JPH0417176B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a novel method for producing 1,3-bis(3-aminophenoxy)benzene (abbreviated as APB). For more details, see the general formula () (In the formula, X represents a chlorine atom or a bromine atom)
1, characterized in that 1,3-bis(3-aminophenoxy)-5-halogenobenzene represented by is reduced and dehalogenated using formic acid and/or formate, or hydrazine in the presence of a palladium catalyst. , 3-bis(3-aminophenoxy)benzene. APB is a heat-resistant polymer monomer, especially polyamide,
It is an important material that is a raw material for polyimide. For example, an acetylene-terminated polyimide made from APB, 3,3',4,4'-benzophenonetetracarboxylic dianhydride, and 3-aminophenyl acetylene has one of the highest heat resistances among polyimides. known to be a polymer. (USP3845018, USP3879349). APB
Conventionally, resorcinol is produced by condensing and reducing 1-bromo-3-nitrobenzene (Ger-Offen2462112), and 3-aminophenol and 1,3-dibromobenzene are condensed (W. Fink et al., Helv.Chim.Acat., 51
971 (1968), USP4222962) is known. In the above method for producing APB, in the reaction of resorcin and 3-nitrobromobenzene, first,
After treating resorcin with sodium methoxide in a large amount of benzene, dehydration is performed while recovering benzene by distillation to produce resorcin disodium, which is then treated with cuprous chloride in a large amount of pyridine solvent. 3-nitrobromobenzene under an argon atmosphere to give a yield of 41
% of 1,3-bis(3-nitrophenoxy)benzene, and then this nitro compound is reduced with ferrous sulfate to produce the desired product. In addition, in the method of manufacturing by condensing 3-aminophenol and 1,3-dibromobenzene, the two may be reacted at 200 to 280°C in the presence of copper powder, or
Alternatively, the desired product has been obtained in a low yield of 45-65% by reacting in a large amount of pyridine in the presence of cuprous chloride. However, such known production methods for APB use large amounts of reaction solvents such as pyridine, which are difficult to handle due to their odor, and also require dehydration such as benzene to suppress side reactions such as hydrolysis. Strict water removal operations are required using a large amount of solvent, and since reaction accelerators such as copper powder and cuprous chloride are used, care must be taken to remove coloration and copper ions. However, these methods are extremely difficult to implement because they have disadvantages in manufacturing operations such as conducting the reaction under an inert gas and in making the waste pollution-free. The inventors have proposed an APB without the drawbacks mentioned above.
We conducted extensive research on the manufacturing method. As a result, we found a novel 1,3-bis(3-aminophenol) which can be obtained in high yield by condensing 1,3,5-trihalogenobenzene and 3-aminophenol, as previously proposed (Japanese Patent Application No. 58-196226). ) -5-Halogenobenzene is reduced with formic acid and/or formate, or hydrazine in the presence of a palladium catalyst, and dehalogenated to produce APB in high yield, and the present invention has been completed by discovering a method for producing APB in high yield. That is, the method of the present invention is based on the general formula () (In the formula, X represents a chlorine atom or a bromine atom)
1, characterized in that 1,3-bis(3-aminophenoxy)-5-halogenobenzene represented by is reduced and dehalogenated using formic acid and/or formate, or hydrazine in the presence of a palladium catalyst. , 3-bis(3-aminophenoxy)benzene. According to the method of the present invention, 1,3-bis(3-aminophenoxy) represented by the general formula ()
-5-halogenobenzene in an organic solvent in the presence of a palladium catalyst, formic acid and/or formate;
Alternatively, by reduction using hydrazine, dehalogenation is achieved and the target product, APB, can be produced in high yield. Therefore, it is suitable as an industrial production method without the disadvantages of conventional methods such as low yield and requiring complicated operations in reaction and purification. The raw material used in the method of the present invention is 1,3-bis(3-aminophenoxy)-5-halogenobenzene represented by the above general formula (), and the halogen species is a chlorine atom or a bromine atom. For example, 1,3-bis(3-aminophenoxy)-5-chlorobenzene, 1,3-bis(3-
aminophenoxy)-5-bromobenzene. These can be used alone or in combination as raw materials for APB according to the method of the present invention, but
It is preferable to use 1,3-bis(3-aminophenoxy)-5-chlorobenzene, which is industrially inexpensive. The reducing agent used in the method of the invention is formic acid, formate or hydrazine. Examples of the formate include alkali metal formates such as sodium formate and potassium formate, organic amine salts such as ethylamine formate, ammonium formate, and the like, and these may be used alone or in combination with formic acid. The palladium catalyst used in the method of the invention is
Can be used in metallic form, but usually
It is used by attaching it to the surface of a carrier. These catalysts include palladium black, palladium-activated carbon, palladium-alumina, palladium-barium sulfate, and the like. The amount of the catalyst used is in the range of 0.01 to 10% by weight based on the raw material 1,3-bis(3-aminophenoxy)-5-halogenobenzene. The reaction solvent used in the method of the present invention includes:
The solvent is not particularly limited as long as it is inert to the reaction, and a water-miscible solvent is usually used.
For example, alcohols such as methanol, ethanol, and isopropanol, glycols such as ethylene glycol and propylene glycol, ethers such as tetrahydrofuran, dioxane, and methylcellosolve, and aprotons such as N,N'-dimethylformamide and N-methylpyrrolidone. Examples include polar solvents. The amount of solvent used is sufficient to suspend or completely dissolve the raw materials, and although there is no particular limitation, it is usually sufficient to use 0.5 to 10 times the weight of the raw materials. The reaction temperature is not particularly limited, but is usually 20-130°C.
℃ range. In carrying out the present invention, in general, raw materials are dissolved or suspended in a solvent, formic acid and/or a formate salt, or hydrazine and a catalyst are added, and then the reaction is carried out at a predetermined temperature with stirring. In either case, the reaction proceeds smoothly and the target product is obtained.
APB can be manufactured. Progress of the reaction can be followed by thin layer chromatography or high performance liquid chromatography. After heating the reaction solution obtained by the above method to remove the catalyst, crystals can be precipitated by concentrating or diluting with water. It can also be precipitated as a salt. Hereinafter, the present invention will be explained in more detail with reference to Examples. Example 1 8.2 g (0.025 mol) of 1,3-bis(3-aminophenoxy)-5-chlorobenzene was added to a glass reactor equipped with a thermometer, reflux condenser and stirrer.
5% PD-C (manufactured by Engelhard Japan) 0.25g,
4.3 g (0.063 mol) of sodium formate and 50 ml of a 60% aqueous isopropanol solution were charged, and the reaction was carried out under reflux with stirring for 5 hours. After the reaction was completed, the catalyst was removed by heating and cooled to precipitate colorless prism crystals. By filtering and drying, 1,3-bis(3-
6.6 g (yield 90.3%) of aminophenoxy)benzene
I got it. 99% purity determined by high performance liquid chromatography
It was hot. Melting point 105-107℃

[Table] Example 2 In a device similar to Example 1, 1,3-bis (3-
Aminophenoxy)-5-bromobenzene 9.3g
(0.025 mol), 0.2 g of 5% PD-C, 3.8 g (0.076 mol) of hydrazine hydrate, and 50 ml of a 50% aqueous methanol solution were charged, and the reaction was carried out under reflux with stirring for 5 hours. The subsequent operations were performed in the same manner as in Example 1, and the purity was determined by high performance liquid chromatography.
6.9 g (yield 94.4%) of the target product was obtained with a yield of 98.8%. melting point
105-108°C Examples 3-6 1,3-bis(3-aminophenoxy)-5-
The reaction was carried out in the same manner as in Example 1 except that chlorobenzene was used as the raw material and the solvent and reducing agent were changed as shown in Table 1.
Aminophenoxy)benzene was obtained. Table 1 shows the solvent and reducing agent used and the yield of the target product.

【table】

Claims (1)

[Claims] 1 1,3-bis(3-aminophenoxy)-5
- A method for producing 1,3-bis(3-aminophenoxy)benzene, which comprises dehalogenating halogenobenzene by reducing it using a reducing agent in the presence of a palladium catalyst. 2. The method according to claim 1, wherein the reducing agent is formic acid and/or a formate salt. 3. The method according to claim 1, wherein the reducing agent is hydrazine.