Process for preparing hydroperoxides

Abstract: Process for preparing hydroperoxides, comprising oxidizing a hydrocarbon of the following formula (I): wherein P and Q, may be the same or different from each other, represent hydrogen or an alkyl group, x is an integer of 1 to 3; and Ar is an aromatic hydrocarbon group, with an oxygen-containing gas in the presence of at least one compound that can capture radicals selected from radicals of phosphorus, sulphur, carbon, or silicon, a compound forming such a radical in the reaction system, phosphine oxide or a compound forming phosphine oxide in the reaction system. The present invention can be applied to oxidation of hydrocarbons including arylalkylhydrocarbons such as cumene, m-diisopropylbenzene, p-diisopropylbenzene, 1,3,5-triisopropylbenzene, isopropylnaphthalene, diisopropylnaphthalene, isopropylbiphenyl, diisopropylbiphenyl, etc.

Description: TECHNICAL FIELD The present invention relates to a process for preparing hydroperoxides, which comprises oxidizing hydrocarbon by a gas containing oxygen and converting it selectively to corresponding hydroperoxides. TECHNICAL BACKGROUND The process of oxidizing hydrocarbon by a gas containing oxygen in the absence of a catalyst to prepare corresponding hydroperoxides is known as autoxidation technology. However, in this reaction, it is necessary to raise the reaction temperature to increase the rate of accumulation of hydroperoxides. Nevertheless, when the reaction temperature is raised to increase the rate of accumulation, the reaction product hydroperoxide is thermally decomposed, resulting in a decline in its selectivity. In other words, since there was such relationship between the rate of accumulation and selectivity that as either one goes up, the other goes down, it was difficult to maintain both of them at high levels. Attempts have been made to oxidize hydrocarbon in the state of gas containing oxygen by a catalyst to produce an effect on the rate of accumulation and/or selectivity in producing corresponding hydroperoxides (Japanese Patent Publication SHO 55-50020, for example). The inventors of the present invention firmly believed that there should be a way to achieve high selectivity, while overcoming the relationship between the rate of accumulation and selectivity and maintaining a commercially viable rate of accumulation at the same time. With this belief, the inventors continued research assiduously. As a result, the inventors successfully made an invention to solve the problem. US 2 734 086 discloses a process for the manufacture of aralkyl hydroperoxides by liquid phase oxidation of aromatic hydrocarbons with an oxygen-containing gas in the presence of an organic nitrogen compound selected from secondary and tertiary amines. As specific examples only quinoline, pyridine and their alkyl substitution products are mentioned. V.V. Berentsveig et al., Bull. Acad. Sci. USSR (Chem.), 31(10), 1949-1952 (1982) discloses the liquid phase oxidation of cumene in the presence of 2,6-di-tert-butyl-4-methylphenol (ionol) or N-benzyl-tert-butylamine oxide (PBN) as free radical acceptors. In the course to the invention, inventors found that a oxidation of a hydrocarbon by a gas containing oxygen in the presence of a specific compound is effective for converting it to the corresponding hydroperoxides. Specifically, the present invention provides a method for oxidizing hydrocarbon by a gas containing oxygen thereby to prepare corresponding hydroperoxides at a high selectivity. DISCLOSURE OF THE INVENTION The process for preparing hydroperoxides by the present invention is based on the attainment of a very high selectivity possible by the use of a compound capable of capturing radicals as a specified compound in the process of oxidizing hydrocarbon by a gas containing oxygen. The present invention is characterized by oxidizing hydrocarbon by a gas containing oxygen in the presence of a compound that can capture radicals and converting it selectively to corresponding hydroperoxides, wherein the compound that can capture radicals is at least one compound selected from a phosphine oxide of the formula (IX) and a compound that forms phosphine oxide in the reaction system of the formula (X) wherein R 14 -R 16 and R 17 -R 19 each individually represent H or another substituent. THE BEST EMBODINMENT OF THE INVENTION The starting material hydrocarbon is a compound represented by the following general formula (I) wherein P and Q stand for hydrogen or the alkyl group, which may be the same or different from each other; x stands for a whole number of 1 to 3; and Ar stands for the aromatic hydrocarbon group of the x value. In the general formula (I), it is preferable that at least either of P and Q is the alkyl group, especially preferable that both of them are alkyl groups. Especially the methyl group is preferable as the aforementioned alkyl group. Further, a hydrocarbon group having the x value that can be derived from benzene, naphthalene, biphenyl, diphenyl ether, etc., preferable a hydrocarbon group of the x value that is derived from benzene or naphthalene, may be cited as examples of the aromatic hydrocarbon group. Therefore, in the present invention, preferable examples of the arylalkyl hydrocarbon include,but not limited to, diisopropylbenzenes such as cumene, cymene, m-diisopropylbenzene and p-di-isopropyl benzene, triisopropylbenzenes such as 1,3,5-tri-isopropylbenzene, ethylbenzene, sec-butylbenzene, sec-butylethylbenzene, isopropylnaphthalenes, diisopropylnaphthalene such as 2,6-diisopropyl naphthalene, isopropyl diphenyls, diisopropylbiphenyls such as 4,4'-diisopropylbiphenyl, and mixtures of not less than two of these. Cumen is most preferable. The compound of the present invention that can capture radicals refers to a compound having the ability to capture radicals, and it does not matter whether the compound itself possesses such ability or such ability is given to the compound under reaction conditions. In the reaction of oxidizing hydrocarbon by a gas containing oxygen, various by-products are formed. In the case of the example of the autoxidation of cumene, dimethylphenylcarbinol, acetophenone and dicumylperoxide may be cited as examples of such by-products. It is presumed that there are alkyl radicals such as cumyl radical and cumenehydroperoxy radical, hydroxy radical, etc. present in the process of reaction. It is presumed in the present invention that the compound that can capture radicals acts on these radicals in some respects, such as capturing the radicals inducing the reaction of the formation of such by-products, and consequently the selectivity of the hydroperoxide corresponding to the raw material hydrocarbon is improved. In selecting the compound that can capture radicals in the present invention, it is possible to use the difference in the SOMO (single occupied molecular orbit) energy level (Δε (SOMO)) between the radical of or derived from said compound that can capture radicals, and the radicals to be captured. The SOMO energy level is calculated by the method as described below. It is desirable to select such compound capable of capturing radicals that the difference in the SOMO energy level, Δε (SOMO), is normally 0 to 10eV, preferably 0 to 4eV, more preferably 0 to 1eV. For example, it is desirable to select such compound capable of capturing radicals in the present invention that its relationship with the radical (formula I-2 below) corresponding to the hydrocarbon to be oxidized is as follows: Δε (SOMO) = |εa (SOMO) - εb (SOMO) | = 0 to 10eV wherein εa (SOMO) stands for the SOMO energy level of the compound cable of capturing radicals or the radical formed therefrom, and εb (SOMO) stands for the SOMO energy level of the radical corresponding to the hydrocarbon to be oxidized. (wherein P and Q, standing for hydrogen or the alkyl group, may be the same or different from each other; x stands for a whole number of 1 to 3; and Ar stands for the aromatic hydrocarbon group of the x value.) ε (SOMO) Calculation Method: The structural calculation of a radical is made by a semiempirical molecular orbit method (MNDO-PM3 method: MOPAC program) to calculate ε (SOMO). The ε (SOMO) of those which are not a radical is determined by the structural calculation of the corresponding radical. As the aforementioned Δε (SOMO) becomes lower, the hydrocarbon radical is easier to capture. The Δε (SOMO) is normally in the range of 0 to 10eV, preferably 0 to 4eV, more preferably 0 to 1eV. The use of a compound having a proper value of Δε (SOMO) has the characteristic that in comparison with the case of adding no such compound, the selectivity goes up over the selectivity of hydroperoxide in other reaction at the same rate of accumulation. Because of this, the use of such compound enables hydrocarbon to be converted at high selectivity and at a high concentration. As the compound that can capture radicals, phosphine oxides may be cited. Phosphine oxides of the present invention include the compounds of the general formula (IX) The compounds of the general formula (IX) (wherein R 14 , R 15 and R 16 stand each separately for hydrogen or another substitutional group.) It is preferable desirable that R14, R15 and R16 are the alkyl group or the aryl group. The substitutional group in the general formula (IX) may be atom, halogen atom, hydrocarbon group, heterocyclic compound residue, oxygen-containing group, nitrogen-containing group, boron-containing group, sulfur-containing group, phosphorus-containing group or silicon-containing group, or a ring formed by not less than two of these being connected to each other. As halogen atom, fluorine, chlorine, bromine and iodine. Specific examples of the hydrocarbon group include straight-chain or branched alkyl groups having 1 to 30, preferably 1 to 20, carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, neopentyl and n-hexyl; straight-chain or branched alkenyl groups having 2 to 30, preferably 2 to 20, carbon atoms, such as vinyl, aryl and isopropenyl; straight-chain or branched alkinyl group having 2 to 30, preferably 2 to 20 carbon atoms, such as ethynyl and propargyl; cyclic saturated hydrocarbon groups having 3 to 30, preferably 3 to 20, carbon atoms, such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl and adamantyl; cyclic unsaturated hydrocarbon group having 5 to 30 carbonn atoms such as cyclopentadienyl, indenyl and fruorenyl and aryl groups having 6 to 30, preferably 6 to 20, carbon atoms, such as phenyl, benzyl, naphtyl, biphenyl, terphenyl, phenanthryl and anthracenyl. Hydrogen atom in the aforementioned hydrocarbon group may be substituted by halogen atom. Examples of such hydrocarbon group include halogenated hydrocarbon groups having 1 to 30, preferably 1 to 20, carbon atoms, such as trifluoromethyl, pentafluorophenyl and chlorophenyl. Furthermore, the aforementioned hydrocarbon group may be substituted by other hydrocarbon groups mentioned above. Examples of such hydrocarbon group include aryl-group-substituted alkyl groups such as benzyl and cumyl; alkyl-group-substituted aryl groups such as tolyl, isopropylphenyl, t-butylphenyl, dimethylphenyl and di-t-butylphenyl; and substituted aryl groups in which an aryl group is substituted by alkoxy group, aryl group or aryloxy group. Moreover, the aforementioned hydrocarbon groups may contain the heterocyclic compound residue, oxygen-containing group, nitrogen-containing group, boric acid-containing group, sulfur-containing group, phosphorus-containing group or silicon-containing group mentioned below. Out of them, especially preferable hydrocarbon groups are particularly straight-chain or branched alkyl groups having 1 to 30, preferably 1 to 20, carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, neopentyl and n-hexyl; aryl groups having 6 to 30, preferably 6 to 20, carbon atoms, such as phenyl, naphtyl, biphenyl, terphenyl, phenanthryl and anthracenyl; and substituted aryl groups having 1 to 5 of substituents such as alkyl group or alkoxy group having 1 to 30, preferably 1 to 20 carbon atoms, and aryl group or aryloxy group having 6 to 30, preferably 6 to 20 carbon atoms. Examples of the heterocyclic compound residue include residues of nitrogen-containing compounds such as pyrrole, pyridine, pyrimidine, quinoline and triazine; oxygen-containing compounds such as furan and pyrane; residues of sulfur-containing compounds such as thiophene; and groups having these heterocyclic compound residues further substituted by substitutional groups such as the alkyl group and alkoxy group having 1 to 30, preferably 1 to 20 carbon atoms. Examples of the oxygen-containing group include the alkoxy group, aryloxy group, ester group, acyl group, carboxyl group, carbonate group, hydroxy group, peroxy group and carboxylic acid anhydride group. Examples of the alkoxy group, out of these, include the alkoxy group having 1 to 30 carbon atoms, specifically, methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, isobutoxy and tert-butoxy. Examples of the aryloxy group include the aryloxy group having 6 to 30 carbon atoms, specifically, phenoxy, 2,6-dimethylphenoxy and 2,4,6-trimethylphenoxy. Examples of the ester group include the ester group having 1 to 30 carbon atoms, specifically, acetyloxy, benzoyloxy, methoxycarbonyl, phenoxycarbonyl and p-chloro-phenoxycarbonyl. Examples of the acyl group include the acyl group having 1 to 30 carbon atoms, specifically, the formyl group, acetyl group, benzoyl group, p-chlorobenzoyl group and p-methoxybenzoyl group. Examples of the nitrogen-containing group include the amino group, imino group, amide group, imide group, hydrazino group, hydrazono group, nitro group, nitroso group, cyano group, isocyano group, ester cyanate group, amidino group, diazo group and amino group having turned into ammonium salt. Examples of the amino group, out of these, include the amino group having 0 to 30 carbon atoms, specifically, dimethylamino, ethylmethylamino and diphenylamino. Examples of the imino group include the imino group having 1 to 30 carbon atoms, specifically, methylimino, ethylimino, propylimino, butylimino and phenyliminb. Examples of the amido group include the amido group having 1 to 30 carbon atoms, specifically, acetoamido, N-methylacetoamido and N-methylbenzamino. Examples of the imido group is the imido group having 2 to 30 carbon atoms, specifically, acetoimido and benzimido. Examples of the boron-containing group include the boranediel group, boranetolyl group and diboranyl group. Examples of the sulfur-containing group include the mercapto group, thioester group, dithioester group, alkylthio group, arylthio group, thioacyl group, thioether group, thiocyanate group, isocyanate group, sulfonester group, sulfonamide group, thiocarboxyl group, dithiocarboxyl group, sulfo group, sulfonyl group, sulfinyl group and sulphenyl group. Examples of the thioester group, out of these, include the thioester group having 1 to 30 carbon atoms, specifically, acetylthio, benzoylthio, methylthiocarbonyl and phenylthio-carbonyl. Examples of the alkylthio group include the alkylthio group having 1 to 30 carbon atoms, specifically, methylthio and ethylthio. Examples of the sulfonamide group include the sulfonamide group having 0 to 30 carbon atoms, specifically, phenylsulfonamide, N-methylsulfonamide and N-methyl-p-toluene-sulfonamide. Examples of the arylthio group include the arylthio group having 6 to 30 carbon atoms, specifically, phenylthio, methylphenylthio and naphthylthio. Examples of the sulfonester group include the sulfonester group having 1 to 30 carbon atoms, specifically, methyl sulfonic acid, ethyl sulfonic acid and phenyl solfonic acid. Examples of the phosphorus-containing group include the phosphide group, phosphoryl group, thiophosphoryl and phosphato group. Examples of the silicon-containing group include the silyl group, siloxy group, hydrocarbon-substituted silyl group, hydrocarbon-substituted siloxy group, specifically, methyl silyl, dimethylsilyl, trimethylsilyl, ethylsilyl, diethylsilyl, triethylsilyl, diphenylmethylsilyl, triphenylsilyl, dimethylphenylsilyl, dimethyl-t-butylsilyl, and dimethyl(pentafluorophenyl)silyl Out of these, methyl silyl, dimethylsilyl, trimethylsilyl, ethylsilyl, diethylsilyl, triethylsilyl, dimethylphenylsilyl and triphenylsilyl are preferable. Especially, trimethylsilyl, triethylsilyl, triphenylsilyl and dimethylphenylsilyl are preferable. Specific examples of the hydrocarbon-substituted siloxy group include trimethylsiloxy. Examples of the general formula (IX) include, but are not limited to, the following: Furthermore, in the process for preparation of the present invention, either phosphineoxide which is stable at room temperature or a compound which turns into phosphineoxide under reaction conditions may be used. As the compound that turns into phosphineoxide under reaction conditions, the compound represented by the general formula (X) may be cited. (wherein R 17 , R 18 and R 19 stand each separately for hydrogen or another substitutional group.) The substitutional group in the general formula (X) may be the same group as an example of the substitutional group X in the aforementioned general formula (II). It is preferable that these substitutional groups are the alkyl group or the aryl group. Specific examples of the compound of the general formula (X) include, but are not limited to, triphenylphosphine and tributylphosphine. A spin trap agent may be used as the compound that can capture radicals. The spin trap agent is a compound which is used for identifying a radical with a short life that cannot be observed directly by means of ESR, and forms a spin trap compound radical observable with the ESR with the radical to enables to identify the original radical with short life time by ESR analysis. Specific examples of the compound include, but are not limited to, nitron and nitroso compound as shown below. In this invention, the oxidation of hydrocarbon is conducted in the presence of at least one compound that can capture radicals. Two or more compounds that can capture radicals can be used. Supposing the compound that can capture radicals has captured a radical, the enthalpy (ΔH) to break the bond between the compound and the radical can be determined by calculation by the method as described below. The appropriate range of ΔH depends on the type of the radical to be captured, and the value may be used to select the compound that can capture radicals of the present invention. Satisfactory results can be obtained by selecting as the compound of the present invention that can capture radicals such compound that the value of enthalpy (ΔH) is -30 to 50KJ/mon when calculated on the basis of the assumption that the radical to be captured is the radical corresponding to the hydrocarbon to be oxidized (formula I-2). The value of the enthalpy (ΔH) is preferably -25 to 50KJ/mon, more preferably -20 to 50KJ/mon. Using the compound that can capture those radicals whose ΔH is within such appropriate range produces satisfactory results as intended by the present invention. H (heat of formation) calculation method: H was calculated by conducting structural optimization for the structure showing the smallest amount of energy (most stable structure) by semiempirical molecular orbital method( AM1 method: MOPAC program) after carrying out conformation search by the molecular force field method (CHARMm force field: QUANTA program). The selection of the compound that can capture radicals has the figures within the appropriate range of Δε (SOMO) aforementioned and the value of the enthalpy(ΔH) is most preferable in this invention. Next, given below is an explanation of the reaction conditions of the present invention. The usage of the compound that can capture radicals or the compound that turns into the compound that can capture radicals in the reaction system in the present invention is normally in the range of 0.00001 to 5.0 parts by weight, preferably in the range of 0.0001 to 0.1 parts by weight, per 100 parts by weight of the starting material hydrocarbon. As the oxygen-containing gas as the oxidizing agent, air is normally used, but oxygen or any mixed gas of oxygen and nitrogen may also be used. The reaction may normally be conducted at atmospheric pressure, but it may also be conducted under elevated pressure. The reaction temperature is normally in the range of 40 to 120°C, preferably in the range of 50 to 100°C. Furthermore, this reaction may be conducted in the presence of a basic compound in the state of a solid or an aqueous solution. Examples of the basic compounds include sodium carbonate, sodium hydrogencarbonate, sodium hydroxide, potassium carbonate, potassium hydrogencarbonate, potassium hydroxide, barium oxide and magnesium oxide. The amount of the basic compound used in the reaction is normally 0.0001 to 10.0 parts by weight, preferably 0.001 to 5.0 parts by weight, per 100 parts by weight of the starting material hydrocarbon. The reaction in the present invention may be conducted by either batch or continuous method. In the case of conducting the reaction by the batch method, if the starting material hydrocarbon is a liquid at the reaction temperature, the aforementioned compound that can capture radicals or the aforementioned compound that turns into the compound that can capture radicals in the reaction system is added to the starting material and normally made to undergo oxidation reaction by blowing air into the material with heating and agitation : If required, an inactive organic solvent may be used as the reaction solvent in the reaction. On the other hand, if the starting material arylalkyl hydrocarbon is a solid at the reaction temperature, it is made to be dissolved in an inactive organic solvent to form a solution, and the aforementioned compound that can capture radicals or the aforementioned compound that turns into the compound that can capture radicals in the reaction system may be added to the solution and made to undergo oxidation reaction by blowing air into the material with heating and agitation. Further, in the present invention, a small amount of hydroperoxide which corresponds to the hydrocarbon may be present, as required, as the initiator in the hydrocarbon at the time of the start of the reaction. A catalyst such as a transition metal complex may also be used additionally as required. Such catalyst may be formed as a fixed bed, and the starting material hydrocarbon or its solution and air may be caused to pass through the fixed bed, while being mixed. According to the method of the present invention, the formed hydroperoxide can be easily recovered from the reaction mixture by distillation or any other conventional means after the completion of the reaction and after filtering out the catalyst as required. Examples Given below is a specific description of examples of preparing organic hydroperoxides from arylalkyl hydrocarbon. However, the present invention is not limited in any way by the following examples: Example 1 5 g.of pure water and 36 mg of triphenylphosphineoxide were added to a mixture of 122 g of cumene and 53 g of cumenehydroperoxide, and all of them were dissolved as an oil phase. This mixture was heated under 6 K pressure to 105°C. Then air was blown into it at a rate of 180 ml/min with vigorous agitation to oxidize cumene. A solution of 36 mg of triphenylphosphineoxide dissolved in a mixture of 122 g of cumene and 53 g of cumenehydroperoxide and pure water were added to the reactor at rates of 175 g/hour and 5 g/hour, respectively, in such manner that the residence time is 1 hour of continuous reaction. The reaction liquid was collected by overflow into another vessel three times every hour after 4 hours from the start of the reaction. The rate of accumulation of cumenehydroperoxide was determined by iodometry and gas chromatography. The average of three determination values was 4.5 wt%/hr. Furthermore, the selectivity of the cumenehydroperoxide which was formed in the reaction was determined by high performance liquid chromatography. The average of three determination values was 90 mol%. Example 2 The reaction was conducted in the same manner as described in Example 1 except that tri-t-butylphosphineoxide was used as an additive in place of triphenylphosphineoxide. The rate of accumulation of cumenehydroperoxide was determined by iodometry and gas chromatography. The average of three determination values was 3.5 wt%/hr. Furthermore, the selectivity of the cumenehydroperoxide which was formed in the reaction was determined by high performance liquid chromatography to be 90 mol%. Comparative Example 1 To a dissolved mixture of 144 g of cumene and 36 g of cumenehydroperoxide 90 g of 0.05 wt% sodium carbonate were added, and this mixture was heated under 6 K pressure to 105°C. Then air was blown into it at a rate of 400 ml/min with vigorous agitation for 3 hours to oxidize cumene. The rate of accumulation of cumenehydroperoxide during 3 hours from the start of the reaction was determined by iodometry and gas chromatography to be 5.5 wt%/hr. Furthermore, the selectivity of the cumenehydroperoxide which was formed in the reaction was determined by high performance liquid chromatography to be 84 mol%. Comparative Example 2 The reaction was conducted in the same manner as Comparative Example 1 except that the reaction temperature was set at 100°C. The rate of accumulation of cumenehydroperoxide during 3 hours from the start of the reaction was determined by iodometry and gas chromatography to be 4.1 wt%/hr. Furthermore, the selectivity of the cumenehydroperoxide which was formed in the reaction was determined by high performance liquid chromatography to be 88 mol%. Comparative Example 3 50 mg of 2,2,6,6-tetramethyl-4-piperidinol were added to a dissolved mixture of 126 g of cumene and 54 g of cumenehydroperoxide 5.6 g of purified water were added, and this mixture was heated under 6 K pressure to 105°C. The cumene was oxidized by continuous reaction at a residence time of 1 hour while blowing air into it at a rate of 400 ml/min with vigorous agitation. The rate of accumulation of cumenehydroperoxide during 3 hours from the start of the reaction was determined and averaged by iodometry and gas chromatography to be 5.5 wt%/hr. Furthermore, the selectivity of the cumenehydroperoxide which was formed in the reaction was determined and averaged by high performance liquid chromatography to be 86 mol%. Comparative Example 4 The reaction was conducted in the same manner as Comparative Example 3 except that the reaction temperature was set at 100°C. The rate of accumulation of cumenehydroperoxide during 4, 5 and 6 hours from the start of the reaction was determined and averaged by iodometry and gas chromatography to be 3.9 wt%/hr. Furthermore, the selectivity of the cumenehydroperoxide which was formed in the reaction was determined and averaged by high performance liquid chromatography to be 89 mol%. Comparative Example 5 5 g of pure water were added to a mixture of 122 g of cumene and 53 g of cumenehydroperoxide, and all of them were dissolved as an oil phase. This mixture was heated under 6 K pressure to 105°C. The cumene was oxidized while blowing air into it at a rate of 180 ml/min with vigorous agitation. A mixture of 122 g of cumene and 53 g of cumenehydroperoxide, and pure water were added into the reactor at rates of 175 g/hour and 5 g/hour, respectively, in such manner that the residence time is 1 hour of continuous reaction. The reaction liquid was collected by overflow into another vessel three times every hour after 4 hours from the start of the reaction. The rate of accumulation of cumenehydroperoxide was determined by iodometry and gas chromatography. The average of three determination values was 5.5 wt%/hr. Furthermore, the selectivity of the cumenehydroperoxide which was formed in the reaction was determined by high performance liquid chromatography to be 86 mol%. Comparative Example 6 The reaction was conducted in the same manner as Comparative Example 5 except that the reaction temperature was set at 100°C. The rate of accumulation of cumenehydroperoxide was determined by iodometry and gas chromatography. The average of three determination values was 3.9 wt%/hr. Furthermore, the selectivity of the cumenehydroperoxide which was formed in the reaction was determined by high performance liquid chromatography to be 88 mol%.

Claims: Process for preparing hydroperoxides, comprising oxidizing a hydrocarbon of the following formula (I) : wherein P and Q, which may be the same or different from each other, represent hydrogen or an alkyl group, x is an integer of 1 to 3; and Ar is an aromatic hydrocarbon group, with an oxygen-containing gas in the presence of at least one compound that can capture radicals selected from a phosphine oxide of the formula (IX) and a compound that forms phosphine oxide in the reaction system of the formula (X) wherein R 14 -R 16 and R 17 -R 19 each individually represent H or another substituent. Process of Claim 1, wherein the arylalkyl hydrocarbon of formula (I) is cumene, cymene, m-diisopropylbenzene, p-diisopropylbenzene, 1,3,5-triisopropylbenzene, isopropylnaphthalene, diisopropylnaphthalene, isopropylbiphenyl, diisopropylbiphenyl or a mixture of two or more thereof. Process according to Claim 2, wherein the arylalkyl hydrocarbon is cumene.

Inventors: FUJITA TERUNORI, HIROKANE NOBUYA, KAMIMURA MAKOTO, KATO KOJI, KURODA HIROSHI, MAKIO HARUYUKI, MATSUI SHIGEKAZU, TAKAI TOSHIHIRO, FUJITA, TERUNORI, HIROKANE, NOBUYA, KAMIMURA, MAKOTO, KATO, KOJI, KURODA, HIROSHI, MAKIO, HARUYUKI, MATSUI, SHIGEKAZU, TAKAI, TOSHIHIRO
Applicants: MITSUI CHEMICALS INC, MITSUI CHEMICALS, INC.
Application year: 1998
Main classification: C07C409
IPC codes: C07C409