JPH0254336B2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a sulfochloride represented by the following formula (). By acting on sulfite, the following formula () is obtained.
expressed as The present invention relates to an industrially advantageous method for producing symmetrical diphenyl urea disulfinic acid or its salt.

Conventionally, vinyl sulfone-based reactive dyes have been widely known as reactive dyes for dyeing cellulose fiber materials, and compounds represented by the following formula () are important intermediates of these reactive dyes. is produced by treating acetylaminophenyl-β-hydroxyethylsulfone with a sulfating agent, but this method involves an elimination reaction of acetic acid, which poses a major obstacle in terms of material quality and wastewater treatment. Therefore, there is a strong desire to establish an industrially advantageous manufacturing method for the important dye intermediate represented by formula ().

The present applicant has previously proposed an industrially advantageous method for producing a dye intermediate represented by the formula () by reacting ethylene oxide or ethylene halohydrin with a sulfuric acid represented by the formula () or a salt thereof. ) is expressed as We have developed a method for producing a dye intermediate represented by the formula () by obtaining a compound, treating it with a sulfating agent, and further hydrolyzing it.

The present inventors have discovered that diphenyl urea disulfinic acid or its salt represented by the formula () used as a starting material in the industrially advantageous manufacturing method of the above-mentioned dye intermediate is combined with a sulfochloride and a sulfite represented by the formula (). We conducted extensive research to establish a more industrially advantageous method for manufacturing by reaction.

When producing a disulfinic acid represented by the formula () or its salt by reacting a sulfite with a sulfite represented by the formula (), the sulfochloride represented by the formula () has two sulfochloride groups in the same molecule. Because of this, not only the disulfinic acid represented by formula () but also the sulfinic acid-sulfonic acid compound produced by decomposition of one sulfochloride group, or/and the decomposition of both sulfochloride groups. Disulfonic acid compounds are formed, which greatly reduce the yield of the target compound. In order to suppress the formation of such side reaction products, it has been proposed to use sulfite in a much larger amount than the theoretical amount, but this is not only uneconomical, but also A large amount of solvent is required to dissolve the solvent, and the volumetric efficiency is extremely poor, making it impossible to provide an industrially advantageous production method.

Furthermore, a method in which sulfite is used in a much larger amount than the theoretical amount causes important problems as described below in the separation and purification process of disulfinic acid, which is the target compound, and is therefore not preferred in industrial scale production.

In other words, it is extremely difficult to crystallize and separate the target compound disulfinate from the excess sulfite remaining after the reaction, and the commonly used purification method involves crystallizing and separating sulfinic acid as a free acid. In some cases, a large amount of harmful sulfur dioxide gas is generated from the residual sulfite due to the action of mineral acids, making it difficult to take countermeasures.

In addition, in order to separate the sulfinate represented by formula () from the reaction solution, mineral acid was added to the reaction solution.
When separating the sulfuric acid precipitated as free acid, the crystal size obtained as free acid is fine;
Over-operation is difficult to carry out on an industrial scale.

The free sulfinic acid represented by formula () is very unstable to heat and oxidation, and the sulfinic acid group decomposes to become a sulfonic acid group, leading to a decrease in yield.

In addition, a large amount of free sulfinic acid is still dissolved in the acidic liquid generated by filtration, but it is extremely difficult to separate and recover this amount due to the instability mentioned above, and the liquid is acidic. Therefore, it cannot be reused for the next reaction and must be treated as wastewater.

The present inventors have made extensive studies to solve the above problems in producing diphenyl urea disulfinic acid or its salt represented by formula () by reacting sulfite with sulfochloride represented by formula (). As a result, they discovered that all of these problems could be solved by selecting specific conditions, and completed the present invention.

That is, the present invention provides the formula () The reaction between the sulfochloride and the sulfite represented by the formula is carried out while maintaining the pH at 7 to 10 by adding an alkali in the solvent, and the formula () is obtained. A reaction solution containing an alkali salt of diphenyl urea disulfinic acid represented by is obtained, and then the reaction solution is subjected to solid-liquid separation treatment either as it is or after cooling to obtain an alkali salt of diphenyl urea disulfinic acid, and the separated liquid phase is used next time. Provided is a method for producing a diphenyl urea compound, characterized in that the diphenyl urea compound is reused as a reaction solvent.

According to the method of the present invention, the crystal size of the alkali salt of diphenylurea disulfinic acid () is large enough to facilitate solid-liquid separation treatment on an industrial scale, and the separated liquid phase can be recycled as the next reaction solvent. Therefore, the target compound can be obtained industrially advantageously and in high yield.

The method of the present invention will be explained in detail below.

The symmetrical sulfochloride represented by the formula () is produced by various known methods, for example, by reacting diphenyl urea with chlorosulfonic acid, and bis-2,2'- or 3,3 ′−
Or 4,4'-urein dibenzene sulfochloride is exemplified.

Examples of the sulfite used in the method of the present invention include alkali salts of sulfite, such as lithium sulfite sodium sulfite, potassium sulfite, sodium hydrogen sulfite, potassium hydrogen sulfite, and ammonium sulfite. Among these, sodium sulfite is preferably used.

The sulfite is used in an amount of 2 to 5 moles per mole of the sulfochloride represented by the formula (), and when sodium sulfite is used as the sulfite, the amount used is preferably 2.1 to 4 moles.

Examples of reaction solvents include water, lower alcohols such as methanol and ethanol, ketones such as acetone, methyl ethyl ketone and methyl isobutyl ketone, halogenated aromatic hydrocarbons such as chlorobenzene and dichlorobenzene, methylene chloride, carbon tetrachloride, etc. ,2-dichloroethane,1,
Examples include aqueous solvents containing halogenated aliphatic hydrocarbons such as 1,2,2-tetrachloroethane and tetrachloroethylene, acetonitrile, dimethylformamide, dimethylsulfoxide, and the like.

Among these, water is preferably used. The mixing ratio of the organic solvent and water may be arbitrary.

The amount of the reaction solvent is 1.5 to 5 times the weight of the sulfochloride represented by formula ().

When water is used as a reaction solvent, the amount used is preferably 2 to 4 times the amount.

The reaction between the sulfochloride represented by the formula () and the sulfite is carried out in the air or under a nitrogen atmosphere, but it may also be carried out under increased pressure or reduced pressure.

The reaction temperature is in the range of 30°C to 60°C, preferably 35°C to 50°C.

The solvent required for the reaction is the whole or part of the liquid obtained by solid-liquid separation after the previous reaction.
If necessary, add new solvent to make up the specified volume.

As an embodiment of this reaction, for example, the reaction solvent and sulfite are charged in predetermined amounts and mixed, and then the sulfochloride represented by the formula () is added while maintaining the desired temperature, and the mixture is further kept warm.

Alternatively, after mixing the sulfochloride represented by the formula () with a predetermined amount of the reaction solvent, sulfite is added while maintaining the desired temperature, and the reaction is completed by further keeping the temperature.

No matter what form it is carried out, as the reaction progresses, add an alkaline substance as appropriate to keep the system in check.
The pH is constantly maintained in the PH range of 7 to 10, more preferably in the PH range of 7 to 9.

Any alkaline substance may be used as long as it can maintain the PHH within a predetermined range without causing side reactions, such as alkali metal hydroxides such as sodium hydroxide, e.g. sodium carbonate. Carbonates of alkali metals such as

The target product obtained by the method of the present invention is usually produced in the form of a salt, such as a sodium salt, but under the above reaction conditions, most of it is precipitated, or it is necessary to cool it after the reaction is completed. Most of it precipitates out, and since its crystal size is large, it can be easily recovered as it is by filtration or by solid-liquid separation operations such as centrifugal sedimentation.

In addition, most of the by-products, such as sodium disulfonate compounds, are dissolved, so even with the above separation procedure, most of them remain on the liquid side, and the target product, sodium disulfinate compounds, is separated at a high content. Refined.

Although the liquid phase still contains a small amount of the target product, the entire amount or most of it can be effectively utilized by reusing it in the next reaction.

EXAMPLES The present invention will be explained in detail below with reference to Examples, but the present invention is not limited to these Examples. Incidentally, in the examples, % and % represent parts by weight and % by weight, respectively.

Example 1 168 parts of recycled liquid with the following composition: Sodium disulfinate 0.5% Sodium sulfinate sulfonate
0.6% Sodium disulfonate 2.0% Inorganic salts 10.6% Water 86.3% Add 42 parts of water and 65 parts of sodium sulfite.
The temperature was raised to 40°C. While maintaining this temperature, screw 4,
70 parts of 4'-ureinbenzene sulfochloride (purity
88%) was added over 2 hours. During this time, a 28% caustic solution was added dropwise to maintain the pH of the reaction solution at 8. After the addition was completed, the mixture was kept at that temperature for an additional 5 hours.
The organic substance composition in the obtained reaction solution was 87% sodium bis-4,4'-ureinbenzene sulfinate, 6% sodium sulfinic acid-sulfonate compound,
The sodium disulfonate compound was 5%.

Most of the sodium disulfinate was precipitated, but the temperature was cooled to 30°C before over-separation. The crystal size of sodium disulfinate is approximately
The size was 300μ x 150μ.

A water wet cake containing sodium bis-4,4'-ureinbenzenedisulfinate was obtained by filtration.
97 copies were obtained. 97% of the sodium bis-4,4'-ureinbenzenesulfinate in the reaction solution was recovered in the water wet cake.

Example 2 432 parts of the same recycled liquid as in Example 1 and 108 parts of water
165 parts of sodium sulfite and 200 parts of bis4,4'-ureinbenzene sulfochloride wet cake (purity 90%) were mixed with 200 parts of bis4,4'-ureinbenzene sulfochloride wet cake (purity 90%) while keeping the temperature at 40°C.
Added over time. During this time, a 28% caustic solution was added dropwise to maintain the pH of the reaction solution at 8. After the addition was completed, the mixture was kept at that temperature for an additional 4 hours. The organic substance composition in the resulting reaction solution was 90% sodium bis-4,4'-ureinbenzenedisulfinate, 6% sodium sulfine sulfonate compound, and 3% sodium disulfonate compound.

By cooling to 30℃ and passing it through, screw 4,
250 parts of a water wet cake containing sodium 4'-ureinbenzenedisulfinate was obtained.

The solid content is 60% and the organic composition is bis4,4'-
Sodium ureinbenzenedisulfinate 96.0
%, sulfin-sulfonate sodium compound
3.5%, sodium disulfonate compound 0.3%.

95% of the sodium bis-4,4'-ureinbenzenedisulfinate in the reaction solution was recovered in the water wet cake.

Example 3 15 parts of water and 21 parts of sodium sulfite were added to 60 parts of the liquid obtained in Example 1, and the temperature was raised to 45°C. While maintaining this temperature, 50 parts of bis-4,4'-ureinbenzene sulfochloride (60% purity) was added over a period of 2 hours. During that time, the pH of the reaction solution was adjusted to 8.5.
28% caustic solution was added dropwise to maintain the temperature.

The organic composition in the obtained reaction solution was bis4,4'-
Sodium ureinbenzenedisulfinate 95
%, sulfin-sulfonate sodium compound 4
%, sodium disulfonate compound 1%. By cooling to 30℃ and passing through, screw 4,
56 parts of a water wet cake containing sodium 4'-ureinbenzenedisulfinate was obtained. 93% of the sodium bis-4,4'-ureinbenzenedisulfinate in the reaction solution was recovered in the water wet cake.

Claims (1)

[Claims] 1 Formula () The reaction between sulfochloride and sulfite represented by the formula is carried out while maintaining the pH between 7 and 10 by adding an alkali in the solvent, and the formula () is obtained. A reaction solution containing an alkali salt of diphenyl urea disulfinic acid expressed by A method for producing a diphenyl urea compound, which comprises reusing it as a reaction solvent. 2. Claim 1, wherein the amounts of the sulfite and the solvent used are 2 to 5 times the mole and 1.5 to 5 times the weight of the sulfochloride represented by the formula (), respectively.
Manufacturing method described in section. 3. The manufacturing method according to claim 1, wherein the solvent is water. 4. The manufacturing method according to claim 1, wherein the sulfite is sodium sulfite.