JPS5810372B2 - Anthraquinone -1- Carbohydrate - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides 1,4-naphthoquinone and trans-1,3-
The present invention relates to a method for producing anthraquinone-1-carboxylic acid using pentadiene as a raw material.

The process according to the invention passes intermediately through the Diels-Alder type adduct tetrahydro-1-methyl-anthraquinone and then through 1-methyl-anthraquinone.

The method for producing 1-methyl-anthraquinone was published in Soviet Patent No. 13.
0892, the Diels-Alder reaction of 1,4-naphthoquinone and 1,3-pentadiene is carried out at the boiling point of a solvent such as butanol, and approximately 8
% of potash-methanol and then at low temperature -
Oxidation is performed using hydrogen peroxide at a concentration of 30%.

And the yield is 66 to 70%.

Additionally, anthraquinone-1 was obtained by reacting a 1-methyl-anthraquinone derivative with chlorine in the presence of nitrobenzene.
-The method for synthesizing carboxylic acids is described in German Patent No. 2507
42 and 259365.

These patents do not contain any examples for 1-methyl-anthraquinone itself, nor do they describe yield rates for derivatives.

When the inventor conducted a follow-up test on this reaction, the yield was 7.
The percentage ranged from 5 to 76%.

Therefore, 1,4-naphthoquinone and 1.
The total yield of anthraquinone-1-carboxylic acid from 3-pentadiene is 50 to 53%.

In contrast, the present inventor has proposed the above-mentioned Diels-Alder
The reaction is carried out using an aromatic nitro compound or a mixture of this and an aromatic chlorine compound as a solvent, and subsequently air is blown into the reaction mixture while removing water generated at a temperature of 150° C. or higher, Next, we found that by contacting with chlorine gas at a temperature of 160°C or higher, the process was simplified and it was possible to produce highly pure anthraquinone-1-carboxylic acid with an unexpectedly high yield (70% or higher). I found it.

As a raw material for the production method of the present invention, pure trans-1
・There is no need to use 3-pentadiene; for example, cyclopentadiene and isoprene are separated and removed from the C5 fraction obtained by naphtha decomposition, etc. to create a 1,3-pentadiene-rich C5 fraction that does not substantially contain these. minutes can be used, which is now commercially available.

Aromatic nitrite compounds used as solvents or oxidizing agents include, for example, nitrobenzene, dinitrobenzene, nitrochlorobenzene, and nitronaphthalene.

In the present invention, if the aromatic nitro compound is solid at room temperature, it will be difficult or impossible to separate the target product by cooling the reaction solution after the reaction, so this aromatic nitro compound is dissolved. It is preferable to mix an aromatic chlorine compound that does not directly participate in the reaction with the aromatic nitro compound as a solvent for dilution.

Examples of such aromatic chlorine compounds include chlorobenzene, dichlorobenzene, and trichlorobenzene.

This is because aromatic nitro compounds, as well as solvents in the Diels-Alder reaction, are themselves oxidizing;
In addition, contact with chlorine at 160°C or higher causes substitution of nitro groups and chlorine groups, and the released NO2Cl or
NO2 also oxidizes chlorinated methyl groups.

Therefore, in the method of the present invention, the solvent after collecting anthraquinone-1-carboxylic acid contains a large amount of nitro compounds as well as the produced aromatic chlorine compounds.

This is easily recovered through operations such as distillation.

Note that the amount of aromatic chlorine compounds produced during the reaction is small compared to the aromatic nitro compounds, so if the aromatic nitro compounds are solid at room temperature, the aromatic chlorine compounds are used as a solvent in advance. It is better to use it in combination with other compounds.

In particular, when a solvent mixture containing m-chloronitrobenzene or m-dinitrobenzene is used, m-dichlorobenzene, which is produced in a small amount, is co-produced in the ordinary chlorination reaction of benzenes. High industrial value.

In the reaction of 1,4-naphthoquinone and trans-1,3-pentadiene, the latter is used in slightly excess of the equivalent amount.

Although the reaction temperature does not need to be strictly defined, good results have been obtained by gradually increasing the temperature from 40°C to 120°C as the reaction progresses.

After completion of the reaction, unreacted low-boiling components in the raw materials are distilled off by raising the temperature or reducing the pressure, and then air is blown into the raw materials while removing water produced as the dehydrogenation and oxidation reactions proceed.

The temperature is at least 150°C, especially between 150°C and 17°C.
0°C is desirable.

After that, contact with chlorine gas is carried out at 160°C or higher, preferably.
It is carried out at 170°C to 180°C.

After the oxidation reaction is completed, the anthraquinone-1-carboxylic acid becomes crystals and can be easily separated by cooling the reaction mixture.

This crude anthraquinone-1-carboxylic acid can be purified to a practically sufficient purity by dissolving it in an alkali to remove a trace amount of undissolved matter, and then performing acid precipitation or salting out.

As mentioned above, the characteristics of the present invention are that pure 1,3-pentadiene is not required as a raw material and that the process can be simplified because the reaction can be carried out continuously in one step. Improvement in yield can be mentioned.

The reason for this improvement in yield is not necessarily clear, but
Since the Diels-Alder reaction is considered to be an equilibrium reaction, a certain amount of 1-methylanthraquinone is produced due to the oxidizing effect of the aromatic nitro compound in the solvent, and the above equilibrium shifts in favor of the production of tetrabidro-1-methylanthraquinone. I can think of what you are doing.

In fact, analysis by liquid chromatography as the Diels-Alder reaction progresses reveals that oxidation has progressed considerably and a considerable amount of 1-methyl-anthraquinone is produced.

In addition, the present invention does not use strong oxidizing conditions such as those used with strong potash methanol and hydrogen peroxide, but uses a combination of mild oxidizing action by an aromatic nitro compound and oxidation by air blowing, which reduces by-products. It was observed that the formation of tar-like condensates was small.

In addition, it is estimated that aromatization does not complete completely at the stage of air blowing, and unreacted substances are first chlorinated by subsequent contact with chlorine gas, and then aromatized by dehydrochlorination reaction. It is also possible that this condition helps improve the yield.

Further, such dehydrogenation reaction and dehydrochlorination reaction may provide favorable conditions for the next step of oxidation of the methyl group.

This will be specifically explained using the following example.

Example 1 A 200 ml four-day flask is equipped with a stirrer, a reflux condenser equipped with a Starkdin lamp, a thermometer, and a gas inlet tube.

■・15.81 (0.1 mol) of 4-naphthoquinone and 150 cc of nitrobenzene were charged, and while stirring at room temperature,
C5 fraction containing 3% 1,3-pentadiene (1,3-
Other than Pentagen, Diels.

(not including those that undergo Alder reaction) 16.6S' (0
, 13 mol) are gradually added.

The gas blowing tube was closed, the reflux was returned to the flask as it was, the temperature was raised, and the temperature was raised at 40-50°C for 2 hours at 60-60°C.
3 hours at 5℃, 2 hours at 75-85℃, 100-1
React at 20°C for 7 hours.

A Stark Din lamp is used to extract low-boiling components.

In this case, the temperature is raised to 165°C. At this temperature, open the gas blowing pipe and draw out the generated water, about 90 m1/h.
Blow air at a rate of r for 3 hours.

8 at 165℃? Chlorine gas is introduced at a rate of /hr for 5 hours.

Cool and separate the formed crystals by filtration.

Crude yield: 18.4 g (crude yield: 73%) The crude product was heated and dissolved in a solution of 5 g of sodium hydroxide and 500 ml of water, and the insoluble matter was filtered off.

The filtrate was acidified with dilute sulfuric acid and filtered to obtain anthraquinone-1-
18.3 g of carboxylic acid are obtained.

Yield 72.6%. Melting point: 289°C to 290°C Example 2 Into the same apparatus as above, 15.8 g of 4-naphthoquinone, 171 g of m-dinitrobenzene, and 100 cc of trichlorobenzene were added.
, the C5 fraction 16.6y' containing 53% of 1,3-pentadiene was reacted in the same manner.

However, the temperature of contact with chlorine gas was set at around 190°C.

Yield of anthraquinone-1-carboxylic acid: 17, 61 (yield 70.6%) Reference Example The results of a follow-up test of German Patent No. 250742 are shown as a reference example.

In the same apparatus as in Example 1, 1-methyl-anthraquinone I
Charge 100 cc of IS' (0.05 mol) nitrobenzene.

The temperature was raised while stirring, and chlorine gas was blown in at 170° C. for about 3 hours.

Cool and filter out the formed crystals.

The yield of anthraquinone-1-carboxylic acid is 9.5? Met.

Therefore, the oxidation yield from 1-methyl-anthraquinone was 75%.

When considering the condensation and dehydrogenation yields for synthesizing (1)-methyl-anthraquinone, it is clear that the method is inferior to the method of the present invention.

Claims (1)

[Claims] 1 Using an aromatic nitro compound or a mixture of this and an aromatic chlorine compound as a solvent, 1,4-naphthoquinone and trans-3-pentadiene are heated at 40°C to 120°C.
After reacting at a temperature of ℃, unreacted low boiling point components are distilled off,
The anthraquinone is then added to the reaction mixture in one bath, characterized in that it is brought into contact with chlorine gas at a temperature of 150° C. or higher, while removing the water formed, and then brought into contact with chlorine gas at a temperature of 160° C. or higher. - A method for producing 1-carboxylic acid.