JPH0653710B2 - Method for producing 1,4-bis (3-aminophenoxy) benzene - Google Patents

Description

TECHNICAL FIELD The present invention relates to a novel method for producing 1,4-bis (3-aminophenoxy) benzene.

More specifically, hydroquinone and m-dinitrobenzene are condensed with an aprotic polar solvent in the presence of a base, and then reduced, which is characterized in that 1,4-bis (3-
Aminophenoxy) benzene production method.

This 1,4-bis (3-aminophenoxy) benzene is
It is an important compound as a raw material for heat-resistant polymers, particularly polyamide, polyamide-imide and polyimide. For example, a polyimide resin composed of this diamine monomer and tetracarboxylic acid anhydride has been developed as a liquid crystal display device or a meltable polyimide (JP-A-55-15691).
7, JP-A-59-170122, etc.).

(Prior Art) Conventionally, in the method for producing 1,4-bis (3-aminophenoxy) benzene, m-aminophenol and p-dibromobenzene are condensed in a pyridine solvent in the presence of a cuprous chloride catalyst. Thus, only an example in which the yield is 42% is known. (JP-A-59-170122) However, this method is not economical because the raw materials are expensive and the yield is low. Furthermore, since a difficult-to-handle solvent such as pyridine is used, it is necessary to pay attention to recovery, etc.
It is difficult to carry out industrially.

The method of the present invention, which will be described in detail later, relates to a method for deriving 1,4-bis (3-aminophenoxy) benzene from m-dinitrobenzene and hydroquinone.

Heretofore, in an aromatic nitro compound, many reactions have been known in which a nitro group activated by an electron-withdrawing group at the o- or p-position is replaced with an alcohol or a phenol (for example, HMelles et al., J. .Polym.Scl., P
olym.Chem.Ed., 15 .2441 (1977); JR Beck et al., J. Org. Che
m., 39 .1839 (1974); T. Takekoshi et al., J. Polym. Sct., Poly.
m.Chem.Ed., 18 .3069 (1980) and other papers and JR Beck.,
There is a review of Tetrahedron. 34 .2057 (1978)). However, regarding the reaction of a non-activated nitro group such as m-dinitobenzene, only some examples of substitution reaction with alcohols are known.

For example, (1) a method for producing m-nitroanisole by reacting m-dinitrobenzene and sodium methoxide in a hexamethylphosphotriamide (HMPA) solvent at 25 ° C. for 16 hours (N. Kornblum et al., J. Org. .Chem., 41 ,
1560 (1976)), (2) In the presence of macrocyclic polyether, in a polar organic solvent, m
-A method for producing m-nitrophenyl alkyl ether by reacting dinitrobenzene with an alkali metal alkoxide (Toyota et al., JP-A-54-39030), (3) m-dinitrobenzene and sodium methoxide with chlorobenzene , A method for producing m-nitroanisole by reacting in the presence of a phase transfer catalyst (F. Montanar
i., Chem. & Ind., 1982 .412) are known. However, since these use special and expensive compounds such as HMPA and crown ethers, it is difficult to say that they are general reactions.

Further, recently, as a method of improving these, m-dinitrobenzene and alcohols were reacted in the presence of an alkali metal carbonate, hydrogen carbonate, trialkali metal phosphate or carbon dioxide gas to give m-nitrophenyl. A method for producing an alkyl ether has also been reported (JP-A-58-180461 and JP-A-5-180461).
9-25353 and 59-44343).

On the other hand, regarding the substitution reaction of m-dinitrobenzene with phenols, conventionally, in the presence of a macrocyclic polyether,
Only a method for producing 3-nitrodiphenyl ethers by reacting m-dinitrobenzene with an alkali metal salt of phenols in a polar organic solvent is known (JP-A-54-39030).

However, in this case, it is necessary to use a special reagent such as expensive and toxic crown ether as a reaction accelerator, and there is a drawback that its recovery is difficult. As described above, the substitution reaction of m-dinitrobenzene with phenols is expected to be considerably more difficult than that of alcohols, and there has been no conventional example under the industrially usual conditions.

(Problems to be Solved by the Invention) As described above, the problem of the present invention is
-Overcoming the difficulties expected from the production example of 3-nitrodiphenyl ethers by the condensation reaction of dinitrobenzene and phenols, in particular by condensing hydroquinone having two hydroxyl groups and m-dinitrobenzene, 1 , 4-
Bis (3-aminophenoxy) benzene is produced and reduced to be a useful raw material for polyimide resins and the like 1,4-
It is to provide bis (3-aminophenoxy) benzene at low cost.

(Means for Solving the Problems) In order to solve the problems of the present invention, the present inventors have conducted intensive studies and as a result, conclude that hydroquinone and m-dinitrobenzene are condensed with a base and an aprotic polar solvent. if,
1,4-bis (3-nitrophenoxy) benzene was obtained in good yield, and it was reduced to give 1,4-bis
The present invention has been completed by finding that bis (3-aminophenoxy) benzene can be easily produced.

That is, the method of the present invention is characterized in that hydroquinone and m-dinitrobenzene are condensed in the presence of a base using an aprotic polar solvent, and then reduced.
-A method for producing bis (3-aminofuphenoxy) benzene.

The method of the present invention is a reaction for producing an intermediate compound 1,4-bis (3-nitrophenoxy) benzene by condensing hydroquinone and m-dinitrobenzene in the presence of a base in an aprotic polar solvent (hereinafter , The first stage reaction)
And a reaction for producing 1,4-bis (3-aminophenoxy) benzene, which is a target substance, by further reducing this intermediate compound (hereinafter referred to as the second-stage reaction).

In the first-step reaction, the amount of m-dinitrobenzene used is usually at least 2 times the molar amount of the starting hydroquinone, but it is preferable to use it in the range of 2.4 to 3 times the molar amount in consideration of the reaction and economy. Then it is convenient. Bases used in this reaction are alkali metal hydroxides, carbonates, bicarbonates and alkoxides, such as potassium hydroxide, sodium hydroxide, lithium hydroxide, potassium carbonate, sodium carbonate, lithium carbonate, Examples include potassium bicarbonate, sodium bicarbonate, potassium isopropoxide, sodium methoxide and the like. Of these, potassium carbonate and potassium bicarbonate are particularly preferably used.

The amount of the base used is not particularly limited, and it is usually 2 to 5 equivalents relative to the raw material hydroquinone, preferably 2.5 to
3.5 equivalents is sufficient.

An aprotic polar solvent is used as the reaction solvent.
Specifically, N-methylformamide, N, N-dimethylformamide, N, N-dimethylacetamide, dimethylsulfoxide, dimethylsulfonesulfolane, 1,3-dimethyl-2-imidazolidinone, hexamethylphosphotriamide, etc. Can be mentioned.

The amount of these solvents used is not particularly limited, but usually, 1 to 10 times by weight of the raw material is sufficient.

The reaction temperature is generally 60 to 200 ° C., preferably 110.
It is in the range of to 150 ° C.

As a general embodiment in the first stage, there is no particular limitation such as a charging method of raw materials, and a predetermined amount of m-dinitrobenzene, hydroquinone, a base and an aprotic polar solvent are charged, and nitrogen gas is used. And react under an inert gas stream such as.

The end point of the reaction can be determined by gas chromatography, high performance liquid chromatography or the like. After completion of the reaction, the solvent is distilled off, or the reaction solution is directly discharged into water to obtain a crude product of the intermediate compound, which can be purified by recrystallization or the like.

In this first-stage reaction, quaternary ammonium salt, 4
Phosphorus salts, macrocyclic polyethers such as crown ethers, nitrogen-containing macrocyclic polyethers such as cryptate,
Phase transfer catalysts such as nitrogen-containing chain polyethers, polyethylene glycol and its alkyl ethers, copper powder and copper salts may be added as reaction accelerators.

There is no particular limitation on the reduction method used in the second step reaction,
Usually, a method of reducing a nitro group to an amino group (for example, New Experimental Chemistry Course, Volume 15, Oxidation and Reduction [II], Maruzen (197
Although 7)) can be applied, catalytic reduction or hydrazine reduction is industrially preferable.

In the case of catalytic reduction, the reduction catalyst used is a metal catalyst generally used for catalytic reduction, such as nickel,
Palladium, platinum, rhodium, ruthenium, cobalt,
Copper or the like can be used. It is industrially preferable to use a palladium catalyst.

These catalysts can be used in a metal state, but usually, they are used by supporting them on a carrier surface such as carbon, barium sulfate, silica gel, alumina, and celite, and nickel, cobalt, copper, etc. It is also used as a catalyst. The amount of catalyst used is not particularly limited,
It is in the range of 0.01 to 10% by weight as a metal with respect to 1,4-bis (3-nitrophenoxy) benzene as a raw material, and usually 2 to 8% by weight when used in a metal state, and it is supported on a carrier. In the case, the range is 0.1 to 5% by weight. The reaction solvent is not particularly limited as long as it is inert to the reaction, and examples thereof include alcohols such as methanol, ethanol and isopropyl alcohol, glygoles such as ethylene glycol and propylene glycol, ether, dioxane and tetra. Ethers such as fudorofuran and methyl cellosolve are preferably used, and in some cases, aliphatic hydrocarbons such as hexane and cyclohexane, aromatic hydrocarbons such as benzene, toluene and xylene, ethyl acetate, butyl acetate and the like. Esters, dichloromethane,
Chloroform, carbon tetrachloride, 1,2-dichloroethane, 1,
Halogenated hydrocarbons such as 1,2-trichloroethane and tetrachloroethane and N, N-dimethylformamide can also be used. When a reaction solvent that is immiscible with water is used, if the reaction proceeds slowly, a quaternary ammonium salt,
It can be accelerated by the addition of commonly used phase transfer catalysts such as quaternary phosphonium salts. The amount of the solvent used is not particularly limited as long as it is sufficient to suspend or completely dissolve the raw material, but 0.5 to 10 times by weight of the raw material is usually sufficient.

The reaction temperature is not particularly limited. Generally, the range of 20 to 200 ° C, particularly 20 to 100 ° C is preferable. Also, the reaction pressure is
Usually, the atmospheric pressure is about 50 kg / cm ² .

In the reaction, a catalyst is usually added in a state where raw materials are dissolved or suspended in a solvent, and then hydrogen is introduced at a predetermined temperature with stirring to carry out a reduction reaction. The end point of the reaction can be determined by the amount of absorbed hydrogen, thin layer chromatography, high performance liquid chromatography, or the like.

On the other hand, in the case of hydrazine reduction, hydrazine is usually
The reduction reaction may be carried out in a slight excess, preferably 1.2 to 2 times the theoretical amount.

As the catalyst, the above metal catalyst generally used for catalytic reduction is used. Industrially, a catalyst in which palladium / carbon, platinum / carbon or ferric chloride is adsorbed on activated carbon is preferable. The amount of catalyst used is not particularly limited,
It is in the range of 0.01 to 30% by weight as a metal with respect to the usual 1,4-bis (3-nitrophenoxy) benzene as a raw material.

As the reaction solvent, the same solvent as in the case of catalytic reduction can be used. The reaction temperature is not particularly limited and is generally in the range of 20 to 150 ° C, preferably 40 to 100 ° C.

The reaction is usually carried out by adding a catalyst in a state where the raw materials are dissolved or suspended in a solvent and then adding hydrazine dropwise at a predetermined temperature with stirring to carry out a reduction reaction. The end point of the reaction can be determined by thin layer chromatography or high performance liquid chromatography.

After completion of the reaction, the reaction solution is heated to remove the catalyst, and then the solvent is distilled off if necessary to obtain the desired 1,4-bis (3
A crude product of aminophenoxy) benzene is obtained. This crude product can be purified by recrystallization or isolation as the hydrochloride salt.

(Functions and Effects) The method of the present invention uses inexpensive raw materials such as m-dinitrobenzene and hydroquinone and a general-purpose aprotic polar solvent to prepare 1,4-bis (3
-Aminophenoxy) benzene production method.
According to this method, it is possible to easily condense hydroquinone of m-dinitrobenzene and a dihydric phenol, which has been considered to be difficult in the past, and further reduce this by a usual method to obtain a desired product in good yield. Obtainable.

Therefore, it can be said that the method of the present invention is a novel method for industrially producing 1,4-bis (3-aminophenoxy) benzene.

(Examples) Hereinafter, the present invention will be described in more detail with reference to Examples.

Example 1 m in a reactor equipped with stirrer, thermometer and reflux condenser
-Dinitrobenzene 21 g (0.125 mol), hydroquinone 5.5 g (0.05 mol), anhydrous potassium carbonate 13.8 g (0.1
Mol) and 100 ml of dimethylsulfoxide were charged, and the reaction was carried out under stirring while nitrogen gas was passed through.

The reaction was carried out at a temperature of 130 to 135 ° C for 7 hours. After completion of the reaction, the mixture was poured into 300 ml of water to cause brownish brown crystals to break out. After this was dried over, it was dissolved by heating with 100 ml of benzene to remove insoluble matter by heating.

When this perfusate is concentrated, light brown crystals break out, which is filtered, washed with hot methanol, and dried to give 10.3 g of 1,4
-Bis (3-nitrophenoxy) benzene was obtained (yield
58.5%).

This was recrystallized from benzene to obtain pure light brown prism crystals of 1,4-bis (3-nitrophenoxy) benzene.

The melting point is 158-160 ° C and the results of elemental analysis are as follows.

Next, 7 g of the above 1,4-bis (3-nitrophenoxy) benzene was placed in a closed reduction reactor equipped with a stirrer and a thermometer.
(0.02 mol), 0.1 g of 5% Pd / C catalyst and 25 ml of isopropanol were charged, and hydrogen gas was introduced with vigorous stirring.

When the reaction was carried out at a reaction temperature of 60 to 70 ° C. for 4 hours, 2700 ml of hydrogen was absorbed and further absorption was not observed, so the reaction was terminated. After completion of the reaction, the reaction mixture was immediately heated at the same temperature and allowed to cool, whereby white needle crystals of 1,4-bis (3-aminophenoxy) benzene were precipitated. After drying, washing and drying, 5.35 g of the desired product was obtained (yield 91.5%).

The melting point was 126 to 127 ° C. and the result of elemental analysis was as follows.

Example 2 m-dinitrobenzene 100.8 g (0.6 mol), hydroquinone 22 g (0.2 mol), potassium hydrogen carbonate 6 in a reactor.
Charge 0 g (0.6 mol) and 500 ml of 1,3-dimethyl-2-imidazolidinone, and keep the temperature at 1 while venting nitrogen gas.
The reaction was carried out at 35 to 138 ° C for 9 hours. After the completion of the reaction, most of the solvent was recovered by an evaporator and poured into water to precipitate dark brown crystals. Example 1
After extraction with benzene in the same manner as above, concentration and washing with hot methanol gave 37.2 g of an intermediate compound (yield: 52.8
%).

10% Pt / C catalyst 0.3 with respect to 7 g of this intermediate compound
g and 20 ml of dioxane were used and the reduction was carried out in the same manner as in Example 1. After the reduction is complete, the catalyst is removed
When 10 ml of water was added to the liquid and allowed to cool, crystals were precipitated. Over
After washing with water and drying, 4.9 g of 1,4-bis (3-aminophenoxy) benzene was obtained (yield 83.8%).

Melting point 125-127 ° C.

Example 3 N-N'-dimethylformamide was used as the solvent, 0.1 g of copper powder was added as a catalyst and the reaction time was changed to 5 hours. Nitrophenoxy) benzene was obtained. This intermediate compound is ferric chloride
A reactor was charged with 0.1 g, 1 g of activated carbon and 35 ml of methyl cellosolve, and 5 g of hydrazine hydrate was added dropwise at a temperature of 100 to 105 ° C over 2 hours. The reaction was continued for 3 hours at the same temperature to complete the reaction. Immediately after removing the catalyst and the like, adding 20 ml of water and allowing to cool, crystals were precipitated. Excess, washing with water and drying to obtain 5.8g of 1,4-bis (3
-Aminophenoxy) benzene was obtained (total yield 39.7
%).

Melting point 123.5-126 ° C.

Claims (1)

[Claims] 1. A 1,4-bis (3-aminophenoxy) benzene characterized in that hydroquinone and m-dinitrobenzene are condensed in the presence of a base using an aprotic polar solvent and then reduced. Production method.