results of com bility characteristics and color stability as compared parative tests of a series of alkyl phenols is reported. with normal or secondary alkyl substituents. The present These tests establish the fact that the tert-alkyl-sub invention provides a convenient means of producing such stituted phenols were significantly more effective as food 60 select compounds where the latter are particularly pre oxidation inhibitors than the normal and secondary alkyl ferred for a given purpose. phenols of corresponding structure. Numerous similar The aromatic compound subjected to alkylation in the observations have shown that the tert-alkyl-substituted present process is herein characterized as an aromatic aromatic compounds, as contrasted to the corresponding compound containing a nuclearly replaceable hydrogen normal- and secondary-alkyl-substituted analogs are sub 65 atom, that is, a hydrogen atom which can be replaced by stantially more effective than the latter derivatives in a tert-alkyl group during the alkylation and in the pres which the alkyl groups are the only distinguishing struc ence of an acidic alkylation catalyst. In general, it is tural difference. The present invention provides a means preferred that the aromatic reactant contain not more for preparing tert-alkyl-substituted aromatic compounds than three nuclear substituents such that the tert-alkyl and is a particularly convenient means for the prepara 70 group which enters the aromatic nucleus during the al tion of such products where the compounds are not avail kylation reaction is not prevented from becoming attached able from natural sources or are difficult to prepare by to a nuclear position as a result of steric hindrance or 2,737,536 3 4. other interference from nuclear substituents already pres carbon radicals; H-- represents an acidic type alkyla ent on the aromatic ring. The process of this invention tion catalyst; and ArH is the aromatic alkyl-acceptor may be utilized as one step in the preparation of the hereinbefore described. Suitable isoparaffinic hydrocar tert-alkyl-substituted derivatives of various aromatic bon alkylating agents containing a tertiary carbon atom compounds such as the mono-, di-, and tri-hydroxy phe 5 in their structure include such compounds as isobutane, nois, including phenol itself, as well as the polycyclic isopentane (2-methylbutane), 2- or 3-methylpentane, naphthols and mono- and dihydroxy-substituted phenan 2,3-dimethylbutane, the methylhexanes and dimethyl threne derivatives etc.; the mono-, and polyamino substi pentanes which contain tert-carbon atoms, 2,2,3-trimeth tuted benzenes, naphthalenes, phenanthrenes, etc.; the ylbutane, the methylheptanes, certain dimethylhexanes, mono- and polynitro substituted aromatic hydrocarbons; O and trimethylpentanes including 2,2,3-trimethylpentane, the mono-, and polycarboxyl, sulfo, cyano, and alkyl de 2-methyl-3-ethylpentane, methylcyclopentane, methylcy rivatives of both the mono-nuclear and polynuclear aro clohexane, dimethylcyclohexane, and homologs of the matic hydrocarbon series, as well as the aromatic com above containing up to about 15 carbon atoms per mole pounds containing mixed nuclear substituents, such as cule, including the branched chain undecanes, decanes, hydroxybenzoic acid, the aminophenols, etc. A particu 5 dodecanes, tridecanes, and the mono-, di-, and tri-alkyl larly preferred series of compounds utilizable as the aro substituted cycloparaffins of the cyclopentane, cyclohex matic reactant in the present alkylation process are the ane, and cycloheptane series. These isoparaffins which lower mono- and dialkyl substituted benzene and naph contain tertiary carbon atoms undergo dehydrogenation thalene hydrocarbons, that is the hydrocarbons of the during the hydrogen transfer reaction to yield the cor above types in which the alkyl substituents are short 20 responding olefins having an olefinic double bond on the chain alkyl radicals, such as methyl, ethyl, n-propyl and tertiary carbon atom, such that during the subsequent isopropyl. Typical representative aromatic compounds alkylation or condensation reaction with the aromatic utilizable as the starting material of the present process reactant, the alkylating agent becomes attached to the which contain the requisite nuclearly replaceable hydro aromatic nucleus at the tertiary carbon atom (the carbon gen atoms are such compounds as phenol, hydroquinone, atom containing least hydrogen) and forms a tert-alkyl resorcinol, pyrogallol, phloroglucinol, catechol, alpha substituted derivative of the aromatic reactant. The and beta-naphthols, benzoic acid, mono-chloro-, mono hydrogen transfer from the isoparaffinic alkylating agent bromobenzene, the dihalogen substituted benzenes and saturates the double bond of the olefinic reactant to form naphthalenes, such as o-dichlorobenzene; thiophene; the a paraffin corresponding in structure to the olefinic hy aromatic alcohols, such as, benzyl alcohol; aromatic com 30 drocarbon involved in the hydrogen transfer reaction. pounds containing various nuclear substituents such as The olefinic hydrocarbon component of the present phenylnitrile, benzene, toluene, ethylbenzene, ethyltoluene, reaction mixture is characterized merely as an olefinic cumene and a host of other compounds containing one hydrocarbon capable of acting as a hydrogen acceptor or more nuclear substituents. in the hydrogen transfer reaction in the presence of an It is to be noted that the aromatic compound utilized acidic alkylation catalyst of the type herein provided. as the alkyl acceptor reactant in the present alkylation The most effective olefins are those which by virtue of reaction must contain a replaceable nuclear hydrogen their greater chain length or particular structure have atom as an essential structural characteristic thereof, the lowered reactivity and hence do not alkylate aromatics nuclear hydrogen atom being replaced during the alkyla as readily as other olefins. The present process involves tion reaction with the tertiary alkyl group derived from 40 a consideration of the relative alkylating activities of the alkylating agent containing a tertiary carbon atom. the olefinic hydrocarbon initially charged to the reaction The aromatic reactant, however, may contain one or mixture with the olefin formed by dehydrogenation of more, but preferably not more than three other nuclear the isoparaffinic hydrocarbon reactant and it becomes a radicals such as the aforementioned hydroxyl, halo, nitro, primary factor in the process to select an olefinic reac carboxyl, etc., provided that the number of other such 4 tant which undergoes the hydrogen exchange reaction additional radicals does not hinder the attachment of more readily than the alkylation reaction, the preferred the tertiary alkyl group involved in the alkylation process. olefins for this purpose being those which differ sub The alkylating agent which is the source of the tertiary stantially in molecular weight from the olefin produced alkyl group actually involved in the present alkyl transfer in situ by the dehydrogenation of the isoparaffin reactant, reaction is derived from an isoparaffinic hydrocarbon or 50 preferably olefins of substantially greater molecular a cycloparaffin containing a tertiary carbon atom which weight such as those containing from 3 to 8 more carbon loses hydrogen during the alkylation reaction via hydro atoms than the isoparaffinic hydrocarbon reactant. Typi gen transfer with an olefinic hydrocarbon present in the cal olefinic hydrocarbons suitable for this purpose in reaction mixture, the hydrogen transfer presumably re clude olefins such as ethylene, propylene, n-butylene (in sulting in the formation of an intermediate olefinic hy cluding butene-1 as well as butene-2), n-amylene, n drocarbon containing an unsaturated linkage on the ter hexene, n-heptene, n-octene, and particularly the olefinic tiary carbon atom. The reaction which is believed to be hydrocarbons of higher molecular weight than normal involved in the present alkylation process is shown in heptene, such as n-decene, n-dodecene and others con the following equation: taining up to about 20 carbon atoms per molecule. Also 60 included in the above group of olefins utilizable as re R. R. Rs. Rs actants in the hydrogen transfer reaction are the cyclo R-C-CIR(-) --R-C-sC-R(-) -->B+ Acidic olefins such as cyclohexene, cycloheptene, and others of B catalyst higher molecular weight. The relatively high molecular Isoparaffin Olefin weight olefins are preferred in the present process, par Rs Rs R. R. R. E. 65 ticularly when an isoparaffin of shorter chain length is Air involved in the alkylation reaction, because of the rela R-C-C-R --R-C-C-Rs shm)Catalyst Air-C-CRl l tively greater ease of alkylation of the olefins formed by H. dehydrogenation of such isoparaffins. The reactants Parafin Tertiary Aromatic Tert-alkyl derived from olefin compound substituted should be chosen, however, so that there is no great olefin aromatic 70 difficulty in separating the alkylate product from the compound paraffin formed from the olefinic hydrocarbon by virtue wherein R1 and R2 represent hydrocarbon radicals, R of the hydrogen transfer reaction. and R3 may each be hydrogen or a hydrocarbon radical, Catalysts utilizable in the alkylation reaction and which and R4, R5, R6, and R1 may likewise be independently PP also catalyze the hydrogen transfer reaction between iso selected from the class comprising hydrogen and hydro f 5 paraffin and olefinic hydrocarbon reactants in the pres 2,737,536 5 6 ence of an aromatic compound charged to the process ing a reaction mixture in which the ratio of aromatic are characterized as acid-acting inorganic compounds compound to olefin is relatively low, some of the alkylate capable of effecting the required hydrogen and alkyl product may consist of dialkyl-substituted aromatic com transfer reactions involved in the process. Acid-acting pounds, and the latter may generally be separated from inorganic compounds having alkylating activity include the mono-alkylate by simple or fractional distillation. certain mineral acids, such as sulfuric acid containing The present invention is further illustrated with respect not more than 10% by weight of water and preferably to certain specific embodiments thereof in the following less than 5% by weight of water, including sulfuric acid examples, which, however, are not intended to limit the catalysts recovered from the alkylation of isoparaffins with broad scope of the invention in strict accordance there olefins, hydrofluoric acid of at least 90% concentration 0 with. and containing less than 10% by weight of water, lique In the following series of experiments benzene was sub fied anhydrous hydrogen fluoride, anhydrous aluminum jected to alkylation in the presence of a sulfuric acid chloride or aluminum bromide, boron trifluoride, pref catalyst containing 91.9% titratable acid (titratable as erably utilized in admixture with concentrated hydro sulfuric acid) and 1.4% by weight of water, comprising fluoric acid, and other acid-acting catalysts, particularly 15 spent isoparaffin alkylation acid (recovered from an iso of the Friedel-Crafts class of metallic halides. The cata butane-butylene alkylation unit), fortified with 25% ole lyst particularly preferred for the present alkylation-hy um to the above concentration of sulfuric acid. In the drogen transfer reaction is hydrogen fluoride containing series of alkylation reactions indicated below, various at least 95% and preferably 98% hydrogen fluoride. A isoparaffin hydrocarbons were utilized as alkylating portion of the acidic catalyst charged to the reaction zone 20 agents, including isopentane, methylcyclopentane and may comprise recycled spent catalyst from a previous methylcyclohexane; the products of these reactions were alkylation reaction which may be combined with fresh compared in composition with the products obtained in acidic catalyst and the mixture charged to the reaction an alkylation reaction in which no paraffinic hydrocar 200. bon was present and also with the product in which n The hydrogen transfer and alkylation reactions of the 25 heptane (containing no tertiary carbon atom) was charged present process occur in the reaction zone in contact with to the reaction. Each of the comparative runs was con the acidic alkylation catalyst as a unit process, although ducted under as closely analogous conditions as possible it is believed that the hydrogen transfer reaction occurs in order to clearly define the difference in results as a prior to the condensation of the feed stock olefin or the factor influencing the reaction. olefin resulting from the hydrogen transfer reaction, the 30 In each of the following runs the olefinic charging stock latter reaction occurring at a much faster rate than the was a propylenepolymer fraction (tetramer) boiling from condensation reaction of the resulting olefin with the 170-225 C., and was made up mainly of branched chain aromatic compound. The combination hydrogen transfer tertiary olefins. The benzene consisted of thiophene-free, alkylation reaction occurs at temperatures of from about 100% benzene. In the experiment utilizing isopentane as -25 to about 150 C. (depending on the particular 35 the paraffinic hydrocarbon portion of the charging stock, catalyst employed and other operating conditions) and the isopentane was 99% pure, the remainder being normal in a preferred method of operating the process, the re pentane. In the experiment utilizing methylcyclopentane action zone is maintained at temperatures of from about as the paraffinic hydrocarbon portion of the charging 0° to about 50° C. The pressure maintained within the stock, the fraction consisted of 82.3% methylcyclopen reactor is desirably sufficient to substantially liquefy both 40 tane, 6.8% benzene, 1.5% cyclohexane and 9.4% normal the catalyst and hydrocarbon reactants. When the de hexane. In the experiment utilizing methylcyclohexane sired product is the mono-alkylate, resulting from the as the paraffinic hydrocarbon portion of the feed stock, condensation of one mole of the aromatic compound with the material utilized was prepared by hydrogenation of one mole of the olefinic hydrocarbon formed by hydro pure toluene and consisted of 99--% methylcyclohexane. gen transfer from the isoparaffin reactant, a molar ex Each of the alkylation experiments was conducted in an cess of the aromatic compound is charged into the reac improved type of alkylation apparatus utilizing a proce tion zone, the molar ratio being based upon the quantity dure which results in maximum yields of alkylate from of the mono-olefin reactant charged. Generally, ratios the system. The benzene feed was mixed with the of from about 2 to 1 to about 10 to 1 or higher mols propylene tetramer fraction and the paraffinic hydro of aromatic compound per mol of olefinic hydrocarbon 50 carbon (where utilized) to provide a hydrocarbon mixture are utilized in the reaction. Since the reaction mech in which the benzene to propylene tetramer mol ratio was anism involved in the present process involves the trans maintained at a value of 10. The sulfuric acid alkylation fer of hydrogen from the isoparaffin to the mono-olefin, catalyst consisted of the sulfuric acid described above and since each molar proportion of mono-olefin is ca (mixed with recycle acid), the mixture being charged into pable of generating a stoichiometric proportion of ole 55 the reaction at the rate of 1.25 pounds per pound of ole fin from the isoparaffin hydrocarbon, the molar ratio of finic tetramer charging stock. The total hydrocarbon to isoparaffin to mono-olefin charged into the reaction is total acid volume ratio maintained throughout the ex preferably maintained at 1 to 1 or greater, up to about periment was 3 to 1. The hydrocarbon feed stock and 10:1. It is generally preferred to charge the isoparaf sulfuric acid alkylation catalyst were each precooled to fin and mono-olefinic hydrocarbon reactants into the 60 0° C. and mixed in a centrifugal pump which discharged reaction zone as a mixture in order to obtain the required the resulting mixture into a time tank alkylation unit con hydrogen transfer between these reactants prior to the sisting of a vertical tube containing orifice plates spaced condensation of the generated olefin with the aromatic at five inch intervals throughout the length of the tube, reactant. The acid-acting catalyst is charged to the re thereby insuring complete mixing of the hydrocarbon and action in amounts of from about 0.1 to about 5 to 1 65 acid phases during the residence of the hydrocarbon and volume proportions of catalyst per volume of hydrocar acid mixture in the time tank, the mixture forming an bon, depending upon the type of catalyst employed in emulsion of acid and hydrocarbons at is flowed through the reaction and its catalytic activity. The mixture of the centrifugal pump and orifice plates. A major por catalyst and reactants may be thoroughly stirred or other tion of the acid-hydrocarbon mixture was continuously wise intimately contacted during the course of the reac 70 recirculated in the unit by removal of the acid-hydrocar tion, which usually proceeds for a period of from about bon emulsion from the bottom of the time tank, cooling 0.2 to about 2 hours. Following completion of the re the removed portion to 0 C. and thereafter recharging action, the mixture is allowed to settle in order to sep the same into the top of the time tank (vertical tube) arate a resulting used catalyst phase from the aromatic after blending into the stream the hydrocarbon feed stock alkylate and unconverted reactants, if any. When utiliz 5 and the mixture of recycle and fresh makeup acid, each 2,787,586 7 8 of the latter streams being supplied to the centrifugal the process was distilled. The following table indicates pump as a mixture at 0°C. A side-strean equal involume the yields of the various hydrocarbon products separated to the total volune of fresh make-up acid and the total from the hydrocarbon phase of the alkylate mixture. TABLE Alkylation of benzene in the presence of propylene tet ranner (B.P.: 170-225 C.) and a paraffinic or cyclo paraffinic hydrocarbon Isopen- Me-Cyclo Me-Cyclo- n-dep Paraffin or Cycloparaffin tane Cs C tane None Yield, Total alkylate, lbs/lb. of olefin charged.------0,76. 0,501 0,795 1.02 0.978 Yield, Residual Olefin, mols/molofolefin f charged.------0.047 0.050 0.043 0.056 0.039 Yield, Dodecane produced, Imols/mol of olefin charged.------0.235 0.452 0.56 0.031 0.027 Yield, Cs, Cs or C alkylate of benzene, (B.P.charged.------170-275 C.) mols/mol of olefin 20, 26 30.125 40,06 50,023 -0.017 Yield, Cs, Cs or C alkylate of dodecyl benzene, B. P. 325 C, mols/mol of . olefin charged.------0,012 0.049 0.017 0. 0. Yield, Dodecylbenzene, molskimol of olefin charged (B.P.275-325°C.).------0.56 0.333 0.536 0.880 . 0.855 Approximately 4 nois charged permol of propylene tetramer. a Comprising tert-anylbenzene. 3 Comprising 1-methyl-1-phenylcycloperatane. Comprising 1-methyl-1-phenylcyclohexane. Contains alkylates of depolymerization products of propylene tetramer. Also includes di- and tri-alkylbenzenes. volume of fresh hydrocarbon feed stock charged to the We claim as our invention: reaction was removed from the center of the vertical time 1. A process for the production of a tert-alkyl-sub tank and discharged into a settling receiver immersed in stituted aromatic compound which comprises subjecting a cooling bath maintained at 0 °C., the acid and hydro 30 to alkylating conditions in the presence of an acidic alkyl carbon phases separating on standing into an upper hydro ation catalyst a mixing of an aromatic compound con carbon layer and a lower recycle acid layer. The acid taining a nuclearly replaceable hydrogen atom, a paraffinic phase was continuously removed from the settling re hydrocarbon having in its structure a tertiary carbon ceiver and utilized as recycle acid as hereinbefore de atom, and an olefinic hydrocarbon containing at least 3 scribed. The upper hydrocarbon phase from the settling 35 more carbon atoms per molecule than said paraffinic hy receiver was continuously removed at the same rate as drocarbon, said aromatic compound being in molar ex it was produced in the alkylation unit, washed with water cess of olefin in said mixture. to remove Small amounts of dissolved and entrained sul 2. The process of claim 1 further characterized in that furic acid alkylation catalyst and thereafter fractionally said olefinic hydrocarbon is a propylene tetramer fraction. distilled to recover alkylate product from unreacted por 40 3. The process of claim 1 further characterized in that tions of the hydrocarbon feed stocks. The operation of said reaction is effected at a temperature of from -25 the unit as indicated resulted in the circulation of the to about 150 C. total hydrocarbon and acid emulsion at the rate of ap 4. The process of claim 1 further characterized in...that proximately 105 gal/hr, and resulted in recirculation of said paraffinic hydrocarbon is an aliphatic isoparaffin. the total contents of the alkylation unit 631 times every 5. The process of claim 4 further characterized in that hour. All streams into the alkylation unit were continu said isoparaffin is isopentane. ously maintained at a temperature of 0° C. by maintain 6. The process of claim 1 further characterized in that ing a cooling bath at this temperature around the time said paraffinic hydrocarbon is an alkyl-substituted cyclo tank, each of the hydrocarbon and acid reservoirs, the paraffin. product receiver vessel and the lines connecting each of 50 7. The process of claim 6 further characterized in that the individual units of the apparatus. At the indicated said cycloparaffin is methylcyclopentane. rate of recirculation of the total acid and hydrocarbons, 8. The process of claim 6 further characterized in that the hydrocarbons were in contact with the acid for a said cycloparaffin is methylcyclohexane. total time of approximately 42 minutes. 9. The process of claim 1 further characterized in that Distillation of the hydrocarbon product separated from said aromatic compound is an aromatic hydrocarbon con the alkylation reaction mixture in the receiver vessel re taining not more than 3 nuclear substituent groups. Sulted in the following yields of individual products, the 10. The process of claim 1 further characterized in that boiling points of the fractions depending upon the type said paraffinic hydrocarbon is present in the reaction mix of paraffin utilized in the alkylation experiment. In ture in a molar excess over said olefinic hydrocarbon. each case, a C5, Cs or C distillate fraction was collected 6) 11. A process for the production of tert-amylbenzene as the unreacted benzene and/or paraffin or cycloparaffin which comprises subjecting a mixture of benzene, iso utilized in the process. A higher boiling fraction con pentane and dodecylene to alkylating conditions in the taining dodecanes formed by hydrogen transfer between presence of sulfuric acid alkylation catalyst, said mix propylene tetramer and the isoparaffinic reactants was ture containing at least 1 molar proportion of benzene separated and the unreacted dodecylenes removed there 65 and at least 1 molar proportion of isopentane per mol of from by adsorption on silica gel by a chromatographic dodecylene. separation method. The purity of the resulting fractions was confirmed by infra-red and ultra-violet spectrographic References Cited in the file of this patent analysis. A higher boiling fraction comprising the C5 UNITED STATES PATENTS and Co mono-alkylates of benzene was separated, followed by a fraction comprising the mono-dodecyl benzene alky 2,419,692 Shoemaker et al. ------Apr. 29, 1947 lates, the di-C5 and C6 alkylates and the mono-Cai or Cs 2.626,966 Kennedy et al. ------Jan. 27, 1953 alkylates of dodecylbenzene, the latter compounds oc OTHER REFERENCES curring as crystalline solids in the high boiling residue of a - Condon et al.: Journal Amer. Chem. Soc., vol. 70 the distillation pot in which the hydrocarbon product of 9 (July 1948), pages 2539-2542.