JPS58110558A - Preparation of naphthalene-1,3,6-trisulfonic acid - Google Patents

Abstract

PURPOSE:To prepare the titled compound useful as an intermediate of azo dye, etc., economically in an industrial scale, by reacting naphthalene with sulfuric acid, supplying the reaction product continuously to a reactor to effect the reaction with sulfuric acid and fuming sulfuric acid under specific conditions, and further reacting the product in another reactor at an elevated temperature. CONSTITUTION:Naphthalene is sulfonated with 0.7-2mols of sulfuric acid per 1mol of naphthalene. The resultant reaction mixture composed mainly of naphthalene-2-sulfonic acid is supplied continuously to a reactor, and made to react with 1-2.5mol of sulfuric acid and 2-4mol of SO3 in the form of fuming sulfuric acid (per 1mol of the naphthalene) supplied continuously to the reactor, at 30-100 deg.C and an average residence time of 0.1-1hr. The reaction product is transferred continuously to another reactor, and is made to react with 0-0.8mol of sulfuric acid and 0-0.8mol of SO3 (per 1mol of naphthalene) supplied continuously to the reactor, at 170-210 deg.C and an average residence time of 1-10hr to obtain the objective compound.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a process for continuously producing naphthalene-1,8,6-drysulephonic acid.

+7$ 17 N-1,8,6-trisulfonic acid is a raw material for producing H acid, which is important as an intermediate for azo dyes. Mol of sulfuric acid and oleum (8
A known method is to carry out sulfonation in a batch manner by adding sulfonating acids in portions while repeatedly heating and cooling the reaction system (as Yutaka Hosoda, "Theoretical Manufacturing Dye Chemistry", p. 584). ).

However, this method converts naphthalene to naphthalene-1,8.
, 6-) The yield to lysulfonic acid is relatively low at about 72%, and the heating and cooling operations are repeated in the same reactor, which not only makes the operation complicated but also causes a large loss of thermal energy. Excess sulfuric acid other than the amount required for the reaction is used, which increases the cost of processing the excess waste acid after the reaction is completed, and the acid concentration changes significantly before and after the reaction in the same reaction vessel. Therefore, there were many disadvantages in industrial implementation, such as the need for a filter material that could withstand this.

In addition, as a method to simplify complicated heating and cooling operations,
A method of batchwise sulfonation at a sulfonation temperature of 150 to 280°C and its improved method (Japanese Patent Publication No.
-4576, JP-A-58-127449) is also known.
However, in both of these methods, fuming sulfuric acid is filtered at high temperatures and the yield is below 724F, which is lower than the above method, and these methods are not suitable for batch production. It can be said that the yield was sacrificed in order to simplify the format.

As described above, since conventionally known methods have problems in many aspects such as workability and yield as described above, the present inventors solved these problems and produced naphthalene with industrial advantage. jgl 1,8,6-trisulfonic acid! To leave behind
As a result of studying the continuous production method, we found that naphthalene was
to obtain a reaction mixture containing nacculin-2-sulfonic acid as a main component, divide the next sulfonation reaction into at least two stages of reaction conditions, and divide the sulfonation reagent as necessary according to the progress of the sulfonation. sex,
It was discovered that the work could be greatly simplified and the desired product could be obtained in good yield by setting specific conditions for temperature and residence time in each step to carry out the sulfonation reaction continuously. This led to the invention.

That is, the present invention provides (a) naphthalene in a range of 0.7 to 1 mole per mole of naphthalene.
Sulfonation using 2 mol of sulfuric acid to obtain a reaction mixture containing naph*') C2-sulfonic acid as a main component (tl) The reaction mixture obtained in (IL) is continuously added to a reaction tank. -1 per mole of naphthalene used;
Step tc+ ( The reaction mixture obtained in b) is continuously supplied to another reaction tank, and θ~
0.8 mol of sulfuric acid and 0-0.8 mol of 803 in the form of oleum were fed continuously and the reaction temperature was 179-21 o.
℃, and an average residence time of 1 to 10 hours.

In the following explanation, the expression "continuous" does not necessarily have a strict meaning, and may also include intermittent means.

In step (a) of the present invention, naphthalene is mixed with 110.7 to 2 mol of sulfuric acid, preferably 98 to 100 mol per liter of naphthalene.
This is a process in which sulfonation is performed using sulfuric acid to obtain a reaction mixture containing naphthalene-2-sulfonic acid as the main component. Although not particularly limited, it is more preferable to carry out the process in a continuous manner to simplify the work.

The reaction mixture thus obtained was further successively sulfonated with sulfuric acid and 803 in the form of oleum to give naphthalene-1.
, 8,6-trisulfonic acid is produced, and this sulfonation reaction involves at least two of (1)) and (0).
It consists of a step process, usually 1 step in each step.
reactors are used. In addition, it is also possible to use two or more reaction vessels in each process and carry out each process further divided, and there is no restriction on the number of reaction vessels, but it is economical to use eight or more vessels. This cannot necessarily be said to be advantageous.

In step (1)), the reaction mixture obtained in step (a) above is continuously supplied to the reaction tank, and at the same time, the amount of naphthalene used to obtain the reaction mixture is 1 to 2.
mol of sulfuric acid and 2 to 4 mol of 803 are continuously fed in the form of oleum, the reaction temperature is maintained at so~100C, preferably -80~80C, and the average residence time is from 80 minutes to
The sulfonation reaction is carried out for 10 hours, preferably 80 minutes to 6 hours, more preferably 80 minutes to 8 hours. Average sulfonic acid groups per nucleus is approximately 2.4-2.7
It is individual.

Since the sulfonation in this fb) step is carried out at a relatively low temperature, it is necessary to use a combination of a heat exchanger using an external heat exchange method and a circulation pump in order to efficiently remove the heat of sulfonation in order to carry out the process advantageously industrially. It is preferable that the reaction mixture formed in step e) is provided in the reaction tank to adjust the temperature. The reactor is continuously supplied as it is to another reactor for carrying out the reaction, and the reactor is supplied with O-O,a per mole of naphthalene used.
mol, preferably 0-0.2 mol of sulfuric acid and 0-0.
8 mol, preferably 0 to 0.4 mol, of 8 in the form of oleum
03 was continuously supplied, and the reaction temperature was set at 170 to 210°C.
Preferably 170-195°C, average residence time 1-10
time, preferably 2 to 6 hours, to increase the acid concentration to 99% sulfuric acid concentration [sulfuric acid concentration ('II) (112804
+ [20 wt.] concentration to complete the reaction.

In addition, +1)) , (((Supplying sulfuric acid and 803 in the form of oleum in the step) may be supplied separately, but it is possible to supply only fuming sulfuric acid by adjusting the concentration and amount of oleum. It is advantageous for practical use.

Thus, according to the method of the present invention, the present sulfonation reaction, which was conventionally considered difficult to carry out continuously, becomes possible in an extremely simplified form, and is also superior to the conventional method in terms of vehicle collection.
Its industrial value is very high.

The present invention will be explained below with reference to examples, and the experimental equipment used in each example is as follows.

The first paddle was a separable flask with an internal volume of 500 heads and a liquid volume of 810 (f, +7), equipped with an ink-type stirrer, a thermometer, a chimney-shaped a-flow port on the lateral edge, a naphthalene supply pipe, and a sulfuric acid supply port. , equipped with a metering pump for continuous supply of sulfuric acid and liquid naphthalene.

Note that the first tank has the role of producing a reaction mixture containing naphthalene-2-sulfonic acid as a main component.

's2 tank has an internal volume of 800 (n It is a separable flask with a liquid volume of 600 cc, and the ice tank is equipped with a circulation line that connects a circulation pump and a cooler in series, and the liquid in the tank is drained from the bottom extraction port. It has the function of removing heat by circulating it into the tank.

Further, the reaction liquid is transferred from the ice tank to the eighth cypress by extracting the circulating amount tS through the circulation pump outlet of this circulation line and the extraction port provided in the middle of the tank.

The 8th cypress is equipped with a cap stirrer, a temperature needle, a pipe that continuously supplies the reaction mixture from the 2nd cypress, a fuming sulfuric acid supply port, and a horizontal chimney-shaped overflow port, with an internal volume of aoooac and a liquid volume of approx. It is a 2880CC 4-paraple flask. The supply of fuming sulfuric acid is carried out by a constant pump, but it may also be supplied into the tank or into the conduit connecting the second tank and the eighth tank.

Example 1 Liquid naphthalene (content 97.51
) is quantitatively fed with 190 f/h%984 sulfuric acid at a rate of 244 f/h.

The amount of sulfuric acid per mol of Naclin charged was 1.6 mol.

Note that the temperature of the first tank is maintained at 170° C., and the average residence time is set to be 1 hour.

The reaction mixture in the first vessel is quantitatively overflowed and supplied to the second vessel.

654 oleum is quantitatively supplied to the second hinoki at a rate of 548.6 th. Cooling is performed by pump circulation so that the temperature in the second tank is 70'C. The average residence time in the second tank is set to 1 hour.

The reaction mixture in the second tank is then quantitatively supplied to the eighth tank.

654 oleum is quantitatively supplied to the eighth tank at a rate of 47.7 tax.

In addition, J! The eight tanks were maintained at a temperature of 185° C., and the average residence time was set to be 4 hours.

The reaction mixture quantitatively overflowing and discharged from the eighth cypress is a trisulfonation reaction mixture containing naphthalene-1,3.6-trisulfonic acid as a main component.

During steady operation, a part of the reaction mixture discharged from the eighth cypress of Jin was poured into ice water, neutralized with caustic soda aqueous solution, and analyzed by high performance liquid chromatography. As a result, naphthalene was found in the reaction mixture. -1,8,6-trisulfonic acid 4
G, 67 weight, naphthalene-1,8,? - trisulfonic acid 7.28% by weight, naphthalene-1,8,5-) trisulfonic acid 2.22% by weight, and naphthalene-1,8,
It contained 1.88 weight grams of 5,7-titrasulfonic acid.

The theoretical yield of naphcrine-t,a,g-trisulfonic acid from naphthalene is 78.61.

The sulfuric acid in the reaction mixture in the second tank was 5.84 SOs.
In terms of concentration, the average number of sulfonic acid groups per mole of naphthalene was 2.67.

Example 2 Sulfonation as in Example 1, but with 6 to 8th cypress
Without supplying 54 oleum, that amount of 66 oleum was combined with 66 oleum supplied to the second tank, and
The operation was carried out under the same conditions as in Example 1 except for supplying to the cypress.
child.

During steady operation, a part of the reaction 1% F product discharged from this eighth paddle was poured into ice water and neutralized with aqueous caustic soda solution.
As a result of analysis by high performance liquid chromatography, the reaction mixture contained nacculin-1,8,6-)lysulfonic acid 4.
0.06 weight, naphthalene-1,8,7-trisulfonic acid 8.00 weight, naphthalene-1,8,5-trisulfonic acid 1.79 weight, and naphthalene-1.8,5.
It contained 1.46 weight saliva of 7-titrasulfonic acid.

The theoretical yield of naphthalene-1,8,6-trisulfonic acid from naphthalene is 77.64.

The sulfuric acid concentration of the reaction mixture in the second tank was 8.914 S.
In terms of Os concentration, the average number of sulfonic acid groups per mole of naphthalene was 2.66.

Example 8 1! A sulfonation as in Example 1, but the 98% sulfuric acid fed to the first cypress is quantitatively fed at a reduced rate to 207.6 t/h.

The amount of sulfuric acid is 1.4 moles per mole of naphthalene charged.

The temperature of the first cypress was maintained at 160°C.

For $2 Hinoki, add 98 tatami sulfuric acid to 87.6 tA! Other than quantitative supply, the conditions are iJ! Example Color Application 1 was run in duplicate.

Naphthalene threat from naphthalene - 1.8. ! -The theoretical value of trisulfonic acid is '18.84.

Example 4 Naphthalene (content 97.64) 1885 in an 8 t round bottom flask equipped with stirrer, condenser, temperature needle and dropping funnel
Add 984 sulfuric acid 18852 to t, heat at 160L for 1 hour to perform sulfonation, cool to 100°C,
A sulfonation reaction mixture based on naphthalene-2-sulfonic acid, prepared in advance in batch mode by adding 8 BOf of sulfuric acid, is quantitatively fed to the second paddle in Example 1 at a rate of 427 thl. The same procedure as in Example 1 was carried out except for the following.

The yield of naphthalene-1,8,6-trisulfonic acid from naphthalene was 78.6% of the theoretical value.

Comparative Example 1 Sulfonation was performed as in Example 2, but the eighth tank was replaced with a separable flask with a liquid volume of 152 (11), and the average residence time in the eighth cypress was 2.5 hours. The procedure was the same as in Example 2 except that the internal temperature of the tank was 146°C.

During steady operation, a part of the reaction mixture discharged from the eighth cypress was injected into ice water, neutralized with aqueous caustic soda solution, and analyzed by high performance liquid chromatography. As a result, the reaction mixture contained nuclin-1, 8,6-trisulfonic acid 88
．． 05 weight, naphthalene-1,8,7-trisulfonic acid 6.97 weight, naphthalene-1,8,5-4 trisulfonic acid 5.47 weight, and naphthalene-1,8,6,7
-Titrasulfonic acid contained 0.754 wt.

The yield of naphthalene-1,8,6-trisulfonic acid from naphthalene was the theoretical value of 7J1.74.

Claims (1)

[Claims] +al Naphthalene is 0.7 to 1 mole of naphthalene.
Sulfonation using 2 molar sulfuric acid resulted in nuclin-2.
- Step of obtaining a reaction mixture containing sulfonic acid as a main component ft)l The reaction mixture obtained in (a) is continuously fed to the reaction tank, and 1 to 2
．． E3 in the form of 5 moles of sulfuric acid and 2-4 moles of oleum
Continuously supply 03 and react under conditions such that the reaction temperature is 80 to 4 oc and the average residence time is 80 minutes to 10 hours.Step (C) Continuously supply the reaction mixture obtained in 11)) to another reaction tank. At the same time, O per mole of naphthalene used
~0.8 mol of sulfuric acid and O~0.8 mol of 803 in the form of oleum are fed continuously, and the reaction temperature is between 170 and 210 mol.
℃ and an average residence time of 1 to 10 hours.