JPH01175987A - Production of palladium chelate complex - Google Patents

Abstract

PURPOSE:To obtain the title complex having a short induction period in using as a catalyst for the oxidative coupling reaction of 0-phthalic diester, by reacting a dinitrapalladium chelate complex with an aliphatic carboxylic acid in the presence of an alkali. CONSTITUTION:A dinitrapalladium chelate complex expressed by formula I (L is base bidentate ligand; x is 1 or 2) (preferably acetic acid) in the presence of an alkali to give the aimed dicarboxylate palladium chelate complex expressed by formula II. Besides, the above-mentioned reaction is preferably run in the state of the complex expressed by formula I dissolved in an aliphatic carboxylic acid, under the reflux of the aliphatic carboxylic acid for 30min<=2hr.

Description

[Detailed description of the invention] [Field of invention 1 The present invention relates to a method for producing palladium chelate complexes.

[Background of the Invention] When a palladium chelate complex formed from a palladium salt and a basic bidentate ligand is oxidatively coupled (trimerized) with 0-phthalic acid diester to produce biphenyltetracarboxylic acid tetraester It has been proposed to be used as a catalyst for
1151).

The above Japanese Patent Publication No. 60-33379 discloses that an organic palladium salt can be used as the palladium salt, and describes a method for producing a dicarboxylatopalladium chelate complex using a palladium salt of an aliphatic carboxylic acid. has been done. Dicarboxylatopalladium chelate complexes can generally be synthesized by reacting the corresponding palladium salt of aliphatic carboxylic acid with a basic binary ligand, and the method for its production is described in Japanese Patent Publication No. 60-3.
In addition to the method described in No. 3379, many other methods have been reported.

For example, it is known that a diacetatopalladium chelate complex can be synthesized by reacting palladium acetate with a basic divalent ligand (J, E, McKe
on, P, Fitton, Tetrahedron, 2
8, 233 (1972), T.A.5tephenso.
n, S., M., Morehouse, A. R.;

Powell, J., P., Heffer, G., Willk.
inson, J., Chem, Soc.

3632 (1965), A.5hiotani, M.Y.
oshikiyo,) 1. Itata-ni, J., Mo.
1ecular (:alysis, 18.23(
1981)).

On the other hand, the above-mentioned Japanese Patent Application Laid-Open No. 60-51151 discloses that by using an inorganic acid palladium salt, particularly palladium nitrate, as the palladium salt, a dinitratopalladium chelate complex having excellent thermal stability can be obtained, and the complex can be used. By doing so, the reaction yield of the dimer is improved compared to the case where a dicarboxylatopalladium chelate complex is used in the above oxidative coupling reaction, and the reaction yield of the dimer is improved, and 3.3', 4゜4゛-biphenyltetracarboxylic acid Tetraester (s-B
It has been described that PTT) can be selectively synthesized.

The method for producing a dinitratopalladium chelate complex described in the above-mentioned Japanese Patent Application Laid-Open No. 60-51151 is a method in which palladium nitrate is reacted with approximately equimolar basic binary ligands, and in this way, General formula [Ia]: L-Pd(NO3)2 ... [Ia] (however,
A dinitratopalladium monochelate complex represented by (L represents a basic divalent ligand) is obtained. but,
In the above method, when the basic divalent ligand is used in excess with respect to palladium nitrate, the general formula [Ib]: L2・Pd(NO3)z...[Ib] (however,
A dinitratopalladium bischelate complex represented by (L represents a basic divalent ligand) is produced.

The present inventor investigated the catalytic action of each of the above-mentioned organic or inorganic palladium chelate complexes, and found that the dinitratopalladium bischelate complex is capable of oxidative coupling of 0-phthalic acid diester to produce biphenylcarboxylic acid tetraester. It was found that the induction period (the time required for the reaction rate to become sufficiently high after the start of the reaction) was longer than that of the dinitratopalladium monochelate complex. Furthermore, it has been found that dicarboxylatopalladium chelate complexes have the advantage of a shorter induction period compared to the respective dinitratopalladium chelate complexes.

[Object of the Invention] An object of the present invention is to provide a method for converting a dinitratopalladium chelate complex into a dicarboxylatopalladium chelate complex.

[Summary of the Invention] As a result of extensive research into the technology of exchanging the anion moiety of palladium chelate complexes, the present inventors have discovered that dicarboxylatopalladium can be obtained by reacting dinitratopalladium chelate complexes with aliphatic carboxylic acids in the presence of an alkali. The present invention was completed by discovering that it can be converted into a chelate complex.

That is, the present invention provides a compound represented by the general formula [I]: L, -Pd (NO3)2 ... [I] (wherein L represents a basic divalent ligand and X is 1 or 2). The dinitratopalladium chelate complex represented by RCOOH is reacted with an aliphatic carboxylic acid represented by RCOOH in the presence of an alkali to form -Math [II]: L-Pd(RCOO)2...[I[] , L represents a basic divalent ligand, and R represents an alkyl group).

[Detailed Description of the Invention It has been found that cosinidradopalladium monochelate complexes, dinitratopalladium bischelate complexes, and dicarboxylatopalladium chelate complexes can all be used as catalysts for the oxidative coupling (duplexing) reaction of O-phthalic acid diesters. Are known.

However, the three types of palladium chelate complexes mentioned above are
It was found that the lengths of induction periods in the above oxidative coupling reactions were different. Since the above-mentioned oxidative coupling reaction is generally carried out at a high temperature, a short induction period is advantageous for carrying out the reaction industrially.

The induction period of each of the palladium chelate complexes described above tends to be as shown, for example, in Tables 1 and 2 below, and in the attached FIGS. 1 and 2.

Table 1 below lists palladium chelate complexes as 1. l
O-phenanthroline dinitrate palladium or 1.
Using 10-phenanthroline diacetate palladium, 0.4 mmol of palladium chelate complex and 0.12 mmol of copper acetate hydrate as a catalyst, the mixture was heated at 200° C. with air flowing through 300 ml for 11 minutes and stirring at 500 rpm. However, dimethyl 0-phthalate (hereinafter abbreviated as DMP)
The reaction results when 119g was subjected to oxidative coupling are shown. FIG. 1 also shows 3, 3', 4.
FIG. 3 is a diagram showing a comparison of the yield of tetramethyl 4'-biphenyltetracarboxylate over time. The case where 1.10-phenanthrolinedinitratopalladium is used is indicated by O, and the case where 1.10-phenanthrolinedinitratopalladium is used is indicated by Δ. As is clear from Figure 1, the diacetatopalladium chelate complex is
Since the induction period is shorter than that of the dinitratopalladium monochelate complex and there is substantially no induction period, it can be used advantageously if the usage conditions are selected.

Table 1 phen-phen-Pd (OAc) 2 Pd (No. 3) 2 dimerization conversion rate (3) 1119 10. Total yield of old S (g) 10.90 9.60 Yield (U 9.16 8.07a Total yield (g) 0.77 0.74
Yield (%) 0.65 0.62 High boiling point yield (g) 1.64 1-57 Yield (%) 1.38 1.32 phen
Pd(08c)2:1.10-phenanthroline diacetatopalladium phenPd(NO3)2: 1, 10-phenanthroline diacetatopalladium biset conversion rate = (DMP consumption)/(DMP usage)
xlOO 5 unit: 3,3°, 4.4'-Tetramethyl biphenyltetracarboxylate a unit: 2,3,3', 4'-biphenyltetracarboxylate tetramethyl 1,1
0-phenanthroline dinitrate palladium (monochelate complex) or bis(1,10-phenanthroline)
Using dinitrate palladium (bischelate complex),
DMP under the same conditions as above except that the temperature was 220°C.
This shows the reaction results when oxidatively coupling . Also the second
The figure is a diagram showing a comparison of changes over time in the yield of tetramethyl 3,3',4,4'-biphenyltetracarboxylate in the above reaction. The case where 1,10-phenanthrolinedinitratopalladium is used is marked with ○, and the case where bis(
The case where palladium dinitrate (1,10-phenanthroline) is used is indicated by an x mark. From Figure 2, when dinitratopalladium bischelate complex is used as a catalyst for the above oxidative coupling reaction, the induction period is longer than when dinitratopalladium monochelate complex is used, and the reaction yield is the same. 2 to get the product
It is clear that it takes more than twice as much time.

Table 2 phen-ph6n2- Pd (NO3)2 Pd (NO3) 2 dimerization conversion rate (4k) 14.90 10.83S
Total quantity (g) 13.54 9.95
Same yield (3) 11.38 8.36
aInclude quantity (g) 1.30 0.74
Same yield (%) 1,09 0.62 High boiling point yield (g) 2.90 2.20
Same yield (t) 2.43 1.85p
hen2Pd (NO3)2: Bis(1,10-phenanthroline) dinitratopalladium If we take the above Tables 1 and 2 and the attached Figures 1 and 2 together, each dinitratopalladium bischelate complex is dinitratopalladium. It is clear that this is disadvantageous compared to carboxylatopalladium chelate complexes, and it is desired to develop a technique for converting dinitratopalladium chelate complexes into dicarboxylatopalladium chelate complexes with a short induction period.

The present invention is based on the general formula [I]: Lx-Pd (NO3)2 ... [1] (however,
and R represent a dinitrate palladium chelate complex represented by
An aliphatic carboxylic acid represented by COOH is reacted in the presence of an alkali to form the general formula [II]: L-Pd (RCOO)2 ... [II] (where L is a basic divalent coordination R represents an alkyl group)
It is characterized by producing a dicarboxylatopalladium chelate complex represented by:

Next, the method of the present invention will be explained in detail.

The dinitratopalladium chelate complex may be a dinitratopalladium monochelate complex or a dinitratopalladium bischelate complex.

The basic binary ligand is preferably 1,10-phenanthroline or 2,2'-bipyridine.

The above reaction is preferably carried out in a state in which the dinitratopalladium chelate complex is dissolved in an aliphatic carboxylic acid corresponding to the target dicarboxylatopalladium chelate complex. Examples of the aliphatic carboxylic acids include lower aliphatic carboxylic acids having 1 to 5 carbon atoms that are liquid at room temperature, such as acetic acid, propionic acid, and acetic acid, but acetic acid is preferred. The amount of aliphatic carboxylic acid used is not particularly limited, but it is sufficient as long as it dissolves the dinitratopalladium chelate complex, and is usually 100 to 2000 mff1, preferably 200 to 70 mff1, per 10 g of the complex.
It is 0mn.

In the method of the present invention, it is necessary to react the dinitratopalladium chelate complex and an aliphatic carboxylic acid in the presence of an alkali.

If no alkali is present, the nidrado group of the dinitratopalladium chelate complex will not be substituted with a carboxylad group, which is not preferred. Examples of the alkali include hydroxides, carbonates, bicarbonates, and carboxylates of alkali metals or alkaline earth metals. The amount of the alkali used is usually 1 to 10 mol, preferably 2 to 5 mol, per 1 mol of dinitratopalladium chelate complex. When adding the alkali to the aliphatic carboxylic acid solution of the dinitrate palladium chelate complex, the alkali may be added in a state dissolved in a solvent soluble in the aliphatic carboxylic acid such as ethanol.

The above reaction is preferably carried out in a temperature range of 20 to 250°C, and more preferably carried out under reflux of the aliphatic carboxylic acid. The reaction time is usually 10 minutes to IO hours, preferably 30 minutes to 2 hours.

Through the above-described treatment, the nidorado group of the dinitratopalladium chelate complex is substituted with a carboxilado group, and the dinitratopalladium chelate complex is converted into a dicarboxylatopalladium chelate complex. The above complex can be isolated as a pure product by removing the inorganic salt insoluble in the organic solvent from the reaction solution and then recrystallizing it from a suitable solvent such as a mixed solvent of chloroform and n-hexane.

When the dinitratopalladium chelate complex is a dinitratopalladium bischelate complex, a dicarboxylatopalladium chelate complex is generated, and at the same time, a basic binary ligand is liberated. The basic binary ligand can be recovered by recrystallizing the dicarboxylatopalladium chelate complex, separating and recovering it, and then recrystallizing it from the mother liquor using a suitable solvent such as n-hexane.

The dicarboxyladopalladium chelate complex produced by the above reaction is a monochelate complex, and will not be converted to a bischelate complex even if an excess of basic divalent ligand is present in the reaction solution. .

[Effects of the Invention] By the method of the present invention, the anion moiety of a dinitratopalladium chelate complex having a long induction period in the oxidative coupling reaction of an 0-phthalic acid diester is replaced to convert it into a dicarboxyladopalladium complex having a short induction period. can do.

Next, Examples and Comparative Examples of the present invention will be shown.

[Example 1] 0.591 g of bis(1,10-phenanthroline)dinitratopalladium is heated with 20 mJ2 of acetic acid and 8 mft of N/2-OH-ethanol solution to form a homogeneous solution. After refluxing for 2 hours, 1? The reaction solution was evaporated to dryness. It was dissolved in 10 m2 of chloroform, and 0.471 g of insoluble matter was filtered off. The insoluble matter was confirmed to be potassium nitrate from the IR spectrum. n- in the filtrate
20 m2 of hexane was added and the mixture was left in a refrigerator (-10°C), and the precipitate deposited was filtered off, washed with n-hexane, and dried to obtain 0.353 g of a product. The product is IR
From the spectrum and elemental analysis, it was confirmed that it was 1.10-phenanthroline diacetatopalladium (
yield 87%). The results of elemental analysis are shown below.

HN Experimental value 45.47 3.73 5.83 Calculated value 47.49 3.49 6.92 (CI6H1
4N 204P d = 404.7) The filtrate obtained by filtering the above product was dried, 10 mfi of n-hexane was added thereto, and the mixture was left in a refrigerator (-10°C). The deposited precipitate was filtered off to obtain 0.094 g of by-product. I of the by-product
The R spectrum matched that of standard 1,10-phenanthroline.

[Example 2] Bis(2,2'-bipyridine)dinitratopalladium 0
．． 543 g were refluxed for 30 minutes with 20 ml of acetic acid and 4+nJZ of N/2-KOH-ethanol solution. The obtained reaction solution was treated in the same manner as in Example 1 to obtain a 0.334
g of product was obtained. The product was confirmed to be 2'2'-biviridine diacetate palladium by IR spectrum and elemental analysis (yield: 88%). The results of elemental analysis are shown below.

CHN Experimental value 42.79 3.58 6.78 Calculated value 44.17 3.71 7.36 (CI4Hr
aN 204P d = 360.68) The filtrate obtained by filtering the above product was treated in the same manner as in Example 1 to obtain 0.33 g.
obtained by-products. The IR spectrum of the by-product matched that of standard 2,2°-bipyridine.

[Example 3] 1.10-phenanthroline dinitrate palladium 0.
411 g was refluxed for 30 minutes with 20 ml of acetic acid and 20 mj2 of N/1O-KOH-ethanol solution to obtain a yellow homogeneous solution. The homogeneous solution was evaporated to dryness using an evaporator, and then dissolved in 10 mft of chloroform.
0.191 g of insoluble matter was filtered off. The insoluble matter was confirmed to be potassium nitrate from the IR spectrum. Add 20mj2 of n-hexane to the filtrate and store in the refrigerator (-10℃)
The resulting precipitate was filtered, washed with n-hexane, and dried to obtain 0.390 g of a product. The product was confirmed to be 1,10-phenanthroline diacetatopalladium by IR spectrum and elemental analysis (yield 96%). The results of elemental analysis are shown below.

HN Experimental value 45.65: 1.59 5.91 Calculated value 47.49 3.49 6.92 (CI8
814N204P d =404.7) [Example 4] N/10-, OH-! The process was carried out in the same manner as in Example 3, except that 0.5 g of potassium bicarbonate was used instead of 20 ml of the ethanol solution, to obtain 0.377 g of 1,10-phenanthroline diacetate palladium (yield 93%). ).

[Example 5] 1,10-Phenanthroline diacetate palladium 0.386 g was obtained (yield 95%).

[Example 6] Example 3 except that 0.164 g of sodium acetate was used instead of 20 mJ2 of OH-ethanol solution for N/10-.
Process in the same manner as 1. 0.376 g of lO-phenanthroline diacetate palladium was obtained (yield 93%).

[Example 7] 2.2°-bipyridine dinitrate palladium 0.387
g was centrifuged for 30 minutes with 20 mIt of acetic acid and 4 mj2 of N/2-OH-ethanol solution. The resulting reaction solution was treated in the same manner as in Example 3 to obtain 0.347 g of product. The product was confirmed to be 2,2'-bipyridine diacetatopalladium by IR spectrum and elemental analysis (yield 91%). The results of elemental analysis are shown below.

HN Experimental value 43.33 3.81 6.25 Calculated value 44.17 3.71 7.36 (C1481
4N 20. P d = 380.68) [Comparative Example 1
] 1, lO-phenanthroline dinitrate palladium 0.
411 g was refluxed with 20 ml of acetic acid for 5 hours without adding an alkali, but a homogeneous solution was not obtained, and 0.392 g of a solid insoluble in acetic acid was obtained. The solid was identified as the starting material, 1,10-7 enanthroline dinitrate palladium, according to IR spectrum and elemental analysis.

[Comparative Example 2] 2.2°-bipyridine dinitrate palladium 0.773
20 m2 of acetic acid was added to the mixture, and the mixture was refluxed for 2 hours without adding an alkali to obtain a homogeneous solution. The homogeneous solution is allowed to cool,
0.760 g of a precipitated yellow solid was obtained. The solid is IR
Spectrum and elemental analysis revealed that the starting material was 2.2'-
It was biviridine dinitrate palladium.

[Brief explanation of the drawing]

Figure 1 shows that using a palladium chelate complex as a catalyst, 2
FIG. 3 is a diagram showing a time-dependent change curve of the yield of tetramethyl 3, 3°, 4°, 4′-biphenyltetracarboxylate when an oxidative coupling reaction of O-7 dimethyl talate was carried out at 00°C. Figure 2 shows that using a palladium chelate complex as a catalyst, 2
FIG. 2 is a diagram showing a time-dependent change curve of the yield of tetramethyl 3.3',4°4°-biphenyltetracarboxylate when an oxidative coupling reaction of O-dimethyl phthalate was carried out at 20°C. Patent applicant Representative of Ube Industries Co., Ltd. Patent attorney Yasuo Yanagawa

Claims (1)

[Claims] 1. Dinitratopalladium chelate complex represented by the general formula [I]: L_x-Pd(NO_3)_2... [I] (L represents a basic bidentate ligand, and x is 1 or 2) and an aliphatic carboxylic acid represented by RCOOH are reacted in the presence of an alkali to form a compound of the general formula [II]: L.Pd(RCOO)_2...[II] (L is a basic bidentate 1. A method for producing a palladium chelate complex, which comprises producing a dicarboxylatopalladium chelate complex represented by R and R represents an alkyl group. 2. The method for producing a palladium chelate complex according to claim 1, wherein the dinitratopalladium chelate complex is a dinitratopalladium bischelate complex. 3. 2. The method for producing a palladium chelate complex according to claim 1, wherein the basic bidentate ligand is 1,10-phenanthroline or 2,2'-bipyridine. 4. The method for producing a palladium chelate complex according to claim 1, wherein the reaction is carried out at a temperature in the range of 20 to 250°C. 5. 2. The method for producing a palladium chelate complex according to claim 1, wherein the reaction is carried out under reflux of an aliphatic carboxylic acid. 6. The method for producing a palladium chelate complex according to claim 1, wherein the aliphatic carboxylic acid is acetic acid.