JPS5814409B2 - Houkouzoku Hydroxykagobutsuno Seizouhouhou - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a corresponding aromatic hydroxy compound by subjecting an aromatic sulfonic acid or its salt to an alkali melting reaction using an alkali metal hydroxide as an alkali melting reagent. The present invention is a new and industrial method which shortens the alkali melting reaction time, reduces the amount of alkali melting reagent used, and lowers the reaction temperature, and which can obtain aromatic hydroxy compounds easily and continuously in high yield. The purpose is to provide a useful method.

Conventionally, a method of obtaining a corresponding aromatic hydroxy compound by an alkali melt reaction using an aromatic sulfonic acid or its salt as a raw material is well known.

For example, industrially, a solid alkali melting reagent is charged into a container such as a melting oven equipped with a stirrer, melted by heating, aromatic sulfonate salts are introduced, and the mixture is heated for 25 minutes under normal pressure.
The melting reaction is usually carried out at a high temperature of about 0 to 400°C for several hours to several tens of hours, and after maintaining the above temperature for several hours, the reactant is taken out into water, and the excess alkali melting reagent is neutralized and separated to obtain the desired product. The method of obtaining aromatic hydroxy compounds is mainly practiced.

However, in this method, the desired product cannot be obtained with a good yield unless the alkali-melting reagent is used in a large amount, about 1.7 to 5 times the theoretical amount, and the alkali-melting reagent is used in considerable excess. However, the biggest drawback is that the reaction takes a long time, several hours or more.

Using a large amount of an alkali melting reagent is not only uneconomical in itself, but also requires a large amount of mineral acid etc. for separation of the target product, treatment of waste liquid, recovery of the reagent, etc. Economically disadvantageous.

Another known method is to perform the above melting reaction under harsh conditions of high temperature and pressure using a pressure-resistant container such as an autoclave, but this method first requires a pressure-resistant container, is complicated to operate, and is dangerous. This is not industrially advantageous.

Moreover, even with this pressurized melting method, the reaction time is not shortened; on the contrary, it takes a long time to obtain the desired product in a high yield.

Furthermore, in order to accelerate the melting reaction, KCl, K2S0
Attempts have also been made to add reaction accelerators such as 3.
A reaction accelerator that can obtain the desired product in a short period of time at an industrial yield has not yet been found.

Generally, as a continuous reaction method, the aromatic sulfonate and solid caustic soda, which have been melted by raising the temperature in advance, are charged into a reaction apparatus as uniformly as possible, or after the sulfonate is dissolved in an aqueous solution of caustic soda, A method is known in which the water is heated to evaporate water before being added.

However, such a method requires a melting device and an evaporation device in addition to the reaction device, making the pretreatment complicated, and the reaction device is required to have pressure resistance due to the increase in pressure caused by water, and is extremely viscous. It is a structurally complex device equipped with a large number of stirring blades to uniformly stir, mix, and transport the various reactants, and its operation requires a high degree of skill.

In view of the above-mentioned current situation, the present inventors used a known alkali melting method to efficiently terminate the reaction in a short time, reduce the amount of alkali melting reagent used, and furthermore easily and continuously produce the desired aromatic hydroxyl Various studies were conducted with the aim of obtaining the compound.

As a result, the present inventors found that when an alkaline earth metal oxide is present in the reaction system, the reaction is extremely accelerated and all of the above objectives are achieved, and the present invention has been completed.

That is, the present invention provides an alkali melting reaction of aromatic sulfonic acid or its salts using an alkali metal hydroxide as an alkali melting reagent to produce a corresponding aromatic hydroxy compound. It relates to a method for producing an aromatic hydroxy compound, characterized in that the aromatic hydroxy compound is present in the aromatic hydroxy compound.

According to the method of the present invention, various aromatic sulfonic acids or their salts can be converted into the corresponding aromatic hydroxy compounds in a very short period of time, from several minutes to 1 to 2 hours, simply by using an approximately stoichiometric amount of an alkali melting reagent. .

Moreover, in the method of the present invention, it is possible to carry out the above-mentioned reactions continuously using ordinary simple equipment without requiring any complicated equipment, and this continuous process also makes it possible to efficiently obtain the target product. .

Further, according to the method of the present invention, it is possible to continuously extract the reaction product as a powder, and the operation itself is extremely easy.

Further, the reaction product can be easily separated into the desired hydroxy compound and other inorganic compounds by simply adding it to water and filtering it.

In addition, in the method of the present invention, it is possible to obtain the corresponding aromatic polyhydroxy compound from aromatic polysulfonic acid or its salts in a single-step reaction in the same manner as aromatic monohydroquine compounds, and in a sufficient yield.

The reason why the present invention can achieve the above-mentioned excellent effects is not clear at present, but the alkaline earth metal oxide present in the system acts as a dehydrating agent that reacts with water produced by-product during the melting reaction. In addition to significantly accelerating the melting reaction, the alkaline earth metal oxides also promote the action of sodium hydroxide, potassium hydroxide, etc., which serve as alkali melting agents, or they themselves act as alkali melting agents in the reaction system. It seems to be for a reason.

In any case, the fact that the alkali melting reaction can be completed in a short period of several minutes simply by having an alkaline earth metal oxide in the system is something that the present inventors discovered for the first time. However, in experiments conducted by the present inventors, calcium carbonate (Ca
It is recognized that C03) or Glauber's salt (Na2SO4) does not promote the reaction at all or hardly even in a similar alkali melting reaction, and that the yield of the target product cannot be improved significantly.

From this, it is clear that the alkaline earth metal oxide used in the present invention not only acts as a dehydrating agent but also directly influences the promotion of the melting reaction.

Examples of aromatic sulfonic acids or salts thereof used as raw materials in the present invention include substituted or unsubstituted aromatic sulfonic acids or salts thereof having at least one sulfo group in the aromatic nucleus.

In the present invention, in particular, it is also possible to selectively substitute one or more sulfo groups of an aromatic sulfonic acid having two or more sulfo groups or a salt thereof.

Representative aromatic sulfonic acids or their salts include, for example, benzenesulfonic acid, alkylbenzenesulfonic acid,
Examples include pyridine sulfonic acid, phenolsulfonic acid, naphthalene sulfonic acid, quinoline sulfonic acid, anthraquinone sulfonic acid, and salts thereof.

Further, as the alkali metal hydroxide, solid caustic alkalis such as caustic soda and caustic alkali can be advantageously used.

The amount of caustic alkali normally used is at least the same as the theoretical amount, preferably 1.0 to 1.8 times the sulfo group of the aromatic sulfonic acid or its salt, and should be used in a smaller amount than conventionally. be able to.

Further, examples of the alkali metal oxides mentioned in the present invention include calcium oxide, magnesium oxide, barium oxide, and the like.

The amount of these alkali group 10 metal oxides to be used is generally equal to or greater than the amount of water produced in the reaction system.

For example, when using 1 mole of aromatic monosulfonate and 2 moles of alkali melting reagent (NaOH), it is sufficient to use 1 mole or more, preferably the same amount as the alkali melting reagent.

If this amount is too small, the reaction cannot be completed, and the reaction time becomes longer and the yield becomes lower.

The alkali melting reaction temperature of the present invention can be appropriately determined depending on the type or amount of the aromatic sulfonic acid or salt thereof and the alkali melting agent used, but sufficient reaction can normally be carried out at a temperature of about 300°C.

Particularly in the present invention, the reaction is usually completed in about several tens of minutes at the above temperature.

In carrying out the method of the present invention, a solid powder mixture of the above-described aromatic sulfonic acid or its salts, an alkali melting reagent, and an alkaline earth metal oxide is charged into a reaction vessel equipped with a forced stirring device, and the mixture is stirred. The reaction is carried out by raising the temperature while carrying out the following steps, and then the heating is stopped and the reactants are extracted into water, or a predetermined amount of the powder mixture is continuously charged in the same manner as above into a continuous reaction apparatus maintained at a specific temperature. , the reactants may be continuously extracted into water.

Furthermore, since the reactant takes on the form of a solid powder by simple temperature control within the apparatus, this extraction operation is extremely easy.

Thereafter, the desired product can be extracted by filtration according to a conventional method.

Examples will be given below to explain the present invention in more detail.

Example 1 230~ of α-naphthalene sulfonate soda, 165 mg of potassium hydroxide powder (2.6 molar ratio to raw materials), and 147 mg of calcium oxide powder (2.62 molar ratio to raw materials) were placed in a forced stirring device, and then stirred. While doing so, the temperature suddenly reached 290℃.
(for about 5 minutes), and at the same time the temperature inside the system reached 290° C., it was cooled, purged with 250 ml of water, and filtered to remove calcium sulfite and the like.

In this way, the desired α-naphthol was obtained.

There were no unresponsive responses. Production rate of α-naphthol: 87.

6%. Example 2 230 mg of sodium α-naphthalene sulfonate, 102 mg of sodium hydroxide powder (molar ratio to raw materials 2.16), and 135 mg of calcium oxide powder (molar ratio to raw materials 2.41)
) into a forced stirring device, and then rapidly stirred while stirring.
The temperature was raised to 00° C., and after stirring at this temperature for 30 minutes, the mixture was cooled and purged into 250 ml of water.

Furthermore, calcium sulfite was removed by filtration.

In this way, the desired α-naphthol was obtained.

There were no unreacted substances. Production rate of α-naphthol is 85%.

Example 3 176 mg of sodium benzene monosulfonate, 229 mg of potassium hydroxide powder (molar ratio to raw materials 3.5), and 213 η powder of calcium oxide (molar ratio to raw materials 3.8) were placed in a forced stirring device, and then stirred. The temperature was rapidly raised to 300°C while stirring, and the mixture was stirred for 110 minutes.

After cooling, it was purged with 250 ml of water and the calcium sulfite was removed by filtration.

In this way, the desired phenol was obtained.

Phenol production rate - 87.6% Unreacted matter - 12.3% Example 4 Naphthalene - 1, 3, 6 - Sodium trisulfonate 43.4 ~, potassium hydroxide powder 33.6 ~ (molar ratio to raw material 5.1) and 28.5 mg of calcium oxide powder (molar ratio to the raw material: 5.1) were placed in a forced stirring device, and the temperature was rapidly raised to 220° C. while stirring, followed by stirring for 60 minutes.

After cooling, it was purged with 25 ml of water and the calcium sulfite was removed by filtration.

In this way, the desired 1,6-dioxy-3-sulfonic acid was obtained.

There were no unreacted substances.

■・6-Dioxy-3-sulfonic acid production rate 77.4%
Example 5 Sodium naphthalene-1,3,6-trisulfonate 200
．． 7) After putting 81.5 mg of potassium hydroxide powder (mole ratio to raw material: 2.68) and 40 mg of magnesium oxide powder (mole ratio to raw material: 2.0) into a forced stirring device, the temperature was rapidly raised to 160°C while stirring. The temperature was raised and stirred for 45 minutes.

The following product was thus obtained. There were no unreacted substances.

1→oxy-3,6-disulfonic acid production rate = 96% 1.
6-Dioxy-3-sulfonic acid production rate-3. 7% Example 6 After putting 231 cm of sodium 8-quinoline sulfonate, 235 mg of potassium hydroxide powder (molar ratio to raw materials 3.56), and 147 mg of calcium oxide powder (molar ratio to raw materials 2.6) into a forced stirring device. , while rapidly stirring to 250 ml.
The temperature was raised to ℃ and stirred for 30 minutes.

In this way, the desired 8-oxyquinoline was obtained at a production rate of 8.5%.

There were no unreacted substances. Example 7 6.5% of KOH powder was added to 1 mole of sodium naphthalene-1,3,6-trisulfonate. 0 6 4 mol and CaO
, BaO, and MgO, respectively, are theoretically 10
The reaction temperature is 235-240℃ when used in an amount that can absorb 0%.
The reaction was carried out for 60 minutes.

The results shown in Table 1 below were obtained.

For comparison, Table 1 also shows the case in which none of Cab, BaO, and MgO was used.

Example 8 Sodium α-naphthalenesulfonate was used as a raw material, and KOH and CaO were mixed in advance at a ratio of 2.6 mol and 2.62 mol per 1 mol of the raw material, respectively, and the mixture was continuously heated under the following conditions. I reacted to it.

Reaction temperature: 300° C.±3° C. Charge rate: 180 g/hr Residence time: 8 minutes The desired α-naphthol was also continuously obtained in a yield of 88% by the continuous method described above.

Comparative Example 1 0.003 mol of potassium 1-oxynaphthalene-3,6-disulfonate and KOH O. 0 1 2 moles, C
a Add (OH)2 at the following ratios and heat to 263-265℃
The reaction was carried out at a temperature of 30 minutes, and the results shown in Table 2 below were obtained.

It can be seen from Table 2 that Ca (OH) 2 does not have a reaction accelerating effect no matter what amount it is used.

Claims (1)

[Claims] 1. When producing the corresponding aromatic hydroxy compound by subjecting aromatic sulfonic acid or its salts to an alkali melting reaction using an alkali metal hydroxide as an alkali melting reagent, it is necessary to include an alkaline earth metal oxide in the reaction system. A method for producing a characteristic aromatic hydroxy compound.