JPH02500108A - Production of bis(amine-containing) benzenediol - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] Production of bis(amine-containing) benzenediol The present invention relates to hydrogenation of benzoquinone compounds. Concerning becoming. More particularly for producing bis(amine-containing) benzenediol This invention relates to a method for hydrogenating bis(amine-containing) dihalobenzoquinones.

Bis(amine-containing) benzenediol is a polybenzoxazole (PBO) Effective as a monomer in manufacturing. Polybenzoxazole is an amine-containing Benzenediols and diacids, diacid halides, bisesters or bisnitrites It is produced by reaction with Polybenzoxazole fiber has high tensile strength and thermal High stability makes it desirable for military, space, and other applications requiring hard materials.

Known methods of making benzenediol monomers typically involve multi-step synthesis. However, this requires expensive reagents and yields are low.For example, one method is 2. Hydrogen peroxide and alkali for producing 5-dihydroxy-p-benzoquinone dihydrogenation with hydrogen chloride and methanol, including the oxidative trihydrogenation of hydroquinone with Reaction with droxybenzoquinone yields 2゜5-dimethoxy-p-benzoquinone , which is aminated with ammonia and then reduced with stannous chloride in concentrated hydrochloric acid. 2,5-diamino-1,4-benze with an overall yield of only 20 percent. give diol. RJolf, M., 0kada and C.S., Marve J of l, Po1y+++er　5science, Bart A, 6.1503 (19 68), another method is to use dihalodiaminobenzooxygen which does not remove the halogen substituent. 9 involving the reduction of non to the corresponding dihalodiaminohydroquinone, e.g., U.S. Pat. 4,337,196, British Patent No. 1,130,275 and French Painting Patent No. 1, See No. 544,504.

Eliminate halogen substituents and benzodiazepines without producing by-products that are dangerous and difficult to dispose of. A simple and economical method for the reduction of quinones that provides both possible and high yields is needed. be. Such a method can be used to produce highly desirable polybenzoxazoles. enables efficient production of bis(amine-containing) benzenediol monomers for Ru.

The present invention provides a well-defined approach to providing high yields of bis(amine-containing) benzenediol. It is an inexpensive and one-step method. This method uses bis(amine-containing) dihalobenzoquino reaction conditions such that the corresponding bis(amine-containing) benzenediol is produced. A group consisting of formic acid, formate salts and mixtures thereof in the presence of a noble metal-containing catalyst under a molar excess of a reducing agent selected from the group consisting of: in this contact , What does "amine-containing" mean?

C,,-,. alkyl, arylalkyl or alkylaryl) means a compound that Surprisingly, the method of the invention provides high yields, It is shown that reduction of benzoquinone and removal of halogen substituent is provided in one step. won.

The bis(amine-containing) benzenediol produced in this way is a diacid, a diacid halogen, Condensed with polybenzene, bisester or bisnitrile, polybenzoxane Give sol. The above polybenzoxazole fibers are used in various industrial applications. It is valid.

According to the method of the present invention, benzoquinone starting material is mixed with formic acid and formic acid in the presence of a solvent and a catalyst. Contact with an acid salt or a mixture thereof 0 used as a starting material in the present invention A preferred benzoquinone compound represented by the following formula, (X)2B (NR'R2)2 (In the above formula, B is 1,4-benzoquinone, and each X is independently chlorine, bromine, or fluorine. and R' and R2 are independently hydrogen, C1-1° alkyl, (arylalkyl or alkylaryl) It is expressed as Preferably, X is chlorine, and R1 and R2 are each hydrogen. stomach.

Typical benzoquinone compounds are 2,5-dichloro-3,6-diami2-1,4- Benzoquinone: 2,5-dibromo-3゜6-diamitu-1,4-benzoquinone; 2.5-dichloro-3,6-bis(benzylamino)-1,4-benzoquinone: 2゜5-dichloro-3,6-bis(methylamino)-1,4-benzoquinone: 2 ．． 5-dichloro-3,6-bis(dimethylamino)-1,4-benzoquinone; Contains 2,5-dichloro-3,6-bis(ethylamino)-1,4-benzoquinone 2,5-dichloro-3,6-diami2-1,4-benzoquinone; Chloro-3,6-bis(methylamino)-1,4-benzoquinone and 2,5- Dichloro-3,6-bis(benzylamino)-1,4-benzoquinone is preferred stomach. The most preferred benzoquinone starting material is 2,5-dichloro-3,6-diamid 2-1,4-benzoquinone. These benzoquinone starting materials are known in the art. manufactured by the method. Typical production usually involves excess ammonia or ammonium hydroxide. For example, U.S. Pat. No. 4,337,19 See issue 6.

In carrying out the invention it is advantageous to use catalysts.

The catalyst comprises a noble metal and in the presence of formic acid, formate, or mixtures thereof; Any substance that catalyzes the conversion of the benzoquinone starting material to the desired benzenediol. Good too. The catalyst may be unsupported or supported on any support known in the art, e.g. Lumina, silica, zeolite, titanium, alkaline earth metal carbonate or An example of a catalyst useful in carrying out the process of the invention that is supported on carbon is precious metals supported on top, precious metal oxides, and alkaline earth carbonates Including genus. Precious metals include gold, silver, platinum, palladium, iridium, rhodium, and water. These are silver, ruthenium and osmium. A preferred catalyst is paradiyl on carbon. The most preferred catalysts include platinum on carbon, platinum on carbon, and platinum oxide. It is Zium.

The catalyst reacts with the corresponding starting material in the presence of formic acid, formate or mixtures thereof. benzenediol. preferably There are o,oos to 0.1 molar equivalents of catalyst per equivalent of benzoquinone starting material. Exists.

More preferably, 0.02 to 0.06 equivalents of catalyst are present during the reaction.

Preferably, the catalyst is added to the reaction mixture under an inert atmosphere.

Examples of inert atmospheres include argon, helium and nitrogen, with nitrogen being preferred.

It is advantageous to use a solvent in the method of the present invention. The solvent used is a polar solvent in which the benzenediol product is soluble. preferred Strong solvents are water and low molecular weight organic polar compounds. Specific examples of preferred solvents are , water, methanol, ethanol, 10 panol, dimethylformamide and di Water is the most preferred solvent, including oxane. Preferably starting with benzoquinone 1 to 50 volumes of solvent are used per volume of substance. More preferably benzene When 5 to 10 volumes of solvent are used per volume of non-starting material, Formic acid, formate salts or mixtures thereof are used as hydrogen transfer agents in the process of the invention. used. @When using an acid, it is preferably aqueous formic acid, a concentrated form of aqueous formic acid. The degree is preferably 5% by weight or more and 90% by weight or less Preferably, 20 weight percent or more and 260 weight percent or less Most preferably, the concentration of formic acid is 30 weight percent.

Acts as a hydrogen transfer agent to reduce benzoquinone and remove halogens from it Preferred formates are those listed below, which may be used in the practice of this invention. Formula, HCO□H (In the above formula, M is Na, Ce, or (R3)3NH; R3 is hydrogen or is hydrocarbyl) An example of a hydrocarbyl substituent useful in the practice of this invention is Cl -6 alicyclic or aliphatic substituent containing 0M is (R3), NH, and R3 is hydrogen It is more preferable that

Preferably the formate is in a polar solvent. Typical examples of suitable polar solvents are water, lower Using acetic acid as a solvent for formate, including alkanols and acetic acid. is preferred.

In the practice of this invention, the hydrogen transfer agent is benzenediol of the benzoquinone starting material. Sufficient amount for reduction to product and removal of halogen substituent of benzoquinone starting material used in Reduced in molar excess relative to the molar amount of benzoquinone starting material used It is preferable to use an agent. Use 4' to 100 molar excess relative to hydroquinone It is more preferable. Most preferably, a 10 to 25 molar excess is used.

The reactants may be added in any order or amount that allows the reaction to proceed; combining a benzoquinone reactant and aqueous formic acid, formate, or a mixture thereof; Preferably, the catalyst is then added.

The process of the invention may be carried out at any temperature and pressure at which the reaction proceeds, preferably Preferably, the method is carried out at a temperature of 20°C to 100°C, more preferably 40°C to 70°C. be called. The process may be carried out under reduced or superatmospheric pressure, but atmospheric pressure is preferred. .

The reaction is carried out for a period of time sufficient to achieve at least 50 percent conversion of the starting material. I'm sexually abused. A total reaction time of 10 minutes to 1 hour is preferred, and 10 minutes to 30 minutes is more preferred. Delicious.

A very small amount of additional reducing agent, e.g. stannous chloride, is added to the reaction mixture to prevent oxidation of the product. Add to mixture. The product is recovered using known recovery methods, such as filtration. oxidation content To prevent decomposition, the product is usually isolated and stored as a hydrohalide salt.

Isolating the product as a salt of a mineral acid, such as hydrochloric acid, sulfuric acid, nitric acid or phosphoric acid, is This is a common method.

Conversion of benzoquinone starting material is at least 70 percent, preferably less than and more preferably at least 95%. desired base The selectivity for zendiol is at least 70%, preferably less than 70%. and more preferably at least 95%. Therefore , the overall yield is at least 50%, preferably at least 75% more preferably at least 90 percent.

This method may be carried out in batch or continuous mode.

Surprisingly, in the method of the present invention, the halogen atom is converted into benzoquinone in one step. removed from the ring and the benzoquinone is converted to the corresponding benzenediol. child The by-products of the process are carbon dioxide and/or ammonia.

The benzenediol compound produced by the method of the present invention has the following formula: (In the above formula, R1 and R2 are as defined above.) typical ben Zendiol is 2,5-diamino-1,4-benzenediol, 2,5-bis (Methylamine)-1,4-benzenediol, 2,5-bis(ethylamino) Contains -1,4-benzenedionyl, 2,5-diamino-1,4-benzenedionyl ol, 2,5-bis(methylamino)-1,4-benzenediol and 2. 5-bis(benzylamino)-1,4-benzenediol is preferred, most preferred Preferred benzenediol is 2,5-diamino-1,4-benzenediol. Ru.

The following examples illustrate the invention. All percentages unless otherwise indicated and ratios are by weight.

Production of 2,5-diamino-1,4-benzenediol using formic acid 400 mg of 10 percent palladium-carbon catalyst in 30 ml of sewage under nitrogen atmosphere ．． 5-dichloro-3,6-diamitu-1,4-benzoquinone 4.14g (20 millimole) and 20 mf of 88% formic acid. . The nitrogen was removed and the mixture was stirred and heated to 60° C. for 15 minutes. this mixture It was kept at 60°C for 10 minutes. Approximately 50 ng of tinned chloride was added, the mixture was filtered, and 1 part of water was added. Washed at 5 companies. Hydrogen chloride was passed through the P solution to saturate it. This mixture was cooled overnight and then Colorless needle-like crystals of 2,5-diamino-1,4-benzenediol as hydrochloride Filter and wash with ethanol and water, yield 4.14g or for benzoquinone. The yield was 98%. This product was identified by proton magnetic resonance as 2,5-dia It was confirmed that it was mino-], ]4-benzenedio.

Preparation of 2,5-diamino-1,4-benzenediol using fLL-formate 10% palladium-carbon catalyst 400 ε 2.5-dichloro under nitrogen atmosphere -3,6-diami2-1,4-benzoquinone 1.40 g (7 mmol), formic acid acetate A suspension of 3.15 g (50 mmol) ammonium, 20 m4 water and 5+ni' acetic acid The suspension was added to the reaction vessel containing the suspension. The nitrogen was removed and the mixture was stirred at ambient temperature for 1 hour. The mixture was then heated and stirred at 60°C to 80°C for 2 hours. chloride number - External 50mg and! (C110 + n 1. was added and the catalyst was separated into 0 and then 20 HCZ companies? added to the liquid. this? Cool the solution overnight and prepare 2. as the dihydrochloride. The colorless needle-like crystals of 5-diamino-1,4-benzenediol were filtered and dissolved in ethanol. I washed it with rice water. Yield is 1.4g or 98% based on benzoquinone starting material. It was cents. This product was identified by elemental analysis and proton magnetic resonance as 2,5 -Diamino-1,4-benzenediol.

These examples show that the process of the present invention surprisingly yields bis(amine-containing) benzenediol. It is shown to be a simple and effective method that can be produced in high yield.

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Claims (10)

[Claims] 1. A method for producing bis(amine-containing) benzenediol, the method comprising: ) dihalobenzoquinone under the reaction conditions for producing the corresponding benzenediol. in the presence of a precious metal-containing catalyst, formic acid, formate salts and mixtures thereof. catalyzing with a molar excess of a reducing agent selected from the group consisting of: 2. The benzoquinone starting material has the following formula, (X-)2B-(HR1R2)2 (In the above formula, B is 1,4-benzoquinone, and X is chlorine, bromine, fluorine, or iodine. and R1 and R2 are independently hydrogen, C1-10 alkyl, arylalkyl or alkylaryl) 2. The method according to claim 1, wherein 3. The molar excess of reducing agent is between 4 and 100 molar excess over the benzoquinone starting material. , the method of claim 1. 4. 2. The method of claim 1, wherein a polar solvent is used. 5. Claim 1, wherein the catalyst is a catalyst supported on an alkaline earth carbonate. How to put it on. 6. 2. The method of claim 1, wherein the catalyst is a noble metal supported on carbon. 7. The catalyst is present in a 0.005-0.1 molar excess over the benzoquinone starting material. , the method of claim 1. 8. 5. The method of claim 4, wherein the solvent is water. 9. 7. The method of claim 6, wherein the catalyst is palladium-carbon. 10. Bis(amine-containing)benzenediol starts with bis(amine-containing) dihalobe at least 70 percent conversion and at least 70 percent 2. The method of claim 1, wherein the method is produced with a selectivity of cents.