JPS6033115B2 - Method for producing olefin oxide - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing olefin oxides from olefins and oxygen.

Ethylene is oxidized to ethylene oxide at high temperatures in the presence of a silver catalyst, but the yield to olefin oxide from higher olefins is low.

Various indirect but superior methods of oxidizing olefinic acid have been studied, and two methods currently in use are shown below.

1 Chlorohydrin Process (US Pat. No. 3,277,189) Olefins are reacted with chlorine in the presence of water to produce chlorohydrin olefins.

The chlorohydrin olefin is further reacted with a basic substance to produce an olefin oxide. The disadvantage of this method is the formation of inorganic chlorides and hydrogen chloride. Various methods for effectively utilizing the inorganic chloride have been proposed (for example, British Patent No. 142,502), but these methods also have the additional drawback of cost quotient due to electrical energy and cell inefficiency. have 2. Other methods (particularly U.S. Pat. No. 3,360, No. 4) produced propylene oxyhydroperoxide with a yield of 80% by reacting tertiary butyl hydroperoxide obtained by liquid phase oxidation of i-butane with propylene. code is generated.

Although this method provides a high yield of olefin oxide, it is disadvantageous that the method consists of multiple steps, that a complex distillation step is required to purify the product, and that the economics of the method are disadvantageous. Capital losses are large because they depend on the market price for the product, t-butanol or i-butane. Recycling of the by-products is possible, but requires hydrogen. In another proposed method, such as that disclosed in US Pat. No. 0M67, olefins are catalytically oxidized with hydrogen peroxide. However, this method uses hydrogen peroxide as an oxidizing agent because hydrogen peroxide is too expensive to produce with current industrial methods and needs to be concentrated when used as an aqueous solution. However, the disadvantage is that there is a large capital loss or a large chemical waste. Direct liquid phase epoxidation methods for higher olefins higher than ethylene are disclosed, for example, in U.S. Pat. No. 5, No. 26, U.S. Pat.
4 (72), etc., various proposals have been made.

These processes consist of contacting an olefin dissolved in a suitable solvent with oxygen at high temperature and pressure in the presence of a catalyst, usually an organic compound of molybdenum.
However, in these methods, the selectivity for olefin oxides is at most 50 to 60%, and the conversion rate to olefin oxides is low. British Patent No. 120
No. 6166 is a compound of group 8 metals capable of reversibly forming oxygen adducts, especially 1(PPh3)2COC1, Rh
A process is disclosed which consists of catalytically reacting oxygen and olefins in the liquid phase using (P Ph3)81 and Rh(PPh3)3CI as catalysts.

This method does not provide specific examples of lower olefins of C6 or lower, and the selectivity for C6 olefins is 26%.
There is no other choice. Dioxygen body (P Ph3) 2M02 (M=P
d, Pt) as an olefin epoxidation catalyst have also been proposed.

However, one of the methods, such as J. ○r hoko no
metamcChem. According to No. 26 417 (?1), the platinum rust body catalyzes the oxidation of cyclohexene by initiating a free radical reaction. This gives a variety of products, with a low selectivity to epoxide, ranging from 1 to 3%. Earl Sheldon and Jay Vandoorne have found that there is no direct reaction between these two key bodies and simple olefins such as cyclohexane at 60°C (J.Orr.
gaMmetllicChem. 94 115 (75)
). Despite the above-mentioned prior art, the present inventors have surprisingly found that the direct epoxidation of olefins, especially low molecular weight direct mirror olefins, can be carried out with certain complexes of Group VIII metals with good selectivity and yield. We found that it can be done quickly. From the above, the present invention provides L2MX2, L2
M or L2M Nagi type bell body (wherein L represents a ligand that is difficult to oxidize under the conditions of the method of the present invention and contains an element of the genus Snake; M represents a metal of the 8th group; represents an acidic anion, and R represents an olefin.

A method for producing an olefin oxide is provided, which comprises contacting olefin oxide with oxygen in the presence of a catalytic amount of olefin oxide. The oxygen may be pure or a gas mixture such as air.

The family element is preferably nitrogen, phosphorus or arsenic, with phosphorus being most preferred.

The Group 8 metal is preferably nickel, platinum or palladium, with palladium being most preferred.

L2 consists of two monodentate ligands or one bidentate ligand.

When L2 consists of a monodentate ligand, the ligand L is preferably of the type represented by AR, R2R3 (wherein A represents a group element, R, , R2 and R3 are independently an alkyl group, Indicates a cycloalkyl group, aryl group or halogen aryl group, hydrogen or halogen.

). When L2 consists of one bidentate ligand, L2
is preferably of the type represented by R4R5A, Rp2R7R8 (wherein A. and A2 represent elements of the genus, R4,
R5, R7, and R8 independently represent an alkyl group, a cycloalkyl group, an aryl group, a halogen aryl group, a halogen, or hydrogen, and R6 represents an alkyl group, a cycloalkyl group, an aryl group, or a halogen aryl group. Indicates a valence group.

). It is preferable that A and A2 are monolithic elements of the genus. the alkyl group has from 1 to 6 carbon atoms, the cycloalkyl group has from 5 to 8 carbon atoms, in particular cyclohexyl, the aryl group is phenyl, the halogenaryl group has It is preferred that the fluorinated compound is pentafluorophenyl, especially the perfluorinated compound, and that the halogen is iodine, fluorine, bromine or especially chlorine.

Particularly preferred monodentate ligands are tri(pentafluorophenyl)phosphine, tricyclohexylphosphine or triphenylarsine.

A preferred bidentate ligand is 1,2-bis(diperfluorophenylphosphine) perfluorobenzene. R
is preferably ethylene or propylene.

The acidic anion is a halide, preferably chlorine.

However, it is something like acetate, for example. Preferred collar bodies include bis(tri(pentafluorophenyl)phosphine)palladium dichloride: bis(tri(pentafluorophenyl)phosphine)palladium; pis(tricyclohexylphosphine)palladium; (fluorophenylphosphine) perfluorobenzene) palladium dichloride; (1,2-bis(diperfluorophenylphosphine) perfluorobenzene) palladium; ethylene bis(tricyclohexylphosphine) palladium; or propylene(1,2-bis(diperfluorophenylphosphine)perfluorobenzene palladium).

If desired, hydrogen may be contacted with the olefin and oxygen.

In this case, it is preferred that the key body is accompanied by a catalytic amount of a transition metal salt or a transition metal body. The transition metal is preferably cobalt, molybdenum, tungsten, /nadium, rhenium, rhodium or iridium. The olefin, oxygen and hydrogen can be contacted in a variety of ways.

For example, the collar body is dissolved in an organic liquid, and the olefin (
This method involves blowing oxygen (gaseous) and oxygen into the liquid. Olefin oxides may be separated by conventional techniques such as distillation or concentration from the effluent gas stream. Meanwhile, the collar body is dissolved in an organic liquid and water is added.

If the two are infusible and the olefin oxide is soluble in water, the olefin oxide produced by bubbling the gas mixture into the reaction system can be separated from the reaction system by extraction in the aqueous phase. I can do it. If the organic liquid and water are dissolved or partially dissolved, the maximum amount of water that can be present in the reaction system is limited by the solubility of the catalyst. As examples of suitable solvents that are soluble in water, which must not react with olefins, oxygen or hydrogen under the conditions of the process according to the invention, mention may be made of 2-methyl-2-propanol and 2-propanol. Suitable solvents that are insoluble in water include 1,2-dichlorobenzene, chlorobenzene and xylene.

Another aspect of the process of the invention is to dissolve the catalyst in the olefin (which is in liquid form) and bubble oxygen or oxygen and hydrogen into the solution.

The collar body may be selectively heterogenized or supported by the use of one or both of the ligands zymologically bonded to a suitable polymer.

Preferred examples include the following L type: [wherein, the vertical line with vertical lines indicates a polymer or copolymer (for example, styrene-divinylbenzene copolymer).

] can be mentioned. The rust body heterogenized or supported in this way is contacted with a gaseous mixture such as an olefin and oxygen or an olefin and oxygen and hydrogen, mixed with an organic liquid or alone, and the product is cooled, for example. Concentrate olefin oxide. In other embodiments of the invention, particularly when mixtures of olefins, oxygen and hydrogen are used, salts of transition metals or A collar body may also be included in the reaction system in a catalytic amount. Examples of suitable transition metals are cobalt, molybdenum, tungsten, vanadium, rhenium, rhodium and iridium. The transition metals are present as complexes soluble in organic liquids such as acetylacetonates or naphthenates, or as salts if they are soluble in the reaction system, e.g. as sulfate salts when immiscible organic/water mixtures are used. It is possible. Preferably, the gas mixture used in any embodiment of the invention is one that does not support ignition under the process conditions.

Such gaseous mixtures include olefins and oxygen, or mixtures of olefins, hydrogen, and oxygen made non-ignitable by dilution with a carrier gas such as nitrogen and nitrogen or methane. Advantageously, the process is carried out under superatmospheric pressure, for example up to 100 psi and at temperatures up to 20°C.

The present invention will be illustrated in a non-limiting manner by the following examples, in which percentages are expressed as volume percentages unless otherwise specified. Example 1 A solution of 100 ml of 4.1 x 10-3 moles of PdCI2 (P(C5)3)2 in 2-methyl-2-propanol was introduced into a Pyrex tube equipped with a reflux condenser and a gas sparger tube. (trade name) into a flask.

The solution in the flask was heated to 4°C and a 0.56N non-flammable mixture of 29% air in propylene was bubbled into the solution at atmospheric pressure. A gas sample exiting the top of the reflux condenser at 2 pC was analyzed by GLC (gas liquid chromatography) and found to be free of CO2 and acetone, but containing 0.03% propylene oxide.

The selectivity was 60 qo or more. Example 2 4.2 x 10-3 mol of PdCI2 (
200 ml of P(C6F5)3)2 solution was placed in a Pyrex vessel equipped with a reflux condenser and a porous Teflon disk sparger.

85 psl non-flammable gas mixture of 3% oxygen in propylene
89 qo was allowed to flow through the solution at an effective flow rate of 1.8 qo/ml. It flows out from the top of the reflux vessel at a temperature of 1 and 0. A gas sample was analyzed by GC. Propylene oxide was found to form at a rate of 1.0 mole per mole of catalyst per hour. The selectivity was over 60%. Example 3 8.1 x 10-3 moles of P in 1,2-dichlorobenzene
dC12(P(C6F5)3)2 solution with 100' of deionized water in a reflux condenser and porous Teflon (
(trade name) into a Pyrex container equipped with a disc sparger.

Propylene 431%, Hydrogen Hiro. A non-combustible gas mixture consisting of 4% oxygen and 2.5% oxygen was bubbled into the solution at a total pressure of 225 psig and an effective rate of 3.6 mm/skin at 670 mm. A gas sample flowing out from the top of the condenser at one scale was analyzed by GC.

Propylene oxide was found to be formed without CQ at a rate of 511 moles/mol of catalyst/hour. The selectivity was over 60%. Example 4 A solution of 1.7 x 10-3 moles of PdCI2 (P(C5)3)2 in 2-methyl-2-propanol, 100' in a Virex flask equipped with a reflux condenser and a gas sparger tube. I invested in it.

The solution in the flask was heated to 2 psi and 0.85 NZ/w of a non-flammable mixture of 2.1% oxygen in propylene was bubbled into the solution at atmospheric pressure. A gas sample exiting the top of the reflux condenser at 18° C. was analyzed by GC and found to be free of CQ and acetone, but containing 0.21% propylene oxide.

The selectivity was over 60%. In all of the above examples, the focus was on investigating the selectivity of the method of the present invention, and the diamonds used were simple experimental instruments without gas circulation means.
It was not possible to efficiently convert the raw material propylene into the target material propylene oxide (reaction time: 7
seconds, no cyclic reuse of unreacted materials).

Claims (1)

[Claims] 1. A method for producing an olefin oxide, which comprises contacting an olefin with oxygen and optionally hydrogen in the presence of a bis(tri(pentafluorophenyl)phosphine)palladium dichloride catalyst.