JPS63122633A - Oxidation method for olefins having aromatic nucleus - Google Patents

Abstract

PURPOSE:To efficiently obtain an oxygen-containing compound useful as a raw material for medicines, etc., in one stage, by oxidizing olefins having an aromatic nucleus in the presence of a Pd complex, Cu complex, oxygen water, preferably further a basic compound. CONSTITUTION:Olefins, e.g. indene, having an aromatic nucleus are oxidized to provide an oxygen-containing compound, e.g. 2-indanone. In the process, the reaction is carried out in the presence of a Pd complex of the formula Pd(2)X2.L.L', Cu complex of the formula Cu(1)X'.L (X and X' are halogen ion, BF4<-2>, PF6<->, CH3COO<->, etc.; L and L' are ligands selected from nitriles and organic phosphorus compounds), oxygen, water, preferably further a basic compound, e.g. sulfolane or DMF. The concentration of the basic compound is 0.2-8M/l. Heptane, toluene, dioxane, etc., are used as a solvent for the reaction system, but the liquid ligand L and L' may be individually used as the solvent.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention relates to a method for oxidizing olefins having an aromatic nucleus, and in particular to a method for oxidizing olefins having an aromatic nucleus in the presence of an oxygen complex and water. It relates to a method of synthesizing a compound.

(Prior Art) 2-Indanone is a compound that is expected to be in demand in the future as a raw material for pharmaceuticals such as antihypertensive agents currently undergoing clinical trials. Existing manufacturing methods include the bromohydrin method and the formate ester method. The bromohydrin method uses the following formulas (1) and (2)
and (3), a method for producing 2-indanone from indene. In formula (1), H is added to indene.
2O and Br2 are reacted to produce 2-hydroxy-3-bromine bean, which is further reacted with methanol and potassium hydroxide to produce 2-hydroxy-3-methoxy bean, which is then mixed with 2-indanone in an aqueous sulfuric acid solution. do.

The formic acid ester method, which is another production method for indene, is expressed by the following formula (4).
, as shown in (5). That is, first, indene is reacted with formic acid and hydrogen peroxide to form 2-hydroxy-3-
Synthesize formisocacidoindane. Next, this is converted into 2-indanone in an aqueous sulfuric acid solution.

(Problems to be solved by the invention) 2 by the above-mentioned bromohydrin method and formate ester method
-The indanone synthesis method has the problem of requiring multiple steps.

On the other hand, using a Pd (2) catalyst, indene was oxidized to 2
- A method for synthesizing indanone is known (Japanese Patent Publication No. 36-7869);
It was found that when Cu (2) C12 is used to oxidize Cu (2) C12, a complex is formed between indene and Cu (2) C1tz, and the oxidation of indene is significantly suppressed.

The purpose of the present invention is to provide a method for oxidizing olefins having an aromatic nucleus, which eliminates the drawbacks of the above-mentioned prior art, shortens the oxidation process of olefins to one step, and promotes the coordination of olefins to Pd complexes. It is about providing.

The present inventors previously proposed a method for producing 2-indanone by oxidizing indene in the presence of a catalyst and oxygen. L') is at least one of the catalyst components, and the general formula MmXn-Lll
A method for producing 2-indanone using a composite catalyst in which one of the catalyst components is at least one selected from a metal complex represented by, an organic oxidizing agent, and calcium carbonate (however,
In the above formula, M is a transition metal that belongs to the iron group of Group 1, Groups ■ to ■, or Group II of the periodic law, X is a halogen ion, and BF4
Anions such as -, PF, G -, CH3COO-1S042-, L and L' are nitrile compounds, organic fluorine compounds, or organic phosphorus compounds, m, n, and n' are constants determined by valence balance, and l is coordination. proposed an integer indicating a number. The reaction formula is as follows.

2@F+2Pd (2) cz,・LL”+2H,O
E2 @)3...pa (2) C12・L-L')
+2H20-2 warm mistake +2Pd+4HCJ! +4L
...(6)2Pd (0) + (Cu (1)
CIl ・L) 4 ・Oz +4HC12Pd
(2) C12+4Cu (1) C1-Lo2H20・<
1) 4Cu (1) C1-Lo02 → (Cu (1
) CIl-L) 4 .02 (8) However, this method still has the problem that the yield of 2-indanone is low.

During the research process, the present invention discovered that an oxygen complex, which is an oxidizing agent for Pd, caused charge transfer, and as a result, Cu was produced.
(2) and indene form a complex (formula (9) below)
, based on the finding that the coordination of indene to Pd (2) is inhibited, the coordination of indene to the Pd complex and the coordination of indene to the charge-transfer type 02 mirror are competitive. It is assumed that the indene oxidation process (formulas (6), (7), (8))
We considered that the rate-determining step was the indene coordination reaction to the Pd complex. Therefore, it was determined that an improvement in the yield of 2-indanone could not be expected without suppressing the formation of charge-transfer type oxygen complexes. This is because the present inventors have already confirmed the existence of the charge transfer type 02 complex using ultraviolet absorption spectra, and in order to suppress this, basic solvents (sulfolane, dimethylsulfolane, dimethylsulfoxide and dimethylformamide) are used. etc.) was found to be effective, that is, Figure 1 shows that Cu (1)
C1-L, Oz! i-form A (basic solvent-free system), i-form B (basic solvent added system) and Cu(2)C12・Ln
It is a figure which shows the ultraviolet absorption spectrum about a complex. First, the spectrum of Cu(1)CIl・L is 230~
Although it did not have a large absorption at 310 nm, when it was subjected to oxygen absorption and measured, absorption appeared at 290 nm, and the absorption increased with the passage of time. This 290
The absorption at nm is unique to Cu (2) C12-Ln, and furthermore, from the calculation of the extinction coefficient, Cu (2) Cl
It was found that the concentration corresponds to half that of 2.Ln.

From this Cu (1) -0-0-Cu (1) to C
Charge transfer occurred with u (1) -0-0--Cu (2) H, and the existence of a charge transfer type 02 complex was presumed. On the other hand, in a solution containing a basic solvent, the wavelength was 290 nm.
No absorption appeared in the sample, and a spectrum almost matching that of Cu(1)C1'·L was shown.

As mentioned above, Cu (1) Cβ・ which is an oxidizing agent for Pd
L・02 mirror causes charge transfer, and part of Cu becomes Cu
(1) changes to Cu (2), and this Cu (2) becomes
2-indanone forms a complex with indene, suppresses the coordination of indene to the Pd complex, and significantly inhibits the indene oxidation reaction of formula (6). It was found that this is the key to producing in high yield.

Therefore, (1) the concentration of Cu (1) C1l-L . In order to suppress migration, it is important to coexist with a basic solvent, and (3) to optimize the concentration by considering the suppression of coordination of the basic solvent to Pd (2). It became clear.

In the present invention, olefins having an aromatic nucleus are combined into palladium complex Pd (2)X2 ・L-Lo, copper complex Cu (1)
X”・L (where X and Xo are halogen ions, BF
4-1PF6-1CH coC00- and so, the same or different anions selected from 2'', L and Lo are the same or different ligands selected from nitriles and organic phosphorus compounds), oxygen and water It is characterized by being oxidized in the presence of

In the present invention, Cu as a complex catalyst capable of forming an oxygen complex (1)X" in X".L is C12
−, B r″″, ■− halogen ion, B F 4−
, P F 6- , CH3COO-, SO42- and the like are preferred, and Cβ-1Br-1■- is more preferred. Ligands include nitriles, phosphoric acid derivatives such as triphenylphosphine oxyto, hexamethylphosphoramide, mono-, di-, or triester formed from the reaction of phosphoric acid with methanol, ethanol, etc., and dimethyl methylphosphonate. , methyl dimethylphosphinate, or derivatives of phosphorous acid, mono-, di-, or triesters produced by the reaction of phosphorous acid with methanol, ethanol, etc.; Organic phosphorus compounds represented by phenylphosphine etc. are preferred, and in particular, hexamethylphosphoramide (hmpa), benzonitrile (P
, hCN) and acetonitrile are preferred. On the other hand, the ligand of palladium complex Pd (2) N2 ・LL,',
L' includes acetonitrile, propionitrile, p
Preferred examples include nitriles such as hCN, the above-mentioned organic phosphorus compounds, and organic fluorine compounds such as fluorinated toluene and pencitrifluoride. L, L
' may be the same. Further, as X, those similar to the above-mentioned X' can be mentioned as preferred.

As for the concentration of the oxygen complex formed by Cu (1)

In the present invention, Cu of Cu (1) in the oxygen complex
In order to suppress charge transfer to (2), at least one basic (electron-donating) compound such as sulfolane, dimethylsulfolane, dimethylsulfoxide, and dimethylformamide may be added to the catalyst system. preferable.

The concentration of this basic compound is preferably 0.2 to 8 M/l
, more preferably 0.4 to 2 M/l.

The solvent for the complex or reaction system includes aliphatic, aromatic, alicyclic hydrocarbons, oxygen-containing organic compounds, organic halogen compounds, nitrogen-containing compounds, organic sulfur compounds, organic fluorine compounds, and heterocyclic compounds, preferably Ethers such as hebutane, toluene, methylcyclohexane, dioxane, propylene carbonate, chlorobenzene, N-methylpyrrolidone, tetrahydrofuran, and ethylene glycol monomethyl ether are used.

The method of the present invention is not limited to the oxidation of indene, but can be similarly applied to the oxidation of other olefins having similar aromatic nuclei.

(Example) Example 1 Pd(2) C was placed in a disturbed rooting reaction container with an internal volume of 50 m1.
j! 2 0.02393 g (13.5 mmol>
, CH3CN 7.4 g (0.18mo (1”)
), sulfolane 1.44 g (0,012 mol
), 16.7 g (0.22 moA) of ethylene glycol monomethyl ether lc was added, and 7
Dissolve at 0°C.

Next, the inside of this reaction vessel was replaced with N2, and Cu(1)C
j! Add 0.2970 g (3 mmoff) of
dissolve. Subsequently, the inside of the reaction vessel was replaced with air, oxygen was absorbed at normal pressure, and a solution with an oxygen complex concentration of 50 mmoff/l was made of steel.The reaction container was then replaced with N2, and the raw material indene 0.3479 g (3 mmo 6 ), N20 2
．． 16 g (0.12 mo J) was added and the reaction was carried out at 70° C. The product was analyzed by gas chromatography. As a result, 2-indanone was
mol/A was generated.

Example 2 An experiment was conducted in the same manner as in Example 1 except that the concentration of the oxygen complex was 10 m m o n / l.
- Indanone-generated gold increased to 11 mmol/l.

Example 3 An experiment was carried out in the same manner as in Example 1 except that the concentration of the oxygen complex was 5 m m o β/l. The amount of 2-indanone produced was 30 m m o e / l, and the catalyst cycle was completed in one cycle. It was confirmed that a section was formed.

From the above, it can be seen that the 2-indanone yield can be improved by making the oxygen complex concentration lower than the Pd complex concentration, and that the oxygen complex concentration greatly influences this reaction. However, the concentration must be such that it does not impair catalyst cycle formation.

Comparative Example I After operating in the same manner as in Example 1 until Pd (2) C1z was melted, 0.3479 g (3 mmo
1), 16g (0.12mol) of H202 were added, and the reaction was started at 70°C.

As a result, 28.6 mmol! /l of 2-indanone was confirmed to be produced, and when combined with the by-product 1-indanone, the total amount produced was equal to the added Pd(2〉C
It was confirmed that it matched with 2□.

Comparative Example 2 The operation up to melting Pd(2)cx2 was carried out in the same manner as Comparative Example 1, and the inside of this reaction vessel was replaced with N2, and Cu
(1) C/! 0.2970 g (3mm.

i) Added and dissolved. Next, quickly add the raw material indene 0.3479g (3mmof), H202゜16
When Pd (0,12 mo j?) was added and the reaction was carried out at 70°C, 23 mmoβ/l of 2-indanone was produced, and the total indanone production port was Pd (
2) It matched with C1z'llJ degree.

Comparative Example 3 10.75 g (0°05
An experiment was carried out in the same manner as in Comparative Example 1 except that 6.2 g (0.08 mo 6) of ethylene glycol monomethyl ether was added. As a result, the amount of 2-indanone produced was 26.5 mm.

It was e/l. Similar to Comparative Example 1.2, the added Pd
(2) It is believed that all C12 was utilized for indene oxidation.

From Examples 1 to 3 and Comparative Examples 1 to 3, it can be concluded that in a system without the addition of an oxygen complex used as an oxidizing agent for Pd (0), indene oxidation by Pd complex occurs stoichiometrically, and charge transfer type oxygen complex It was found that the complex formation of indene and indene significantly affects indene oxidation.

Next, an example will be shown below in which an oxygen complex was stabilized using a basic solvent, sulfolane, in order to suppress the formation of a charge transfer type oxygen complex.

Example 4 Sulfolane concentration was 3 m o (t/l % ethylene glycol monomethyl ether was 0.38 m o
An experiment was conducted in the same manner as in Example 2 except that the ratio was changed to l/l, and the amount of 2-indanone produced was 5 m m o
l/(1), which was about half the yield of Example 2 and was 7.

From the above results, if the concentration of sulfolane added to stabilize the charge of the oxygen complex is too high, sulfolane will cause Pd.
(2) It is thought that it coordinates with C12 and reduces the activation of indene by the Pd complex, and it was found that there is an optimum concentration range.

Example 5 Sulfolane concentration was 2 m o f2/1, ethylene glycol monomethyl ether concentration was 5.17 m o
The reaction conditions were the same as in Example 2 except that l / β was used.
When an experiment was conducted, the amount of 2-indanone produced was 10 m
moJ/β, which was almost the same as in Example 2.

Example 6 Sulfolane concentration was 1 m o I! / I! , 6.37m0ff of ethylene glycol monomethyl ether
An experiment was carried out using the same reaction conditions as in Example 2 except that /β was changed, and the amount of 2-indanone produced was almost the same as in Example 2.

From the above, the basic (electron-donating) solvent is 0.4 to 2M
A concentration range of is considered preferable.

Comparative Example 4 H2O2 degree is Q mol/l, ethylene glycol monomethyl ether concentration 7.28 mol/l
When an experiment was conducted in the same manner as in Example 2 except that the amount of 2-indanone was changed to 1, almost no amount of 2-indanone was produced. From the above, it is considered that 2-indanone synthesis is preferably carried out in the presence of H20.

(Effects of the Invention) According to the present invention, in order to suppress the coordination of olefins having an aromatic nucleus to the charge transfer type oxygen complex, a low concentration of the oxygen complex is used to suppress the charge transfer J of the oxygen complex. As a result, we were able to efficiently modify olefins and increase the amount of oxygen-containing compounds produced.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the ultraviolet absorption spectrum of the complex catalyst used in the present invention. Agent Patent Attorney Takeshi Kawakita Diagram 1 Wavelength (nm)

Claims (1)

[Claims] (1) Olefins having an aromatic nucleus are converted into palladium complex P.
d(2)X_2・L・L′, copper complex Cu(1)X′・L
(Here, X and X' are halogen ions, BF_4^-
, PF_6^-, CH_3COO^- and SO_4^
the same or different anions selected from 2^-, L and L' are the same or different ligands selected from nitriles and organophosphorus compounds), characterized in that they oxidize in the presence of oxygen and water; A method for oxidizing olefins having an aromatic nucleus. (2) In claim 1, Cu(1)X'
- A method for oxidizing olefins having an aromatic nucleus, characterized in that the concentration of the oxygen complex formed by L and O_2 and the Pd(2) complex is such that the oxygen complex<Pd(2) complex. (3) In claim 1, the solvent for the complex is an aliphatic, aromatic, or alicyclic hydrocarbon, an oxygen-containing organic compound, an organic halogen compound, a nitrogen-containing compound, an organic sulfur compound, or an organic fluorine compound. A method for oxidizing olefins having an aromatic nucleus, the method comprising using at least one compound selected from compounds and heterocyclic compounds. (5) In claim 1, the basic (electron-donating) compound is sulfolane, dimethylsulfolane,
A method for oxidizing olefins having an aromatic nucleus, the method comprising adding at least one compound selected from dimethyl sulfoxide and dimethyl formamide to a catalyst system. (4) The method for oxidizing olefins having an aromatic nucleus according to claim 5, wherein the concentration of the basic compound is 0.2 to 8 M/l. (6) In any one of claims 1 to 5, the aromatic nucleus is characterized in that the ligands L and L' are liquids, and the ligands themselves also serve as a solvent. A method for oxidizing olefins having