JPH0583532B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a method for producing arylpolycarboxylic acids such as terephthalic acid, isophthalic acid, and trimesic acid, or their alkali metal salts, which are useful as plasticizers and resin raw materials. Conventional technology The carbonylation reaction of aromatic halides, especially aromatic chlorides, and aromatic bromides using CO gas has been studied for a long time, and among them, nickel,
It is known that cobalt, iron halides, carbonyl complexes, etc. become effective catalysts in the presence of alkali metal salts (potassium acetate, soda carbonate, caustic soda, etc.). However, the reaction conditions for these catalysts are high temperature and high pressure [200℃ or higher, 200 to 600 kg
(cm ² )], the yields are generally low and satisfactory results have not been obtained [Tetrahedrom Lett., 1841 (1963); J.Org.
Chem., 34 , 1500 (1969); JACS, 91 , 1233
(1969); Bull.Chem.Soc.Jpn, 44 , 508 (1971);
ibid, 42 , 1124 (1969)]. Among them, the nickel carbonyl catalyst can carry out the reaction under the mildest conditions, but its reaction substrates are limited to monoiodinated benzene and monobrominated benzene derivatives [J.Organomet.Chem.,
51.381 (1973)]. Then, using a palladium/base catalyst,
It has been reported that carbonylation of aromatic halides (benzene iodide, benzene bromide and their derivatives) proceeds even under mild conditions. The application of this expensive catalyst system is limited to benzene iodide and benzene bromide and their derivatives [J.Ore.Chem., 39 , 3318
(1974); ibid, 40 , 532 (1975); Bull.Chem.Soc.
Jpn., 48 , 2075 (1975); Nippon Kagaku
Kaishi, 1974 , 1386; Bull.Chem.Soc.Jpn., 48 ,
2091 (1975)]. Recently, carbonylation reactions using cobalt catalyst systems have been studied, and for example, Brunet et al. reported that benzoic acid is produced from benzene iodide, benzene bromide, and benzene chloride [J.
Organomettollic Chem., 204 , (1980), 229; J.
Org.Chem., 44 , (1979), 2199]. Furthermore, Brunet et al. conducted a photocarbonylation reaction of aryl halides [J.Org.Chem.,
48, (1983), 1161]. This photocarbonylation reaction uses dicobalt octacarbonyl as a catalyst precursor and a quaternary ammonium salt (tetrabutylammonium bromide, tetrabutylammonium chloride, etc.) as a phase transfer catalyst in a two-phase system of sodium hydroxide aqueous solution/benzene. The process is carried out at normal pressure and around 65℃ in the coexistence of [Chemical] The reactivity of phenyl halide is benzene iodide, benzene bromide (yield >90%) >> chlorobenzene (very small amount), and chlorobenzene is inactive in this system as well. The present inventors have conducted research on the photocarbonylation reaction of 4-chlorophthalic acid and have found that trimellitic acid can be synthesized almost quantitatively (Japanese Patent Application No. 58-236888). On the other hand, aryl polyhalides, such as 1,4
- Carbonylation reactions using carbon monoxide such as dichlorobenzene and 1,3-dichlorobenzene have been studied under high temperature and high pressure (200°C or higher, 200 to 400 atmospheres) [H.KROEPER, West German Patent No. 1074028] (1960), Kazumi Yamamoto, Bull.Chem.
Japan., 27 , 389 (1954)], the reaction conditions are harsh and no industrially advantageous method has been found. moreover,
No knowledge is known regarding the preparation of the corresponding arylpolycarboxylic acids by photocarbonylation of arylpolychlorides under mild reaction conditions, for example. As pointed out by Brunet et al., the production of benzoic acid by the photocarbonylation reaction of monochlorobenzene is very small, and the results of experiments conducted by the present inventors also showed a yield of around 1%. Based on such findings, it was thought that the photocarbonylation reaction of aryl polyhalides, especially aryl polychlorides, was extremely difficult. However, as a result of various studies conducted by the present inventors, we unexpectedly found that 1,4-dichlorobenzene, 1,3-dichlorobenzene,
It was discovered that terephthalic acid, isophthalic acid, and trimesic acid can be obtained in high yield by photocarbonylation reaction of 1,3,5-trichlorobenzene, and furthermore, 1,2-dichlorobenzene, 1,2,4-
It has been found that corresponding aryl polycarboxylic acids can also be obtained from polyaryl halides such as trichlorobenzene and 1,2,4,5-tetrachlorobenzene through a similar reaction. Problems to be Solved by the Invention The present invention relates to a method for producing an aryl polycarboxylic acid or an alkali metal salt thereof from an aryl polyhalide under milder conditions than conventional methods. Means for Solving the Problems The present invention is based on the formula () ArClX _o-1 () (wherein Ar represents an aryl group, X represents a halogen atom, and n represents 2, 3 or 4) Aryl polyhalide represented by [hereinafter,
It is called a compound (). The same applies to compounds having other formula numbers. ] and carbon monoxide in the presence of a carbonylation catalyst in an aqueous solution of an alkali metal compound under irradiation with light of 300 to 400 nm, and then, if necessary, the reaction solution is made acidic. Provided is a method for producing an arylpolycarboxylic acid represented by the formula () Ar(CO ₂ H) _o () (wherein Ar and n have the same meanings as above) or an alkali metal salt thereof. In the definition of formula (), the aryl group includes phenyl group, naphthyl group, etc., and the halogen atom includes chlorine, bromine, iodine, etc. Specific examples of compound () include 1,3-dichlorobenzene, 1,4-dichlorobenzene, 1,2
-dichlorobenzene, 4-bromochlorobenzene, 3-bromochlorobenzene, 2-bromochlorobenzene, 1,4-dibromobenzene, 1,
Examples include 3,5-trichlorobenzene, 1,3,5-tribromobenzene, 1,2,4-trichlorobenzene, and 1,2,4,5-tetrachlorobenzene. Alkali metal compounds include alkali metal hydroxides (e.g., sodium hydroxide, potassium hydroxide), alkali metal carbonates (e.g., sodium carbonate, potassium carbonate), and alkali metal bicarbonates (e.g., sodium bicarbonate, bicarbonate). potassium), but alkali metal hydroxides are particularly preferred. The reaction solvent may be an aqueous solvent, and water or a mixed solvent of water and a hydrophilic organic solvent (eg, methanol, ethanol, acetone, etc.) is used. The concentration range of the alkali metal compound in the reaction solvent is preferably 0.5 to 10N, preferably 4 to 6N. In order to carry out the photocarbonylation reaction smoothly, the compound () is preferably dissolved or partially dissolved in an aqueous alkali metal compound solvent, and therefore the use of the above-mentioned hydrophilic organic solvent is recommended. The carbonylation catalyst used in the present invention is cobalt carbonyl (such as dicobalt octacarbonyl),
These include nickel carbonyl and iron carbonyl, and these may be used alone or in combination. The appropriate amount of catalyst to be used is 1/200 to 1/2 times the mole of compound (). The reaction of the present invention is preferably carried out under irradiation with light around the maximum value of the light absorption spectrum of the catalyst.
It is carried out under irradiation with light of 300 to 400 nm. A mercury lamp, especially a high-pressure mercury lamp, is suitable as a light source. The reaction temperature of photocarbonylation in the present invention is 40
It is preferably between 110°C and 50°C and 70°C, more preferably between 50 and 70°C under low pressure (normal pressure to 10 atmospheres) reaction. When the temperature rises to 110°C or higher, the dechlorination reaction of the starting material increases, and the yield of the target polyhydric carboxylic acid tends to decrease. The reaction pressure is suitably from normal pressure to 50 atm, but practically it can be carried out at normal pressure to 20 atm, for example normal pressure to 10 atm. Although the reaction starts immediately upon exposure to light, a reaction time of 3 to 20 hours is usually appropriate in order to obtain a high conversion rate of compound (). After the photocarbonylation reaction, unreacted compounds () are extracted and removed from the reaction solution using a solvent such as diethyl ether. Then, the aqueous layer is either left as is or is neutralized with an acid such as hydrochloric acid and then concentrated or evaporated to dryness to obtain a crude alkali metal salt of compound (). Alternatively, when the aqueous layer is made acidic (for example, PH3) with an acid, for example, hydrochloric acid, the compound () is liberated. By passing through this, a crude product of compound () is obtained. These crude compounds ()
Alternatively, the alkali metal salt thereof can be purified by an appropriate combination of conventional purification methods, such as extraction (with diethyl ether etc. in the case of compound ()), concentration, column chromatography, recrystallization, etc. The above operation yields a compound () corresponding to compound () or an alkali metal salt thereof, but
Isophthalic acid, terephthalic acid, trimesic acid or their alkali metal salts are obtained in particularly high yields. Next, embodiments of the present invention will be described. Example 5,
As is clear from the comparison of No. 7 and No. 8, the substitution reaction proceeds more easily with the dihalo form at the meta and para positions than at the ortho position. This is thought to be due to steric effects. Furthermore, in Examples 3, 5, 7, 8, and 9, a system in which a 10% aqueous solution of tetrabutylammonium hydroxide was coexisting in the reaction solution as a phase transfer catalyst was used; Although no difference in effectiveness was observed at the end of the reaction, an effect of reducing the reaction rate at the initial stage of the reaction was observed. Example 1 A Pyrex glass autoclave (60 ml) equipped with a stirrer having electromagnetic high-speed rotating stirring blades and a CO inlet on its stirring shaft was used as a reaction vessel. The light source is a high-pressure mercury lamp (500W).
The distance from the reaction vessel was set to 30 cm, and a condenser lens was placed between them so that the light from the light source could be effectively collected into the reaction liquid portion in the reaction vessel. 12 ml of 4N sodium hydroxide aqueous solution in the reaction pot.
7.2 ml of ethanol, _Co2 (CO) ₈ as catalyst
0.2 mmol was added, followed by 2 mmol of 1,3,5-trichlorobenzene. Next, CO gas was introduced from the CO inlet, and the CO partial pressure was set to 1 to 5 atm. The reaction solution was heated under light irradiation while stirring, and the reaction temperature was maintained at 65° C. for 20 hours. As the reaction progressed, the CO partial pressure decreased due to CO consumption, so CO gas was occasionally replenished to maintain the CO partial pressure of 1 to 5 atm. After the reaction was completed, the reaction solution was extracted twice with 10 ml of diethyl ether to remove unreacted reaction substrates, and then the aqueous layer was acidified (PH3) with hydrochloric acid (10% aqueous hydrochloric acid solution) and then dried under reduced pressure. 20 ml of diethyl ether was added to the evaporated product, and diazomethane was introduced for methylation, followed by analysis and quantification by gas chromatography. The conversion rate of the reaction substrate 1,3,5-trichlorobenzene [(moles of reactant consumed/moles of reactant loaded) x 100] was almost 100%, and the analytical results showed that the trimesic acid yield (moles of reactant loaded) was almost 100%. Calculated based on moles of reacted substrate.) 85.5%, isophthalic acid
It was 11.9%. Examples 2 to 9 In the reaction vessel of Example 1, 4N sodium hydroxide aqueous solution (12 ml), ethanol (7.2 ml),
0.2 mmol of Co (CO) ₈ and 2 mmol of compound () were charged, and the CO partial pressure was 1 to 5 atm, and the reaction temperature was 65°C.
The reaction was carried out for 20 hours. In Examples 3, 5, 7, 8 and 9, 0.5% of a 10% aqueous solution of tetrabutylammonium hydroxide (Bu ₄ NOH) was added to the reaction system.
ml was added before introducing CO gas to see the effect.
After the reaction was completed, the same treatment as in Example 1 was carried out, and the reaction product was analyzed and quantified. The results are shown in Table 1. In the table below, reaction products 1 to 9 are as follows. 1 : Benzoic acid, 2 : 4-chlorobenzoic acid, 3 :
Terephthalic acid, 4 : 3-chlorobenzoic acid, 5 : isophthalic acid, 6 : 2-chlorobenzoic acid, 7 : phthalic acid, 8 : 3,5-dichlorobenzoic acid, 9 : trimesic acid. [Table] [Table] Example 10 The reaction was carried out in the same manner as in Example 1 except that 1,2,4,5-tetrachlorobenzene was used as the compound (). As a result, the conversion rate was almost 100%, Acid yield: terephthalic acid 13.2%, isophthalic acid 10.8%
%, trimellitic acid 18.5%, pyromellitic acid 1.0
It was hot. Effects of the Invention A method for producing an aryl polycarboxylic acid or an alkali metal salt thereof from an aryl polyhalide under milder conditions than conventional methods is provided.

Claims (1)

[Claims] 1 Aryl polyhalide represented by the formula ArClX _o-1 (wherein Ar represents an aryl group, X represents a halogen atom, and n represents 2, 3 or 4) and monoxide The formula Ar(Co A method for producing an arylpolycarboxylic acid or an alkali metal salt thereof represented by _2H ) _o (wherein Ar and n have the same meanings as above). 2 Aryl polyhalide is 1,3-dichlorobenzene, 1,4-dichlorobenzene or 1,3,
The manufacturing method according to claim 1, which is 5-trichlorobenzene. 3. The production method according to claim 1, wherein the carbonylation catalyst is cobalt carbonyl. 4. Claim 1, wherein the aqueous solution of the alkali metal compound is a solution in which the alkali metal hydroxide is dissolved in a mixed solvent of water and a hydrophilic organic solvent.
Manufacturing method described in section.