DE1568801A1 - Process for the production of oxirane compounds - Google Patents

Description

The invention relates to an improved method of manufacture of oxirane compounds and in particular the epoxidation of olefinically unsaturated compounds to the corresponding oxirane compounds with the help of organic Peroxyboranes as oxidizing agents.

The production of oxirane compounds, for example of ethylene oxide or propylene oxide, is very technical Meaning. There are already various methods of manufacture of these compounds from the olefinic

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BATH

For example, ethylene oxide is produced by the oxidation of ethylene on various solid catalysts with molecular oxygen. Furthermore, various processes for the epoxidation of olefins, for example propylene, have been developed through the catalytic reaction of a hydroperoxide with the olefin.

Despite the ready technological advances achieved There is still a need in this area for new processes for the preparation of the valuable oxirane compounds.

The invention therefore aims at a new process for epoxy * dation of olefinically unsaturated compounds to the Oxirane derivatives.

Surprisingly, it has now been found that the organic Peroxyborane excellent epoxidizing agents for the conversion of olefinically unsaturated compounds into the Oxlranderlvate are. In particular, it has been found that the Peroxyboranes are easily adjustable reaction conditions olefinic compounds in good yields and with high selectivities react smoothly to the oxirane product.

According to the invention, an olefinically unsaturated compound is used with an alkyl or aralkyl peroxyborane in the liquid phase reacted, and the reaction mixture obtained is worked up to separate an oxirane compound as a product, for example by distillation.

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The olefinically unsaturated ones that can be epoxidized according to the invention Substances include, for example, substituted and non-substituted aliphatic and alicyclic olefins, the coals. hydrogen, esters, alcohols, ketones, ethers or the like could be. Preferred compounds are those with about 2 to 30 carbon atoms and preferably at least 3 carbon atoms « Examples of such olefins are ethylene, propylene, n-butylene, isobutylene; the pentenes, the methyl pentenes, the n-hexene, the ootent, the dofieoene, cyclohexene, diethyl

oyοlohexene, butadiene, styrene, methyl styrene, vinyl toluene, Tinyloyclohexen and the phenylcyolohexenes. One can use olefins such as halogen, oxygen and sulfur having substituents containing. Such substituted olefins include, for example, allyl alcohol, methyl alcohol, Cyclohexanol, diallyl ether, methyl methaorylate, methylene chloride, Methyl vinyl ketone and allyl chloride «In general, according to des Process according to the invention all olefinic substances, including olefinically unsaturated polymers, which can be epoxidized by known methods.

A feature of the invention is the implementation of the Olefins with the peroxyborane. There are generally two embodiments the methods according to the invention which can be used successfully. The olefinic compound can with preformed peroxyborane reacted v / ground. This execution form

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The inventive method let berorsugt. Dae peroxyborane but can also be produced in eitu by inserting nan into the Epoxidationezone the olefin and the eur formation of the peroxyborane introduces the necessary reaction participants

The eroxyboranes, which are one of the participants in the reaction of the process according to the invention, and compounds which have an organic peroxyethylene (R ₁ OO-) bonded directly to a boron atom «· Acid, made with boron oxide or an alkoxyborane. The reactions involving IU peroxyboranes can be illustrated by the following equations

(1) B- (OR) ₃ ♦ R ₁ OOH >> (Ri0 °) _B -B- (OR) _n ♦ (3-n) R0H

where m is a number τοη 1 to 3, η is an integer ton O ble 2 and the sum of aue m and ή is 3 let, R is a waeeenftöffatom or a lower alkylreet with 1 to 6 carbon atoms and R _{1 is} an alkyl, aryl "Alkaryl" or Araikylreet with 2 to 30 carbon atoms means;

(2) OB-OR + R ₁ OOH -frO-BO-OR «, * • ROH

009813/1769 BAD OR »G * ^NAt

wherein R and H _{1 are} as defined above and

(3) B ₂ O ₃ + R ₁ OOH> 0-BO-OR ₁ + 0-B-OH

wherein R _{1 is} as defined above

The preparation of the peroxyboranes is detailed in the patent application of the same applicant from the same filing date with the internal file Caae 851.

Individual examples of peroxyboranes which can be used according to the invention are dimethoxy-alpha-phenylethylperoxyborane, methoxy-dialpha-phenylethylperoxyborane, Tri-alpha-phenylethylperoxyborane, alpha-phenylethylperoxyboroxine, the corresponding alpha, alpha-dime thylperoxyborane, the corresponding Xthoxy-, n-Propoxy «» i-Propoxy compounds: Di-tert-butoxy-tert-butylperoxyborane » tert-butoxy-di-tert-butylperoxyborane, tri-tert-butylptroxyborane, tert-butyl peroxyboroxine and the like.

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Examples of boron compounds that are Aa starting material for the reactions given above are suitable are tri »- methoxyborane, triothoxyborane, tri-tert.-butoxyborane, tri-npropoxyborane, Orthoboric acid, metaboric acid, boron oxide, methyl « boroxine, tert-butoxyboroxine and the like.

Suitable organic hydroperoxides for the above reactions are compounds of the formula R ₁ ⁰ OH wherein R ₁

as defined above 1st. Preferred hydroperoxides are at ..-? e.g. tert-butylhydroperoxidefCumolhydroperoxideCalpha, alpha-dimethylbenzyl hydroperoxide), ethylbenzene hydroperoxide (alpha-phenylethyl hydroperoxide), Cyclohexyl hydroperoxide, benzyl hydroperoxide and tetrahydronaphthalyl hydroperoxide.

In the preparation of Peroxyborane according to the above reactions, the reaction is advantageously carried out at 40 - 175 ⁰ C carried out under pressures which are generally in the range of 0.07 to 3.5 atmospheres (1 to 50 psia). The pick-up ratio of the reaction participants, given in moles of hydroperoxide per atom of boron, is preferably in the range from 1:10 to 10: 1 and most expediently in the range from 1: 2 to 2: 1. It is possible to use feroxyboranes with 1 to 3 peroxy groups per Making atom of boron. All such compounds are suitable for the purposes of the invention.

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In addition to the methods described above, similar Peroxyboranes are produced by reacting organic hydroperoxides with boron trichloride. Be there generally similar reaction conditions were used.

The ^ eroxyboranes can also be obtained by autoxidation of boron trialkyls, eum example boron trimethyl or boron tri-tert.-butyl, can be produced with molecular oxygen. This way of working however, it is less preferred.

When carrying out the method according to the invention, the peroxyborane with the olefin according to the following general principles Reactions implemented

n _{2 2}

♦ ^ JO -4 (R ₁ O) _n -B- (OR) _n + f

* r ^ s ^ R

R ₂ ^R 2 R ₂

R ₂ R ₂

0-BO-OR ₁ + CO '). 0-BOR ₁ ♦ CO

R ₂ "2 * 2

in which R, R ₁ , m and η are as defined above and the radicals R ₂ , which can be identical or different from one another, are hydrogen atoms or substituted or unsubstituted hydrocarbon radicals having about 1 to 20 carbon atoms.

8AD ORiGINAt 009813/1769

The reaction mixture is used to recover the olefin oxides worked up. It has a particular advantage in the invention Process that the al coproduct of Bpoxydatlon formed borateeters simply recovered and re-used for subsequent epoxidations can be used. One can Also manufacture extremely valuable co-products, such as glycols.

If, for example, R and 'R _{1 are the} same, the borateeter from the epoxidation can be reused directly for the reaction with further hydroperoyd to produce peroxyborane.

^w hen R ₁ and R are different and R is, for example, a lower alkyl radical and R _{1 is} an aralkyl radical, the aralkyl borate ester can be converted from epozydation by alcoholysis into the lower alkyl (preferably methyl) borate and aralkyl alcohol. This lower alkyl borate ester can then be reacted with hydroperoxide to produce further peroxyborane. The aralkyl alcohol can be converted into the aralkane by hydrogenation and the aralkane can be oxidized to hydroperoxide for further use in the production of peroxyborane. But you can also dehydrate the aralkyl alcohol to a valuable styrene product of the process.

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In the preferred embodiment of the invention In the process, pre-formed peroxyborane is reacted with the olefin Peroxyborane production done in situ.

In embodiment _{f, in} which the peroxyborane is prepared in siiu, it is generally necessary to remove the alcohol or the water formed as a coproduct of the peroxyborane formation reaction. This removal is necessary to ensure the formation of significant amounts of peroxyborane. In this embodiment, the reactants should be chosen so that easy removal of the water or alcohols formed as a coproduct is ensured. The alkyl substituent on the boric acid ester used as the reactant must be taken into account, so that the corresponding alcohol is easily removed by distillation. It is often advantageous to introduce an inert material into the reaction mixture which will aid in the removal of alcohols or water by stripping or azeotroping; Suitable amounts of boron compound are 0.3 to 10 moles per mole of hydroperoxide.

BAD ORlGlNAt

009813/1769

~ ίο. ·

Dae peroxyborane can either be in BtÖohiometry or can be used in catalytic amounts. In the case of catalytic processes, an excess of hydroperoxide is poured into the water reacts continuously with the alkoxyborane and then more Amounts of peroxyborane regenerated. You can, for example in a system in which trleyolohexylperoxyborane and hexadaoen-2 are reacted, a catalytic amount of trioyclohexyloxyborane with an excess of Cyolohexylhydroperoxid and Unite Hexadeoen-2. By distilling off cyclohexanol from the system, this can occur during epoxidation 'rloyelohexyloxyborane with further amounts of the hydroperoxides with the formation of further peroxyborane reaction participants Implementation. For such a catalyst one Amounts of boron compound from 0.0001 mol to 0.3 mol per mol of hydro « peroxide suitable.

In general, let it "be worthless to do the eonsentration." Peroxyborane duroh removal of faeeer when metaboretfure all reactants is used, or by removal of alcohol when an alkoxyborane is used as all reactants will, however, in some systems let this increase not required. Beiepieleweiee forms eich in systems, in * where a tertiary hydroperoxide is used together with an alkoxyborane derived from a tertiary alcohol, sufficient

BAD 009813/1769

Alkylperoxyborane without simultaneous removal of alcohol The alkoxyborane can therefore be used in amounts of 0.0001 to 10 moles per mole of hydroperoxide to achieve an advantageous reaction without removing water or alcohol. Such systems include, for example, tert-butyl hydroperoxide + tri * tert-butoxyborane and alpha, alpha-dimethylbenzyl hydroperoxide + tri-alpha, alpha-dimethy1-benzyloxyborane.

PUr the epoxidation Bind in general temperatures of from 50 - from 90 200 ⁰ C, preferably - suitable - (1000 Peig peia 5) 150 ⁰ C, "and pressures of 0.35 atmospheres to TOatü..

The following examples illustrate the invention without specifying it.

example 1

Duron solution of trimethoxyborane with ethylbenzene hydroperoxide produces a peroxyborane suitable as an epoxidation reaction participant. The ethylbenzene hydroperoxide in the form of a 12-hour solution in ethylbenzene and the trimethoxyborane are combined in proportions of 1 to 5 and reacted at 70-80 ⁰ ^ and 0.35 atmospheres (5 psig). During the reaction, a mixture of methyl alcohol and trimethoxyborane is distilled off from the reaction zone. This distillate is condensed and the trimethoxyborane is separated off and returned to the reaction zone. The reaction will continue

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put until practically all of the hydroperoxide in one Borate ester transferred, which is determined by that 1 mole of methanol per mole of hydroperoxide reactants is won.

The the Feroxyboran containing solution is then combined in a Epoxydationszone with propylene and reacted (650 psig) at a temperature of 115 ⁰ C and 45.5 atm. The Ilolverhältnis of Peroxyboran to propylene is 1: 15 ^N aoh a re ~ action time of 4 hours is the Peroxyboranumwandlung 94 ^C S at a React ion selectivity to propylene oxide of 55 £, based on converted Ptroxyboran.

The reaction mixture obtained is used to separate the spilled Ingredients distilled. The propylene oxide deetillate represents a product of the process. Hiohtumgeeetatee Propylene is recovered and recycled. The per-; ' pxyborane is almost complete through the oxidation reaction

has been reduced to a mixed alkoxyborane. This material was recovered and treated old an excess of methyl alcohol at 70 ⁰ C, whereby the entire borane in the Trlmethoxyboran passes over as an azeotrope with the methanol and // - phenylethanol is removed. The trimethoxyborane is returned to the peroxy formation stage after the methanol has been separated off. Dae Jj -phenylethanol is dehydrated over a titanium dioxide catalyst to styrene, a coproduct of the process.

009813/1769

Example 2

A solution of 1.0 mole of triethoxyborane and 0.50 mole of ethylbenzene hydroperoxide in a solvent mixture, which consists practically of 9 moles of ethylbenzene and 9 moles of cyolohexane, is placed in a device made entirely of glass at atmospheric pressure using a 20-tray Oldershaw column a reflux ratio of about 10: 1 distilled. The distillate having a boiling range of 65 ~ 80 ⁰ C contains 0.5 mol Xthanol and remaining as a residual bubble content Cyclohexan.Im not be unreacted borane and more al i 98 "of Peroxydgehalts the feed predominantly in the form of alpha-diethoxy phenyläthylperoxyboran before ·

The peroxyborane solution thus obtained is used for a number of different Epoxidation tests used. The following table gives the reaction conditions and the results obtained again.

BATH ORIGINAL

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Table I.

Try olefin • millimoles

Peroxy

borane,

Millimoles

Peroxide

oxygen

Reaction time, hours temp

O _n

Grain, of peroxide, in charge millimoles per gram

Peroxide conversion

5 «

Selectivity to epoxy. £

none

(O
OO • ρ » 2. Propylene δ 219 to ο 5. 2-methyl 9 2 ^ -butene O) 2 · 200 CO 4th 2-methyl 2 buten 200 5. Propylene 209

15 15

15th

2 2

100 100

100

115

0.50 0.56

0.34

0.28

0.40

0 57

88

80

67

0 21

87

90

53 _> cn

- 15 Example 3

This example illustrates the production of peroxyborane in situ and the epoxidation with molar amounts of boron compound.

500 g of a 4 fig solution of gyolohexyl hydroperoxide in cyclohexane (0.173 liol) are mixed with 11.7 g (0.08 mol) of triethoxyborane and 78.5 g (0.7 mol) of 2-octene. The mixture is heated to reflux in a distillation column and a mixture of ethanol and cyclohexane is distilled off overhead. NaOH 6 hours, the Peroxydumwandlung 75 i> and the selectivity is eu 2,3-epoxyoctane 68 i ".

Example 4

This example illustrates the preparation of peroxyborane in situ and epoxidation with a catalytic amount Boron compound.

A solution with a content of 5 wt. # Cyclohexyl hydroperoxide in Dodeoen-1 is added by adding a cyclohexane solution of Cyclohexyl hydroperoxide to the olefin and vacuum distillation to remove cyclohexane. This solution will added cyclohexyloxyboroxine in a ratio of 0.02 moles of boron per mole of hydroperoxide. The mixture is in vacuo for 3 hours

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heated to 115 ⁰ C, while the cyclohexanol do continuously Mitohung is abdestllliert. The peroxide conversion * - bears £ 60, and the selectivity «u. 1,2-Bpoxydodeoan 49 t.

In a similar umeetsung, at which the solution Ton alcohol is heated to 115 ⁰ O 3 hours without removal, a 20 5 * owned conversion de »peroxides is erslelt ·

• - ■ - '■

Example 5

Dleeee example explains the use of τοη Metaboreaure for a Bpoxidation. 500 g of a 10% solution of Cyoloootylhydroperoxid in Cyoloootsn (0.343 mol) is rereetet with 190 g (1.7 mol) Cyoloooten and 0.2 mol Metaboreaure. The mixture is kept under stirring at about 400 mm (110 ⁰ O) in RüokfluBsieden, wherein a water separator is used and the hydrocarbon into the reactor lurUokläuft. LAOH six hours is the Peroxydumwandlung 88 i "and dl · 8elektlTi * did au Bpoxyoyolootan 76 f. Bine in the same fei ·· performed reaction in which the Metaboreäure was omitted, showed a * eroxydumwandlung τοη only 16 $ and a selectivity to äpoxyd Sound less than 3 40 jC.

BATH ORIGINAL
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- 17 Example 6

This example explains the catalytic conversion with in peroxyborane produced in situ and without removal of hydroxyl compound.

In all experiments an olefin is used in a 75 ecm steel bomb epoxidized. In experiments 6 to 10, benzene is used as the solvent and propylene to propylene oxide epoxy « dated. In experiments 11 to 12, cyclohexane is used as the solvent used una cyolohexene epoxidized to cyclohexene oxide · Experiment 13 was carried out for comparison purposes «

In every experiment there is a mixture of the solvent, tert-butyl hydroperoxide, the olefin and tri-tert-butoxyborane filled into the bomb and implemented at the specified temperature and for the specified time. In the trials. 6 to 10 was the hydroperoxide concentration in the Beeohiokgemieoh 6.1% by weight, in experiments 11 and 12, on the other hand, 4.4% by weight The term "conversion" in the following table means hydroperoxide conversion, and the term "selectivity" Selectivity to the olefin oxide, based on the hydroperoxide *

The results obtained are shown in the following table

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4 »
: d

4 »· Ή

5 »

0
CO

S.

ο d

• η «3

• Ρ 4 »

O
■ Η
4> O

ir

«4»

at

; 3

'J 4 »ΟΉ

H • β O

& 3

in in

O O VO

ι-

σ «« ο

τ- CO

r- CM ^ t CM

CM CM

M CM

CM

· CM

ITV

in in ιη

CM

in in in

CM CM T-

<νο

νο νο νο

CM CM

ιη

CM CM *

t- r-

CM CM

CM

CM CM CM

VO · QO Φ r-

^ 009813/1769 cm

156880t

The above results are clearly evident that they are part of the equation low molar concentrations of alkoxyborana achieve high hydroperoxide conversions and yields of olefin oxide will.

The boron compounds were used herein according to modern nomenclature designated. So esters of orthoboreic acid became ale alkoxyboranes (for example trimethoxyborane instead of clay Trimethyl borate) and eater of metaboric acid as alkoxyboroxines (sum Beiapiel trimethoxyboroxine instead of methyl metaborate) designated.

In the equations given, the metaboric acid and its Bater ά & ν have been shown in the monomeric form for the sake of simplicity. It can be assumed that these substances are actually present as cyclic trimers.

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Claims (1)

- 20 Pttttnttnipllche 1. Process for the production of τοη Oxlranverblndungen, thereby characterized that one is an olefinically unsaturated compound with an organic * eroxyborane. 2. The method according to claim 1, characterized Dafi, one uses a Peroxyboran which has been prepared by reacting an organic hydroperoxides old lt alkoxyborane a lower hergeste. ¹ % Procedure naoh Anepruoh 1, daduroh marked thatB a peroxyborane is used which is produced by umsetiung an organisohen Hydroperoxides have been made with orthoboreic acid. 4 * Procedure naoh Anepruoh 1, daduroh marked da0 a peroxyborane used, which duroh implementation of an orgs> nlschsB Hydroperoxides produced with MetaboreKure »orden 1st. 0098 13/1765 15S88Q1 5. The method according to claim 1, characterized in that one uses a peroxy "borane, d & a by reacting a · organic hydroperoeyda with boron oxide is. 6. The method according to claim 1 _S, characterized in that the peroxyborane is produced before the spoxidation. 7. The method naofa claim 1, characterized in that one al © unsaturated compound propylene and as peroxyborane a Ί "• Phenyläthylperoxy'box'an Tsrwendste. 8. The method according to claim 1, »dadurefe characterized ,, dafl man an olefinically unsaturated compound, an organisones Hydroperoxide and a boric acid ·, boron oxide or an alkoxyborane reacts. 9 * Method according to claim 8, characterized in that as the unsaturated compound propylene, as HydroperoxyΊ tert-butyl hydroperoxide and as alkoxyborane tert-Alkoxyborane used. 009813/1769