WO2003014074A1 - Production of peroxides of ethylbenzole and use thereof - Google Patents

Abstract

The invention relates to method for the production of hydroperoxides of ethylbenzole by catalytic oxidation and to the use thereof for the oxidation of olefins. A compound of formula (I) is used as an oxidation catalyst, wherein R<1>, R<2> = H, an aliphatic or aromatic radical, a carboxyl radical, an allkoxycarbonyl radical or a hydrocarbon radical, respectively comprising 1 -20 carbon atoms, SO3H, NH2, OH, F, Cl, Br, I and/or NO2, wherein R<1> und R<2> are identical or represent different radicals or R<1> and R<2> can be linked by means of a covalent bond, wherein X, Z = C, S or CH2; Y = O or OH; k = 0, 1 or 2; l = 0, 1 or 2 and m = 1 - 3; in the presence of a radical starter, the molar ratio of the catalyst to ethylbenzole being 0.15 mol % - 10 mol % .

Description

Production of peroxides of ethylbenzene and their use

The invention relates to a process for the preparation of peroxides of ethylbenzene and their use for the oxidation of olefins, in particular for the epoxidation of propene.

Epoxidized propene or propylene oxide is very important in the chemical industry. Among other things, it serves as a basic raw material for the production of propylene glycols, glycol ethers, glycerin, isopropanolamines and for various propoxylation products for polyurethanes.

Due to the low dissociation energy of the C-H bond, propylene oxide is in contrast to e.g. B. ethylene oxide and butylene oxide difficult to manufacture. The hydrogen of the allyl-containing methyl group is preferably subject to oxidation, so that predominantly acrolein is formed.

For example, the chlorohydrin process was initially used for the production of propylene oxide. was largely replaced by various indirect oxidation processes due to the formation of worthless chlorine salt solutions. Indirect oxidation processes include the use of hydrogen peroxide and the use of organic peroxides ("Industrielle Organische Chemie" 1994, 287-299, VCH Verlagsgesellschaft mbH Weinheim). The use of hydrogen peroxide, which usually takes place on titanium silicalite catalysts, offers one The advantage of high selectivity (over 90%), on the other hand, however, additional costs for the procurement of hydrogen peroxide have to be accepted in the first step ("European Chemical News, Volume 74, 20, March 5-11, 2001).

The use of organic peroxides is therefore of particular interest in indirect processes. After the epoxidation of propene, the use of the tert-butyl hydroperoxide obtained via i-butane leads to tert-butanol, which is required in large quantities for the production of methyl tert-butyl ether (MTBE) ("Industrial Organic Chemistry" 1994, 290 VCH Verlagsgesellschaft mbH Weinheim ). The same applies to ethylbenzene hydroperoxide (EBHP). After the epoxidation of propene, this peroxide produces the corresponding alcohol, which can be dehydrated to styrene (SMPO process) and which is ultimately absorbed by a large styrene market (“European Chemical News, Volume 74, 19 - 20, 5-11. March 2001). The disadvantage here is the too low selectivity of 75% with a turnover of 10 to 15%, which costs the system in terms of costs (“European Chemical News, Volume 74, 20, March 5-11, 2001).

Sumitomo has therefore developed a new process based on cumene hydroperoxide (CHP). This offers the particular advantage that the technology for the production of cumene hydroperoxide from phenol / acetone chemistry is well known on the one hand, and on the other hand cumene can be converted relatively easily into the peroxide (European Chemical News, Volume 74, 20, 5-11. March 2001). The cumene is relatively easy to oxidize, since the oxidation takes place with high selectivity at the tertiary C atom, which is also sterically hindered by 2 methyl groups (in practice air is used, usually without any catalyst). Radicals on tertiary carbon atoms are much more stable than those on secondary carbon atoms, which is why ethylbenzene is more difficult to oxidize. A number of processes for the preparation of hydroperoxides with atmospheric oxygen have recently been described.

In these processes, compounds of the N-hydroxyphthalimide (NHPI) type are used in combination with a radical initiator for the oxidation of hydrocarbons with atmospheric oxygen.

Despite the high amount of catalyst (up to equimolar ratios compared to the substrate), the processes described in the literature are unsatisfactory in terms of conversion and selectivity (J. Mol. Catalysis A. 1997, 117, 123-137). No. 5,030,739 describes the use of N-hydroxydicarboximides for the oxidation of isoprene derivatives to the corresponding acrolein compounds. A combined oxidation / dehydration of cyclohexadienes such as α-terpinene leads to the cumene derivative, which however is not further oxidized.

Generally, amounts of catalyst of at least 10 mol% in relation to the Substrate used, higher amounts of catalyst are used to increase the reaction rate (J. Org. Chem. 1995, 60, 3934-3935). Product selectivity is not sufficient for a technical application.

A further development of the system is the use of co-catalysts. Metal compounds, in particular heavy metal salts, enzymes or strong Bronsted acids can be used as co-catalysts. For example, Ishii et al. Showed that NHPI in combination with redox metal salts as cocatalyst can have advantages over oxidation with NHPI without cocatalyst (e.g. EP 0878234, EP 0864555, EP 0878458, EP 0858835, JP 11180913, J Mol. Catalysis A. 1997, 117, 123-137). In addition to the undesirable heavy metal content, the disadvantage of this system is the high amount of NHPI used. To ensure a satisfactory reaction rate, at least 10 mol% of catalyst must be used. Another disadvantage is that the redox metals used partially catalyze further reactions of the products and thus reduce the selectivity of the reaction.

Another process variant is the use of NHPI in conjunction with alcohols or aldehydes (Chem. Commun. 1999, 727-728, Tetrahedron Letters 1999, 40, 2165-2168, Chem Commun. 1997, 447-448). The disadvantage of these processes is the formation of by-products and the high catalyst-substrate ratio used (10 mol%).

DE 19723890 describes an oxidation system consisting of an organic catalyst and the redox enzyme laccase for the production of aromatic and heteroaromatic aldehydes and ketones. Here too, the amount of catalyst used is very high. In addition, through the use of an enzyme, this method has a complicated reaction system with a biologically necessary buffer system, which limits the broad applicability of this system. Finally, EP 0 198 351 (1985) reports on the oxidation of isoprenoid structures and thus activated structures with NHPI. The prerequisite here, however, is that an allylic hydrogen atom is contained which is oxidized. In addition, the amount of NHPI used in the examples is very high, according to the description at least 10 mol%, but preferably 25% to 100 mol%.

EP 0 927 717 (1997) generally describes a process for the preparation of hydroperoxides from hydrocarbons. The focus of this invention is on the isopropyl derivatives of benzene, that is - on account of the tertiary carbon atom - on easily oxidizable substrates and on sterically hindered piperidine derivatives (so-called TEMPO products) as catalysts. However, examples of the use of NHPI are also given, the examples showing that this catalyst is present in very small amounts (approx. 0.1 mol%) and a relatively high content of radical initiator (approx. 20 mol%) is used becomes. The person skilled in the art can at best conclude from the examples and comparative examples that NHPI has no effect. The reaction is also started with a very large excess of radical initiator (200 times the amount of catalyst).

It was therefore an object of the present invention to provide a process for the oxidation of ethylbenzene in which a high conversion of hydrocarbon and a high selectivity of hydroperoxide are achieved, the content of radical initiators preferably being able to be reduced.

Surprisingly, it was found that hydroperoxides of ethylbenzene can be obtained with significantly higher selectivity with an increased addition of catalyst of the type N-hydroxyphthalimide (NHPI). In addition, the process can be operated with a smaller amount of radical initiators. Although the catalysts of the NHPI type have been known from the literature for a long time, it has not been recognized that the molar concentration of the catalyst or NHPI combined with the use of a suitable radical initiator and its concentration in conjunction with a suitable starting product such as ethylbenzene is essential Meaning. The solution to the problem was therefore all the more surprising, especially since it was found that the ratio of all the amounts used had a significant influence on the course of the reaction.

The present invention therefore relates to a process according to claim 1 for the preparation of hydroperoxides of ethylbenzene by catalytic oxidation in the side chain to the corresponding hydroperoxide, which is characterized in that Ethylbenzene with a compound of formula I.

with R ¹ , R ² = H, aliphatic or aromatic alkoxy radical, carboxyl radical, alkoxycarbonyl radical or hydrocarbon radical, each with 1 to 20 carbon atoms, SO ₃ H, NH ₂ , OH, F, Cl, Br, I and / or NO ₂ , where R ¹ and R ^{2 are} identical or denote different radicals or R ¹ and R ² can be linked to one another via a covalent bond, with

X, Z = C, S or CH ₂

Y = O or OH k = 0, 1 or 2

1 = 0, 1 or 2 and m = 1 to 3; is implemented as an oxidation catalyst in the presence of a radical initiator, the molar ratio of the oxidation catalyst to the aromatic hydrocarbon being from 0.15 mol% to 10 mol%.

The present invention also relates to the use of a hydroperoxide prepared according to claims 1 to 9 for the oxidation of linear and cyclic olefins, for the epoxidation of linear and cyclic olefins or for the epoxidation of propene.

The process according to the invention has the advantage that hydroperoxides of hydrocarbons, in particular ethylbenzene, can be obtained with significantly higher selectivity than according to processes according to the prior art. In contrast to conventional methods, considerably fewer radical starters are required. The reaction can even be started without the addition of a radical starter. This is then either formed beforehand as an intermediate or is still present in traces from previous reactions. Since the product obtained as hydroperoxide is usually reused as a radical initiator, the overall yield of the process according to the invention is significantly higher than in the processes according to the prior art due to the smaller amount of radical initiator required to start the reaction. The larger amount of catalyst to be used, however, is irrelevant, since the catalyst is not consumed, but can be separated from the reaction mixture and reused. Of course, the process according to the invention also manages without heavy metals or strong acids as co-catalysts for the oxidation of ethylbenzene and its derivatives to the corresponding hydroperoxides and is therefore more environmentally friendly and more economical than corresponding processes in which these co-catalysts are used.

The process according to the invention is characterized in that for the preparation of hydroperoxides of ethylbenzene by catalytic oxidation in the side chain to the corresponding hydroperoxide, the ethylbenzene with a compound of the formula I

with R ¹ , R ² = H, aliphatic or aromatic alkoxy radical, carboxyl radical, alkoxycarbonyl radical or hydrocarbon radical, each with 1 to 20 carbon atoms, SO ₃ H, NH ₂ , OH, F, Cl, Br, I and / or NO ₂ , where R ¹ and R ^{2 are} identical or different

1 9

Designate radicals or R and R can be linked to one another via a covalent bond, with X, Z = C, S or CH ₂

Y = O or OH k = 0, 1 or 2

1 = 0, 1 or 2 m = 1 to 3; is implemented as an oxidation catalyst in the presence of a radical initiator, the molar ratio of the oxidation catalyst to ethylbenzene being from 0.15 mol% to 10 mol%. The molar ratio of the catalyst to ethylbenzene is preferably from 0.3 mol% to 5 mol% or from 5 mol% to 10 mol%, in particular from 0.5 mol% to 2.5 mol%, from 2.5 to 5 mol -%, from 5 to 7.5 mol% or from 7.5 to 10 mol% and very particularly preferably from 0.5 to 2.0 mol%.

The use of the compound (of the catalyst) according to formula I in this ratio to the ethylbenzene to be oxidized surprisingly not only results in high conversions with short reaction times, but is also distinguished by the selectivity compared to the prior art. Another advantage of the method according to the invention is the improvement in economy by reducing the amount of radical initiator required.

Examples of compounds of formula I are e.g. B. N-hydroxyphthalimide, 4-amino-N-hydroxyphthalimide, 3-amino-N-hydroxyphthalimide, tetrabromo-N-hydroxyphthalimide, tetrachloro-N-hydroxyphthalimide, N-hydroxyhetimide, N-hydroxyhimimide, N-hydroxytrimellitimide, N-hydroxy- benzene-l, 2,4-tricarboximide, N, N'-dihydroxy-pyromellitic acid diimide, N, N'-dihydroxy-benzophenone-3,3 ', 4,4'-tetracarboxylic acid diimide, N-hydroxymaleimide, N-hydroxy-pyridine-2 , 3-dicarboximide, N-hydroxysuccinimide, N-hydroxy tartarimide, N-hydroxy-5-norbonen-2,3-dicarboximide, exo-N-hydroxy-7-oxabicyclo [2.2. l] -hept-5-en-2,3-dicarboximide, N-hydroxy-cis-cyclohexane-1, 2-dicarboximide, N-hydroxy-cis-4-cyclohexen-1, 2-dicarboximide, N-hydroxynaphthalic acid imide sodium - Salt, N-hydroxy-o-benzenedisulfonimide.

The process is preferably carried out in organic solvents in the absence of strong acids, and the use of an aqueous solution, the pH of which can range from weakly acidic to basic, is also possible. The reaction is particularly preferably carried out in a solvent system which has at least 50% by weight, preferably 95% by weight and very particularly preferably at least 99.9% by weight of ethylbenzene. Carrying out in pure ethylbenzene is very particularly preferred Solvent, which means that the reaction is carried out in bulk.

In special embodiments of the method according to the invention, derivatives or special cases of compounds of the formula I can also be used.

Z are preferred. B. catalysts of the formula II, ie compounds of the formula I with m ^: 1.

where R ¹ , R ² = H, aliphatic or aromatic alkoxy, carboxyl, alkoxycarbonyl or hydrocarbon, each with 1 to 20 carbon atoms, SO ₃ H, NH ₂ , OH, F, Cl, Br, I and / or NO ₂ , wherein R ¹ and R ² denote identical or different radicals or R ¹ and R ² can be linked to one another via a covalent bond, and X, Z = C, S or CH ₂ , Y = O or OH, k = 0, 1 or 2 , and

1 = 0, 1 or 2.

Catalysts of the formula III are particularly preferred

with R, R, R, R = H, aliphatic or aromatic alkoxy radical, carboxyl radical, Alkoxycarbonyl radical or hydrocarbon radical, each having 1 to 20 carbon atoms, SO ₃ H, NH ₂ , OH, F, Cl, Br, I and / or NO ₂ , where R ¹ , R ² , R ³ and R ⁴ denote identical or different radicals can, with X, Z = C, S or CH ₂ , Y = O or OH, k = 0, 1 or 2 and

1 = 0, 1 or 2.

In a special embodiment of the invention, the ethylbenzene is oxidized to the hydroperoxide in the liquid phase at a temperature of 0 to 300 ° C., preferably at a temperature of 20 to 200 ° C., in particular at a temperature of 40 to 150 ° C. Both a solvent or solvent mixture and the ethylbenzene itself can be used as the solvent.

The process according to the invention is advantageous with ethylbenzene as the substrate to be oxidized. The selectivity in the oxidation of ethylbenzene without a catalyst suffers in particular from the fact that it takes place on a secondary carbon atom. On the other hand, it is much easier to oxidize cumene, in practice even often without a catalyst, since a tertiary carbon atom capable of forming stable radicals is oxidized here. In addition, two neighboring methyl groups stabilize the radical.

A radical initiator is added to the reaction mixture, which is either itself a radical or disintegrates to form radicals, such as. B. a peroxy compound or an azo compound. Examples of such compounds are cumene hydroperoxide, cyclohexylbenzene hydroperoxide, cyclododecylbenzene hydroperoxide, 1,4-di (2-neodecanoyl-peroxyisopropyl) benzene, acetylcyclohexanesulfonylperoxide, cumylperoxyneodecanoate, di-cyclohexylperyl (4-cyclohexyl) (4-cyclohexyl) (4) hexyl) peroxydicarbonate, dimyristyl peroxydicarbonate, dicetyl peroxydicarbonate, tert-butyl peroxyneodecanoate, tert-amyl peroxyneodecanoate, tert-amyl peroxypivalate, tert-butyl peroxypivalate, diisononanoyl peroxide, didecanoyl peroxide, tert-butylperoxy-2-ethylhexanoate, tert-butyl peroxyisononanoate, 2,2 ^c -Di-tert-butyl-peroxybutane, di-tert-butyl peroxybenzoate, di-tert-butyl peroxide, tert-butyl hydroperoxide, 3,4-dimethyl-3,4-diphenylhexane, dibenzoyl - peroxide, 1,4-di-tert-butylperoxycyclohexane, tert-butylperoxyethylhexyl carbonate, 1,1-di-tert-butylperoxycyclohexane, 2,2'-azobis (2,4-dimethylvaleronitrile, 2,2'-azobis (2- methyl-propionitrile), l, -azobis (cyclohexane carbonitrile), cyclohexyl hydroperoxide, of course intermediate peroxides and azo compounds can also be used as radical initiators.

A radical initiator which is an azo compound or contains an oxygen atom bonded to a carbon atom is preferably used. A radical initiator which contains an oxygen atom bonded to a secondary or tertiary carbon atom is particularly preferably used. In a special embodiment, the radical initiator is derived from the end product. The radical initiator is usually added separately, but it can also be generated as an intermediate prior to the actual reaction (e.g. from the solvent) or can still be present from previous reactions. At the start of the reaction, the radical initiator is present in a molar ratio of less than 12 mol%, preferably less than 10 mol%, particularly preferably less than 1 mol% and very particularly preferably less than 0.5 mol%. In other words, the molar content of the radical initiator at the beginning of the reaction, based on ethylbenzene, is preferably from 0.2 mol% to 10 mol%, particularly preferably from 0.5 mol% to 5 mol% or from 5 mol% % to 10 mol% and very particularly preferably from 0.2 to 0.7 mol% or from 0.7 mol% to 2.5 mol%.

The molar ratio of oxidation catalyst to radical initiator at the beginning of the reaction can be decisive for the speed and selectivity of the reaction. This is therefore preferably at least 1: 1, based on mol%. This means that the oxidation catalyst should be in excess at the start of the reaction and should not be less than the amount of radical initiator at the start of the reaction.

The oxidation product formed can be isolated as such, but the direct further conversion of this compound into the desired epoxidized product is also possible. Existing plants are expediently used for the production of propylene oxide and only the oxidation to ethylbenzene hydroperoxide is modified according to the invention. According to the invention, the process can be carried out either batchwise or continuously.

The process according to the invention can be carried out using an oxygen-containing gas as the oxidizing agent. The proportion of oxygen in the gas can be between 5 to 100% by volume. Atmospheric oxygen or pure oxygen is preferably used as the oxidizing agent. It is important to ensure that the liquid and gaseous phases are thoroughly mixed. This can e.g. B. in stirred tanks by a corresponding stirring speed or by internals and in tubular reactors with packing elements and with bubble acids.

As mentioned above, the process according to the invention can be carried out at a temperature of 0 to 300 ° C., preferably at a temperature of 20 to 200 ° C., in particular at a temperature of 40 to 150 ° C. The pressure can be both at atmospheric pressure (1 bar) and at increased pressure up to 100 bar. A pressure of 1 bar to 50 bar is preferred, a pressure of 1 bar to 20 bar is particularly preferred.

The ethylbenzene hydroperoxide produced can be used for the oxidation of linear and cyclic olefins, for the epoxidation of linear and cyclic olefins or for the epoxidation of propene.

The following examples are intended to illustrate the invention without restricting its scope.

Example 1 (according to the invention):

30 mmol of ethylbenzene are mixed with 0.6 mmol of N-hydroxyphthalimide and 1.2 mmol of cumene hydroperoxide in 100 ml of acetone in a round-bottomed flask with a reflux condenser at a temperature of 56 ° C. The reaction mixture is stirred for 8 hours at the temperature mentioned while passing air at 5 l / h. There is obtained ethylbenzene hydroperoxide with a selectivity of 95.9% with an ethylbenzene conversion of 13.8%. Example 2 (according to the invention, temperature 105 ° C.)

30 mmol of ethylbenzene are mixed in a round-bottomed flask with a reflux condenser at a temperature of 105 ° C. with 0.6 mmol of N-hydroxyphthalimide and 1.2 mmol of 1-cumene hydroperoxide in 100 ml of ethylbenzene. The reaction mixture is stirred for 3 hours at the temperature mentioned while passing air at 5 l / h. There is obtained ethylbenzene hydroperoxide with a selectivity of 93.8% with an ethylbenzene conversion of 14.7%

Example 3 (According to the Invention, Intermediate Generation of the Radical Starter)

30 mmol of ethylbenzene are mixed in a round-bottomed flask with a reflux condenser at a temperature of 125 ° C. with 0.15 mmol of N-hydroxyphthalimide in 100 ml of ethylbenzene. The radical starter is then generated by passing air through it as an intermediate from ethylbenzene. The reaction mixture is stirred for a total of 8 hours at the temperature mentioned while passing air at 5 l / h. There is obtained ethylbenzene hydroperoxide with a selectivity of 91.5% with an ethylbenzene conversion of 22.6%.

Example 4 (not according to the invention, with cobalt catalyst): 30 mmol of ethylbenzene are in a round-bottomed flask with a reflux condenser at a temperature of 56 ° C. with 0.6 mmol of N-hydroxyphthalimide and 0.6 mmol of Co (II) acetate in 100 ml of acetone are added. The reaction mixture is stirred for 8 hours at the temperature mentioned while passing air at 5 l / h. It is not the target product but acetophenone with a selectivity of approx. 22%, benzaldehyde approx. 9%, as well as a lot of different products (approx. 64%) and oligomers (rest) with an ethylbenzene conversion of 12.3%.

Example 5 (not according to the invention, analogous to EP 0 927 717 (1997), temperature 56 ° C.) 30 mmol of ethylbenzene are in a round-bottomed flask with a reflux condenser at a temperature of 56 ° C. with 0.03 mmol of N-hydroxyphthalimide and 6 mmol of 1- Cumene hydroperoxide in 100 ml acetone. The reaction mixture is 8 hours at mentioned temperature stirred while passing air of 5 1 / h. There is obtained ethylbenzene hydroperoxide with a selectivity of 12.3% with an ethylbenzene conversion of 0.3%.

Example 6 (not according to the invention, analogous to EP 0927717 (1997), temperature 105 ° C.)

30 mmol of ethylbenzene are mixed in a round-bottomed flask with a reflux condenser at a temperature of 105 ° C. with 0.03 mmol of N-hydroxyphthalimide and 6 mmol of 1-cumene hydroperoxide in 100 ml of ethylbenzene. The reaction mixture is stirred for 3 hours at the temperature mentioned while passing air at 5 l / h. There is obtained ethylbenzene hydroperoxide with a selectivity of 22.7% with an ethylbenzene conversion of 3.4%.

Example 7 (not according to the invention, analogous to Sumitomo experience)

30 mmol of cumene are converted into 100 ml of cumene in a round-bottom flask with a reflux condenser at a temperature of 105 ° C. The reaction mixture is stirred for 3 hours at the temperature mentioned while passing air at 5 l / h. Cumene hydroperoxide is obtained with a selectivity of 93.1% and a cumene conversion of 5.6. Cumene and atmospheric oxygen (without catalyst) form cumene hydroperoxide.

The conversion of the oxidation reaction was determined on the one hand by titration of the peroxide with iodine and on the other hand by GC analysis with an internal standard (naphthalene). The selectivity of the oxidation reaction was also determined by GC analysis with an internal standard (also naphthalene).

As can be clearly seen from the examples, in particular when comparing examples 1 and 5 and 2 and 6, an increased use of NHPI and a lower use of radical initiators can result in a significantly better conversion of ethylbenzene and a significantly better selectivity in relation be achieved on ethylbenzene.

Claims

claims: 1. A process for the preparation of hydroperoxides of ethylbenzene by catalytic oxidation in the side chain to the corresponding hydroperoxide, characterized in that the ethylbenzene with a compound of formula I

with R ¹ , R ² = H, aliphatic or aromatic alkoxy radical, carboxyl radical, alkoxycarbonyl radical or hydrocarbon radical, each with 1 to 20 carbon atoms, SO ₃ H, NH ₂ , OH, F, Cl, Br, I and / or NO ₂ , where R ¹ and R ² denote identical or different radicals or R ¹ and R ² can be linked to one another via a covalent bond, with X, Z = C, S or CH ₂ Y = O or OH k = 0, 1 or 2 1 = 0, 1 or 2 and m = 1 to 3; is implemented as an oxidation catalyst in the presence of a radical initiator, the molar ratio of the oxidation catalyst to ethylbenzene being from 0.15 mol% to Is 10 mol%. 2. The method according to claim 1, characterized in that the molar ratio of the catalyst to ethylbenzene of 0, 3 mol% to 5 mol%. , A method according to claim 1, characterized in that a compound of formula III as the oxidation catalyst

with R ¹ , R ² , R ³ , R ⁴ = H, aliphatic or aromatic alkoxy, carboxyl, alkoxycarbonyl or hydrocarbon, each with 1 to 20 carbon atoms, SO ₃ H, NH ₂ , OH, F, Cl, Br, I and / or NO ₂ , where R ¹ , R ² , R ³ and R ⁴ can denote identical or different radicals, with X, Z = C, S or CH ₂ , Y = O or OH, k = 0, 1 or 2 and 1 = 0, 1 or 2 is used. 4. The method according to claim 3, characterized in that the catalyst is N-hydroxyphthalimide (NHPI). 5. The method according to any one of claims 1 to 4, characterized in that a peroxy compound or azo compound is used as the radical initiator. 6. The method according to claim 5, characterized in that the radical initiator is at the beginning of the reaction in a molar ratio to ethylbenzene of less than 10 mol%. 7. The method according to claim 6, characterized in that the radical initiator is at the beginning of the reaction in a molar ratio to ethylbenzene of less than 1 mol% 8. The method according to any one of claims 1 to 5, characterized in that no radical initiator is added at the beginning of the reaction, but this is formed as an intermediate. 9. The method according to any one of claims 1 to 8, characterized in that at the beginning of the reaction the ratio of catalyst to Radical starter is greater than 1: 1. 10. The method according to any one of claims 1 to 9, characterized in that the reaction is carried out in a solvent system which has at least 50.0% by weight of ethylbenzene. 11. The method according to claim 10, characterized in that the reaction is carried out in a solvent system which has at least 95.0% by weight of ethylbenzene. 12. The method according to claim 11, characterized in that the reaction is carried out in a solvent system which has at least 99.0% by weight of ethylbenzene. 13. The method according to any one of claims 1 to 12, characterized in that the catalytic oxidation in the liquid phase is carried out at a temperature of 0 to 300 ° C. 14. The method according to any one of claims 1 to 13, characterized in that a gas with 5 to 100 vol .-% oxygen is used as the oxidizing agent. 15. The method according to any one of claims 1 to 14, characterized in that the catalytic oxidation is carried out under a pressure of 1 to 100 bar. 16. Use of the hydroperoxide prepared according to claims 1 to 15 for the oxidation of linear and cyclic olefins. 17. Use of the hydroperoxide prepared according to claims 1 to 15 for the epoxidation of linear and cyclic olefins. 18. Use of the hydroperoxide prepared according to claims 1 to 15 for the epoxidation of propene.