JPH04221341A - Production of carboxybiphenyl compound - Google Patents

Abstract

PURPOSE:To produce a carboxybiphenyl compound in a high yield by oxidizing the corresponding acylated biphenyl compound under a profitable condition. CONSTITUTION:An acylated biphenyl compound is oxidized with molecular oxygen (air) in the presence of a prescribed oxidation catalyst and a specific aldehyde, etc., to produce the corresponding carboxybiphenyl compound. The oxidation catalyst contains a heavy metal selected from cobalt, manganese and cerium, and a brominated compound. The aldehyde. etc., are selected from paraldehyde, methyl ethyl ketone and 2-4C saturated aldehydes. A method in which the acylated biphenyl compound is oxidized while the aldehyde is continuously or intermittently fed at a rate of 0.1-100 pts.wt./h per 100 pts.wt. of the acylated biphenyl compound is profitable.

Description

[Detailed description of the invention]

0001

FIELD OF THE INVENTION The present invention relates to a method for producing carboxybiphenyls useful as raw materials for resins such as polyesters and polyamides, resin modifiers, raw materials for pharmaceuticals and agricultural chemicals, and the like. More specifically, it relates to a method for producing the corresponding carboxybiphenyls by oxidizing acylated biphenyls with molecular oxygen.

0002

BACKGROUND OF THE INVENTION Conventionally, the following methods have been known as methods for producing carboxybiphenyls. (1) A method of oxidizing alkylbiphenyl or formylbiphenyl with molecular oxygen in the presence of a heavy metal catalyst and a bromine compound (European Patent No. 300922). (2) A method of oxidizing alkylbiphenyl or acetylbiphenyl with permanganic acid or chromic acid (Japanese Unexamined Patent Publication No. 83046/1983). (3) A method of reacting halogenated biphenyl and carbon monoxide in the presence of a noble metal catalyst (Japanese Patent Application Laid-open No. 185055/1983).

However, although method (1) allows the use of inexpensive air as an oxidizing agent, the raw material alkylbiphenyl or formyl biphenyl has poor regioselectivity, is difficult to purify and separate, and is extremely corrosive. Since a strong catalyst is used, special equipment materials are required, and at the same time, there are disadvantages such as danger in handling.

[0004] Method (2) not only increases the cost of the oxidizing agent, but also discharges a large amount of highly toxic heavy metals such as manganese and chromium, and is not a preferable method from the viewpoint of preventing environmental pollution.

The method (3) requires the use of a large amount of expensive catalyst and has a low yield, which is economically disadvantageous.

[0006] Therefore, none of these known methods is necessarily satisfactory as a method for industrially producing carboxybiphenyls at low cost.

[0007]

Acylated biphenyls are compounds that can be easily obtained by reacting biphenyls with an acylating agent such as an acid anhydride or acid chloride. However, oxidation of this substance by molecular oxygen such as air is difficult compared to alkylbiphenyl and formyl biphenyl, and known methods (for example, European Patent No. 3009
No. 22), the reaction did not proceed at all.

The present inventors have thought that a method using acylated biphenyls, which are easy to produce and inexpensive, as a raw material, and inexpensive air as an oxidizing agent is advantageous, and has been conducting intensive studies. As a result, by using a specific mixed catalyst system and reacting in the presence of paraaldehyde, methyl ethyl ketone, acetaldehyde, etc., acylated biphenyls, which were previously considered difficult, can be air-oxidized extremely easily, and the desired purpose can be achieved. The inventors have discovered that carboxybiphenyls can be obtained with good selectivity and in high yields, and have completed the present invention based on this knowledge.

That is, an object of the present invention is to provide a new and useful method for producing carboxybiphenyls, which is characterized by an oxidation reaction method.

0010

[Means for Solving the Problems] In the method for producing carboxybiphenyls according to the present invention, in producing the corresponding carboxybiphenyls by oxidizing the acylated biphenyls represented by the general formula 1, cobalt, manganese and cerium Using a mixed catalyst containing one or more heavy metals selected from para-aldehyde,
1 selected from methyl ethyl ketone and saturated aldehydes having 2 to 4 carbon atoms (hereinafter collectively referred to as "aldehydes, etc.")
It is characterized by being oxidized with molecular oxygen in the presence of one species or two or more species.

[0011]

[Figure 2]

[In the formula, R represents an alkyl group having 1 to 10 carbon atoms, and X and X' are the same or different and represent F, Cl, Br, NO
2, represents a CN or SO3H group. h and i represent integers of 0 to 3. l represents 0 or 1. ]

The acylated biphenyls used as raw materials in the present invention have a structure represented by the general formula 1 above. The biphenyl skeleton includes those substituted with oxidation-stable groups such as F, Cl, Br, NO2, CN or SO3H groups, and the substitution position does not matter.

Among these, 4-acetylbiphenyl,
4,4'-Diacetylbiphenyl, 4-acetyl-4'
-Cyanobiphenyl, 4-acetyl-4'-chlorobiphenyl, 4-acetyl-4'-nitrobiphenyl, ethyl-4-biphenyl ketone, etc. are relatively easy to produce and are easily oxidized in the method of the present invention, so they can be used as raw materials. preferable.

The catalyst according to the method of the present invention is a mixed catalyst containing one or more heavy metals selected from cobalt, manganese and cerium and a bromine compound. At this time, a part of the bromine compound may be replaced with a chlorine compound.

Heavy metals such as cobalt, manganese, and cerium may be added to the reaction system in any form such as simple substances, oxides, hydroxides, organic salts, inorganic salts, and complexes, but at least partially in the reaction system. It is necessary to dissolve it.

Among these, organic acid salts having 2 to 20 carbon atoms and salts of bromine and chlorine are particularly preferred, and specifically, cobalt acetate, cobalt propionate, cobalt octylate, cobalt naphthenate, cobalt bromide, cobalt chloride,
Examples include manganese acetate, manganese propionate, manganese octylate, manganese naphthenate, manganese bromide, manganese chloride, cerium acetate, cerium naphthenate, cerium bromide, cerium chloride, cobalt acetylacetonate, manganese acetylacetonate, etc. .

[0018] As the bromine compound, any of bromine molecules, their acids, salts, oxyacids or organic bromides can be used, and in particular hydrogen bromide, ammonium bromide, sodium bromide, potassium bromide, calcium bromide, bromine Preferred are magnesium chloride, cobalt bromide, manganese bromide, cerium bromide, tetrabromoethane, tribromoethane, and the like. The same applies to chlorine compounds.

As the mixed catalyst according to the present invention, for example, the following catalyst systems can be advantageously used. namely, cobalt bromide, cobalt acetate and ammonium bromide, cobalt acetate and sodium bromide, cobalt acetate and hydrogen bromide, cobalt acetate and tetrabromoethane, manganese bromide, manganese acetate and hydrogen bromide, manganese acetate and bromide. These include ammonium, manganese acetate and sodium bromide, manganese acetate and tetrabromoethane, etc.

Furthermore, the combination of two or more of the heavy metals and a bromine compound is advantageous in that the induction period is eliminated and the reaction rate is high. Such combinations include, for example, cobalt bromide and manganese bromide, cobalt bromide and manganese acetate, cobalt acetate and manganese bromide, cobalt acetate and manganese acetate and ammonium bromide, cobalt acetate and manganese acetate and hydrogen bromide, Cobalt bromide and cerium acetate, cobalt acetate and cerium bromide, manganese bromide and cerium acetate, cobalt acetate and manganese acetate and cerium acetate and ammonium bromide, cobalt naphthenate and manganese naphthenate and tetrabromoethane, cobalt acetylacetonate and manganese acetylacetonate and hydrogen bromide.

The appropriate amount of the heavy metal used is about 0.05 to 10 g/l in terms of metal concentration in the reaction system. If the concentration is less than 0.05 g/l, a sufficient reaction rate cannot be obtained, and if it is used in excess of 10 g/l, the catalyst cost will increase and side reactants will tend to increase. occurs.

The appropriate amount of bromine to be used is 0.1 to 10 equivalents in terms of bromine atom per heavy metal atom. If the amount is less than 0.1 equivalent, a sufficient reaction rate cannot be obtained, and if more than 10 equivalents are used, the product will be contaminated by bromine and the catalyst cost will be high, which is not preferable.

When a bromine compound and a chlorine compound are used together, the ratio of chlorine to bromine is suitably 0.7 or less in terms of atoms.

The aldehydes used in the present invention include para-aldehyde, methyl ethyl ketone, and saturated aldehydes having about 2 to 4 carbon atoms, and one or more of them can be used in combination.

Examples of the saturated aldehyde having about 2 to 4 carbon atoms include acetaldehyde, propylaldehyde, n-butyraldehyde, and isobutyraldehyde. Among these, paraldehyde is preferred because it can achieve high yield with a small amount.

[0026] The amount of aldehyde etc. used is 1 biphenyls.
0.5 parts by weight or more is appropriate, usually about 0.5 to 100 parts by weight, more preferably 2 to 50 parts by weight.
It is about parts by weight. If the amount added is less than 0.5 parts by weight, the reaction will hardly proceed, and if the amount exceeds 100 parts by weight, there will be no advantage to the reaction.

Regarding the method of adding aldehyde, etc., the entire amount may be added together with the raw materials, catalyst and solvent at the start of the reaction, but it is preferable not only to make them coexist at the start of the reaction but also continuously or intermittently during the reaction. By supplying the same amount, it is possible to obtain the desired effect with a smaller amount.

The feed rate of this aldehyde etc. is 0.1 to 100 parts by weight per 100 parts by weight of the acylated biphenyls as raw materials.
A range of parts by weight/h can be adopted, more preferably 1 to 50 parts by weight/h.
The range is parts by weight/h.

As the reaction solvent, an aliphatic monocarboxylic acid having 2 to 10 carbon atoms is used, and acetic acid is particularly preferred. It is usually preferable to use this solvent in an amount of about 100 to 2000 parts by weight per 100 parts by weight of the acylated biphenyls as raw materials.

[0030] As the molecular oxygen used as the oxidizing agent, pure oxygen or industrial exhaust gas can be used, but air is most suitable from an industrial point of view.

[0031] The reaction temperature is about 100 to 250°C, more preferably about 120 to 220°C. If the temperature is less than 100°C, the reaction rate is slow, and if it exceeds 250°C, oxidation of the solvent and decomposition of the product will become significant, which is not preferable.

[0032] The reaction pressure is a total pressure of 1 to 50 kg/cm.
In the range of about 2G, especially about 3 to 30 kg/cm2G,
Moreover, it is preferable that the oxygen partial pressure is about 8 kg/cm2 or less.

The reaction time varies depending on the types and amounts of raw materials, reaction activator and catalyst, reaction temperature, oxygen partial pressure, etc., but is generally appropriately selected within the range of about 10 minutes to 10 hours.

The invention is generally practiced as follows. That is, a predetermined amount of raw materials, a catalyst, an aldehyde, etc., and a reaction solvent are charged into a pressure-resistant reactor equipped with a stirrer and equipped with a gas inlet and a gas outlet, and the system is replaced or pressurized with nitrogen or oxygen-containing gas, and then heated to a predetermined temperature. Heat to. In this heating process, it is preferable to stir the system for the purpose of raising the temperature uniformly, but blowing gas is not necessarily required.

[0035] Oxygen absorption generally starts at around 100°C. After the absorption starts, oxygen or an oxygen-containing gas is introduced, and the reaction is carried out while maintaining the reaction pressure and oxygen partial pressure within a predetermined range. The exhaust gas is cooled and the condensate is returned to the reactor.

After the reaction for a predetermined period of time, the reaction mixture is cooled, the reactants are taken out, and the desired carboxybiphenyls are crystallized by distilling off the solvent as it is or by distilling off a part of the solvent, or by adding another solvent such as water. After removing the solvent by distillation, recrystallize.

In the above reaction operation, when the reaction is carried out while supplying aldehyde, etc., a pressure charging pump is connected to the reaction group, and a predetermined amount of aldehyde, etc. is continuously supplied alone or dissolved in the reaction solvent. It is preferable to prepare it. However, an intermittent preparation method, such as preparing a certain amount at once and then restarting the preparation, may also be used.

The reaction device is not limited to the above-mentioned device equipped with a stirrer; for example, a bubble column type device can also be used.

The reaction method is not limited to a batch reaction, but also a continuous or semi-continuous method. Specifically, raw materials, catalysts, aldehydes, etc., and solvents are continuously supplied to the reaction stage, and reaction products are continuously extracted, or catalysts, solvents, and in some cases, part of the raw materials, aldehydes, etc. are supplied to the reaction stage. Examples include a method in which the raw materials are charged and then only the raw materials are charged, and a method in which the raw materials are reacted with aldehyde, etc. and/or a solvent while being charged.

[0040]

[Examples] The present invention will be explained in detail with reference to Examples below. Example 1 A titanium oven with an internal capacity of 1.5 liters was equipped with a gas inlet, a gas outlet with a reflux cooler, a thermometer, and an electromagnetic stirrer.
In a toclave, put 200 g of 4-acetylbiphenyl, 6.7 g of cobalt bromide hexahydrate, and 0 manganese acetate tetrahydrate.
．． Catalyst consisting of 5 g, paraldehyde 30 g and acetic acid 8
00g was charged, pressurized to 18kg/cm2G with nitrogen, and heated while stirring.

Air was introduced from 120°C, the evaporated acetic acid was cooled and refluxed, and the system was heated to 15°C while extracting exhaust gas.
The temperature was maintained at 0°C to 180°C and the pressure was 20kg/cm2. Approximately 4
After 0 minutes of reaction, almost no oxygen absorption was observed. At this point, the introduction of air was stopped and the reaction mixture was cooled. The contents were taken out and the crystals were filtered off, and the obtained solid was washed with water and hot water, and then dried.

As a result of analysis, 172 g of 4-carboxybiphenyl crystals with a purity of 99.5% (as determined by gas chromatography) were obtained. This corresponds to a yield of 85.1% based on the raw material 4-acylbiphenyl. Furthermore, the filtrate contained 25.6 g of 4-carboxybiphenyl. This corresponded to a yield of 12.7% based on the raw material 4-acetylbiphenyl. From the above results, objective 4
-The overall yield of carboxybiphenyl was 97.8%.

Example 2 In the same reaction as in Example 1, 4-acetylbiphenyl 200
g, 6.5 g of cobalt bromide hexahydrate and manganese acetate.
Catalyst consisting of 0.5 g of tetrahydrate, 10 g of paraldehyde
and 800g of acetic acid and nitrogen at 18kg/cm2G.
The mixture was heated under pressure and stirred.

[0044] Air was introduced from 120°C, and the temperature increased to 150°C.
From the time when this was reached, feeding of paraldehyde was started at 10 g/h. The evaporated acetic acid was cooled and refluxed, and the temperature was further increased while extracting the exhaust gas, and the reaction temperature was maintained at 150° C. to 180° C. and the pressure was 20 kg/cm 2 G. The supply of paraaldehyde was stopped one hour after the start, and the introduction of air was also stopped to cool the reaction mixture. A total of 20 g of paraldehyde was used in the above reaction.

Next, the contents were taken out and analyzed in the same manner as in Example 1. As a result, 4-4-2 with a purity of 99.1% was obtained from the solid.
Carboxybiphenyl was obtained with a yield of 87.0%. The total yield when 4-carboxybiphenyl contained in the filtrate was added in the same manner was 98.5%.

Example 3 4,4'-diacetylbiphenyl was used as the acylated biphenyls, and 7.2 g of cobalt acetate tetrahydrate was used as the catalyst.
, 4,4'-dicarboxybiphenyl was prepared according to Example 1, except that 0.6 g of manganese acetate tetrahydrate and 13.0 g of hydrobromic acid (47% hydrogen bromide) were used. As a result, the target product was obtained with a yield of 94.8%.

Example 4 40 g of methyl ethyl ketone was used in place of paraaldehyde, and 20 g of cobalt naphthenate (Co=6%) was used as a catalyst.
4-g, according to Example 1 except that 9 g of manganese naphthenate (Mn = 10%) and 8.5 g of sodium bromide were used.
Carboxybiphenyl was prepared. As a result, the target product was obtained with a yield of 96.5%.

Example 5 4-cyano-4'-acetylbiphenyl was used as the acylated biphenyls, 40 g of acetaldehyde was used instead of paraaldehyde, and cobalt acetate tetrahydrate was used as the catalyst.6.
4-cyano-4'-carboxybiphenyl was prepared according to Example 1, except that 5 g of manganese acetate tetrahydrate, 0.8 g of manganese acetate tetrahydrate, and 13.0 g of ammonium bromide were used. As a result, the target product was obtained with a yield of 94.5%.

Example 6 4-chloro-4'-acetylbiphenyl was used as the acylated biphenyls, and cobalt acetate tetrahydrate 1 was used as the catalyst.
1.3g, manganese acetate tetrahydrate 6.0g and tetrabromoethane 8.8g were used.
-Chloro-4'-carboxybiphenyl was prepared. As a result, the target product was obtained with a yield of 95.5%.

Example 7 The reaction was carried out under the same conditions as in Example 1 except that ethyl-4-biphenyl ketone was used as the acylated biphenyls.
．． Obtained with a yield of 9%.

Example 8 Example 1 except that the amount of paraldehyde added was changed to 10 g.
The reaction was carried out under the same reaction conditions. As a result, the desired 4-carboxybiphenyl was obtained with a yield of 92.5%.

Comparative Example 1 In Example 1, the reaction was carried out without adding paraldehyde at all. That is, in the same reaction as in Example 1, 200 g of 4-acetylbiphenyl, a catalyst consisting of 6.5 g of cobalt bromide hexahydrate and 0.5 g of manganese acetate tetrahydrate, and acetic acid 8
00g was charged, pressurized to 18kg/cm2G with nitrogen, and heated while stirring.

Air introduction started at 120°C. Although heating was carried out at a reaction temperature of 150 to 180°C for 3 hours, no oxygen absorption was observed.Although the temperature was further raised to 230°C, no oxygen absorption was observed. When the reaction mixture was cooled and the contents were taken out and analyzed in the same manner as in Example 1, the target 4-carboxybiphenyl was not detected.

[0054]

[Effects of the Invention] By applying the method of the present invention, acylated biphenyls that are easily available industrially can be easily oxidized with an inexpensive oxidizing agent such as air, and the corresponding carboxybiphenyls can be oxidized. It can be obtained in extremely high yields.

Claims (2)

[Claims] Claim 1: In producing the corresponding carboxybiphenyls by oxidizing the acylated biphenyls represented by the general formula 1, one or more heavy metals selected from cobalt, manganese, and cerium and a bromine compound are used. A method for producing carboxybiphenyls, which comprises oxidizing them with molecular oxygen in the presence of one or more selected from para-aldehyde, methyl ethyl ketone, and saturated aldehydes having 2 to 4 carbon atoms. . [Figure 1] [In the formula, R is an alkyl group having 1 to 10 carbon atoms, X, X'
are the same or different and represent F, Cl, Br, NO2, CN or SO3H groups. h and i represent integers of 0 to 3. l
indicates 0 or 1. ] 2. One or more of paraldehyde, methyl ethyl ketone, and saturated aldehydes having 2 to 4 carbon atoms in an amount of 0.1 per 100 parts by weight of the acylated biphenyls.
2. The method for producing carboxybiphenyls according to claim 1, wherein the reaction is carried out while being continuously or intermittently supplied at a rate of 100 parts by weight/h.