JPS6191148A - Synthesis of acetone - Google Patents

Abstract

PURPOSE:To improve yield of the titled compound in oxidation of propylene in the presence of a metal complex catalyst, by oxidizing propylene using a composite complex containing both an oxygen-complex and a propylene-complex as a metal complex in the presence of water under mild conditions in a short time by the one-stage process. CONSTITUTION:Propylene is oxidized in the presence of both a composite complex containing a complex (MmXn.Ll) capable of forming an oxygen-complex by being coordinately bonded with oxygen and a complex (M'm'X'n'L'l') (M represents a transition metal belonging to the iron group of Groups I, IV-VII and VIII of the periodic table; X represents anion; L represents organic phosphorus compound; M' represents transition metal belonging to the platinum group of Group VII of the periodic table; L' represents nitriles, organic fluorine compound, etc.; m, m', n and n' each represent a number defined by the valency of the above-mentioned transition metal and the anion; l and l' each represent coordination number) and water to obtain acetone.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a method for synthesizing acetone, and particularly to a method for producing acetone by oxidizing propylene in the presence of water and an oxygen complex.

(Prior art) Acetone is a typical aliphatic ketone, and is used in large quantities industrially as a solvent for acetylcellulose, nitrocellulose, acetylene, etc., and is also used as a solvent for fats, resins, camphor, etc. in the pharmaceutical field. It occupies an important position in the chemical industry, serving as a raw material for the synthesis of many intermediate products, such as methyl isobutyl ketone, methyl isobutyl carbinol, methyl methacrylate, bisphenol A1, and even ketene.

Industrial methods for synthesizing acetone are broadly classified into three types: (1) isopropanol dehydration method, (2) cumene method, and (3) propylene oxidation method.

Among these, the dehydrogenation method of isopropanol uses Zno or Cu as a dehydrogenation catalyst at 300 to 500°C, 3a
It is operated under severe conditions of tm, and is said to have an isopropanol reaction rate of about 98% and an acetone selectivity of 90%.

In addition, in the cumene method, cumene is oxidized with oxygen in the liquid phase at normal pressure and 120°C using Cu, CO salts, etc. as catalysts to synthesize cumene hydroperoxide, which is then oxidized at 60 to 65°C with 0.1 to
It decomposes with 2% H2SO4 and co-produces phenol and acetone. The selectivity based on cumene is about 90%, with phenol accounting for 60% and acetone accounting for 40%. These processes are currently in operation, but a method that is attracting attention as a one-step method for producing acetone under milder reaction conditions is palladium chloride (Pd(2)c12)-dichloride using propylene as a raw material. Copper (Cu (2)
This is the so-called Hooka method, which uses CJ2) as a catalyst, and is the most distinctive of the acetone manufacturing methods.

In this method, the catalyst Pd(2)CJz and Cu (
2) A composite catalyst in which C5 is dissolved in a hydrochloric acid solution (pH 2) is used. First, divalent palladium (Pd (2
)) and water, propylene is oxidized to acetone (C
H3COCH3) is produced. The reaction is shown by the following formula, and water is involved in the reaction.

CH3CH-CH, +Pd (2) cz2+H, 0→C
H3-C-CH +pt1 (0) ↓+2HC
& (1) As can be seen from the reaction formula, pa (2) is reduced to become metallic palladium (Pd (0)') and precipitated.

In addition to preventing this, a large amount of Cu (2) CIlz is allowed to coexist, and pa (0) is changed to Pd (2) as shown in the following formula.
) and needs to be regenerated.

Pd (0)+2Cu (2)C12 -Pd (,2)C12+2Cu (1)C7!
(2) Furthermore, poorly soluble Cu produced as a by-product at this time (1)
C1 is oxidized with oxygen in the presence of HCl according to the following formula, and C1 is
u (2) Returned to CI12.

2Cu (1)C1+ -02+2HC#→2Cu (
2) CIlz +H20 (3) Like this? dC2
)/Pd (0) and Cu (2)/Cu (1) redox systems are employed to enable continuous oxidation of propylene. However, as mentioned above, instead of oxygen molecules directly reacting with propylene, pd (2)/P
Since the redox reaction of d(0) and Cu(2)/Cu(1) systems is utilized, these are the rate-determining steps. In addition, during the reaction, sparingly soluble pa (0) and Cu (1) (1!) are produced, so HC with high concentration
7! An aqueous solution (pH 40) is employed, which necessitates the selection of corrosion-resistant materials. Furthermore, since the solubility of oxygen in water is low, the solubility must be increased, and the higher the olefin, the lower the reactivity, so the reaction conditions are as severe as 140° C. and 14 atm. Note that under these conditions, the propylene reaction rate was 99% or more, and the selectivity to acetone was 92%.
%, and 2 to 4% propionaldehyde is said to be produced as a by-product. Furthermore, if excess dissolved oxygen is released into the gas phase, propylene and oxygen will mix, potentially causing problems such as explosions, and countermeasures are required.

As described above, both methods are carried out at relatively high temperatures and pressures, and a method that can synthesize acetone under milder conditions has been desired.

(Problems to be Solved by the Invention) In order to solve these problems, the purpose of the present invention is to oxidize propylene under milder conditions to selectively synthesize acetone in high yield. be.

(Means for Solving the Problems) In short, the present invention uses a transition metal complex in which oxygen molecules coordinate to metal ions to form an oxygen complex as one of the catalyst components, and further coordinates propylene. , is a method for synthesizing acetone under mild conditions by using a different type of transition metal complex that can form a propylene complex and water. That is, the present invention provides a method for synthesizing acetone by oxidizing propylene in the presence of a metal complex catalyst. l> and a complex catalyst (M"m'Xn"L"j!') that can coordinate with propylene to form a propylene complex, and water (where M Group 1, Group IV
~A transition metal belonging to Group VII or Group 1 iron group, X is a halogen such as Cl-, Br-1I-'', or BF4-
Anion such as 1PF feeling-1CH3COO-1so42-, L is an organic phosphorus compound, M9 is a transition metal belonging to the platinum group of the periodic law group, L' is a nitrile, an organic fluorine compound or an organic phosphorus compound, m, m ", n, n' are numbers determined by the valence of the transition metal and anion, 1, It
' indicates the coordination number).

The present inventors first determined that a transition metal capable of forming an oxygen complex by coordinately bonding an oxygen molecule to a metal ion is used as at least one of the catalyst components to coordinately bond propylene to form a propylene complex. Acetone is synthesized under mild conditions in a non-aqueous solvent system by directly oxidizing propylene activated by complex formation with bound oxygen activated by complex formation using a composite catalyst consisting of transition metals obtained. proposed a method (Japanese Patent Application No. 59-12144, Japanese Patent Application No. 59-444)
No. 69).

The present invention is based on the discovery in the course of its research that the oxygen complex of the invention has the ability to efficiently oxidize pa(0) to <Pd(2)Cβ2. In other words, to give a typical example, Cu
(1) A mirror body (Cu (
1) Oxygen complex (C1-hm p a ) generated from
Cu (1) CI・hmpa)2 ・C2) and, for example, a complex formed from Pd (2) C12, h m p a and benzonitrile (Pd (2) C1z
・Propylene complex (Pd(2) of PhCN-hmpa)
C12.PhcN-C3H6) is reacted in the presence of water, and is thought to proceed by the following mechanism.

・a) Generation of propylene complex and oxidation of propylene P(1(2)C12-PttCN -hmpa+c3
++.

=Pd(2)C1z ・PhCN −C+Ha+h
mpa (4)Pd(2)C/z ・P h CN
-Cl14-I-1120-Cl COCll3
+Pd (0) ↓+211(1!+PhCN
(5)b) Regeneration of Pd(0)Pd(0)-2(CuCIA-hmpa) 2-0H
+2HCj+PhCN+hmpa −=Pd (r,)C12・PhCN−hmpa+C
u (1) CA! -hmpa (6)C)O□
Regeneration of complex Cu (1) CI -hmpa+-02→ (Cu
(1) CJ)2'02 (7) - Figure 1 schematically shows the cycle of this reaction to make it easier to understand.
(2)/Cu (1) This is completely different from the method using a redox system (Fig. 2).

Further, to explain the characteristics of each reaction in more detail, the rate at 60t of the oxidative regeneration reaction of Pd (0) to Pd (2) (1!2 complex, shown in the following equation) is
(2) It was about 10 times faster than the one using C7!2 (formula (2)).

(Cu (1) CI・hmpa)2 ・Oz→-Pd
(0) +HCj! +PhCN+hmpa-=Pd (
2) CIA2・PhCN-hmpa+(:, u (1)
C1-hmp a +H20 (7) Where, the complex forming the above-mentioned oxygen complex is expressed by the general formula MmXnLj
! Cu(1)CIA-hmpa is m=
This corresponds to the cases of 1, n-1, and 1t-1. Furthermore, for example, when Sn (2) or Ti (3) is the central metal and the anion is Cl-, the complex formed is Sn (
2) CIA2-hmpa, Ti (3) C13・
hmpa, and the former is m=l, n=2)! =1, the latter corresponds to the case where m=l, n=3, i-1.

By the way, Cu generated by equation (7) (1) CIl・
h m p a selectively absorbs oxygen from oxygen-containing gases such as air and returns to the original oxygen complex, but the speed is 6
At 0°C, the above-mentioned Cu (1)l! The reoxidation reaction of Cu (2) to CIl2 by 02 (formula (3)) is about 8 times faster.

Therefore, if the propylene is activated by forming a propylene complex and reacted in the presence of water, acetone synthesis from propylene can be performed efficiently. Therefore, we investigated complexes of various platinum group transition metals. As a result, to describe a typical example, Pd (2) C1
In No. 2, when a nitrile (hereinafter referred to as PhCN) such as benzonitrile was added to the h m pa as a modifying ligand (auxiliary complexing agent), the following new complex was generated.

Pd (2) C12(hmpa)2 +PhCN, =:
Pd (2) CIA2 ・PhCN-hmpa+hmp
a (8) In addition, this complex can be expressed by the general formula M'm'X
When indicated by n'L'l', m1=1, n°
=2.1f=1.

This new Pd (2) complex forms a propylene complex with propylene according to formula (4), but in the generated propylene complex, propylene is significantly activated, so
The oxidation reaction (formula (5)) between Pd (2) in the complex and water proceeds easily, and acetone can be synthesized in one step under mild conditions.

Pd (2) C12'PhCN-hmpa+C3H4;
Pd (2) CIA2 ・PhCN-C5H4+hmp
a(4)Pd (2)C1z ・P h CN
-C3H& + H20-CH3COCll3 +
pct (0)1 +2HCj+PhCN (5) The generated Pd (0) can be easily converted to the original Pd (2)Cj! by the oxygen complex as described above. Return to the 2-complex.

(Function) As described above, in the present invention, propylene is activated as a complex, oxidized by the oxidizing power of pa (2) and H20, and the generated Pd (0) is converted to the activated Pd (0) in the oxygen complex. Since it can be reoxidized with oxygen, acetone can be synthesized with high selectivity and high yield in a short time under mild conditions such as under heavy pressure and at 60° C. or lower. Moreover, since it can be synthesized using a one-stage method, it is possible to reduce the equipment, cost, and utility to a large extent compared to conventional methods.

In the composite catalyst system of the present invention, MmXnll! is used as a complex catalyst that forms an oxygen complex and generates f6! As for M in
Cu of Group 1 of the periodic law, A g %T of Group Ⅰ, Zr
, Group ■V, Nb, Group ■Cr %Mo5W, Group ■
Group M n % Group 1 Fe, Co.

Transition metals such as Ni are preferred, and Cu(1), 5n(
2) , Ti (3) are more preferred. In addition, as X, CR”-, Br-1■- halogen, BF4-1P
Anions such as F≦-1SO42-1CH and COO- are preferred, and CIA- and Br-1- are more preferred. Examples of the ligand include triphenylphosphine oxyto, which is a derivative of phosphoric acid, hexamethylphosphoramide, mono-, di-, or triester formed from the reaction of phosphoric acid with methanol, ethanol, etc., as well as dimethyl methylphosphonate, Methyl dimethylphosphinate, or derivatives of phosphorous acid, mono-, di- or triester formed from the reaction of phosphorous acid with methanol, ethanol, etc.; Preferable examples include organic phosphorus compounds such as triphenylphosphine, and hexamethylphosphoramide (hm pa ) is particularly preferable.

On the other hand, a complex catalyst (M ”
As Ml in m″ Preferred examples include nitriles such as , acetonitrile, propionitrile, and benzonitrile, and the above-mentioned organic phosphorus compounds, as well as organic fluorine compounds such as fluorinated toluene and pencitrifluoride.

In addition, as a solvent for the reaction system, in addition to dissolving the complex, acetone (b, p, 56 ° C / 760 wHg
) is preferred, and one that reduces the viscosity of the catalyst solution and promotes mass transfer, such as heptane,
Toluene, methylcyclohexane, ethanol, dioxane, propylene carbonate, chlorobenzene, N-
At least one solvent selected from various solvents such as methylpyrrolidone and tetrahydrofuran or a mixture thereof may be used, or when the ligand or L' is a liquid, it may also be used as the solvent.

In addition, in order to increase the selectivity and yield of the reaction, basic (electron-donating) compounds such as sulfolane, dimethylsulfolane, dimethylsulfoxide, dimethylformamide, trimethylmethane, and dimethylsulfone were used as shown in the examples below. It is preferable to coexist in the reaction system.

The reaction examples in which acetone is synthesized by forming an oxygen complex and a propylene complex and oxidizing propylene in the presence of water have been described above.The present invention will now be explained in more detail with reference to Examples.

(Example) Example 1 Cu (1) was placed in a volumetric flask with an internal volume of 20 m2.
50 g (0.5 mol) of Cl and 2 h m p a
00g preparation, Cu(1)CI・hmpa complex solution 194mj! was prepared. In addition, another 200 ml
Pd (2)CA'22.6g (15
mmol) and benzonitrile (hereinafter referred to as PhCN) and 120 g of Shmpa,
148 ml g of 2-PhCN-hmpa complex solution
Made by H. After that, both were transferred to a reactor with a capacity of 1.5jl, 828g of sulfolane was added thereto, and Cu (1)
0.5 m o j as CIA! / 1, Pd (
2) A 0.015 mol/l catalyst solution 11 was prepared as C1. To this, 98 g (9%) of water was added, and air was introduced at 30° C. under normal pressure to prepare a solution with an oxygen complex concentration of 0.145 mol/l. Afterwards, it was heated to 60°C and nitrogen gas was passed through it, but only the oxygen remaining in the gas phase of the reactor and the physically dissolved oxygen were removed, and the theory that the combined oxygen from the oxygen complex in the liquid was removed. No separation was allowed. After this operation, the propylene was heated to 0 at 60°C.
．． When aeration was performed at a rate of 341/min, it was confirmed by gas chromatography that 7.0 g of acetone was produced in 10 minutes. Additionally, 0.2 g of propylene aldehyde was produced.

Example 2 In Example 1, when the amount of water added was 31 g (3%), 5.6 g of acetone was obtained in 45 minutes. Also, when the amount of water added was 176g (15%), 20
Only 5.2 g of acetone was obtained in minutes.

From this example and example 1, the amount of water in this reaction system is 1
A value around 0% is considered appropriate.

Example 3 In Example 1, the concentration of Pd (2) Cffi was set to 0°03 mol/j! A similar reaction was performed. As a result, 7.2 g of acetone was obtained in 10 minutes, which is almost the same as in Example 1, and in the present invention, Pd(2)C
It has been found that there is no need to increase the I12fi degree unnecessarily.

Example 4 In Example 1, the reaction was carried out without adding PhCN.

As a result, 4.7g of acetone was obtained in 30 minutes (
yield of about 65% of Example 1). Therefore, it was shown that the addition of PhCN as a modifying ligand plays an important role in promoting the reaction.

Example 5 In Example 1, Sn was used instead of Cu (1) ClIO.
(2) When the same operation was performed except that 95 g (0.5 mol) of C12 was used, 5.9 g of acetone was removed in 10 minutes.

Example 6 In Example 1, Cu (1)C7! Ti instead of
(3) When the same operation was performed except that 77 g (0.5 mol) of cty3 was used, 6.3 g of acetone was obtained in 10 minutes.

Example 7 In Example 1, Pd (2) was substituted for C12.
(2) When the same operation was carried out except that 3.0 g (15 mmol) of SO4 was used, 6.8 g of acetone was obtained in 10 minutes.

Example Day In Example 1, Pd (2) PL instead of CI2
(2) When the same operation was performed except that 4.0 g (15 mmol) of Cj'z was used, 6.5 g of acetone was obtained in 10 minutes.

Example 9 In Example 1, Cu (1) C1l was replaced with cuprous bromide and cuprous iodide, and the other operations were similar, resulting in 6.9 g and 6.6 g of acetone in 10 minutes, respectively. was gotten.

Example 10 The same procedure as in Example 1 was carried out except that propionitrile and pencitrifluoride were used instead of benzonitrile, and 6.3 g and 6.5 g of acetone were obtained in 10 minutes, respectively.

Example 11 In Example 1, 1 mo I as Cu (1) CI
t/l, P d (2) 0.0 as C12
15m.

A catalyst solution of 1./II was prepared. At this time, h m p
698 g of a, 31 g of benzonitrile, and 360 g of sulfolane were added. After that, ventilate the air to 0°29
As an oxygen complex solution of mol/11, Example 1
When propylene was aerated in the same manner as above, 13.8 g of acetone was produced in 20 minutes. It is shown that increasing the oxygen complex concentration results in higher acetone production.

Example 12 In Example 11, the oxygen complex concentration was 0.48 M,
The reaction was carried out at 60°C. As a result, 11.3 in 30 minutes
g of acetone was obtained.

Example 13 A catalyst liquid having the composition of Example 11 was kept at 80°C and 30% air was added.
When a mixed gas of 70% propylene was passed through the reactor at a rate of 0.31/min for 30 minutes, 14.5 g of acetone was produced. □ Comparative Example 1 When the same procedure as in Example 1 was carried out except that no oxygen complex was formed, only 0.6 g of acetone was produced in 1 hour. This result shows that in the method of the present invention, oxidative regeneration of Pd (0) with an oxygen complex is repeatedly performed.

(Effects of the Invention) According to the present invention, acetone can be synthesized by oxidizing propylene with high efficiency at around room temperature and under normal pressure.

Furthermore, even if air is used as an oxygen source, since oxygen is selectively absorbed, exactly the same effect as using pure oxygen gas can be obtained. Further, since oxygen absorption is irreversible, excess free GTT oxygen can be easily removed after forming an oxygen complex, which is extremely advantageous in terms of safety.

[Brief explanation of the drawing]

FIG. 1 and FIG. 2 are schematic diagrams illustrating the present invention and the conventional acetone synthesis method, respectively. Agent Patent Attorney Kawakita 2'Nagao D

Claims (7)

[Claims] (1) In a method of synthesizing acetone by oxidizing propylene in the presence of a metal complex catalyst, a complex (MmXn Ll) capable of forming an oxygen complex by coordinate bonding with oxygen is used as the metal complex catalyst, and propylene A complex catalyst (M'm'Xn'L) that can coordinate with and form a propylene complex
'l') and water (where M is a transition metal belonging to the iron group of Group 1, IV to VII or VIII of the periodic law, X anion, L is an organic phosphorus compound, M' is a transition metal belonging to the platinum group of group VIII of the periodic law,
L' is a nitrile, an organic fluorine compound, or an organic phosphorous compound, m, m', n, n' are numbers determined by the valence of the transition metal and anion, and l, l' indicate the coordination number)
A method for synthesizing acetone characterized by: (2) In claim 1, X is Cl^-
, Br^-, I^-, etc., halogen, BF_4^-, PF
A method for synthesizing acetone, characterized in that it is an anion such as _6^-, CH_3COO^-, SO_4^2^-. (3) In claim 1 or 2, the organic phosphorus compound as the ligands L and L' is a compound represented by an alkoxy, alkyl or amide derivative of phosphoric acid or phosphorous acid. A method for synthesizing acetone characterized by the following. (4) A method for synthesizing acetone according to any one of claims 1 to 3, wherein m, m', n, n'l, and l' are each from 1 to 4. (5) In any one of claims 1 to 4, sulfolane which is a basic (electron donating) compound;
A method for synthesizing acetone characterized by adding dimethylsulfolane, dimethylsulfoxide, dimethylformamide, etc. to a catalyst system. (6) In any one of claims 1 to 5, the complex capable of producing an oxygen complex and the solvent capable of producing a propylene complex include aliphatic, alicyclic or aromatic hydrocarbons, oxygen-containing At least one selected from the group consisting of organic compounds, organic halogen compounds, and nitrogen-containing compounds
A method for synthesizing acetone, characterized in that a seed compound is used, or when the ligands L and L' are liquids, the ligands themselves are used as a solvent. (7) In any one of claims 1 to 6, oxygen, an oxygen-containing gas such as air, and the propylene are aerated into the composite catalyst solution to form an oxygen complex and a propylene complex, and the A method for synthesizing acetone characterized by carrying out the reaction in the presence of acetone.