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Patented Mar. 17, 1953 2,632,026

UNITED STATES PATENT OFFICE 2,632,026 OXDATION OFAROMATIC Joshua C. Conner, Jr., Wilmington, Dei, assignor to Hercules Powder Company, Wilmington, Dei, a corporation of Delaware No Drawing. Application February 18, 1950, Serial No. 145,091 9 Cairms. (C. 260-610) 1. 2 This invention relates to a process for oxidizing of at a temperature in excess of 20° C. an -substituted aromatic organic compound while simultaneously passing a stream of an having the , -containing gas containing gaseous am Rt H monia, in catalytic amounts through the reac N / tion mixture. The reaction is continued until standard analytical data, such as refractive in R / Air dex, indicate the conversion of from about 10% to about 70% of the original cumene to oxygen in which R1 and R2 represent alkyl groups and ated products. The reaction mixture may then Ar represents either an aryl group or an alkaryl 0. be treated in accordance with known techniques group. More particularly, the invention relates to obtain a product containing preponderant to a process for the oxidation of compounds Such amounts of a,c-dimethylbenzyl hydroperoxide. as cumene in the liquid phase by naeans of no Having thus described the invention, the foll lecular. Oxygen. lowing examples are specific embodiments there It is known that cunene, for example, may be 5 of. All parts are parts by weight unless otherwise oxidized in the liquid phase by means of molec indicated. ular oxygen, but none of the processes hereto EXAMPLE 1. fore disclosed for the oxidation of cumene have resulted in substantial yields of a,c-dimethyl A glass reaction vessel equipped with a reflux benzyl hydroperoxide. Under the conditions condenser, a high Speed Stirrer and an Oxygen practiced in prior procedures, difficulties are en 2) inlet was charged With 400 parts of cunene. countered in initiating the reaction and the a,c- Twelve and three-tenths parts of oxidized cul dimethylbenzyl hydroperoxide has not been ob mene containing 97.8% of aa-dinnethylbenzyl hy tained in substantial yields as the major product droperoxide was added to the charge as a reac by the oxidation of cumene. The oxidation has, tion initiator. Oxygen containing 0.26% gaseous instead, led to mixtures containing preponderant was passed through the reaction mix amounts of and Sinall amounts of ture at the rate of 15 liters per hour per kilo aa-dimethylbenzyl . gran of cumene. A temperature of 90° C. Was Now in accordance with this invention, it has maintained throughout the reaction , been discovered that tertiary hydroperoxides Which extended for 51.0 hours. Table I shows having the structural formula 30 the data for the oxidation. R OOH Table I

DoC Oxidation Prod R Yar ucts in Product 35 . Rate of may be prepared by contacting an alkyl-substi - (Percent) Oxidatiation tuted aromatic organic compound having the Time (Hr.) no - (Pigent? structural formula previously described in the Hydro- T. liquid phase at a temperature in excess of 20° C. Total befoxiie with an oxygen-containing gas in the presence 40 20.6.--- 15.7 14.8 0.62 of gaseous ammonia, the ammonia, acting cata 28.7 20.5 19.6 0.61 44.6- 27.4 26.9 0, 55

lytically as an initiator for the reaction. In the structural formula of the hydroperoxides, R1 and 5-0------...! .. 5002 30.0 28.9 0.53 R2 represent alkyl groups which may be either the same or different and Ar represents a Sub During the oxidation the effluent OXygen gaS COI)- stituent selected from the group consisting of tained a substantial amount of ammonia. Upon aryl and alkalyl groups. These tertiary hydro completion of the oxidation, the pH determined peroxides may be referred to as a,a-dialkylaryl on distilled after shaking with the organic methyl hydroperoxides or, if desired, as aryl phase was 9.3 showing the presence of excess (dialkyl)methyl hydroperoxides. Thus, the hy ammonia, and the crude amber reaction product droperoxide derived from cunene in accordance amounted to 350 parts. Analysis of the reaction with the process of this invention may be nained product indicated the presence of 28.9% a,c- a,a-dimethylbenzyl hydroperoxide, or, if desired, dimethylbenzyl hydroperoxide, 70% unreacted phenyl (dimethyl)methyl hydroperoxide. cumene, 0.90% ca,a-dimethylbenzyl alcohol, and The process of this invention may be practiced, {0.22% acetophenone. Based on the amount of for example, by vigorously agitating a mixture the aa-dimethylbenzyl hydroperoxide initiator 2,632,026 3 4. and the amount of each of the reaction products taining a,c-dimethylbenzyl hydroperoxide was expressed in terms of cumene, the recovery of Withdrawn through a valve at the bottom of the the components making up the reaction product tower adjacent the air inlet. A sample taken at amounted to 90.6%. The yield of a,c-dimethyl the end of 16 hours after the continuous with benzyl hydroperoxide was 95.5% of the theoreti drawal of product had continued 8 hours showed cal amount based on the cumene, taking into 26.8% a,a-dimethylbenzyl hydroperoxide. Dur consideration that the conversion at 51.0 hours ing this period the ammonia, content of the air WaS 30.0%. The conversion of 30.0% represents entering the tower was 1.24% by volume and that Conversion to total oxygenated products. of the air leaving the tower was 0.78% by volume. O During the next 8-hour period the cumene flow EXAMPLE 2 rate was 7.2 lb. per hour and the ammonia con The same equipment and the same conditions tent of the air entering the tower was 1.06% by of temperature and oxygen flow as those de Volurne While that leaving the tower was 0.29% Scribed in Example 1 were again utilized. In by volume. The rate of air flow was 0.7-1.0 cu. this case, however, the oxygen contained 1% ft. per minute as in the previous periods. At ga-SeOS annonia. At the end of 22.8 hours of the end of this 8-hour period the product being reaction, a Sample of the oxidized product had Withdrawn at the same rate as the cumene being a refractive index at 20° C. of 1.4945, thus indi introduced analyzed 23.1% a,a-dimethylbenzyl Cating a conversion of the cumene to 12.0% oxy hydroperoxide. Further analysis of this prod genated products. The per cent a,c-dimethyl uct ShoWed that a,c-dimethylbenzyl hydroperox benzyl hydroperoxide at this time was 11.4%. ide constituted 89.1% of the total oxidation prod At the end of 44.8 hours the reaction was termi ucts in the crude product. nated. At this time the refractive index of the During the next 8-hour period the cunene flow. reaction product was 1.4981, thus indicating a rate averaged 6.5 lb. per hour, the air flow rate total conversion of 24.6% and the hydroperoxide Varied from 0.7 to 1.0 cu. ft. per minute and the content was 24.0. The pH determined on dis annonia, content of the air entering the tower tilled Water after shaking with the organic phase Was about 0.83% by volune, While that of the air Was 8.6. Analysis of the reaction product indi leaving the tower was about 0.30% by volume. cated that a yield of 97.1% of a,a-dimethylbenzy. The a,c-dimethylbenzyl hydroperoxide content of hydroperoxide had been obtained based on the 30 the product continuously being withdrawn av Cunene utilized and the percentage total con eraged 23.7%. version. Calculations showed that the per cent The examples have set forth the use of cumene recovery was 96.2. The product also contained and p-cymene as compounds which may be 0.47% a,a-dimethylbenzyl alcohol and 0.11% acetophenone. treated in accordance with the process of this 3 invention. Other compounds, however, having EXAMPLE 3 the structural formula previously set forth Such The same equipment and the same conditions as diisopropylbenzene may be utilized. The pri of temperature and oxygen input as those de nary requirement for compounds which may be Scribed in Example 1 were again utilized. In this Oxidized in accordance With this invention is the case, however, p-cymene was oxidized, the presence of a tertiary , the fourth amount of this compound charged to the reactor valence bond of which is satisfied by a being 400 parts. At the beginning of the oxida aton. AS indicated by the structural formula, tion the mixture also was charged with 17.5 the carbon atom is tertiary because it is directly parts of oxidized cymene containing 68.4% ag connected to three other carbon One of dimethyl-p-methylbenzyl hydroperoxide as ini i. which is contained in each of the groups repre tiator. The oxidation reaction was carried out Sented by R1 and E2 and Ar. as in Example 1 and continued for 47.9 hours. The aryl or alkaryl group need not be derived At the end of this time the reaction product from as in the case of Cunene, p-cymene, Showed a content of 15.7% a,a-dimethyl-p-meth and p-diisopropylbenzene. Other compounds ylbenzyl hydroperoxide, 1.51% a,c-dimethyl-p- containing aromatic nuclei, Such as those derived nethylbenzyl alcohol, and 0.66% p-methyl aceto from , , and phenan phenone. threne, which otherwise meet the requirements of the structural formula, are also operable. How EXAMPLE 4 ever, such compounds, if solids, must be dissolved A charge of 53 lb. cumene containing 145 lb. in a suitable such as benzene during the 96.1% a,c-dimethylbenzyl hydroperoxide was liquid phase Oxidation reaction. Furthermore, placed in a Steam heated stainless tower 20 the aryl group may be substituted with alkyl feet high and 3 inches in inside diameter. Air groupS. Such as methyl, ethyl, propyl, isopropyl, containing 1% gaseous ammonia by volume was butyl, isobutyl, sec-butyl, tert-butyl, and the like. pumped into the tower through a pipe fitted with The alkyl groups represented by R. and R2 in a sintered Stainless steel dispersion disk in the 60 the structural formula need not be limited to botton of the tower while maintaining a tem methyl groups as in the case of cumene, p-cy perature of 20° C. in the tower. The pressure nene, and p-diisopropylbenzene. Other alkyl in the tower Was maintained at 80 p.s. i. (gauge) groups such as those indicated as Suitable Sub by slowly bleeding off the exhaust gases at the Stituents for the aryl groups may be utilized. top Of the tower. The rate of input of air con 65 Furthermore, R1 and R2 may be either the same taining 1% ammonia, was 0.7-1.0 cu. ft. per min or different. ute. After an 8-hour oxidation period, a Sam The examples have illustrated the use of air ple was withdrawn. It analyzed 30% aa-dimeth and molecular oxygen as the oxygen-containing ybenzyl hydroperoxide. gas Which may be utilized in accordance With While continuing to pass air containing 1% the process of this invention. The oxygen, how gaSeOUS annonia into the to Wer at a rate of eyer, may be furnished in the form of mixtures 0.7-1.0 cu. ft. per minute, cunene Was Simul of nolecular oxygen with or other inert taneously added slowly to the charge in the tower gases. Oxygen, When used alone, may be either through a pipe at the top of the tower at a rate a commercial or chemically pure product. Air of 6. b. per hour While oxidized cunene Con may be utilized either with or without partial or

2,682,026 5 6 complete dehumidification. The amount of oxy and the like may be used. Oil-soluble catalysts gen in the oxygen-containing gas is preferably also may be used, for example, catalysts which are at least about 10% of the gas. The rate of in soluble in p-cymene, cunene, and diisopropyl put of the oxygen-containing gas may vary With benzene. Exemplary are manganese-butyl in a wide range, depending upon the concentra phthalate and manganese linoleate. Activated tion of oxygen in the gases, the pressure at which carbon may also be used as a catalyst. the oxidation is carried out and the efficiency of In addition to the use of ammonia as an ini dispersion. At pressures of from 50 to 200 p.s. i., tiator, one may also use other initiators to advan for example, the rate of input may be from about tage. For instance, as shown by the examples, 2 to about 200 liters of oxygen/hr./kg. of alkaryl those oxidized oils obtained according to the compound. A preferable range is from about 20 process of this invention and containing appre to about 60 liters of oxygen/hr./kg. At atmos ciable amounts of hydroperoxides are oil-soluble pheric pressure the rate of input may, in gen and are, therefore, useful in initiating the oxida eral, vary from about 1 to about 100 liters/hr./kg. tion reaction by relieving inhibitions caused by of alkyl compound, a preferable range being from harmful impurities. These oxidized oils, however, about 5 to about 25 liters/hr./kg. do not act as actual oxidation catalysts and are, Since this reaction is heterogeneous, Suitable therefore, highly desirable initiators for those agitation is necessary. It is particularly impor oxidations in which it is desired to obtain op tant to bring the air, oxygen, or other oxygen." timum yields. When it is desired to speed up the containing gas into intinate contact with the oxidation reaction, these hydroperoxide-rich oils liquid phase, and this may be effected by using may be used in an araount up to about 50% by high speed stirrers, suitable nozzles, porous plates weight of the compound to be oxidized. A pre or their combinations. This may suitably involve ferred range is from about 1% to about 20%. It also recirculation of the oxygen-containing gas. is not essertial in the process of this invention, The oxygen is contacted with the alkyl-substi- ;2 5 however, that such a reaction initiator be uti tuted arolinatic organic compound until the de lized. Other Well-known peroxides and hydro sired amount of hydroperoxide is formed. in genr peroxides such as acetyl peroxide, benzoyl per eral, at least about 5% hydroperoxide formation , tert-butyl peroxide, tert-butyl hydroper will be desired. This will require approximately oxide, tetralin hydroperoxide, and the like may 1.3 parts oxygen per 100 parts alkyl-substituted 30 also be used in place of the above oxidized oils aromatic organic compound. Under these condi to act as initiators for the reaction. tions it will be preferable to use at least about he teaperature at which the oxidation is 0.006 part gaseous ammonia, which is about 0.5% carried out depends on the various conditions of of the amount of oxygen entering into reaction reaction, particularly on the presence or absence for the formation of the hydroperoxide. 35 of a catalyst and the nature of the catalyst. Since the ammonia, acts catalytically as an ini When no catalyst is used, the reaction is too slow tiator for the reaction, only a catalytic amount is at temperatures below about 20° C. and it is ad necessary to satisfy that function. However, Wisable in Such case to Work at a temperature be-, since the annonia will combine with any traces tween about 45° C. and about 95° C., preferably of formed, thereby destroying its catalytic 40 between about 60° C. and about 95 C. The reac function, it is preferable that an excess of an tion proceeds at a convenient rate at a tempera monia, over that entering into combination be ture between about 20° C. and about 95 C. When employed. In general, a minimum of at least a catalyst is used, and a preferabl range is fron 0.5% of the oxygen to be reacted will provide a about 25° C. to about 60° C. When a catalyst is sufficient excess so that free ammonia is present used, however, the concentration must be kept throughout the entire reaction. The entire below 0.8% as pointed out previously. All of the amount may be present from the beginning of the tenniperatures So far discussed are temperatures reaction or it may be added gradually during the aS neaSured at atrioSpheric pressure. It is pos course of the reaction. It is conveniently added sible, however, to obtain high yields of the hydro along with the oxygen-containing gas if that gas : peroxides after a relatively short period of oxi is being recircuiated and the amount added may dation by utilization of superatmospheric pres be that sufficiant to permit a trace of ammonia, Sure and tenperatures above 95° C. as shown in in the exit gases. Although a large excess of Example 4. When Superatmospheric pressure is ammonia, is not harmful, a large excess is avoided used, the temperatures may vary from about for economic reasons. In general, over 50% am 5 5 95° C. to about 200° C. The preferable tempera monia based upon the oxygen would be consid ture range under these conditions, however, is ered an objectionable eXceSS. from about 100° C. to about 130° C., and a par The oxidation may be carried out either in the ticularly applicable range is from about 115° C. presence or absence of an oxidation catalyst. It to about 120° C. The pressures which are oper is preferable, however, to carry out the oxidation able in conjunction with temperatures above in the absence of an cxidation catalyst as shown 95 C. are limited only by equipment design. by the examples. When a catalyst is utilized, From a practical standpoint, pressures of from nevertheless, high yields of hydroperoxides may atmospheric to about 560 p.s. i. are feasible. The be effected provided the amount of catalyst is preferred pressure range is from about 60 p.s. i. maintained at a minimum. In general, high hy to about 200 p.s. i. droperoxide yields may be obtained if the concen The course of the reaction may be followed tration of the catalyst in the oxidation reaction by determining the refractive index of the oily mixture is at any particular instant from about layer at periodic intervals. With respect to the 0.1% to about 0.8%, based on the alkyl-Substi Oxidation of cunene, refractive index values from tuted aromatic organic collapound. A preferable about 1.4939 to about 1.5116 indicate that from range on this basis is from abcut 0.2% to about about 10% to about 70% of the original material 0.8%, and a particularly applicable range is from has been oxidized. The reaction is advisably in about 0.25% to about 0.5%. Well-known cata terrupted within this range of conversion. In lysts, such as manganese dioxide, manganese the oxidation system of this invention, the re acetate, cobaltous hydroxide, cobaltous acetate, 75. fractive indices depend somewhat upon two fac:

2,632,026. 7 8 tors: (1) The nature of the material being oxi of this hydroperoxide is then decomposed, re dized and (2) the nature of the end product. The Sulting in the formation of free radicals which first of these factors-the compound being oxi are sufficient to initiate the formation of more dized-is of less significance than the other. hydroperoxide . Oxidation catalysts The nature of the end product is of particular apparently cause increased amount of hydro significance when the compound undergoing oxi peroxide to decompose, thus resulting in an ac dation has two tertiary carbon atoms, as in the celeration of the over-all oxidation, but decreasing case of diisopropylbenzene. From such a come the amount of undecomposed hydroperoxide at pound there may be prepared either a mono- or the expense of the formation of secondary prod a di-hydroperoxide. To obtain the monohydro ucts, such as and ketones. That the peroxide, the oxidation is interrupted at a rela Oxidation follows a chain mechanism is known tively low refractive index, whereas the pres by the existence of an induction period, by cases ence of a substantial amount of a dihydroper of inhibition, and by the fact that both may be oxide is indicated by an appreciably higher re eliminated by the addition of hydroperoxide-rich fractive index. oils from a previous oxidation run. Conversion to oxygenated materials of from The process of this invention is advantageous in about 10% to about 70% of the alkyl-substituted that it has been found possible by utilization of aromatic organic compounds previously described annonia, in the oxidizing gas to obtain a,c-di may be effected by the process of this invention. alkylarylmethyl hydroperoxides in high yields in It is desirable for the purpose of obtaining a high a relatively short time and without the formation yield of hydroperoxide to effect conversion of of Substantial amounts of secondary reaction from about 10% to about 30% of the Original Ina, products and the product may be concentrated terial inasmuch as undesirable amounts Of SeC simply by Stripping off the unreacted hydrocar ondary reaction products, such as the correspond bon from the crude product by distillation. ing alcohol or ketone, are formed after this de Moreover, ammonia in being Soluble to an ap gree of conversion is exceeded. preciable extent in the organic compounds being The method utilized in recovery of the reaction Oxidized acts largely as a homogeneous catalyst products will vary, depending upon the use to and prevents undesired formation not only which the hydroperoxide is to be put. If the use in the licuid phase but also in the gaseous phase of the hydroperoxide does not require Separation and in the liquid film On the Walls of the re of the hydroperoxide from other components, action Wessel. In this respect annonia, even as such as alcohols, ketones, and unreacted Starting a neutralizer of acids is Superior to inorganic material which may be present in the crude re alkallies and may be used. Without resort to use action mixture, the oily reaction product may be of any such alkalies, filtered through a layer of Some filter aid to re The expression "gaseous annonia' as used in move the catalyst, if any is used, by adsorption, this Scecification and claims is intended to cover then washed with dilute aqueous alkali and used uncombined ammonia, other than liquid annonia either as the crude slightly cloudy product for Whether dispersed in the liquid phase or dispersed various purposes or after clarification and drying in the space above the liquid phase. The hydro by filtration. The dilute aqueous alkali used in 40 peroxides formed in the process of this invention the Washing step may be , are highly useful and find various commercial sodium , sodium bicarbonate, and the applications. They are excellent catalysts for the like, the concentration of these alkalies in aqueous polymerization of vinyl, vinylidene, and vinylene solution ranging from about 1% to about 10%, but compounds, being for example, highly useful in preferably from about 2% to about 5%. If it is the copolymerization of and desired, however, to obtain a highly concentrated to form synthetic rubber. They also are useful hydroperoxide, the crude reaction product, even in rubber reclaiming, infotation, and in kier boil without removal of ammonia, first, may be ing, bleaching, and other textile operations. stripped of unreacted by distillation What I claim and desire to protect by Letters at pressures of about 1 to about 10 millimeters of 50 Patent is: . This is a particularly important ad 1. The process of oxidizing an alkyl-substi vantage in the use of gaseous ammonia in the . tuted aromatic organic compound to a tertiary process of oxidation because the ammonia, tends Organic hydroperoxide which comprises con to stabilize the hydroperoxide. The hydroperOX tacting Said aromatic organic compound in the ides themselves may be safely distilled attempera liquid phase at a temperature in excess of 20° C. tures below about 100° C., this requiring the use, With an oxygen-containing gas in the presence however, of pressures of about 0.01 to about 1.0 of gaseous annonia, the aromatic organic com millimeter. a,a-Dimethylbenzyl hydroperoxide, pound and the tertiary hydroperoxide having, for example, may be distilled at 60° C. under a respectively, the structural formulae pressure of 0.2 millimeter and at 68° C. under a O pressure of 0.3 millimeter. Another method of separating the hydroperoxides from the crude oily reaction product involves precipitation of the hydroperoxide with a concentrated aqueous and solution (25% to 40%) of sodium hydroxide. The precipitate is crystalline. The precipitate of asa dimethylbenzyl hydroperoxide, for example, ana lyzes for the sodium of the hydroperoxide associated with four molecules of Water. in which R1 and R2 represent alkyl groups and The oxidation according to this invention ap 70 Ar represents a selected from the parently proceeds by a free chain mecha group consisting of aryl and alkary groups. nism. Using cumene as an example, When this 2. The process of oxidizing an alkyl-substi compound is oxidized with molecular oxygen, a tuted aromatic organic compound to a tertiary hydroperoxide is first formed on the tertiary car organic hydroperoxide which comprises con bon of the isopropyl group. A very Small fraction 75 tacting Said aromatic organic compound in the

2,632,026 O liquid phase at a temperature in excess of 20° C. With molecular oxygen in the presence of gas eous ammonia, the aromatic Organic compound and the tertiary hydroperoxide having, reSpec" tively, the structural formulae 5 in which R1 and R2 represent alkyl groups and Ar represents a substituent selected from the group consisting of aryl and alkaryl groupS. 6. The process of oxidizing an alkyl-SubSti and O tuted aromatic organic compound to a tertiary organic hydroperoxide which comprises contact ing said aromatic organic compound in the liquid phase at a temperature in exceSS of 20° C. with an oxygen-containing gas and gaseous in which R1 and R2 represent alkyl groups and 5 armonia, until at least 1.3 partS OXygen has re Air represents a substituent selected from the acted with 100 parts said organic compound, the group consisting of aryl and alkaryl groupS. amount of aminonia, used being at least 0.5% of 3. The process of oxidizing an alkyl-substi the oxygen to be reacted, the aromatic Organic tuted aromatic organic compound to a tertiary compound and the tertiary hydroperoxide hav organic hydroperoxide which comprises Con 20 ing, respectively, the structural formulae tacting said aromatic organic conpound in the liquid phase at a temperature in excess of 20 C. R H with air in the presence of gaseous annonia, o the aromatic organic compound and the tertiary R Yar hydroperoxide having, respectively, the struc- 25 and tural formulae R vo OH R1 Nc^ R /S Air R?. Yar 30 in which R1 and R2 represent alkyl groups and and Ar represents a substituent selected from the R OOE group consisting of aryl and alkaryl groups. N / 7. The process of oxidizing cumene to a,c- C dinnethylbenzy hydroperoxide Which comprises R?. Yar 35 contacting cunene in the liquid phase at a ten perature in excess of 20° C. With an Oxygen in which R1 and R2 represent alkyl groups and containing gas and gaseous annonia, until at Ar represents a substituent Selected from the least 1.3 parts oxygen has reacted with 100 parts group consisting of aryl and alkaryl groupS. cumene, the annount of ammonia used being at 4. The process of oxidizing an alkyl-SubSti 40 least 0.5% of the oxygen to be reacted. tuted aromatic organic compound to a tertiary 8. The proces of oxidizing p-cymene to a.a- organic hydroperoxide which comprises contact dimethyl-p-nethylbenzyl hydroperoxide which ing said aromatic organic compound in the comprises contacting p-cymene in the liquid liquid phase at a temperature in exceSS of 20° C. phase at a temperature in excess of 20° C. With with molecular oxygen in the presence of gaSe 45 an oxygen-containing gas and gaseous annonia, ous ammonia, in an amount of at least 0.5% of until at least 1.3 parts oxygen has reacted. With the oxygen to be reacted, the aromatic Organic 100 partS p-cymene, the annount of ammonia, compound and the tertiary hydroperOXide hav used being at least 0.5% of the oxygen to be ing, respectively, the structural formulae reacted. R H 50 9. The process of Oxidizing p-diisopropylben c/ Zene to a,c-dimethyl-p-isopropylbenzyl hydro peroxide which comprises contacting p-diisopro pylbenzene in the liquid phase at a temperature in excess of 20° C. With an oxygen-containing gas R1 O OB 55 and gaSeous annonia, until at least 1.3 parts N / Oxygen has reacted with 100 parts p-diisopropyl benzene, the amount of anonia used being at least 0.5% of the oxygen to be reacted. in which Ri and R2 represent alkyl groups and JOSHUAC. CONNER, JR. Air represents a substituent Selected from the 60 group consisting of aryl and alkaryl groups. REFERENCES (CED 5. The process of oxidizing an alkyl-Substi The following references are of record in the tuted aromatic organic compound to a tertiary file of this patent: organic hydroperoxide which comprises con tacting said aromatic organic compound in the 65 UNITED STATES PATENTS liquid phase at a temperature in excess of 20° C. Ninder Name Date with air containing gaseous annonia, in an 2,438,125 Lorand et al. ------Mar. 23, 1948 amount of at least 0.5% of the oxygen of the air 2,484.841 LOrand et al. ------Oct. 8, 1949 to be reacted, the aromatic organic compound 70 FOREIGN PATENTS and the tertiary hydroperoxide having, respec Number Country Date tively, the structural formulae 610,293 Great Britain ----. Oct. 13, 1948 R H R /o Air 75