JPH01224330A - Dimerization of aromatic halogen compound - Google Patents

Abstract

PURPOSE:To readily obtain diaryl compounds in high selectivity and yield, by subjecting an aromatic halogen compound to dehalogenodimerization in the presence of a platinum metal catalyst and alkali metal compound in an aqueous medium while coexisting chloroform and amine. CONSTITUTION:An aromatic compound having at least one halogen such as 4-chloroorthophthalic acid monosodium salt at an aromatic nucleus carbon subjected to dehalogeno dimerization reaction in the presence of a platinum group metal catalyst such as Pd/C and an alkali (earth) metal compound such as NaOH together with chloroform and amine such as methyl amine in an aqueous solvent consisting of only water or water and inert solvent such as tetrahydrofuran at 50-200 deg.C under ordinary pressure - 200kg/m<2> to provide the aimed compound such as 3,4,3',4'-biphenyltetracarboxylic acid sodium salt useful as a raw material for producing heat resistant polyimide resin.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method for producing biaryl compounds by dehalogenating and dimerizing aromatic halogen compounds.

[Conventional technology]

Biaryl compounds obtained by trimerizing aromatic compounds are useful as various industrial raw materials6.For example, 3,41.3',IA'-biphenyltetracarboxylic acid alkali metal salts are used for heat-resistant polyimide resins. It is a useful substance as a raw material for manufacturing. Conventionally, as a method for producing biphenyl compounds by dehalogenating and dimerizing aromatic halogenated compounds, for example, a method of dehalogenating and dimerizing aromatic halogenated compounds in the presence of methanol and a catalyst supporting metal palladium in an aqueous alkali hydroxide solution (J , Am, Chem.

Soc, 7/77 (/911), Tokko Akira! ? −
/110/! Furthermore, improvements to this method include a method using a polyhydric alcohol or formaldehyde instead of methanol (Japanese Patent Application Laid-open No. 2-2623g), and a method using formic acid or a formate salt (SYnthesiscommun).
cations 331. (/ri7r), JP-A-6
7-/371r31 and Unexamined Japanese Patent Publication No. 1987-47tlA
No. 2, etc.), - method using carbon oxide (JP-A-Sho t/J), because the conversion rate of the compound is insufficient or a large amount of dehalogenated aromatic compound is produced as a by-product, it is difficult to obtain the desired biphenyl compound. There is a problem of low yield, and no satisfactory method for obtaining piphenyl compounds in high yield has been found.

[Problem to be solved by the invention]

In view of the above circumstances, the present inventors conducted studies to obtain the target biphenyl compound in high yield, and as a result, they first found that it is advantageous to use chloroform instead of methanol in the above-mentioned known method. A headline patent application was filed. (Refer to Japanese Patent Application No. 103/1982 R2) As a result of further study on the above-mentioned method, it was found that when using chloroform, the yield of the target compound can be further improved by the presence of an amine. I found out.

That is, the present invention aims to provide a method capable of producing biaryl compounds in high yield by dehalogenating and dimerizing aromatic halogen compounds.

[Means to solve the problem]

The gist of the present invention is to dehalogen-dimerize aromatic compounds having at least one halogen atom on the aromatic carbon in an aqueous medium in the presence of a platinum metal catalyst, an alkali metal or alkaline earth metal compound, chloroform and an amine. The present invention relates to a method for demerging aromatic halogen compounds.

The present invention will be explained in detail below.

The starting material used in the process of the invention is an aromatic compound having at least 7...rogen atoms on the aromatic carbon.

At least seven halogen atoms in the aromatic carbon include chlorine, bromine, and iodine, with bromine and chlorine being preferred.

The number of halogen atoms bonded to the aromatic nuclear carbon can be 7 to 6, but preferably 7 to 3. When there are 2 or more halogen atoms, these halogen atoms may be the same or different from each other.

The core carbon of this aromatic halogen compound may be substituted with a substituent other than the 7% halogen atom that does not adversely affect the dehalogen dimerization reaction, but...substituted with a carbon adjacent to the aromatic core carbon having a halogen atom. When it has a group, the yield of the target dimeric biaryl compound tends to decrease.

Specific examples of the aromatic compounds used in the present invention include chlorobenzene, bromobenzene, p-chlorobromobenzene, p-chlorodiphenyl, p-chlorophenol, p-chloroaninol, p-v lorophenetole, p- -Chlorobenzamide, p-chloroaniline, p-chlorobenzophenone, p-chloroacetophenone, p-chlorodine dinitrile, p-chlorobenzenesulfonic acid sodium salt, α-chloronaphthalene, Hiro-chloroorthoxylene, p-chloro (or bromo ) benzoic acid, m-chloro (or bromo) benzoic acid, hiro-chloro (
or bromo)orthophthalic acid, alkali metal salts of hi-chloro(or haplomo)orthophthalic acid, and F,j-dichloro(or bromo)phthalic acid. especially,
μm chloro(or bromo)orthophthalic acid, hiro-alkali metal salt of chloro(or bromo)orthophthalic acid, μm
Chloro (or bromo) orthophthalic anhydride, Hiro,! −
Particularly preferred are guhalophthalic acids such as dichloro(or bromo)phthalic acid, and halobenzoic acids such as p-chloro(or bromo)benzoic acid and m-chloro(or bromo)benzoic acid.

In the method of the present invention, these aromatic halogen compounds are usually used as a single type, but if necessary, a mixture of different aromatic halogen compounds can also be used.

Examples of the central metal of the platinum group metal catalyst used in the present invention include palladium, rhodium, ruthenium, platinum, and iridium, with palladium and rhodium being particularly preferred.

These platinum group metal catalysts include halides, inorganic acid salts such as nitrates and sulfates, organic acid salts such as acetates, benzoates, and phthalates, chelate salts including β-diketones such as acetylacetone, and simple substances. used as. Among them,
It is preferable that a metal element is supported on a carrier such as activated carbon, silica, alumina, silica alumina, zeolite, titanium oxide, magnesia, diatomaceous earth, graphite, asbestos, ion exchange resin, barium carbonate, calcium carbonate, etc., and in particular supported on activated carbon. Catalysts are preferred. In these supported metal catalysts, the metal is usually o, i to co-O to the carrier.
It is preferable that it is supported in an amount of about 0.5 to io weight %, particularly about 0.5 to io weight %. The amount of platinum group metal catalyst used is usually 100 to 0 in terms of metal atoms per 1 mole of aromatic halogen compound.
, 0θ/mmol, preferably 30 to 0.0/mmol.

On the other hand, alkali metal compounds or alkaline earth metal compounds include inorganic acid salts of alkali metals, alkaline earth metals such as carbonic acid, nitric acid, phosphoric acid, boric acid, organic acid salts such as acetic acid, hydroxides, and Examples include alkoxides.

Particularly preferred specific examples include hydroxides such as lithium hydroxide, sodium hydroxide, potassium hydroxide, magnesium hydroxide, calcium hydroxide, and barium hydroxide; carbonates such as sodium carbonate, potassium carbonate, and sodium bicarbonate; Alkoxides such as methoxide, sodium ethoxide, and potassium tert-butyrate are used, but carbonates may have a slightly lower reaction yield than hydroxides, so hydroxides are more preferred.

The amount of these alkali metal compounds or alkaline earth metal compounds to be used varies depending on the number of halogen atoms contained in the aromatic halogen compound as a starting material and the presence of acidic substituents such as carboxyl groups, and is not particularly limited, but usually, 3 to 2 for nuclear halogen, excluding the amount of acidic substituent
0 equivalent is preferred, and 6 to 1J' equivalent is particularly preferred.

The present invention is directed to the trimerization reaction of an aromatic compound in the presence of a platinum group metal catalyst and an alkali metal compound or an alkaline earth metal compound as described above, in which chloroform and an amine are further present. is an essential requirement.

The amount of chloroform used is not particularly limited, and is 0 for the nuclear halogen/atom of the aromatic halogen compound.
．． The amount is about 7 to 20 moles, but from an economical point of view, it is sufficient to use the minimum amount required to industrially obtain a piphenyl compound in good yield. o, t, i, s mol is preferably 0.7 to 0 mol.

Methods for making chloroform exist in the reaction system include adding the necessary amount of liquid chloroform to the reaction system from the beginning, or supplying liquid chloroform intermittently or continuously while stirring the reaction solution thoroughly. However, in order to effectively carry out the present invention, it is preferable to maintain chloroform intermittently or continuously. In such a case, the feed rate of chloroform is preferably 0.0/~1.0 mol per unit time of the nuclear halogen/atom, preferably o, oi~0.
It is selected from the range of 1 mole.

On the other hand, as another method for causing chloroform to be present in the reaction system, it is also preferable to flow gaseous chloroform into the reaction system.

In this case, if necessary, replace chloroform with nitrogen, argon,
- It may be used in combination with a carrier gas such as carbon oxide. The concentration of chloroform in the gas mixture is not particularly limited, but usually! A capacity of 1 or more is preferable. The gas supply rate is not uniquely determined by the chloroform concentration, but is 0.0/, /, 0 mol, preferably 0.0//, per unit time, per unit time, per unit time.
The amount may be about 0.1 mol, and is usually about 100 mol per liter of reaction solution/100 mol/hr (converted to standard conditions).

On the other hand, the amines used in the present invention include methylamine,
Ethylamine, n-propylamine, isopropylamine, n-butylamine, n-amylamine, n-hexylamine, n-octylamine n-laurylamine, hexamethylene diamine, ethanolamine, allylamine, para-aminobenzoic acid, para-aminobenzoic acid methyl ester , para-aminobenzoic acid sodium salt, 7th class amines such as glycine, secondary amines such as di-n-propylamine and di-n-butylamine, Toso n-propylamine,
Examples include tertiary amines such as tri-n-butylamine.

Among these, seventh-class amines are preferred, and more preferred are methylamine, ethylamine, n-propylamine,
C8 to C1□ alkylamines such as isopropylamine, n-butylamine, n-hexylamine, n-octylamine, and n-laurylamine, and cx to C4 alkylamines are particularly preferred.

The amount of amine used is 0.0% based on the platinum group metal/atomic weight. /
~/00-E:)Lt, preferably Oj, 2O-E-
It is le. Outside the above range, the yield of the biphenyl compound will be low and the effects of the present invention will not be fully exhibited.

In the reaction of the present invention, water alone or an aqueous solvent mainly composed of water and inert to the reaction, such as ethers such as tetrahydrofuran and dioxane, is used as the solvent. The amount of solvent used in this case is usually 0.00% relative to the aromatic halogen compound. / , j It is about twice the capacity of O.

The reaction temperature of the present invention is usually ! 0-200″C1 is preferably 100~/j O'C, and the reaction pressure is usually normal pressure x o o H7ait, preferably normal pressure~1
0O#/cIIl.

The method of the present invention can be carried out in a batch, semi-batch or continuous manner.

The platinum group metal catalyst used in the reaction is separated and recovered from the reaction solution by conventional methods such as extraction, crystallization, or reduction.

When a supported metal catalyst is used, it can be easily separated and recovered by filtration and used again in the dehalogenation dimerization reaction.

The biaryl compounds obtained in the present invention are separated and obtained from the reaction solution by an evaporation method, a distillation method, a crystallization method, an acid precipitation method, etc. according to their physical properties.

〔Example〕

Next, the present invention will be explained in more detail with reference to examples, but the present invention is not limited to the following examples unless it exceeds the gist thereof.

Example/~! In a stainless steel induction rotary autocooler with a content/l, equipped with a vaporizer and a gas inlet tube, 2% by weight palladium carbonate was added. , add 2J of Hiro-chloroorthophthalic acid monosodium salt (hereinafter abbreviated as Hiro-CPA salt) to 3 rolls of demineralized water in advance.2. Tamimol, 3-chloroorthophthalic acid monosodium salt / 444 mmol, to! - dichlorophthalic acid monosodium salt (hereinafter ≠
, r-D CP A salt. )/μ, tamilimoles,
3. Hiro-dichlorophthalic acid monosodium salt/j, G
An aqueous solution containing 209 mmol of sodium hydroxide in a mixture of 7 tl of monosodium orunphthalic acid salt, 100 liters of demineralized water, the amine shown in Table 7, and 100 f of sodium hydroxide were charged. While stirring this mixture at 7jO rotations per minute, nitrogen was introduced from the bottom of the autoclave through the vaporizer and gas inlet pipe to a pressure of Jr14/a/l·G, and the flow rate was increased to /jNl/
It was distributed in Hr.

After raising the temperature of the autoclave to 720°C and the vaporizer to 100°C, add 2.0% of chloroform. A mixed gas of chloroform/nitrogen was sent to the vaporizer at Itnl/Hr and supplied into the autoclave through the gas introduction pipe. At r hours, the supply of chloroform was stopped to stop the reaction.

Analysis of the reaction solution by high performance liquid chromatography revealed that the sodium salt of orunphthalate produced by dehalogenation and the desired 3. II-,3',II',-biphenyltetracarboxylic acid sodium salt (hereinafter abbreviated as 5-BTC salt) was produced.

The results are shown in Table 1.

Comparative Example 1 The reaction was carried out in the same manner as in Example 1, except that no amine was used.

The results are shown in Table 1.

-8' Table 1, j-DCPA salt (mmol) + 1, t-DCPA salt (mmol) [Effects of the invention] According to the present invention, a platinum group metal catalyst, an alkali metal compound or an alkaline earth metal compound By further presence of an amine in the method of dehalogenating an aromatic compound in an aqueous medium in the presence of chloroform, a duplex of an aromatic compound can be obtained in high yield and with good selectivity. This is an industrially extremely advantageous method.

Applicant: Mitsubishi Chemical Industries, Ltd. Agent: Patent Attorney Hase - (7 others)

Claims (1)

[Claims] (1) Dehalogen-dimerizing an aromatic compound having at least one halogen atom in the aromatic carbon in an aqueous medium in the presence of a platinum metal catalyst, an alkali metal compound or an alkaline earth metal compound, chloroform and an amine. A method for dehalogenating and dimerizing aromatic halogenated compounds.