JP2008115117A - Method for producing 2,3,6,7,10,11-hexahydroxytriphenylene - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing 2,3,6,7,10,11-hexahydroxytriphenylene from catechol by using inexpensive hydrogen peroxide in a high yield in excellent operability. <P>SOLUTION: 2,3,6,7,10,11-Hexahydroxytriphenylene is produced by reacting catechol with hydrogen peroxide in the presence of a compound containing an element selected from molybdenum, tungsten and rhenium. The reaction is carried out in the presence of preferably a molybdenum-containing compound. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method for producing 2,3,6,7,10,11-hexahydroxytriphenylene from catechol. 2,3,6,7,10,11-hexahydroxytriphenylene is useful as a raw material for liquid crystal materials and the like.

  As a method for producing 2,3,6,7,10,11-hexahydroxytriphenylene by directly trimerizing catechol, JP-A-9-118642 (Patent Document 1) discloses a transition metal compound, specifically Reacts iron (III) chloride hexahydrate with catechol to obtain a mixture containing 2,3,6,7,10,11-hexahydroxytriphenylene, an iron complex of the compound and a quinone, and then And a method of reducing the mixture and converting the iron complex and quinone into 2,3,6,7,10,11-hexahydroxytriphenylene.

  In addition, WO05 / 037754 pamphlet (Patent Document 2) describes a method of reacting a peroxide, specifically, a persulfate or hydrogen peroxide with catechol, and JP-A-2005-104870. (Patent Document 3) discloses a method for trimerizing catechol by using a transition metal compound, specifically, iron (II) sulfate, as a catalyst in the presence of an oxidizing agent, specifically, hydrogen peroxide. Is described.

JP-A-9-118642 International Publication No. 05/037754 Pamphlet JP 2005-104870 A

  However, in the method described in Patent Document 1, it is necessary to reduce the mixture containing the iron complex, and the operation is complicated. In the methods described in Patent Documents 2 to 3, it is preferable to use inexpensive hydrogen peroxide as a peroxide or an oxidizing agent. In this case, 2,3,6,7,10,11-hexa The yield of hydroxytriphenylene was low and not satisfactory.

  Therefore, an object of the present invention is to provide a method capable of producing 2,3,6,7,10,11-hexahydroxytriphenylene from catechol with good operability and good yield using inexpensive hydrogen peroxide. It is to provide.

  As a result of intensive studies, the present inventor has found that the above object can be achieved by reacting catechol and hydrogen peroxide in the presence of a predetermined metal compound, and has completed the present invention.

  That is, the present invention is characterized in that catechol and hydrogen peroxide are reacted in the presence of a compound containing an element selected from molybdenum, tungsten, and rhenium, 2, 3, 6, 7, 10, 11-hexahydroxy A method for producing triphenylene is provided.

  According to the present invention, 2,3,6,7,10,11-hexahydroxytriphenylene can be produced from catechol with good operability and good yield using inexpensive hydrogen peroxide.

  Hereinafter, the present invention will be described in detail. In the present invention, catechol and hydrogen peroxide are reacted in the presence of a compound containing an element selected from molybdenum, tungsten, and rhenium. By this reaction, 2,3,6,7,10,11-hexahydroxytriphenylene can be produced from catechol in good yield.

  Examples of the compound containing molybdenum include molybdate such as sodium molybdate, potassium molybdate, and ammonium molybdate, molybdic acid, phosphomolybdic acid, molybdenum oxide, molybdenum carbide, molybdenum boride, molybdenum nitride, molybdenum sulfide. , Molybdenum silicide, molybdenum chloride and the like. Examples of the compound containing tungsten include tungstates such as sodium tungstate, potassium tungstate, and ammonium tungstate, tungstic acid, tungsten oxide, tungsten carbide, tungsten boride, tungsten nitride, tungsten sulfide, and tungsten silicide. And tungsten chloride. Examples of the compound containing rhenium include rhenium oxide and methyltrioxorhenium. In addition, you may use those 2 or more types as needed. Among these, a compound containing molybdenum is preferable.

  The said compound is normally used as a catalyst, and the usage-amount is 0.0005-0.2 mol normally with respect to 1 mol of catechol, Preferably it is 0.001-0.05 mol.

  The hydrogen peroxide used in the present invention may be an aqueous solution or a solution prepared by dissolving in an organic solvent. From the viewpoint of availability and handling, an aqueous solution is preferably used.

  The usage-amount of hydrogen peroxide is 0.8-5.0 mol normally with respect to 1 mol of catechol, Preferably it is 1.0-1.5 mol.

  The above reaction is usually performed using a solvent. Such solvents include water, alcohols such as methanol, ethanol, n-propanol and isopropanol, ketones such as acetone and methyl isobutyl ketone, ethers such as tetrahydrofuran and 1,4-dioxane, and esters such as ethyl acetate. , Aliphatic hydrocarbons such as hexane and heptane, chlorinated aliphatic hydrocarbons such as dichloromethane and chloroform, aromatic hydrocarbons such as toluene and xylene, chlorinated aromatic hydrocarbons such as monochlorobenzene, acetonitrile Such nitriles, formamides such as N, N-dimethylformamide and the like may be used, and two or more of them may be used as necessary. Among these, water or a mixed solvent of water and another solvent is preferable, and water is more preferable. The usage-amount of a solvent is 1-50 weight times normally with respect to catechol.

  Furthermore, the above reaction is preferably performed in the presence of an organic acid or an inorganic acid. Examples of organic acids include carboxylic acids such as acetic acid, benzoic acid, and trifluoroacetic acid, sulfonic acids such as methanesulfonic acid and p-toluenesulfonic acid, and inorganic acids include sulfuric acid, hydrochloric acid, nitric acid, Examples include phosphoric acid. In addition, you may use those 2 or more types as needed. Of these, inorganic acids are preferable, and sulfuric acid is more preferable.

  Moreover, an organic acid or an inorganic acid may be used as it is, or may be used as a solution obtained by dissolving in a solvent. Among these, 50 to 80% by weight sulfuric acid is preferably used. The usage-amount of an organic acid or an inorganic acid is 1-100 mol normally with respect to 1 mol of catechol.

  When performing the above reaction, tetrabutylammonium chloride, tetrabutylammonium bromide, tetrabutylammonium salt such as tetrabutylammonium hydrogensulfate, methyltrioctylammonium chloride, methyltrioctylammonium bromide, methyltrioctylammonium hydrogensulfate Quaternary ammonium salts such as methyl trioctyl ammonium salt may be added, sulfonates such as sodium dodecyl sulfate, polyethers such as polyethylene glycol, Lewis acids such as boron trifluoride ether complex, etc. May be added. In addition, you may use those 2 or more types as needed.

  There is no particular limitation on the compound formulation of the compound containing an element selected from molybdenum, tungsten and rhenium, catechol and hydrogen peroxide, but when a solvent is used for the reaction, the mixture of the compound, catechol and solvent is used. It is preferable to add an aqueous solution of hydrogen peroxide (hydrogen peroxide solution). At that time, the hydrogen peroxide solution may be added all at once or may be dropped. Also when adding the organic acid and inorganic acid, and / or additive which were mentioned above, the mixing prescription is selected suitably.

  The reaction can be carried out under normal pressure, reduced pressure or pressurized conditions. Moreover, reaction temperature is 0-100 degreeC normally, Preferably it is 0-50 degreeC, More preferably, it is 10-40 degreeC.

  The progress of the reaction can be traced by gas chromatography, high performance liquid chromatography, thin layer chromatography, nuclear magnetic resonance spectrum or the like. The post-treatment operation after the reaction is appropriately selected. For example, by purifying the filter residue obtained by filtering the reaction mixture by a known method such as recrystallization or washing, the desired 2, 3, 6, 7,10,11-Hexahydroxytriphenylene can be obtained.

  Examples of the present invention will be described below, but the present invention is not limited thereto.

Example 1
To a 200 mL three-necked flask, 82 g of 75 wt% sulfuric acid, 16.5 g of catechol and 0.1 g of sodium molybdate were added. To the obtained mixture, 10.2 g of 60 wt% hydrogen peroxide water was added dropwise at 30 ° C., and then the mixture was stirred while keeping at 30 ° C. for 4.5 hours. The obtained reaction mixture was filtered and the residue was washed with water. As a result, 9.4 g of 2,3,6,7,10,11-hexahydroxytriphenylene was contained in the residue. The yield of 2,3,6,7,10,11-hexahydroxytriphenylene based on catechol was 58%.

Example 2
To a 200 mL three-necked flask, 82 g of 75 wt% sulfuric acid, 16.5 g of catechol and 0.1 g of rhenium oxide were added. To the obtained mixture, 10.2 g of 60 wt% hydrogen peroxide water was added dropwise at 30 ° C., and then the mixture was stirred while keeping at 30 ° C. for 4.5 hours. The obtained reaction mixture was filtered and the residue was washed with water. As a result, 6.0 g of 2,3,6,7,10,11-hexahydroxytriphenylene was contained in the residue. The yield of 2,3,6,7,10,11-hexahydroxytriphenylene based on catechol was 37%.

Comparative Example 1
To a 200 mL three-necked flask, 82 g of 75 wt% sulfuric acid and 16.5 g of catechol were added. To the obtained mixture, 10.2 g of 60 wt% hydrogen peroxide water was added dropwise at 30 ° C., and then the mixture was stirred while keeping at 30 ° C. for 4.5 hours. The obtained reaction mixture was filtered and the residue was washed with water. As a result, 4.6 g of 2,3,6,7,10,11-hexahydroxytriphenylene was contained in the residue. The yield of 2,3,6,7,10,11-hexahydroxytriphenylene based on catechol was 29%.

Claims (2)

  A method for producing 2,3,6,7,10,11-hexahydroxytriphenylene, comprising reacting catechol and hydrogen peroxide in the presence of a compound containing an element selected from molybdenum, tungsten and rhenium. The method of claim 1, wherein the element is molybdenum.