JPH0541623B2 - - Google Patents

Description

[Detailed description of the invention]

FIELD OF THE INVENTION The present invention relates to a method for producing aromatic dicarboxylic acid chlorides. More specifically, the invention relates to a method for producing carboxylic acid chloride through a homogenization reaction between a trichloromethyl group and a carboxyl group. [Industrial Application Fields] Aromatic dicarboxylic acid chlorides are mainly used as polymer raw materials. Polymers derived from these raw materials include polyester, polyamide, polyimide, etc., but they are especially used as raw materials for polymers with excellent properties such as strength and heat resistance, such as arylates, fully aromatic polyamides, and fully aromatic polyimides. be done. [Prior Art] There are two main methods for producing aromatic dicarboxylic acid chlorides industrially. One is a method in which an aromatic dicarboxylic acid is reacted with a bistrichloromethyl-substituted aromatic compound, and the other is a method in which an aromatic dicarboxylic acid is reacted with phosphorus pentachloride, phosphorus trichloride, thionyl chloride, or phosgene. This method involves reacting with a chlorinating agent such as In particular, if an aromatic dicarboxylic acid and a bistrichloromethyl-substituted aromatic compound having substituents at the same position are used, this method is economically and technically very effective. A method for producing terephthalic acid chloride and isophthalic acid chloride from terephthalic acid and hexachloropara-xylene, and from isophthalic acid and hexachloromethacylene is described in Japanese Patent Application Laid-open No. 1973-
This method has been proposed in Publication No. 105027 and Japanese Patent Application Laid-open No. 53-53636. Furthermore, as a method for producing an equimolar mixture of terephthalic acid chloride and isophthalic acid chloride,
JP-A-53-121733 proposes to react terephthalic acid and hexachloromethaxylene or isophthalic acid and hexachloroparaxylene. Since this method uses raw materials that differ only in the position of the substituent, it is possible to adopt exactly the same reaction conditions as when using an aromatic dicarboxylic acid and a bistrichloromethyl-substituted aromatic compound that have substituents in the same position. I can do it. [Object of the Invention] In producing a specific aromatic dicarboxylic acid chloride, the present inventors used an aromatic dicarboxylic acid with completely different structures and a bistrichloromethyl-substituted aromatic compound as raw materials to produce aromatic dicarboxylic acid chlorides with completely different structures. The present invention was achieved as a result of extensive research into a method for simultaneously returning group dicarboxylic acid chlorides easily and in good yield. In particular, even with aromatic compounds such as phenoxy groups, which have electronic substituent effects different from those of carboxyl groups and trichloromethyl groups, the reaction occurs easily and in good yields, and decomposition and elimination of phenoxy groups hardly occur. This is what I found. [Structure of the invention] The present invention has the following general formula [] [However, in the formula, n represents 0 or 1, and when it is 0, it represents a bond. Furthermore, the two bonds in each benzene ring are not located at ortho positions to each other in the benzene ring. ] The following general formula [] is characterized by reacting a chloromethyl-substituted phenyl ether represented by with terephthalic acid and/or isophthalic acid in the presence of a Friedel-Crafts catalyst. [However, the definitions of n in the formula and the position of the bond in each benzene ring are the same as in the above general formula []. ] This is a method for producing a carboxylic acid chloride consisting of phenyl ether carboxylic acid chloride represented by the following and terephthalic acid chloride and/or isophthalic acid chloride. The method of the present invention preferably has the above general formula []
A chloromethyl-substituted phenyl ether represented by terephthalic acid and/or isophthalic acid in the presence of a Friedel-Crafts catalyst such as an iron catalyst,
It is carried out by heating the liquid, ie molten or solution state, to a temperature of 100°C to 250°C. Trichloromethyl-substituted phenyl ethers are
Usually, it can be obtained by reacting the corresponding methyl-substituted phenyl ether with chlorine gas under irradiation with ultraviolet-containing light, but it can be obtained by separating it from the reaction solution.
It can be used without purification by simply removing unreacted chlorine and hydrogen chloride produced by the reaction. In particular, the above method is sufficient if the product trichloromethyl-substituted phenyl ether can be liquid under this photochlorination condition, i.e. in the range of 50°C to 150°C, and then terephthalic acid and/or Alternatively, it may be carried out by adding isophthalic acid and a catalyst and heating to a predetermined temperature.
Further, when a chlorinated hydrocarbon is used as a solvent in the photochlorination reaction, it is also possible to use the solvent as it is as a solvent in the disproportionation reaction of the present invention without distilling off the solvent. Such solvents include
Examples include chlorinated hydrocarbons that are inert to the photochlorination reaction and the disproportionation reaction, such as chlorinated paraffins such as dichloroethane, trichloroethane, and tetrachloroethane, and chlorinated aromatic compounds such as chlorobenzene. is preferred. The total amount of trichloromethyl-substituted phenyl ether, terephthalic acid, and isophthalic acid relative to the solvent is preferably 20% or more. The reaction temperature is preferably in the range of 100°C to 250°C. At temperatures lower than 100°C, the reaction rate is too slow due to the low solubility of terephthalic acid and isophthalic acid, which is not industrially practical. If the temperature is higher than 250°C, desorption of chlorine and formation of tar-like substances occur, resulting in a decrease in yield. The preferred reaction temperature is 150
It ranges from ℃ to 230℃. As the Friedel-Crafts catalyst, chlorides of aluminum, antimony, iron, titanium, tin, and zinc are used, and ferric chloride is particularly preferably used. The amount of catalyst is 0.005% to 5% by weight based on the total amount of trichloromethyl-substituted phenyl ether, terephthalic acid, and isophthalic acid,
Preferably it is 0.1% to 2.50%. The ratio of chloromethyl-substituted phenyl ether to terephthalic acid and/or isophthalic acid is preferably set so that the number of chloromethyl groups and the number of carboxyl groups are approximately equal, and may be from 1:0.95 to 1:1.05. It is sufficient. The reaction time is 10 minutes to 100 hours, usually about 1 to 8 hours. The reaction between a trichloromethyl group and a carboxyl group generates two molecules of chlorocarbonyl group and one molecule of hydrogen chloride. Therefore,
The reaction must continue until the evolution of hydrogen chloride has ceased. After the reaction is completed as described above, the target product is recovered and produced by solvent distillation, distillation, and crystallization, if necessary. The phenyl ether carboxylic acid chloride and the terephthalic acid chloride and/or the isophthalic acid chloride can be recovered as a mixture, or the terephthalic acid chloride and/or the isophthalic acid chloride can be first separated and then the phenyl ether carboxylic acid chloride can be recovered. can. Hydrocarbons containing paraffins such as hexane and heptane, and chlorinated hydrocarbons such as carbon tetrachloride or chlorobenzene are used for crystallization and purification of phenyl ether carboxylic acids. [Effects of the Invention] According to the method of the present invention, an equimolar mixture of phenyl ether carboxylic acid chloride and terephthalic acid chloride and/or isophthalic acid chloride can be easily obtained with good yield. Example 1 Put 40 g (0.099 mol) of 3,4'-bistrichloromethyldiphenyl ether, 16.8 g (0.100 mol) of terephthalic acid, and 0.5 g (3 mmol) of anhydrous iron chloride into a 200 ml eggplant-shaped flask, and place it in a magnet. The temperature was raised in an oil bath while stirring with a taste stirrer. It melts at around 70℃ and continues to increase the temperature to 200℃.
The reaction temperature was maintained at °C. When the reaction started, hydrogen chloride was generated, which was absorbed with an aqueous NaOH solution. After the reaction is completed, continue to 1-2 mmHg.
The pressure was reduced to 19.6 g (0.0965 mol) of terephthalic acid dichloride having a boiling point of 105 to 115°C. Add 30ml of carbon tetrachloride to the distillation residue and dissolve by heating.
After separating the insoluble residue and cooling, 23.4 g of 3,4'-diphenyl ether carboxylic acid chloride was obtained.
(0.079 mol) was precipitated. The boiling point of this product was 185-190°/0.5 mmHg. The results are shown in the table. Example 2 The reaction was carried out in the same manner as in Example 1, except that 4,4'-bistrichloromethyldiphenyl ether was used instead of 3,4'-bistrichloromethyldiphenyl ether, and isophthalic acid was used instead of terephthalic acid. I went. The results are shown in the table. Example 3 Bis-p-(p
-Trichloromethylphenoxy)benzene 50g
The reaction was carried out in the same manner as in Example 1, except that 0.101 mol of terephthalic acid was used and the amount of terephthalic acid used was slightly changed. The results are shown in the table.

【table】

【table】

Claims (1)

[Claims] 1. The following general formula [] [However, in the formula, n represents 0 or 1, and when it is 0, it represents a bond. Furthermore, the two bonds in each benzene ring are not located at ortho positions to each other in the benzene ring. ] The following general formula [] is characterized by reacting a chloromethyl-substituted phenyl ether represented by with terephthalic acid and/or isophthalic acid in the presence of a Friedel-Crafts catalyst. [However, the definitions of n in the formula and the position of the bond in each benzene ring are the same as in the above general formula []. ] A method for producing a carboxylic acid chloride consisting of phenyl ether carboxylic acid chloride represented by the following and terephthalic acid chloride and/or isophthalic acid chloride. 2. The production method according to item 1, wherein the reaction is carried out at a temperature in the range of 100°C to 250°C. 3. The production method according to item 1, wherein the reaction is carried out in a chlorinated hydrocarbon solvent. 4. The production method according to item 1, wherein the reaction is carried out in the presence of an iron catalyst.