JPH02229143A - Production of 1,3-dihydroxy-4,6-diaminobenzene or salt of same compound - Google Patents

Abstract

PURPOSE:To obtain the subject compound in high yield without generation of nitro body having high danger by reacting 1,3-dihalo-4,6-diaminobenzene derivative as a raw material in the presence of metal alcoholate and copper- containing catalyst in organic liquid phase. CONSTITUTION:1,3-dihalo-4,6-diaminobenzene derivative expressed by formula I (X is Cl, Br, I or F; R1 is H or protecting group of amino group, further said compound expressed by said formula may be acidic salt) is reacted in the presence of metal alcoholate and copper-containing catalyst (e.g. cuprous iodide or cuprous chloride) in organic liquid phase (e.g. methanol or dimethyl sulfoxide), preferably at 100-250 deg.C. Next, resultant compound is treated in the presence of reducing agent (preferable combination is stannous chloride- hydrobromic acid) in acidic solution to afford the aimed compound. Besides, said compound is useful for synthesis of raw material of polymer having excellent properties such as high strength or heat resistance.

Description

Detailed Description of the Invention <Industrial Application Field> The present invention relates to 1,3-dihydroxy-4, which is a monomer of polyhenzopisoxazole (hereinafter abbreviated as PBO).
, 6-diamithuzene or its salt by a novel process.

[Prior art and its problems]

Threads and membranes made from liquid crystalline tope, which is a polyphosphoric acid solution of PBO, are polymers with high strength, high modulus, and excellent heat resistance and chemical resistance, making them extremely useful in industry. Highly useful (Special Publication No. 61-501452
Publication No.).

The general structural formula of PBO is shown below.

On the other hand, 1,3-dihydroxy-4,6-diamithuzene or a salt thereof (hereinafter abbreviated as DAOH) and terephthalic acid are used as monomers for synthesizing PBO. Conventionally, DAOI+ has been obtained, for example, by the following reaction process. (Ber, Dtsch, C
hemGes, 16.552 (1883), ) (a) (b) (c) (d) However, when using the conventional technology, dinitroresorcinol (c) is obtained as an intermediate product, which is rapidly It becomes explosive when heated or subjected to strong impact. Furthermore, when resorcinol (a) is nitrated, a trinitro compound is produced as a reaction byproduct, and this is also known to be a highly explosive substance. These facts are industrially dangerous and require sufficient care from a safety standpoint. In addition, the nitration efficiency was also poor at 30%. First,
The present inventors have discovered a novel compound 1,3-shodo-4゜6
- Succeeded in obtaining diamitsubenzene or its g-conductor (Japanese Patent Application No. 63-65887).

[Problem to be solved by the invention]

The present invention utilizes 1,3-dihalo-4,6-diamitbenzene derivatives including 1,3-johto-4,6-diamitbenzene or its derivatives as an intermediate in the synthesis of D A 011. The first stage monomer DAO does not go through a reaction process that uses a highly dangerous nitro compound as an intermediate.
The purpose of this paper is to provide a method for obtaining H.

[Means to solve the problem]

The present invention that achieves the above object is as follows.

That is, the present invention is based on the general formula (wherein, The 1,3-dihalo-4,6-diamitbenzene derivative represented by (the compound may be an acid salt) is reacted in an organic liquid phase in the presence of a metal alcoholade and a copper-containing catalyst, and then This is a method for producing 1,3-dihydroxy-4,6-diamitbenzene or a salt thereof, which is characterized in that it is treated in an acidic solution in the presence of a reducing agent.

The method for producing 1,3-dihydroxy-4,6-diamitbenzene or a salt thereof of the present invention includes 1,3-dihalo-4,6
It is produced by a two-step reaction using a diaminobenzene derivative as a starting material.

The starting material 1,3-dihalo-4,6-diamitbenzene derivative is represented by the following (formula A), where χ is a group independently selected from chlorine, bromine, iodine, and fluorine atoms. (In the present invention, halo means chlorine, bromine, iodine, and fluorine atoms. However, iodine is preferred.) In the formula, R independently represents a hydrogen atom and a protecting group for an amino group. acyl groups, urea and urethane residues, alkyl and aryl groups, which are known as For example, -COCII3. -COC,
R5, -Coal, -QCI(.

oczus etc. However, these R1 are introduced as a protecting group for the amine group, and are not limited to those shown here. Moreover, the compound of (Formula A) may be an acid salt of hydrochloric acid, phosphoric acid, sulfuric acid, nitric acid, carbonic acid, or the like.

In the first step, a 1,3-dihalo-4,6-diamithuzene derivative and a metal alcoholade are reacted in an organic liquid phase in the presence of a copper-containing catalyst to obtain a stable intermediate. -The reaction equation for boat fishing is as follows.

In the formula, R,, and X are as shown above. l? OM represents metal alcoholade. R is a hydrocarbon chain C711□7゜1 (where n is an integer from 1 to 10), for example, C1
1+, -CzHs, CJt, Ctl(C1h) 2
．． C4H9CH(CHz)z. Also, the eyes are alkali metals, alkaline earth metals, etc., and Na+ K+ L
i, Mg+Ca, etc. However, in the case of divalent metal alcoholades such as alkaline earth metals, R in the reaction formula
OM is expressed as (RO)zh.

The amount of metal alcoholade used is 1,3-dihalo4.
0.5-10II for 6-diamitbenzene derivatives
IoQ% (preferably 1-5 moj2%).

The copper-containing catalyst is preferably cuprous iodide, cuprous chloride or cuprous oxide, and the amount of catalyst used is 1
, 04 for 3-dihalo-4,6-diamitzhensen
A good amount is 0.01 to 5% by weight (preferably 0.1 to 1.0% by weight).

The reaction medium used in the Kinola method can be any organic solvent as long as it is stable during the reaction, but preferred reaction media include alcohols such as methanol and ethanol, dimethyl sulfoxide, N-methylpyrrolidone, and dimethylacetamide. , or mixtures thereof can also be used. Since the metal alcoholade decomposes and impurities other than the desired intermediate are formed, it is preferable that the reaction medium used does not contain water.
It is better to carry out the reaction at less than pp (more preferably less than 1100 pp). An appropriate amount of the reaction solvent can be used to obtain the desired 1,3-dihydroxy-4,6-diamitbenzene derivative, but preferably 1 gram of the 1,3-dihalo-4,6-diamitbenzene derivative.
~500g (more preferably 5g~100g).

The reaction temperature can be any temperature at which the desired product is produced, but is preferably between 100 and 250'C.
It is a good idea to keep it. The pressure is usually natural pressure, but preferably under autoclave pressure. Also, higher pressures may be used, optionally in the presence of nitrogen or other inert gas.

Further, the reaction is desirably carried out under an inert gas atmosphere in order to prevent the formation of impurities.

After the reaction, the halide can be reconverted to halogen alone.

The 1,3-dialkoxy-46-diamitbenzene derivative obtained in the first step can be isolated or transferred to the second step as it is, but it is preferable to add hydrochloric acid or the like to the reaction solution. It is therefore better to isolate the 1,3-dialkoxy-4,6-diamitzhensen derivative from the organic solvent.

The second step reaction is 1,3-dialkoxy-46
- 1,3-dihydroxy-4,6-diamitbenzene or a salt thereof is produced by reacting a diamitsubenzene derivative in an acidic solution in the presence of a reducing agent. - Boat reaction formula % formula % In the formula, R, , R are as defined above.

A method for converting 1,3-dialkoxy-4,6-diamitshuzene derivatives to 1,3-dihydroxy-4,6-diamitshuzene is, for example, by adding a reducing agent such as stannous chloride, iron powder, tin, or palladium to an acidic medium. It can be generated by using it inside. The reducing agent is the target substance 1,
Since 3-dihydroxy-4,6-diamitbenzene is easily denatured by oxidation, it is used for the purpose of preventing this. As the oxidation reaction medium, concentrated hydrochloric acid, hydrobromic acid, hydroiodic acid, etc. are used as they are. The reduction reaction is preferably carried out in combination with tin-tin-hydrobromic acid chloride. The reaction is preferably carried out under an inert gas atmosphere, and the reaction temperature may be any temperature condition that produces a product, but is preferably 0 to 100°C. In this case, the amine salt usually precipitates out of solution and can be filtered off. The product can then be purified by recrystallization. Moreover, the obtained 1,3 dihydroxy-4,6-diamitsuhensen salt can be converted into other salt forms.

The isolated 1,3-dihydroxy-4,6-diamitsuhensen salt is easily oxidized by oxygen in the air, so sufficient care must be taken when storing it. For this reason, it is recommended to store it in a cool open space, for example, in a container purged with nitrogen gas.

〔Example〕

The present invention will be explained in detail below with reference to examples, but the present invention is by no means limited to these.

Example 1 1.3-Diobi 4,6-diamitschene cyacetylated product Log, sodium methylate 1-5, Og, 0.5 g of copper iodide, and 100 g of anhydrous methanol were placed in a reaction vessel purged with nitrogen, and heated to 180 g. The reaction was carried out at 110°C for 6 hours. Then, add 1 stannous chloride to the taken out mixture.
00g of dissolved concentrated hydrobromic acid was added over 4 hours under stirring in a nitrogen gas atmosphere. The precipitate was separated by filtration and recrystallized with 6N hydrochloric acid to obtain 2.3 g (yield: 49%) of DAO)I. Recrystallization was performed in the following manner. 6g of stannous chloride,
The above precipitate was added to 200 ml of hydrochloric acid containing 2 g of activated carbon, and undissolved matter was filtered off at 90°C under a nitrogen atmosphere. The filtrate was cooled to 0°C, recrystallized, filtered, washed with acetone, and dried in vacuo (room temperature).

Example 2 1.3-dibromo-4,6-diamitzhenzene diacetylated product Log, 4.0 g of sodium methylate, 0.5 g of copper iodide, and 100 g of anhydrous methanol were placed in a reaction volume 4 purged with nitrogen and heated to 220 ” The reaction was carried out in CC115at for 6 hours.Then, 1 stannous chloride was added to the taken out mixture.
300 ml of concentrated hydrochloric acid in which 0.00 g was dissolved was added over 4 hours under stirring in a nitrogen gas atmosphere. The precipitate was filtered and recrystallized with 6N-hydrochloric acid to give 2.53 g of DAOH (yield: 42
%)Obtained.

Example 3 1.10 g of 3-Jodo 4,6-diamitbenzene diacetylated product and potassium-tert-butyralide5.
5g of copper iodide, 0.5g of copper iodide, and 100g of anhydrous methanol were placed in a reaction vessel purged with nitrogen, and heated at 180°C at 11Oat.
It reacted for 6 hours. Thereafter, 300 mR of concentrated hydrobromic acid in which 100 g of stannous chloride was dissolved was added to the taken out mixture.
was added over 4 hours under stirring in a nitrogen gas atmosphere. The precipitate was filtered and recrystallized with 6N hydrochloric acid to give D A 011 of 2.6
3 g (yield 55%) was obtained.

Example 4 ■, 10 g of 3-jodo 4,6-diamitzhenzene diacetylated product and potassium-tert-butyler 1-5
．． Put 5 g of copper iodide, 0.5 g of copper iodide, and 100 g of anhydrous dimethyl sulfoxide into a reaction vessel purged with nitrogen, and heat at 190°C.
The mixture was refluxed for 6 hours. Thereafter, 300 rtdl of concentrated hydrochloric acid in which 100 g of stannous chloride was dissolved was added to the taken out mixture over 4 hours under stirring in a nitrogen gas atmosphere.

The precipitate was filtered and recrystallized with 6N hydrochloric acid to obtain 2.0% DAOH.
14 g (yield 45%) was obtained.

DAOll obtained in Examples was confirmed by elemental analysis (Table 1), infrared absorption analysis (Fig. 1), mass spectrometry (direct mass spectrum, CI method) (Fig. 2), and liquid chromatography.

Liquid chromatograph (detector (UV), column: TSK
gel, ODS, 80TM Had a peak.

It has excellent industrial characteristics.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the results of an infrared absorption spectrum of DAOH obtained in Example 1. FIG. 2 is a diagram showing the results of mass spectrometry (direct mass spectrum, CI method) of D A OI+ obtained in Example 1. Patent applicant: Asahi Kasei Industries, Ltd. [Effects of the invention]

Claims (1)

[Claims] General formula ▲ Numerical formula, chemical formula, table, etc. ▼ (In the formula, The 1,3-dihalo-4,6-diaminobenzene derivative represented by A method for producing 1,3-dihydroxy-4,6-diaminobenzene or a salt thereof, which comprises reacting in the presence of a reducing agent, and then treating it in an acidic solution in the presence of a reducing agent.