JPH06312957A - Dialkyldimethylbiphenyldicarboxylate and its production - Google Patents

Abstract

PURPOSE:To provide a new compound which is useful as monomer in the production of a variety of polymers or as a polymer modifier. CONSTITUTION:A dialkyl 3,3'-dimethylbipheny1-2,4'-dicarboxylate of formula I (R is alkyl). The compound of formula I is obtained by oxidative coupling reaction of an inexpensive alkyl o-toluate of formula II using a palladium catalyst, a copper catalyst and a beta-diketone in a molecular oxygen atmosphere at 50 to 300 deg.. The catalyst comprises a palladium salt such as palladium acetate, 0.5 to 10-fold moles (based on the palladium) of a copper salt and 0.5 to 5-fold moles (based on the total amount of the palladium salt and the copper salt) of a beta-diketone such as acetylacetone. Further, 3,4'-thetadimethylbipheny1-2,3'- dicarboxylic acid dialkyl ester of formula III is also a new 2,3,3',4'-substituted compound of dialkyl dimethylbiphenyldicarboxylate.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to novel dialkyl ester compounds of dimethylbiphenyldicarboxylic acid
Dimethyl dimethyl biphenyl dicarboxylate was obtained by oxidatively coupling an orthotoluic acid alkyl ester in the presence of molecular oxygen using a 3 ′, 4′-substituted compound, a palladium catalyst, a copper catalyst and β-diketones. Novel 2,3,3 ′, 4′-of ester compounds
The present invention relates to a method for synthesizing a substitution product in good yield. The novel 2,3,3 ′, 4′-substituted dimethylbiphenyldicarboxylic acid dialkyl ester compound of the present invention is a monomer component or polymer in the production of various novel polymers.
Can be suitably used as a modifier of the respective corresponding dimethylbiphenyldicarboxylic acids,
Alternatively, it can also be used as a raw material for producing a 2,3,3 ', 4'-substituted form of the acid halide thereof.

[0002]

2. Description of the Related Art Conventionally, dimethylbiphenyldicarboxylic acid dialkyl ester has been produced by producing the corresponding biphenyldicarboxylic acid by various known production methods, and then esterifying it with alcohol. As a method for producing the above-mentioned biphenyldicarboxylic acid, 3-bromobenzoic acid is used as Pd.
/ C catalyst in the presence of KOH-methanol aqueous solution for coupling (USP2809210),
A method of preparing a Grignard reagent from 4,4′-dichlorobiphenyl and then reacting it with CO ₂ (USP2508)
022), 3,3′-dimethylbiphenyl is oxidized with potassium permanganate [J. Am. Chem. S
oc. 72 , 3221 (1950)], a method of iodating biphenyl and then reacting with CO (JP-A-63-1).
No. 22645) is known. In addition, as a method for producing the above-mentioned biphenyldicarboxylic acid, 3,3 ′,
There is also known a method of oxidizing 4,4'-tetramethylbiphenyl with molecular oxygen to synthesize 3,3'-dimethylbiphenyl-4,4'-dicarboxylic acid (Japanese Patent Publication No. 52-3377). .

However, these known methods for producing biphenyldicarboxylic acid have drawbacks such as difficulty in obtaining raw materials, having extremely complicated and long steps, and having many by-products. The method of producing and then producing the biphenyldicarboxylic acid dialkyl ester was industrially impractical. A method for producing a 3,4,3 ′, 4′-substituted dimethylbiphenyldicarboxylic acid dialkyl ester compound by oxidative coupling of an orthotoluic acid alkyl ester has already been disclosed by the present inventor (JP-A-2- 1
No. 15143 gazette), the present invention is 2, 3, 3 ',
It is intended to provide a method for producing a 4'-substituted product in good yield.

[0004]

DISCLOSURE OF THE INVENTION The present invention provides novel 2,3,3 ′, 4′-substituted dimethylbiphenyldicarboxylic acid dialkyl ester compounds and a method for producing them in high yield. To aim.

[0005]

The first invention of the present application is based on the general formula (I):

[0006]

[Chemical 5]

A second invention of the present application relates to 3,3'-dimethylbiphenyl-2,4'-dicarboxylic acid dialkyl ester represented by the formula (wherein R represents an alkyl group).
General formula (II)

[0008]

[Chemical 6]

(Wherein R has the same meaning as described above), 3,4'-dimethylbiphenyl-2,3'-dicarboxylic acid dialkyl ester, and the third invention of the present application is a palladium salt. And 0.5 to 10 times mol of copper salt, and 0.5 to 5 times mol of β-diketone relative to the sum of palladium salt and copper salt in the reaction solution, General formula (III)

[0010]

[Chemical 7]

An orthotoluic acid alkyl ester represented by the formula (wherein R has the same meaning as described above) is subjected to an oxidative coupling reaction at 50 to 300 ° C. in an atmosphere in the presence of molecular oxygen to give a compound represented by the general formula ( IV)

[0012]

[Chemical 8]

(In the formula, R ¹ and R ² are —CH ₃ or —
COOR, wherein R ¹ and R ² are different substituents, and R has the same meaning as defined above) 2,3,3 of dimethylbiphenyldicarboxylic acid dialkyl ester
The present invention relates to a method for producing a biphenyl compound that produces a 3 ', 4'-substituted product in good yield.

In the present invention, R in the 3,3'-dimethylbiphenyl-2,4'-dicarboxylic acid dialkyl ester represented by the general formula (I) is, for example, a methyl group, an ethyl group, a propyl group, an isopropyl group, Linear or branched carbon number 1 such as butyl and pentyl groups
To an alkyl group having 5 carbon chains, preferably a linear or branched alkyl group having 1 to 3 carbon atoms, more preferably a methyl group, and Specifically, for example, dimethyl 3,3′-dimethylbiphenyl-2,4′-dicarboxylate,
Diethyl 3,3′-dimethylbiphenyl-2,4′-dicarboxylate, 3,3′-dimethylbiphenyl-2,4 ′
-Dipropyl dicarboxylate (including isomer group of propyl group), 3,3'-dimethylbiphenyl-2,4'-dibutyl dicarboxylate (including isomer group of butyl group), 3,
3′-dimethylbiphenyl-2,4′-dicarboxylic acid dipentyl (including an isomer group of pentyl group) and the like can be mentioned, and preferably 3,3′-dimethylbiphenyl-2,4′-dicarboxylic acid dimethyl ester. Is.

In the present invention, R in the 3,4'-dimethylbiphenyl-2,3'-dicarboxylic acid dialkyl ester represented by the general formula (II) has the same meaning as described above, and more specifically, For example, dimethyl 3,4′-dimethylbiphenyl-2,3′-dicarboxylate, 3,4 ′
-Diethylbiphenyl-2,3'-dicarboxylate, dipropyl 3,4'-dimethylbiphenyl-2,3'-dicarboxylate (including isomers of propyl group),
3,4'-Dimethylbiphenyl-2,3'-dicarboxylate dibutyl (including isomer group of butyl group), 3,4'-
Examples thereof include dimethylbiphenyl-2,3'-dicarboxylic acid dipentyl (including an isomer group of a pentyl group), and preferably 3,4'-dimethylbiphenyl-2,
It is dimethyl 3'-dicarboxylate.

The manufacturing method of the present invention can be represented, for example, by the following reaction formula. Reaction formula

[0017]

[Chemical 9]

In the production method of the present invention, an inexpensive orthotoluic acid alkyl ester is used as a starting material to carry out an oxidative coupling reaction in the atmosphere of a specific palladium salt and molecular oxygen to obtain 3,3'-dimethylbiphenyl-. 2,4 '
The dicarboxylic acid dialkyl ester and the 3,4′-dimethylbiphenyl-2,3′-dicarboxylic acid dialkyl ester can be produced at a high yield.

R in the alkyl ester of orthotoluic acid represented by the general formula (III), which is a starting material in the production method of the present invention, has the same meaning as described above, and more specifically, for example, methyl orthotoluylate or orthotoluylate. Examples thereof include ethyl acidate, propyl orthotoluate, isopropyl orthotoluate, butyl orthotoluate, and pentyl orthotoluate, and preferably methyl orthotoluate. In addition, orthotoluic acid alkyl ester has orthotoluic acid and carbon number 1
It can be produced by subjecting ~ 5 aliphatic alcohols to an esterification reaction in the presence of a catalyst such as sulfuric acid.

In the production method of the present invention, R ¹ , R ² in the 2,3,3 ', 4'-substituted dimethylbiphenyldicarboxylic acid dialkyl ester represented by the general formula (IV), which is a target substance, is -CH. ₃ or —COOR is represented, and R ¹ and R ² are different substituents. R has the same meaning as described above. 2,3,3 ′, 4′-of dimethylbiphenyldicarboxylic acid dialkyl ester
Specific examples of the substituted product include 3,3′-dimethylbiphenyl-2,4′-dicarboxylic acid dialkyl ester represented by the general formula (I) and 3,3 ′ represented by the general formula (II).
Mention may be made of 4'-dimethylbiphenyl-2,3'-dicarboxylic acid dialkyl ester.

In the production method of the present invention, the catalyst used for the oxidative coupling reaction of the alkyl ester of orthotoluic acid is a palladium salt, and a catalyst of 0.
It is a catalyst composed of 5 to 10 times mol of copper salt, and 0.5 to 5 times mol of β-diketone with respect to the total amount of palladium salt and copper salt.

Examples of the above-mentioned palladium salts include palladium salts of organic acids or inorganic acids, or palladium chelate compounds of β-diketones. Examples of the palladium salt of an organic acid include a palladium salt of an aliphatic carboxylic acid having a carbon chain of 1 to 5 carbon atoms such as formic acid, acetic acid, propionic acid, butyric acid, and valeric acid. Examples of the palladium salt of an inorganic acid include a palladium salt with an inorganic acid such as hydrochloric acid, nitric acid, nitrous acid, sulfuric acid, sulfurous acid and phosphoric acid. Examples of the palladium chelate compound of β-diketones include, for example, bis (acetylacetonate) palladium, bis (benzoylacetonate) palladium, bis (trifluoroacetylacetonate) palladium, bis (hexa). Palladium chelate compounds such as fluoroacetylacetonato) palladium can be mentioned. In the production method of the present invention, the palladium salt is preferably a palladium salt of an organic acid and a palladium chelate compound, and more preferably palladium acetate and bis (acetylacetonate) palladium. The amount of the palladium salt used is preferably 1 × 1 per mol of the orthotoluic acid alkyl ester.
It is 0 ^{−5 to} 1 × 10 ⁻² mol.

Examples of the above-mentioned copper salts include copper salts of organic acids or inorganic acids, or copper chelate salts of β-diketones. As the copper salt of an organic acid, for example, formic acid,
1 to 5 carbon atoms such as acetic acid, propionic acid, butyric acid, and valeric acid
The copper salt of aliphatic carboxylic acid can be mentioned. As the copper salt of an inorganic acid, for example, hydrochloric acid, nitric acid, nitrous acid, sulfuric acid,
Examples thereof include copper salts of inorganic acids such as sulfurous acid and phosphoric acid. Examples of the copper chelate compound of β-diketones include, for example, bis (acetylacetonate) copper, bis (benzoylacetonate) copper, bis (trifluoroacetylacetonate) copper, and bis (hexa). Copper chelate compounds such as fluoroacetylacetonato) copper may be mentioned.
In the production method of the present invention, the copper salt is preferably a copper salt of an organic acid or a copper chelate, and more preferably copper acetate or bis (acetylacetonate) copper. The amount of the copper salt used is preferably 0.5 to 10 times the mol of 1 mol of the palladium salt.

Examples of the above β-diketones include:
Acetylacetone, benzoylacetone, trifluoroacetylacetone, hexafluoroacetylacetone and the like can be mentioned, with preference given to acetylacetone. When the β-diketones are continuously or intermittently supplied to the reaction system during the oxidative coupling reaction, the activity of the catalyst can be maintained. Further, β-diketones are palladium chelate compounds and / or copper chelate compounds.
It can also be added to the reaction system as a todide, in this case,
The β-diketone may or may not be added. The amount of β-diketones used is preferably 0.5 to 5 times mol per mol of the palladium salt and the copper salt.

The catalyst used in the production method of the present invention is
It may be a mixture of an inorganic salt and / or an organic salt of the above metal, or may be prepared in advance as a chelate compound of β-diketones.

In the production method of the present invention, the reaction temperature of the oxidative coupling reaction is, for example, 50 to 300 ° C., preferably 140 to 260 ° C., and the reaction pressure is, for example, normal pressure to 300 atm (atm). ) Can be mentioned, and it is preferably atmospheric pressure to 100 atm (atm).
Further, the molecular oxygen at the time of the above reaction is supplied to the reaction system by a gas containing the molecular oxygen (for example, by bubbling into the reaction solution). As the gas containing molecular oxygen, pure oxygen gas may be used as it is, but in order to prevent danger such as explosion, for example, an inert gas such as nitrogen gas, carbon dioxide gas, neon gas, or argon gas may be used. Diluted oxygen-containing gas or air can be used.
At that time, the oxygen partial pressure in the reaction system is, for example, 0.01
˜200 atm (atm) can be mentioned, in particular 0.
The pressure is preferably 05 to 50 atm.

The product obtained by the production method of the present invention can be separated by a distillation method, a recrystallization method, a chromatography method or the like.

The above dialkyl dimethylbiphenyldicarboxylate is hydrolyzed under high temperature and high pressure conditions, or
The corresponding dimethylbiphenyldicarboxylic acid can be produced by a known hydrolysis method such as hydrolysis with acid or alkali. Dimethylbiphenyldicarboxylic acid can be used as a monomer component for polymerizing polyesters or polyamides by polymerizing with diols or diamines.

[0029]

The "3,3'-dimethylbiphenyl-2,4 'obtained from the novel compound of the general formula (I) of the present invention.
-Dicarboxylic acid ", and"3,4'-dimethylbiphenyl-2, obtained from the novel compound of general formula (II).
The "3'-dicarboxylic acid" can be used for producing various novel polymers and as a modifier for the polymers. Further, by using the production method of the present invention, a novel 2,3,3 ′, 4′-substituted dimethylbiphenyldicarboxylic acid can be produced in good yield.

[0030]

EXAMPLES The present invention will be described in more detail with reference to Examples and Comparative Examples below, but the scope of the present invention is not limited thereto. The total yield of dimers shown in the examples is 2X [total dimers produced (mol)] X100.
/ Used orthotoluic acid alkyl ester (mol)
It is the value calculated in. Palladium conversion produced
It is a value calculated by total dimer (mol) / palladium (mol) used .

Example 1 (Oxidative Coupling Reaction) A four-necked flask having a capacity of 300 ml was equipped with a reflux condenser, a thermometer, a stirrer and a gas blowing tube, and the four-necked flask was charged with methyl orthotoluate 1
00 ml (107 g), palladium acetate [Pd (OA
c) ₂ ] 90 mg (0.4 mM), bis (acetylacetonato) copper [Cu (acac) ₂ ] 524 mg (2 m
M) and 80 mg (0.8 mM) of acetylacetone were added, and the reaction solution in the four-necked flask was placed on an oil bath for 18
Keep the temperature at 0 ° C and stir at 500 rpm while adding air to 30
Air was bubbling into the reaction solution through a gas injection tube at a supply rate of 0 ml / min (normal pressure), and an oxidative coupling reaction was carried out at the reaction temperature for 8 hours. After the reaction was completed, the reaction solution was analyzed by gas chromatography (column: Apiezon grease L, 15%, 2 m, 280 ° C, FID).
As a result of performing a detector, dimethyl 3,3′-dimethylbiphenyl-2,4′-dicarboxylate (hereinafter, also referred to as M-form) 7.72 g (7.21%), 3,4′-dimethylbiphenyl- Dimethyl 2,3'-dicarboxylate (hereinafter N
8.36 g (7.81%), dimethyl 3,3′-dimethylbiphenyl-4,4′-dicarboxylate (hereinafter also referred to as P-body) + 3,4′-dimethylbiphenyl-4,3 ′ 3. Sum of dimethyl dicarboxylate (hereinafter also referred to as Q-form) + dimethyl 4,4'-dimethylbiphenyl-3,3'-dicarboxylic acid (hereinafter also referred to as R-form) 4.
05 g (3.78%) and other dimers 1.38 g
(1.29%) had been produced. The result of gas chromatography analysis is shown in FIG. Total yield of dimer: 20.09% Palladium conversion rate: 180 [sum of M + N (g)] / total of dimer (g);
0.75

[Isolation Operation of Each Reaction Product] After recovering methyl orthotoluate from the above reaction solution by vacuum distillation, Kp ₃ 180-1
Fraction at 95 ° C. 11.98 g (first fraction), Kp ₃ 195
6.35 g (second fraction) of a fraction at ˜240 ° C. was obtained. Separation of M Form and N Form The above-mentioned first fraction is subjected to high performance liquid chromatography (column;
Inertsil ODS-2, eluent; methanol /
Water = 75/25, flow rate; 3.4 ml / min).
Peak 1 with a retention time of 30 minutes and peak with a retention time of 33 minutes
Ku 2 was separately collected. Each of the separated peaks was isolated and subjected to ¹ HNMR (CDCl ₃ ) analysis and mass spectrometry. As a result, peak 1 was 3,4′-dimethylbiphenyl-
Dimethyl 2,3'-dicarboxylate (N-form) and peak 2 were assigned to dimethyl 3,3'-dimethylbiphenyl-2,4'-dicarboxylate (M-form).

3,4'-dimethylbiphenyl-2,3 '
-For dimethyl dicarboxylate (peak 1; N-form)
¹HNMR (CDCl₃) The analysis chart is shown in Fig. 4,
The mass spectrometry charts are shown in FIG. 5, respectively. In Figure 4
About the N body shown¹Each peak of the HNMR chart is as follows.
It is the bottom. δ (ppm): 2.40 (3H, 3-CH₃) 2.6
3 (3H, 4'-CH₃), 3.64 (3H, 2-CO
₂CH₃), 3.89 (3H, 3'-CO₂CH₃),
7.20-7.29 (3H,^FourH,⁶H,^Five'H), 7.
37 (1H, ^FiveH), 7.41 (1H,^{6 '}H), 7.9
5 (1H,^{2 '}H) J_5,6= 7.5 Hz, J_{6 ', 5'}= 7.8Hz, J_{2 ', 6'}
= J_{6 ', 2'}= 2.0 Hz

3,3'-Dimethylbiphenyl-2,4 '
-For dimethyl dicarboxylate (peak 2; M form)
The chart of ¹ HNMR (CDCl ₃ ) analysis is shown in FIG.
The mass spectrometry charts are shown in FIG. 3, respectively. The peaks of the ¹ H NMR chart of the M-form shown in FIG. 2 are as follows. δ (ppm): 2.41 (3H, 3-CH ₃ ), 2.6
_{4 (3H, 3'-CH 3} ), 3.60 (3H, 2-CO
_{2 CH 3), 3.91 (3H} , 4'-CO 2 CH 3),
^{7.20~7.26 (4H, 4 H, 6} H, 2 'H,
^{6 'H), 7.37 (1H} , 5 H), 7.95 (1H, 5'
H) J _5,6 = 7.5 Hz, J _{5 ', 6'} = 8.8 Hz

Examples 2 to 6 The amount of bis (acetylacetonato) copper used was changed (first
The oxidative coupling reaction was performed in the same manner as in Example 1 except that the reaction temperature was changed (see Table 1).
After completion of the reaction, the reaction solution was subjected to gas chromatography analysis (analytical conditions were the same as those described in Example 1). As a result, yield of each reaction product produced, yield, total yield of dimer, conversion rate of palladium , (M + N) -form selectivity ratios are shown in Table 1, respectively. Table 1

[0036]

[Table 1]

Example 7 Instead of bis (acetylacetonato) copper, copper acetate [C
The oxidative coupling reaction was performed in the same manner as in Example 1 except that u (OAc) ₂ ] 363 mg (2 mM) was used and the amount of acetylacetone used was changed to 480 mg (4.8 mM). After the reaction was completed, the reaction solution was subjected to gas chromatography analysis (analysis conditions were the same as described in Example 1).
Dimethyl 3,3′-dimethylbiphenyl-2,4′-dicarboxylate 6.78 g (6.34%) (M form), and dimethyl 3,4′-dimethylbiphenyl-2,3′-dicarboxylate 7.34 g (6.86%) (N-form) had been formed. Total yield of dimer: 16.23% Palladium conversion rate: 146 [total amount of M + N (g)] / total amount of dimer (g);
0.81

Example 8 Bis (acetylacetona) was used instead of palladium acetate.
G) The oxidative coupling reaction was performed in the same manner as in Example 1 except that 122 mg (0.4 mM) of palladium was used and acetylacetone was not added. After the reaction,
The reaction solution was subjected to gas chromatography analysis (analytical conditions were the same as those described in Example 1). As a result, 7.26 g of dimethyl 3,3′-dimethylbiphenyl-2,4′-dicarboxylate (6.
79%) (M-form), and 7.55 g of dimethyl 3,4'-dimethylbiphenyl-2,3'-dicarboxylate (7.
(06%) (N-form) was produced. Total yield of dimer: 18.79% Palladium conversion rate: 169 [sum of M + N (g)] / total of dimer (g);
0.74

Example 9 Oxidative coupling reaction was performed in the same manner as in Example 8 except that 100 mg (1 mM) of acetylacetone was added at the start of the reaction, and 100 mg (1 mM) of acetylacetone was further added 3 hours after the start of the reaction. I went. After the reaction is completed, the reaction solution is analyzed by gas chromatography (analysis conditions are described in Example 1).
The same as the above), as a result, 7.54 g of dimethyl 3,3′-dimethylbiphenyl-2,4′-dicarboxylate
(7.05%) (M isomer), and 8.51 g of dimethyl 3,4'-dimethylbiphenyl-2,3'-dicarboxylate.
(7.95%) (N-form) was produced. Total yield of dimer: 20.20% Palladium conversion rate: 181 [total amount of M + N isomer (g)] / total amount of dimer (g);
0.74

Comparative Example 1 The amount of palladium acetate used was changed to 225 mg (1 mM), 182 mg (1 mM) of copper acetate was used instead of bis (acetylacetonato) copper, and β-diketone was not used. The oxidative coupling reaction was performed in the same manner as in Example 5 except that the period was changed to 15 hours. After the reaction is completed, the reaction solution is analyzed by gas chromatography (analysis conditions are described in Example 1).
As a result, the total dimer yield was 0.3.
It was 8%.

[Brief description of drawings]

FIG. 1 is a chart of a gas chromatography-analysis on a reaction liquid of Example 1.

FIG. 2 is a chart of ¹ HNMR (CDCl ₃ ) analysis of M-form.
It is

FIG. 3 is a chart of mass spectrometry of M body.

FIG. 4 is a chart of ¹ HNMR (CDCl ₃ ) of N-form.

FIG. 5 is a chart of N-body mass spectrometry.

Claims (3)

[Claims] 1. A compound represented by the general formula (I): (In the formula, R represents an alkyl group) 3,3′-
Dimethylbiphenyl-2,4'-dicarboxylic acid dialkyl ester. 2. A compound represented by the general formula (II): (Wherein R has the same meaning as described above) 3,
4'-Dimethylbiphenyl-2,3'-dicarboxylic acid dialkyl ester. 3. A palladium salt, 0.5 to 10 times by mole of a copper salt with respect to the palladium salt, and 0.5 to 5 times by mole of β-diketone with respect to the total amount of the palladium salt and the copper salt are reacted. The compound of the general formula (III): (Wherein R has the same meaning as described above), an orthotoluic acid alkyl ester is subjected to an oxidative coupling reaction at 50 to 300 ° C. in an atmosphere in the presence of molecular oxygen to give a compound represented by the general formula (IV): Chemical 4] (In the formula, R ¹ and R ² represent —CH ₃ or —COOR, R ¹ and R ² are different substituents, and R has the same meaning as described above). Ester 2,3,3 ', 4'-
A method for producing a biphenyl compound which produces a substitution product in good yield.