DE2605041B2 - Process for the epoxidation of olefins - Google Patents

Description

R ₂ R4

and wherein the two components of the catalyst system separately in different Molecules occur.

2. The method according to claim 1, characterized in that that a catalyst is used which consists of 0.1 to 2% by weight of the first component and 0.1 to 1 % By weight of the second component, based on the total reaction mixture

in which Ri, R ₂ , R3 and R ₄ , which can be identical or different, represent hydrogen atoms, linear alkyl radicals with 1 to 30, branched alkyl radicals or cycloalkyl radicals with 3 to 12 carbon atoms or a phenyl group, or Rj and R3 or R ₂ and R ₄ together form a straight-chain or branched alkylene radical with 3 to 11 carbon atoms, the radicals Ri, R ₂ , R ₃ and R4 optionally unsaturated and / or with chlorine or bromine atoms or with hydroxyl, alkoxy, Carbonyl, acid, ester or nitrile groups are substituted with hydrogen peroxide in the liquid phase, optionally in the presence of a solvent, at a temperature between 50 and 100 ° C and at normal pressure or under a pressure of up to 100 bar in the presence of a catalytic system , which consists of at least one derivative of arsenic, antimony or bismuth as the first component and at least one inorganic or organic derivative of vanadium, molybdenum, tungsten or titanium as the second component, dadur ch characterized in that the reaction is carried out in a homogeneous aqueous or non-aqueous phase at an apparent pH between 6 and 9 in the presence of a first component of the catalyst system of at least one organic arsenic, antimony or bismuth compound of the formula

R, MX "

in the

π and tn are each an integer between 0 and 5 and η + rn = 5, the radicals

R, which can be the same or different,

each for a hydrogen atom, a linear alkyl radical with 1 to 4 carbon atoms, a branched alkyl radical or cycloalkyl radical with 3 to 6 carbon atoms or a phenyl radical,

Μ means arsenic, antimony or bismuth and

the rest

X, which can be the same or different,

represent hydroxyl groups, halogen radicals or the anion of an inorganic or organic oxygen acid,
or of at least one arsenic, antimony or bismuth oxide, hydroxide, fluoride, chloride, nitrate, sulfate, phosphate, pyrophosphate, borate or carbonate or a corresponding salt of an aliphatic or aromatic carboxylic acid that does not Contains more than 20 carbon atoms, each of the two components of the catalyst system being used in an amount of 0.01 to 10% by weight, based on the total amount of the reaction mixture. The invention relates to a process for the catalytic epoxidation of olefins according to claim 1.

The olefins of the formula (I) of Claim 1 are those in which the radicals Ri, R ₂ , R3 and R _{4 are} identical or different and are linear for hydrogen atoms

.'ο alkyl radicals with 1 to 30, preferably 1 to 8 carbon atoms, branched alkyl radicals or cycloalkyl radicals with 3 to 12, preferably 4 to 6 carbon atoms or a phenyl radical. Ri and R3 or Rj and R ₄ can also together be a straight-chain or branched one

. '■> Form an alkylene radical with 3 to 11, preferably 4 to 6, carbon atoms, the radicals Ri, R ₂ , R3 and R ₄ optionally unsaturated and / or with chlorine or bromine atoms or with hydroxyl, alkoxy, carbonyl -, acid, ester or nitrile groups are substituted.

in GB-PS 13 24 763 catalysts are described, which cause phase transfer catalysis in a heterogeneous reaction system, with which olefins can be oxidized to aldehydes, ketones and carboxylic acids. The catalyst system consists of

i> a first component in the form of an organic quaternary salt, which is soluble in the less polar phase and a second component, which is a Metal compound of the metals osmium, ruthenium, molybdenum, tungsten, selenium, vanadium, chromium, titanium,

κι cerium, nickel, manganese, cobalt, platinum, iron, lead or (II) is palladium.

The oldest industrial process for the epoxidation of double bonds is the so-called chlorohydrin process, with chlorine as an oxidizing agent

• i "> is used. However, this procedure is not without Disadvantage mainly due to the simultaneous formation of calcium chloride, which is a by-product of dehydrochlorination of the chlorohydrin is obtained and can only be used economically with difficulty.

■ ίο It is also known that ethylene with good yields in the gas phase with molecular oxygen can be epoxidized over a silver-based catalyst. However, this procedure is due its lack of selectivity for other olefins

V) unsuitable.

Other epoxidation processes have therefore been proposed in which the oxidation with air in two Stages is carried out. For example, in the process described in US Pat. No. 3,351,635

Wi hydrocarbon, e.g. B. isobutane or ethylbenzene, with Air is oxidized to the corresponding hydroperoxide and this hydroperoxide then with the olefin in Reacted in the presence of a vanadium, molybdenum or tungsten compound. However, this method has

at the disadvantage that as a by-product of the reaction Alcohol is formed in the amount equivalent to the epoxy compound formed and difficult is economically usable.

Processes have also been proposed in which hydrogen peroxide is present as an oxidizing agent a catalyst, e.g. B. tungstic acid or in the presence a nitrile is used (US-PS 30 53 856). However, these two methods are also unsatisfactory, because in the first case not only the epoxy but also the corresponding glycol is obtained, while in the second case, in addition to the epoxide, an equivalent amount of the nitrile used corresponding amide is formed. The economy of such a process is therefore strongly dependent on the Recovery of this by-product bound. In BE-PS 7 47 316 the use of hydrogen peroxide as an epoxidation agent in the presence of a catalyst based on organic tin derivatives described. However, the compounds now mentioned have not yet been used on an industrial scale.

From US-PS 28 33 787 it is known äthylentsch unsaturated compounds with hydrogen peroxide in an aqueous medium at a pH greater than 3 to epoxidize in the presence of a heavy metal acid salt as a catalyst. Salts of heteropoly acids are named as catalysts.

The object of the present invention was to provide a process for the catalytic epoxidation of olefins with H2O2 to create that using milder Conditions allows a high selectivity of the epoxy.

The present invention relates to a process for catalytic epoxidation with hydrogen peroxide, which is characterized in that the reaction in homogeneous aqueous or not aqueous phase at an apparent pH between 6 and 9, in the presence of a Catalyst system that consists of two components.

The expression apparent pH was chosen because the measurement with the usual devices in one organic liquid or a mixture of water with an organic liquid and the Measured values are only to be regarded as numerical values.

It has been found that the double bonds with hydrogen peroxide in the presence of a catalyst can be epoxidized, consisting of a combination of

(1) at least one inorganic or organic arsenic, antimony or bismuth derivative as the first Component and

(2) at least one inorganic or organic derivative of vanadium, molybdenum, or tungsten Titanium is the second component.

The use of such a catalyst system allows a good selectivity of the epoxide, the Catalyst has a long service life.

The two main components are combined by adding two different ones Molecules for the reaction medium, which optionally with one another to form an active catalytic system react.

As inorganic arsenic, antimony or bismuth derivatives one can use the oxides, hydroxides, the salts of inorganic hydroacids and oxo acids and of aliphatic or aromatic carboxylic acids which contain not more than 20 carbon atoms and their Anions are stable under the reaction conditions. Examples are the fluorides, chlorides, Nitrates, sulfates, phosphates, pyrophosphates, borates, carbonates, formates, acetates, propionates, butyrates, Isobutyrate, Hexanoi.te, Octanoate, Dodecanoate, Naphtenate, Stearate, Oxalate, Succinate, Glutarate, To mention adipates, benzoates, phthalates. These salts can be used as such, but also in situ be formed by starting from the hydroxide and adding the corresponding acid.

The organic arsenic, antimony and bismuth derivatives have the general formula

(R) "M (X)"

in which M arsenic, antimony or bismuth and η and m are integers from 0 to 5, but where m + n is -5 . The radicals R, which can be identical or different, are each a hydrogen atom, a linear alkyl radical with 1 to 4 Carbon atoms, a branched alkyl radical or a cycloalkyl radical with 3 to 6 carbon atoms or a phenyl radical

The radicals X can be the same or different and are hydroxyl groups, halogen radicals, the anion of a inorganic or organic oxygen acid.

As examples of organic arsenic, antimony or bismuth derivatives of the formula II, which for the purposes of The following are suitable for the invention: The hydroxytetraalkyls, hydroxytetraphenyls, dihydroxytrialkyls, dihydroxydiphenyls of arsenic, antimony or bismuth, the fluorides, chlorides, bromides, iodides, nitrates, acids Sulfates, neutral sulfates, mono-, di- and tri-phosphates, pyrophosphates, polyphosphates, borates, carbonates, Thiophosphates, arsenates, selenates, formates, acetates, propionates, butyrates, isobutyrates, hexanoates, octanoates, Dodecanoates, stearates, oxalates, succinates, glutarates, adipates, benzoates, phthalates, acetylacetonates, Methanesulfonate, ethanesulfonate, benzenesulfonate or p-ToluoIsulfonate of tri- or tetraalkyl or phenyl arsenic, antimony or bismuth.

The arsenic, antimony or bismuth compounds used as the first component of the catalyst. can used as such or formed in situ from other arsenic, antimony or bismuth compounds will. The amount of the arsenic, antimony and bismuth derivative is between 0.01 and 10% by weight of the total reaction mixture and in particular between 0.1 and 2%.

At least one inorganic or organic derivative is used as the second component of the catalyst system used by vanadium, molybdenum, tungsten or titanium. Examples of soluble organic derivatives are Naphtenates, acetylacetonates, stearates, octoates, carbonyl derivatives or polyacids of the above To name metals. Suitable inorganic derivatives are the oxides, the corresponding oxygen acids and their salts, the phosphates, nitrates, sulfates, carbonates and arsenates. As a second part of the A carbonyl compound is preferably used as the catalyst system.

This second component of the catalyst is used in an amount of 0.01 to 10% by weight of the total Reaction mixture, in particular in an amount of 0.1 to 1 wt .-%, used.

The two basic components of the catalyst belong to different molecules.

As unsaturated compounds that can be oxidized by the process according to the invention, come for example: ethylene, propylene, the butenes, butadiene, the pentenes, hexene-1, hexene-3, Heptene-1, octene-1, octene-2, diisobutylene, nonene-1, Decene-1, limonene, pinene, myrcene, camphene, undecene-1, Dodecene-1, tridecene-1, tetradecene-1, pentad-

cen-1, hexadecene-1, heptadecene-1, octadecene-1, nonadecene-1, Eicosen-1, the trimers or tetramers of Propylene, the polybutadienes, styrene, «-Methy! Styrene, Divinylbenzene, stilbene, cyclopentene, cyclohexene, cycloheptene, Cyclooctene, Cyclooctadiene, C.yclododecen, Cyclododecatriene, Vinylcyclohexen, Methylallylketon, Allylchlorid, Allyl bromide, methacrylic acid, acrylic acid, crotonic acid, vinyl acetic acid, methallyl chloride, the Dichlorobutenes, allyl alcohol, allyl carbonate, allyl acetate, the alkyl methacrylates, the acrylates. Dial'yl maleate Dialkyiphtalat, the unsaturated glycerides such as soybean oil, sunflower oil, corn oil, cottonseed oil, olive oil, Castor oil, peanut oil, tall oil, talc oil and linseed oil, unsaturated Fatty acids, such as oleic acid, linolenic acid, whale oil, erucic acid, oleostearic acid, myristic acid, palininoleic acid, Licanic acid, ricinoleic acid or arachidonic acid and the esters of these acids.

The preferred procedure for the epoxidation of the ethylenic compounds according to the invention Process consists in that the two reactants in the presence of the catalyst in aqueous or non-aqueous solution or in the presence of a solvent that will homogenize the mixture relieved, implements. Aliphatic monohydric alcohols with 1 to are preferably used as the solvent 4 carbon atoms, e.g. B. methanol, ethanol, n-propanol, Isopropanol, n-butanol, isobutanol, sec-butanol and tert-butanol used. It can also be a nitrile, preferably an aliphatic C2 to Cs nitrile, such as Acetonitrile, an amide such as dimethylformamide, or an ether such as dioxane or tetrahydrofuran is used will.

The reaction can be carried out at normal pressure or under a pressure of up to 100 bar, if this is necessary in order to keep the olefin dissolved in the reaction mixture. A pressure between 1 and 50 bar is preferably used. The temperature is between 50 and 100 ^° C. The apparent pH of the mixture is kept between 6 and 9 and preferably 7 and 8.

Depending on the apparent pH of the reaction mixture, this setting can either include the addition a base, preferably a hydroxide or carbonate of an alkali or alkaline earth metal, or require an acid. Preferred acids are the customary inorganic hydrogen acids or oxo acids, such as. B. hydrochloric acid, sulfuric acid, phosphoric acid and the aliphatic or aromatic Carboxylic acids or alkyl or aryl sulfonic acids with less than 20 carbon atoms used-

The reaction time depends on the catalyst system used as well as the type of olefin used. It can last from a few minutes to 100 hours and be more.

The reactants can be used in equimolar amounts, but one or other reactants can also be used in a molar excess or deficiency. For example 0.1 to 5 moles of olefin can be used per mole of hydrogen peroxide, preferably however, 1 to 2 moles of olefin per mole of H2O2 used. The reactants can be used in their commercial forms. In particular, can the hydrogen peroxide in the form of aqueous solutions containing 30 to 90 wt .-% H> O_i, used will.

The reactants and the catalyst can be used simultaneously or in any order at a rate and at a temperature that is in particular a allow effective control of the thermal effects of the reaction introduced into the reaction medium will.

It can be advantageous to the reaction mixture Stabilizer for hydrogen peroxide, e.g. B. phosphoric acid, Add nitrilotriacetic acid, ethylenediaminetetraacetic acid or the sodium salts of these acids.

The epoxides are valuable intermediates.

ίο especially for the production of polymers or plasticizers.

The following examples illustrate the invention. The selectivity is defined as the number of formed Epoxy moles in relation to the number of reacted

r> moles of hydrogen peroxide.

example 1

In a maintained at 70 ^c C reactor is stirred, a mixture of 0.120 g Dihydroxytrimethylantimon (0.6 mmol), 11 g n-propanol, 4.1 g of cyclohexene (50 mmol), 0.1 g of tungsten hexacarbonyl and 1.58 g of a 70% by weight aqueous hydrogen peroxide solution (32.5 mmol). After 3 hours of reaction, 1.8 g of epoxycyclohexane (17.9 mmol) are determined by gas chromatography in the reaction mixture, which corresponds to a selectivity of 60% of epoxide when 92% hydrogen peroxide is converted.

B e i s ρ i e I 2

The same procedure as in Example 1 is repeated, the tungsten hexacarbonyl being replaced by 0.043 g Replaced molybdenum dioxide (0.3 mol). The formation of 4.6 mmol of epoxycyclohexane is measured, indicating a selectivity r> of 16% with a conversion of 86.5% hydrogen peroxide is equivalent to.

Example 3

The procedure of Example 1 is repeated, replacing the tungsten hexacarbonyl with 0.080 g of molybdenum hexacarbonyl (0.3 mmol) replaced. 4.5 mmol of epoxycyclohexane are formed, which gives a selectivity of 15% corresponds to a conversion of 90% hydrogen peroxide.

Example 4

A mixture of 35 g of n-propanol, 41.4 g of cyclohexene (505 mmol), 0.503 g of dihydroxytrimethylantimony (2.5 mmoles), 0.514 g tungsten hexacarbonyl (13 mmoles), 5.92 g

w of a 70% aqueous hydrogen peroxide solution (121.5 mmol) is heated to 60 ⁰ C. After 3 hours reaction was determined by gas chromatography 10.0 g epoxycyclohexane (102 mmol), which at a conversion of 90% hydrogen peroxide selectivity

ν- .92.5 %.

Example 5

Example 4 is repeated using propanol

replaced by Ν ', Ν-dimethylacetamide. One determines 71

bo mmol epoxycyclohexane, which gives a selectivity of 66% corresponds to a conversion of 88% hydrogen peroxide.

Example 6

tr- Example 1 is repeated by adding dihydroxytrimethylantimony replaced by 0.268 g of hydroxytelraphenylantimony (0.6 mmol). 6.3 mmol are formed Epoxycyclohexane, which has a selectivity of 22%

corresponds to a 91% conversion of hydrogen peroxide.

Example 7

Example 1 is repeated by replacing the hydroxytrimethylamine with 0.316 g ((',, HO ₁ SbPO ₄ H' %% corresponds to conversion of hydrogen peroxide.

Example

Example 7 is repeated, using the prop; inol replaced by 20 g of acetonitrile. Then 25 mmoles of epoxycyclohexane are determined. what a selectivity of 88% corresponds to a conversion of 94%. ι

H eis ρ ici V

250 g of n-propanol, 1.58 g of (CH, JiSbPO ₄ H: (3 mmol) and 0.5 g of tungsten hexacarbonyl are placed in a 1 liter autoclave. The mixture is heated to 50 ° C. and then placed under propylene of 3 When the solution is saturated, 4.8 g of 70% by weight aqueous hydrogen peroxide (0.1 mol) are introduced with the aid of a metering pump. After 2 hours of reaction, the propylene oxide formed is measured by gas chromatography; a selectivity of 5 is achieved % with a conversion of 60% hydrogen peroxide.

Example 10

A mixture of i <0.204 g of dihydroxytriphenyl arsenic (0.6 mmol) is left at 63 ° C. for 2 hours. 0.1 g Tungsten oxacarbonyl. 11 g acetonitrile. 4.1 g of cyclohexene (50 mmol) and 30 mmol of 70% aqueous Hydrogen peroxide react. 0.46 g of epoxycyclohexane (4.7 mmol) is measured by gas chromatography. what one; Selectivity to epoxide of 35% corresponds to a 45% conversion of hydrogen peroxide.

Example 11

In a 70 "C held reactor is stirred for a"> mixture 0.07 g of antimony trichloride (0.3 mmol), 20 g of acetonitrile. 4.1 g cyclohexene (50 mmol). 0.1 g of tungsten hexacarbonyl and 1.56 g of a 75% strength by weight aqueous hydrogen peroxide solution (32.3 mmol). After 4 hours of reaction, 1.5 mmol of epoxycyciohexane are determined in the reaction mixture by gas chromatography. which corresponds to an 8% selectivity of fipoxide with a 58% conversion of hydrogen peroxide.

Eg game 12

The procedure of Example 13 is repeated, replacing the antimony trichloride with arsenic (III) oxide As: O j replaced. With a hydrogen peroxide conversion of 23%, this corresponds to an epoxide selectivity of 22%.

Example 13

The procedure of Example I is repeated, but by passing n-propanol through 20 g of tetrahydrofuran replaced. The formation of 2 mmol of epoxycyclohexane is found, which corresponds to a 16% selectivity for epoxide corresponds to a conversion of 38% hydrogen peroxide.

Example 14

A mixture of 20 g of acetonitrile. 5.2 g of styrene (50 mmol), 0.6 mmol (CH OiSbPO ₄ H. 0.1 g of tungsten hexacarbonyl and 1.46 g of a 70% strength by weight aqueous hydrogen peroxide solution are heated to 70 ° C. After a 5-hour reaction, 2.3 g of epoxide ( 19 mmol), which corresponds to a 68% selectivity with an 86% conversion of hydrogen peroxide.

Example 15

Example 16 is repeated by replacing styrene with 5.6 g of 1-octene (50 mmol). Gas chromatography 1.6 g of epoxide (12.5 mmol) are determined. what with a 69% conversion of hydrogen peroxide corresponds to a 60% selectivity.

Claims (1)

Patent claims: 1. Process for the epoxidation of olefins of the formula R _{1 1}
\ C = C