JP2002187867A - Method for producing anthracene-9-carboxylic acid - Google Patents

Abstract

PROBLEM TO BE SOLVED: To develop an industrial method for producing anthracene-9-carboxylic acid. SOLUTION: 9-Anthraaldehyde is reacted in a nonpolar organic solvent in the presence of an alkali metal hydroxide under heating to give anthracene-9- carboxylic acid.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a novel process for producing anthracene-9-carboxylic acid useful as a photographic drug.

[0002]

2. Description of the Related Art As a method for producing anthracene-9-carboxylic acid, there is known a method of hydrolyzing an acid chloride obtained by reacting anthracene with phosgene or oxalyl dichloride (Helv. Chim. Acta. , 2 volumes, 4
82 (1919). In this method, since toxic phosgene is handled and the reaction temperature is high,
There is a drawback that the equipment is limited in the production with the actual machine. There is also known an example of producing anthracene-9-carboxylic acid by oxidizing anthracene with a compound of a heavy metal such as manganese or chromium (Bull. Chem. Soc. Japan, 6).
2, 545 (1989)), all of which have problems such as low yield or high catalyst cost, and cannot be said to be industrially applicable methods.

Therefore, the present inventors have thought of producing anthracene-9-carboxylic acid by oxidizing 9-anthraldehyde, and firstly oxidized with potassium permanganate or oxidized with molecular oxygen in the presence of a heavy metal catalyst. As a result, although oxidation products such as anthraquinone could be obtained, the desired anthracene-9-carboxylic acid could not be obtained.

[0004] In addition, an alkaline aqueous solution was allowed to act on 9-anthraldehyde in an attempt to apply the Cannizzaro reaction, but anthracene-9-carboxylic acid could not be obtained.

[0005] Anthracene-9-carboxylic acid has its own property of being easily decarboxylated and easily converted to anthracene, and it is difficult to produce it by diversion of a general production method of aromatic carboxylic acid as described above. Anthracene-9
-The development of an efficient process for the production of carboxylic acids has been accompanied by great difficulties.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for industrially and advantageously producing anthracene-9-carboxylic acid. More specifically, an object of the present invention is to provide a method for producing anthracene-9-carboxylic acid under mild conditions and with good yield.

[0007]

According to the present invention, 9-anthaldehyde is reacted by heating in a nonpolar organic solvent in the presence of an alkali metal hydroxide. Is provided.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION 9 used as a raw material of the present invention
The anthralaldehyde may be produced by any method; In general, it can be easily obtained on the market, and can be obtained, for example, by reacting anthracene with hydrogen cyanide in the presence of aluminum chloride or by reacting N-methylanilide with phosphorus oxychloride, or by a Sommelet reaction. Is possible.

In the present invention, the reaction of 9-anthraldehyde is carried out in a non-polar organic solvent. Non-polar organic solvents that can be used include hexane, heptane, aliphatic hydrocarbons such as kerosene, cyclopentane, cyclohexane,
Alicyclic hydrocarbons such as methylcyclohexane, aromatic hydrocarbons such as benzene, toluene, xylene, ethylbenzene, cumene, methylnaphthalene, and methylbiphenyl; halogenated hydrocarbons such as chlorobenzene and dichlorobezen; diisopropyl ether; methyl Examples thereof include ethers such as phenyl ether, and mixtures thereof. A small amount of water may be present in the non-polar organic solvent as long as the reaction is not significantly affected, but it is preferably substantially anhydrous in order to smoothly carry out the reaction.

The amount of the nonpolar organic solvent used can be arbitrarily selected and is not particularly limited, but is usually preferably in the range of about 2 to 20 parts by weight based on 1 part by weight of 9-anthraldehyde. That is, if the amount of the solvent is too small, it is difficult to uniformly perform the stirring and mixing in the reaction vessel, and if the amount of the solvent is too large, the load of the post-treatment operation becomes too large.

[0011] The reaction of the present invention is carried out in a non-polar organic solvent.
This is performed by suspending and mixing anthralaldehyde and an alkali metal hydroxide. Examples of the alkali metal hydroxide include potassium hydroxide, sodium hydroxide, lithium hydroxide and the like, and the use of potassium hydroxide is particularly preferred from the viewpoint of the reaction yield. There is no particular limitation on the shape and size of these alkali metal hydroxides, and flake products that are generally available can be used as they are. Further, in order to improve dispersibility, it is also possible to use by pulverizing in advance.

The amount of alkali metal hydroxide used is
-It is preferably in the range of about 2 to 20 mol, particularly about 3 to 10 mol, per 1 mol of anthralaldehyde.
That is, if the amount is too small, it is difficult to promote the reaction or to increase the yield of the desired anthracene-9-carboxylic acid. Further, even if the amount used is excessive, there is no influence on the improvement of the yield, and no economic advantage can be found.

The reaction temperature is from 20 to 150 ° C., preferably from 30 to 150 ° C.
The temperature is preferably about 70 ° C. That is, the reaction proceeds at a very low temperature such as less than 20 ° C., but the reaction rate is low, and cooling is required, so that it is not economical. On the other hand, if the temperature is too high, the yield of anthracene-9-carboxylic acid decreases, and the by-product of anthracene due to decomposition increases.

The reaction time varies depending on the type of solvent and alkali metal hydroxide used, the amount used and the reaction temperature, but is usually about 1 to 20 hours.

In order to recover anthracene-9-carboxylic acid from the reaction solution, for example, the following method can be adopted. That is, by adding sufficient water to the reaction solution, the remaining alkali metal hydroxide is dissolved, and anthracene-9-carboxylic acid is extracted as an alkali metal salt into the aqueous layer, while 9-anthracene methanol crystals by-produced are filtered. To remove. The filtrate is allowed to stand and separated, and the lower aqueous layer is separated. The crystals of anthracene-9-carboxylic acid obtained by acid precipitation are collected by filtration. High-purity anthracene-9-carboxylic acid can be obtained from the obtained crude crystals by ordinary production means such as washing and recrystallization.

[0016]

The present invention will be described in more detail with reference to the following examples.

Example 1 300 g (1.45 mol) of 9-anthraldehyde, 408 g (7.27 mol) of potassium hydroxide and 2100 g of xylene were charged into a 10 L reaction vessel equipped with a stirrer, and the contents were stirred while stirring. The mixture was heated to a temperature of 50 ° C. and kept for 12 hours. After confirming the decrease of 9-anthraldehyde by HPLC (high performance liquid chromatography), 3500 g of cold water was added to dissolve the remaining potassium hydroxide. The remaining crystals (9-anthracene methanol) were removed by filtration, the filtrate was allowed to stand, and the lower layer (aqueous layer) was separated. 3 in the resulting aqueous solution
770 g (7.38 mol) of 5% aqueous hydrogen chloride was added,
Was neutralized to 5.0 to precipitate pale yellow crystals. After holding for 1 hour, the precipitated crystals were separated by filtration, and then washed with water 3
The crystals were washed with 00 g. 80 ° C.
Under reduced pressure to obtain 134.9 g of the desired product (anthracene-9-carboxylic acid) as a pale yellow powder. The purity of the target product by titration was 89.9%, and the yield was 37.5 mol%.

Example 2 The reaction was carried out in the same manner as in Example 1 except that the reaction temperature was 80 ° C. and the reaction time was 3 hours. When the reaction solution was analyzed by HPLC, anthracene-corresponding to 31% in area percentage was obtained.
The formation of 9-carboxylic acid was confirmed.

Example 3 The reaction was performed in the same manner as in Example 1 except that the reaction temperature was 110 ° C. and the reaction time was 5 hours. When the reaction solution was analyzed by HPLC, formation of anthracene-9-carboxylic acid corresponding to 23% in area percentage was confirmed.

[Comparative Example 1] 150 g of a 50 wt% aqueous potassium hydroxide solution and 10.0 g of 9-anthraldehyde were placed in a stainless steel reaction vessel equipped with a stirrer having an internal volume of 300 ml.
And kept at an internal temperature of 50 ° C. for 6 hours while stirring.
Thereafter, the internal temperature was raised to 80 ° C. and maintained for 4 hours. When the reaction solution was analyzed by HPLC, no peak other than 9-anthraldehyde could be confirmed, confirming that the reaction did not proceed.

Comparative Example 2 A reaction vessel equipped with a stirrer having an internal volume of 200 ml was charged with 5.15 g of 9-anthraldehyde.
103.1 g of xylene, 7.02 g of potassium hydroxide, and 4.5 g of water were charged, and the temperature was raised to an internal temperature of 50 ° C. with stirring, and maintained for 8 hours. Thereafter, the internal temperature was raised to 65 ° C. and maintained for 6 hours. When the reaction solution was analyzed by HPLC, it was confirmed that trace amounts of anthracene-9-carboxylic acid were generated, but that 9-anthraldehyde had not substantially reacted.

[Comparative Example 3] 5.20 g of potassium permanganate and water 10
0 g was added and dissolved by stirring. Subsequently, 5.15 g of 9-anthraldehyde and 12.0 g of a 20% aqueous KOH solution were added, the temperature was raised to an internal temperature of 80 ° C., and the temperature was maintained for 8 hours. The reaction solution was confirmed by HPLC, and although a decrease in 9-anthaldehyde was confirmed, generation of anthracene-9-carboxylic acid was not confirmed.

[Comparative Example 4] In a 500 ml reactor equipped with a gas inlet and a stirrer, 30.0 g of 9-anthraldehyde, 1.58 g of potassium bromide, 3.3 g of cobalt acetate tetrahydrate, Manganese acetate tetrahydrate 3.3
g and 230 g of acetic acid were added and stirred. 60 ° C
When the temperature was raised to, the mixture was dissolved to form a uniform solution. Subsequently, oxygen gas was bubbled into the liquid at a rate of 25 ml / min.
Hold for hours. After cooling, the reaction solution was confirmed by HPLC, and 29% of 9-anthraldehyde remained.
The formation of anthracene-9-carboxylic acid could not be confirmed.

[0024]

According to the present invention, anthracene-9 can be produced from 9-anthaldehyde under mild conditions and in a high yield.
A carboxylic acid can be produced.

Claims (4)

[Claims] 1. A process for producing anthracene-9-carboxylic acid, comprising reacting 9-anthaldehyde with heat in a nonpolar organic solvent in the presence of an alkali metal hydroxide. 2. The process for producing anthracene-9-carboxylic acid according to claim 1, wherein the reaction is carried out in a substantially anhydrous state. 3. The method for producing anthracene-9-carboxylic acid according to claim 1, wherein the alkali metal hydroxide is potassium hydroxide. 4. An amount of 2 per mole of 9-anthraldehyde.
2. The method according to claim 1, wherein the alkali metal hydroxide is used in an amount of from 20 to 20 mol.
A method for producing the anthracene-9-carboxylic acid as described above.