JP2018123064A - Method for producing dichloroglyoxime - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing dichloroglyoxime, which makes it possible to obtain dichloroglyoxime more safely and more efficiently, the oxime being used as an industrial bactericide, an antiseptic agent, a slime controlling agent, or the like.SOLUTION: Provided is a method for producing dichloroglyoxime which, in a method of producing dichloroglyoxime by a scheme represented by the following formula by reacting glyoxal and hydroxylamine, followed by chlorination, comprises the steps of: adding a water-immiscible, low-boiling point organic solvent; adding 20 to 90% of water after chlorination to make the mixture separate into two layers and, thereafter, separating the organic layer; and removing the water-immiscible, low-boiling point organic solvent from the organic layer.SELECTED DRAWING: None

Description

  The present invention relates to a method for producing dichloroglyoxime used as an industrial disinfectant, preservative, slime control agent, etc. safely and more efficiently than before.

  Conventionally, dichloroglyoxime is known to be used as an excellent active ingredient such as industrial bactericides, preservatives, slime control agents (Patent Document 1).

And as a manufacturing method of dichloroglyoxime (Dichloroglyoxime), it is common to produce | generate glyoxime (Glyoxime) from glyoxal (Glyoxal), and to chlorinate this (Formula I). For example, in Patent Document 2, an aqueous solution of glyoxal and hydroxylamine hydrochloride are mixed by adding water, sodium carbonate is added as an alkali to form glyoxime, isolated as crystals, dissolved in ethanol,- A method for obtaining dichloroglyoxime by blowing chlorine at 20 ° C. is disclosed.

  However, this method treats at least the intermediate glyoxime as a crystal, but the glyoxime crystal tends to explode due to mechanical impact and friction, and is extremely dangerous. In the method of Patent Document 2, dichloroglyoxime is obtained only by blowing chlorine into a solution of 17.6 g of glyoxime in 200 ml of ethanol in a short time of 30 minutes while maintaining -20 ° C. This is obviously unsuitable for large-scale production.

  On the other hand, in Patent Document 3, an organic solvent having a boiling point higher than that of water is added to a glyoxime reaction solution obtained by reacting an aqueous solution of glyoxal with an inorganic acid salt of hydroxylamine or an organic acid salt with an alkali, and water is removed by distillation. An organic solvent having a boiling point higher than that of water in a glyoxime solution (or a glyoxime reaction solution obtained by reacting a glyoxal aqueous solution with an acidic hydroxylamine aqueous solution under acidic conditions) And the chlorinating agent is reacted while maintaining the ratio (molar ratio) of glyoxime: chlorinating agent = 1: 2 to 1: 4. A method is disclosed in which a dichloroglyoxime organic solvent solution is efficiently obtained in a high yield by being simultaneously injected into a container and reacted. By this method, industrial mass production of dichloroglyoxime organic solvent solution has been realized.

  However, in the method of Patent Document 3, it is necessary to remove a large amount of water by distillation, and in order to prevent decomposition and coloring of the intermediate glyoxime, distillation must be performed at a low temperature under reduced pressure. Power and energy costs and work hours are forced.

  Further, after completion of chlorination, dissolved hydrogen chloride by-produced by the reaction of glyoxime and chlorinating agent must be removed from the dichloroglyoxime organic solvent reaction solution under a high vacuum, for example, dichloroglyoxime 10 When 2 tons of a 1% diethylene glycol monomethyl ether solution is produced, enormous work time is required, for example, it takes 3 to 7 days to remove hydrogen chloride in this final step. In addition, when removing hydrogen chloride under high vacuum, part of the hydrogen chloride passes through the alkali trap and corrodes the parts related to the airtightness of the vacuum pump, and the capacity of the vacuum pump is reduced or its life is significantly impaired. The problem is also serious. That is, in terms of production efficiency, improvement of a method for removing by-product hydrogen chloride is a major issue.

Japanese Patent Laid-Open No. 7-2601 U.S. Pat. No. 4,539,405 Japanese Unexamined Patent Publication No. 7-33728

  The object of the present invention is to produce dichloroglyoxime, which solves the above-mentioned problems and can obtain dichloroglyoxime used as an industrial disinfectant, preservative, slime control agent, etc. more safely and efficiently. Is to provide a method.

In order to solve the above-mentioned problems, the present inventors have intensively studied and, as a result, based on the method for producing a dichloroglyoxime organic solvent solution described in Patent Document 3, a step of containing a water-immiscible low-boiling organic solvent; Adding 20 to 90% of water after completion of chlorination, separating the two layers, and separating the organic layer and removing the water-miscible low boiling point organic solvent from the organic layer Thus, it has been found that dichloroglyoxime can be produced more safely and more efficiently than the conventional method, and the present invention has been completed.

That is, the configuration of the present invention is as follows.
(1) Glyoxal is reacted with hydroxylamine or a salt thereof to prepare a glyoxime solution containing a water-miscible organic solvent, and the glyoxime solution and the chlorinating agent are simultaneously injected into the reaction vessel to react. A method for producing dichloroglyoxime, which comprises the following steps.
(A) A step of containing a low-boiling organic solvent that is immiscible with water and has a boiling point at 760 mmHg of 200 ° C. or lower.
(B) The water content in the reaction vessel after completion of chlorination is adjusted to 20 to 90% by weight in the reaction mixture, and the organic layer and the aqueous layer are separated into two layers, and then the organic layer is separated. Process.
(C) A step of removing the low-boiling organic solvent (a) from the organic layer (b).
(2) The glyoxime solution is characterized by containing a water-miscible organic solvent in a glyoxime reaction solution obtained by reacting a glyoxal aqueous solution with a hydroxylamine inorganic acid salt or organic acid salt and an alkali. The method for producing dichloroglyoxime according to (1) above.
(3) In the above (1), the glyoxime solution is a glyoxime reaction solution obtained by reacting a glyoxal aqueous solution with hydroxylamine under acidity and containing a water-miscible organic solvent. The manufacturing method of the dichloroglyoxime of description.
(4) A glyoxime solution containing a water-miscible organic solvent having a boiling point higher than that of water was added to a glyoxime reaction solution obtained by reacting a glyoxal aqueous solution with a hydroxylamine inorganic acid salt or organic acid salt and an alkali. The method for producing dichloroglyoxime according to (1) above, wherein water is removed by distillation, and then the precipitated salt is removed by filtration.
(5) After the glyoxime solution contained a water-miscible organic solvent having a boiling point higher than water in the glyoxime reaction solution obtained by reacting the aqueous solution of glyoxal with hydroxylamine under acidic conditions, water was removed by distillation. The method for producing dichloroglyoxime according to (1) above, wherein
(6) The glyoxime solution contains a water-miscible organic solvent in a glyoxime reaction solution obtained by reacting a glyoxal aqueous solution with a hydroxylamine inorganic acid salt or organic acid salt and an alkali, and then the above (1) The method for producing dichloroglyoxime according to (1) above, which is an organic layer obtained by liquid-liquid extraction (separation) with the low-boiling organic solvent described in (a).
(7) After the glyoxime solution contains a water-miscible organic solvent in the glyoxime reaction solution obtained by reacting the aqueous solution of glyoxal with hydroxylamine under acidic conditions, the low boiling point described in the above (1) (a) The method for producing dichloroglyoxime according to (1) above, which is an organic layer obtained by liquid-liquid extraction (separation) with an organic solvent.
(8) The method for producing dichloroglyoxime according to any one of (1) to (7) above, wherein the chlorinating agent is chlorine or sulfuryl chloride.

  According to the present invention, it is possible to produce dichloroglyoxime more safely and efficiently while saving time and energy as compared with the conventional method.

  Hereinafter, the manufacturing method of the dichloroglyoxime of this invention is demonstrated in detail.

  First, the oximation reaction in the present invention will be described. One raw material glyoxal used for the oximation is usually supplied as a 40% aqueous solution. As the other raw material hydroxylamine, a commercially available hydroxylamine hydrochloride, an inorganic acid salt such as sulfate or nitrate, or an organic acid salt such as acetate may be used, or free hydroxylamine may be used. When using a commercially available inorganic acid salt or organic acid salt of hydroxylamine, a free hydroxylamine aqueous solution is prepared by neutralizing with alkali at the time of use. This neutralization reaction is performed simultaneously with the oximation reaction. That is, an oxime reaction is carried out while neutralizing with an aqueous solution or solid of an alkali such as sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate in a hydroxylamine inorganic acid salt or organic acid salt aqueous solution and a 40% glyoxal aqueous solution. Do. After the reaction, part of the glyoxime is dissolved in water and is obtained in the form of a suspension.

  When using free hydroxylamine, a commercially available 50% hydroxylamine aqueous solution (manufactured by BASF, etc.) is mixed with 40% glyoxal aqueous solution under acidic conditions with hydrochloric acid to prevent polymerization, and the same as described above. In addition, the glyoxime after the reaction is obtained in the form of a suspension.

  In the method disclosed in Patent Document 2, after the reaction, the reaction solution is filtered to separate solids, which are washed and dried to obtain glyoxime crystals. However, this crystal has a risk of explosion due to mechanical shock and friction. In the filtrate, the glyoxime of the target product inevitably partially escapes together with the inorganic salt, resulting in a decrease in yield. Therefore, the present invention employs a method of obtaining a glyoxime solution by adding a water-miscible organic solvent to the glyoxime suspension, as in the following method.

<Method 1> By adding a water-miscible organic solvent to the glyoxime reaction solution obtained by reacting an aqueous solution of glyoxal with an inorganic acid salt of hydroxylamine or an organic acid salt and an alkali before or after the reaction. A method for obtaining a glyoxime solution.
<Method 2> A method for obtaining a glyoxime solution by adding a water-miscible organic solvent to a glyoxime reaction solution obtained by reacting an aqueous glyoxal solution with hydroxylamine under acidity before or after the reaction.
<Method 3> A water-miscible organic solvent having a boiling point higher than water is added to a glyoxime reaction solution obtained by reacting an aqueous solution of glyoxal with an inorganic acid salt of hydroxylamine or an organic acid salt and an alkali before or after the reaction. And then removing the water by distillation, and then removing the precipitated salt by filtration to obtain a glyoxime solution.
<Method 4> A water-miscible organic solvent having a boiling point higher than that of water is added to a glyoxime reaction solution obtained by reacting an aqueous glyoxal solution with hydroxylamine under acidity before or after the reaction, and then distilled. To obtain a glyoxime solution by removing water.
<Method 5> A water-miscible organic solvent was added to the glyoxime reaction solution obtained by reacting an aqueous solution of glyoxal with an inorganic acid salt or hydroxyl acid salt of hydroxylamine and an alkali before or after the reaction. Thereafter, a liquid-liquid extraction (separation) is performed with a water-immiscible low-boiling organic solvent to obtain a glyoxime solution as an organic layer.
<Method 6> A water-miscible organic solvent is added to a glyoxime reaction solution obtained by reacting an aqueous glyoxal solution with hydroxylamine under acidity before or after the reaction. A method for obtaining a glyoxime solution as an organic layer by liquid-liquid extraction (separation) with a boiling organic solvent.

In the present invention, examples of the water-miscible organic solvent used in the methods 1 to 6 for obtaining the glyoxal solution include the following.
Ethylene glycol type: For example, ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, 2-methoxyethanol, 2-ethoxyethanol, 2-methoxyethyl acetate, 2-ethoxyethyl acetate, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol Examples include dimethyl ether, diethylene glycol diethyl ether, diethylene glycol monomethyl ether acetate, and diethylene glycol monoethyl ether acetate.

  Propylene glycol type: For example, propylene glycol, dipropylene glycol, tripropylene glycol, polypropylene glycol, 2-methoxypropanol, 2-ethoxypropanol, 2-methoxypropyl acetate, 2-ethoxypropyl acetate, dipropylene glycol monomethyl ether, dipropylene Examples include glycol monoethyl ether, dipropylene glycol dimethyl ether, dipropylene glycol diethyl ether, dipropylene glycol monomethyl ether acetate, and dipropylene glycol monoethyl ether acetate.

  Alkanol type: For example, methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, isobutanol, tertiary butanol, pentanol, hexanol, heptanol, octanol, nonanol, decanol, dodecanol and the like can be mentioned. .

  Others: Amides such as N, N-dimethylformamide and N, N-dimethylacetamide, pyrrolidones such as N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone and N-octylpyrrolidone, and dimethyl sulfoxide It is done.

  Of these water-miscible organic solvents, when it is desired to obtain the final dichloroglyoxime in the form of an organic solvent solution, a water-miscible organic solvent having a boiling point higher than that of water is preferably used. Preferably, diethylene glycol monomethyl is used. Ether, diethylene glycol monoethyl ether or diethylene glycol may be used.

  In addition, when it is necessary to obtain the final dichloroglyoxime as crystals, a water-miscible organic solvent having a relatively low boiling point such as methanol, ethanol or 2-propanol can be used.

  In the above method 5 or 6, the boiling point of the water-immiscible low-boiling organic solvent used for liquid-liquid extraction (separation) after the water-miscible organic solvent is contained in the glyoxime reaction solution is 760 mmHg. The boiling point should be 200 ° C. or lower, and preferably 150 ° C. or lower. Examples of such low boiling point organic solvents include benzene, toluene, xylene, carbon tetrachloride, chloroform, dichloromethane, 1,2-dichloroethane, diethyl ether, octanol, ethyl acetate, propyl acetate, butyl acetate, and carbon disulfide. Preferably, it is good to use ethyl acetate and chloroform more preferably.

  When performing liquid-liquid extraction (separation) with a water-immiscible low-boiling organic solvent in method 5 or 6, an appropriate amount of salt such as sodium chloride or potassium chloride is added to improve extraction efficiency. Then, salting out may be performed.

  In the above method 5 or 6, the glyoxime solution obtained as an organic layer after liquid-liquid extraction (separation) may be used for the next chlorination reaction as it is, and a dehydrating agent such as anhydrous sodium sulfate or magnesium sulfate is used. The chlorination reaction may be carried out after dehydration.

  Next, the chlorination of the glyoxime solution obtained above and the subsequent treatment will be described.

  In the method of the present invention, a molar ratio of the glyoxime solution prepared by the oximation and the chlorinating agent is 1: 2 or more in a reaction vessel such as a reaction vessel equipped with a stirrer and a cooling device according to the cooling capacity. It is recommended to inject at the same time. At this time, one or both of them are intermittently injected while maintaining the molar ratio of 1: 2 or more within a short limited time. The injection molar ratio of the glyoxime solution and the chlorinating agent is preferably 1: 2 to 1: 4. The reaction temperature is +20 to −20 ° C., preferably +10 to −10 ° C.

  Next, post-treatment of the dichloroglyoxime reaction solution after completion of chlorination will be described.

  When the glyoxime solution obtained in the methods 1 to 4 for obtaining a glyoxime solution is used, a water-immiscible low-boiling organic solvent is added to the dichloroglyoxime reaction solution and sufficiently stirred and mixed. The water-immiscible low-boiling organic solvent used at this time has a boiling point at 760 mmHg of 200 ° C. or lower, preferably 150 ° C. or lower. Examples of such low boiling point organic solvents include benzene, toluene, xylene, carbon tetrachloride, chloroform, dichloromethane, 1,2-dichloroethane, diethyl ether, octanol, ethyl acetate, propyl acetate, butyl acetate, and carbon disulfide. Preferably, it is good to use ethyl acetate and chloroform more preferably. In addition, when using the glyoxime solution obtained in the methods 5 and 6 for obtaining the glyoxime solution, the water-immiscible low boiling point organic solvent is already contained in the dichloroglyoxime reaction solution, so the amount added accordingly Or the addition thereof can be omitted.

  Subsequently, water is added and adjusted so that the water content in the dichloroglyoxime reaction solution in the reaction vessel is in the range of 20 to 90% by weight, preferably in the range of 30 to 80% by weight in the reaction mixture. . At this time, an appropriate amount of salt such as sodium chloride or potassium chloride may be added to promote the salting out effect. Thereafter, two layers are separated into an organic layer and an aqueous layer, and the organic layer is separated. Since most of the hydrogen chloride by-produced by chlorination of glyoxime is transferred to the aqueous layer, the residual hydrogen chloride in the organic layer containing dichloroglyoxime is considerably reduced. Moreover, the yield of dichloroglyoxime can also be improved by further adding the above-mentioned water-immiscible low-boiling organic solvent to the aqueous layer and performing liquid-liquid extraction (separation). Thereafter, the separated organic layer can be dehydrated with a dehydrating agent such as anhydrous sodium sulfate or anhydrous magnesium sulfate.

  Subsequently, by removing the low-boiling organic solvent from the organic layer under reduced pressure, when a low-boiling water-miscible organic solvent is used, the dichloroglyoxime crystals are converted into a water-miscible organic solvent having a boiling point higher than that of water. When is used, an organic solvent solution of dichloroglyoxime can be obtained. At this time, when it is desired to further reduce the water content, the water may be removed at a low temperature under reduced pressure.

  EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated in detail, this invention is not limited only to a following example. In the following description, “part” means part by mass.

<Example 1>
A 300 ml four-necked flask is charged with 32.8 g (0.2 mol) of hydroxyammonium sulfate, 29 g (0.2 mol) of 40% aqueous glyoxal solution, and 35 g of water. 45.9 g (0.4 mol) of an aqueous sodium solution was added dropwise. After stirring and aging overnight, 150 g of ethanol was added and stirred until uniform to obtain 290 g of a yellow glyoxime ethanol (water-containing) solution. In a 1-liter four-necked flask, 70 g of ethanol is added, and the ethanol (water-containing) solution of glyoxime and chlorine is added at −5 to 0 ° C. so that the injection molar ratio of glyoxime and chlorine in the solution is 1: 3. Were injected simultaneously. After completion of the reaction, 200 g of ethyl acetate was added and stirred, and then 120 g of 5% brine was added and stirred. After the stirring was stopped, when the reaction mixture solution separated into two layers, the organic layer (upper layer) was separated. 10 g of anhydrous sodium sulfate was added to the separated organic layer, dehydrated for about 1 hour, filtered through 5A filter paper, and ethyl acetate and ethanol in the filtrate were distilled off under reduced pressure to obtain 22 g of a white solid. . When the dichloroglyoxime content was analyzed by the HPLC method, it was 95.2% (yield: 66.7%). Since the hydrogen chloride odor was not felt from the white solid of dichloroglyoxime, the by-produced hydrogen chloride was sufficiently removed. The time required to obtain a white solid of dichloroglyoxime after completion of the chlorination reaction was about 2.5 hours.

<Example 2>
To a 300 ml four-necked flask, 29 g (0.2 mol) of 40% aqueous glyoxal solution, 0.35 g of concentrated hydrochloric acid and 105 g of ethanol are added, and 26.4 g (0.4 mol) of 50% aqueous hydroxylamine solution is added dropwise at 20 ° C. did. After stirring and aging overnight, 160 g of a yellow glyoxime ethanol (water-containing) solution was obtained. In a 1-liter four-necked flask, 70 g of ethanol is added, and the ethanol (water-containing) solution of glyoxime and chlorine is added at −5 to 0 ° C. so that the injection molar ratio of glyoxime and chlorine in the solution is 1: 3. Were injected simultaneously. After completion of the reaction, 200 g of ethyl acetate was added and stirred, and then 170 g of 10% brine was added and stirred. After the stirring was stopped, when the reaction mixture solution separated into two layers, the organic layer (upper layer) was separated. 10 g of anhydrous sodium sulfate was added to the separated organic layer, dehydrated for about 1 hour, filtered through 5A filter paper, and ethyl acetate in the filtrate was distilled off under reduced pressure to obtain 26 g of a white solid. When the dichloroglyoxime content was analyzed by HPLC, it was 94.0% (yield: 77.8%). Since the hydrogen chloride odor was not felt from the white solid of dichloroglyoxime, the by-produced hydrogen chloride was sufficiently removed. At this time, it took about 2.5 hours to obtain a white solid of dichloroglyoxime after completion of the chlorination reaction.

<Example 3>
A 300 liter glass-lined reaction kettle is charged with 32.8 kg (200 mol) of hydroxyammonium sulfate, 29.0 kg (200 mol) of 40% aqueous glyoxal solution, and 35.0 kg of water. 45.9 kg (400 mol) of an aqueous sodium oxide solution was added dropwise. After stirring and aging overnight, 130 kg of diethylene glycol monomethyl ether was added, and water was distilled off under reduced pressure (internal temperature: 60 ° C. or lower). After cooling to 10 ° C. or lower, the precipitated sodium sulfate crystals were filtered under reduced pressure. The crystals were washed with 20.0 kg of diethylene glycol monomethyl ether, and the filtrate and the washings were combined to give a brown glyoxime diethylene glycol monomethyl solution of 147.3 kg. Got. 70.0 kg of diethylene glycol monomethyl ether is put into a 1000 liter glass-lined reaction kettle, and the molar ratio of glyoxime and chlorine in the solution of glyoxime and diethylene glycol monomethyl ether solution and chlorine is 1: 3 at 5 ° C. or lower. Were injected at the same time. After completion of the reaction, 200 kg of ethyl acetate was added and stirred, and then 200 kg of 5% brine was added and stirred. After the stirring was stopped, when the reaction mixture solution separated into two layers, the organic layer (upper layer) was separated. Ethyl acetate in the organic layer was distilled off under reduced pressure to obtain 160 kg of a pale yellow transparent solution. When the dichloroglyoxime content was analyzed by the HPLC method, it was 18.1% (yield: 92.2%). The pH of this dichloroglyoxime solution (1% purified aqueous solution) was 2.4, and hydrogen chloride produced as a by-product was sufficiently removed. At this time, it took about 3 hours to obtain a pale yellow transparent solution after completion of the chlorination reaction.

<Example 4>
To a 300 liter glass-lined reaction kettle, 29.0 kg (200 mol) of 40% glyoxal aqueous solution, 0.35 kg of concentrated hydrochloric acid and 105 kg diethylene glycol monomethyl ether were added, and 26.4 kg (400 mol) of 50% hydroxylamine aqueous solution was added at 20 ° C. It was dripped. After stirring and aging overnight, water was distilled off under reduced pressure (internal temperature: 60 ° C. or lower). 125 kg of a diethylene glycol monomethyl solution of brown glyoxime was obtained. Into a 1000 liter glass-lined reaction kettle, 70 kg of diethylene glycol monomethyl ether is put, and the diethylene glycol monomethyl ether solution of glyoxime and chlorine are added at 5 ° C. or less so that the molar ratio of glyoxime and chlorine in the solution is 1: 3. Injected simultaneously. After the reaction for 10 hours, 200 kg of ethyl acetate was added and stirred, and then 200 kg of 10% brine was added and stirred. After the stirring was stopped, when the reaction mixture solution separated into two layers, the organic layer (upper layer) was separated. Ethyl acetate in the organic layer was distilled off under reduced pressure to obtain 142 kg of a pale yellow transparent solution. When the dichloroglyoxime content was analyzed by the HPLC method, it was 20.0% (yield: 90.4%). The pH of this dichloroglyoxime solution (1% purified aqueous solution) was 2.3, and hydrogen chloride produced as a by-product was sufficiently removed. At this time, it took about 3 hours to obtain a pale yellow transparent solution after completion of the chlorination reaction.

<Example 5>
A 300 ml four-necked flask is charged with 32.8 g (0.2 mol) of hydroxyammonium sulfate, 29 g (0.2 mol) of 40% aqueous glyoxal solution, and 35 g of water. 45.9 g (0.4 mol) of an aqueous sodium solution was added dropwise. After stirring and aging overnight, 70 g of diethylene glycol monomethyl ether was added, and then the glyoxime white solid precipitated was dissolved while stirring. Further, 7 g of sodium chloride was added, and 70 g of ethyl acetate was added for extraction. The organic layer (upper layer) was separated to obtain 105 g of a pale yellow glyoxime ethyl acetate / diethylene glycol monomethyl ether solution (hereinafter also referred to as glyoxime solution). When this glyoxime solution was analyzed for glyoxime content by HPLC, it was 11% (yield: 65.6%).
Into a 1 liter four-necked flask, 40 g of diethylene glycol monomethyl ether is added, and the glyoxime solution and chlorine are simultaneously injected at −5 to 0 ° C. so that the injection molar ratio of glyoxime and chlorine in the solution is 1: 3. did. After completion of the reaction, 70 g of 10% brine was added and stirred. After the stirring was stopped, when the reaction mixture solution separated into two layers, the organic layer (upper layer) was separated. 10 g of anhydrous sodium sulfate was added to the separated organic layer, dehydrated for about 1 hour, filtered through 5A filter paper, and ethyl acetate in the filtrate was distilled off under reduced pressure to obtain 107 g of a pale yellow liquid. When the dichloroglyoxime content was analyzed by HPLC, it was 17.7% (yield from starting material: 60.1%). The pH of this dichloroglyoxime solution (1% purified aqueous solution) was 2.5, and the by-produced hydrogen chloride was sufficiently removed. The time required to obtain a white solid of dichloroglyoxime after completion of the chlorination reaction was about 2.5 hours.

<Example 6>
To a 300 ml four-necked flask, 29 g (0.2 mol) of 40% glyoxal aqueous solution, 0.35 g of concentrated hydrochloric acid and 70 g of diethylene glycol monomethyl ether were added, and 26.4 g (0.4 mol) of 50% aqueous hydroxylamine solution at 20 ° C. Was dripped. After stirring and aging overnight, 7 g of sodium chloride was added, and 70 g of ethyl acetate was added for extraction. The organic layer (upper layer) was separated to obtain 101 g of a pale yellow glyoxime solution in ethyl acetate / diethylene glycol monomethyl ether (hereinafter also referred to as glyoxime solution). When the glyoxime content of this glyoxime solution was analyzed by HPLC, it was 11.8% (yield: 67.5%). 40 g of diethylene glycol monomethyl ether was placed in a 1 liter four-necked flask, and -5 to The glyoxime solution and chlorine were simultaneously injected at 0 ° C. so that the injection molar ratio of glyoxime and chlorine in the solution was 1: 3. After completion of the reaction, 70 g of 10% brine was added and stirred. After the stirring was stopped, when the reaction mixture solution separated into two layers, the organic layer (upper layer) was separated. 10 g of anhydrous sodium sulfate was added to the separated organic layer, dehydrated for about 1 hour, filtered through 5A filter paper, and ethyl acetate in the filtrate was distilled off under reduced pressure to obtain 102 g of a pale yellow liquid. When the dichloroglyoxime content was analyzed by HPLC, it was 18.3% (yield from starting material: 59.4%). The pH of this dichloroglyoxime solution (1% purified aqueous solution) was 2.6, and the by-produced hydrogen chloride was sufficiently removed. The time required to obtain a white solid of dichloroglyoxime after completion of the chlorination reaction was about 2.5 hours.

<Comparative Example 1>
A 300 ml four-necked flask is charged with 32.8 g (0.2 mol) of hydroxyammonium sulfate, 29 g (0.2 mol) of 40% aqueous glyoxal solution, and 35 g of water. 45.9 g (0.4 mol) of an aqueous sodium solution was added dropwise. After stirring and aging overnight, 100 g of diethylene glycol monomethyl ether was added, and water was distilled off under reduced pressure using a rotary evaporator. The precipitated sodium sulfate crystals were filtered off with 5A filter paper, the crystals on the filter paper were washed with 64 g of diethylene glycol monomethyl ether, and the filtrate and the washing solution were combined to obtain a diethylene glycol monomethyl solution of brown glyoxime. Into a 500 ml four-necked flask, 60 g of diethylene glycol monomethyl ether is placed, and the diethylene glycol monomethyl ether solution of glyoxime and chlorine are added at −5 to 0 ° C. so that the injection molar ratio of glyoxime and chlorine in the solution becomes 1: 3. Were injected simultaneously. After completion of the reaction, by-product hydrogen chloride was deaerated under reduced pressure using a vacuum pump until the reaction mixture did not emit smoke to obtain 251 g of a pale yellow liquid. When the dichloroglyoxime content was analyzed by the HPLC method, it was 11.0% (yield: 87.9%). The pH of this dichloroglyoxime solution (1% purified aqueous solution) was 2.2 and hydrogen chloride produced as a by-product was sufficiently removed. However, after completion of the chlorination reaction, hydrogen chloride was sufficiently removed (hydrogen chloride). It took about 36 hours to obtain a light yellow liquid of dichloroglyoxime (without smoking). In addition, problems such as clogging of the alkali trap during deaeration and reduction of the suction capacity of the vacuum pump due to hydrogen chloride that could not be captured by the alkali trap were observed.

<Comparative example 2>
To a 300 liter glass-lined reaction kettle, 29.0 kg (200 mol) of 40% glyoxal aqueous solution, 0.35 kg of concentrated hydrochloric acid and 105 kg diethylene glycol monomethyl ether were added, and 26.4 kg (400 mol) of 50% hydroxylamine aqueous solution was added at 20 ° C. It was dripped. After stirring and aging overnight, water was distilled off under reduced pressure (internal temperature: 60 ° C. or lower). 125 kg of a diethylene glycol monomethyl solution of brown glyoxime was obtained. In a 300 liter glass-lined reaction kettle, 70 kg of diethylene glycol monomethyl ether is put, and the diethylene glycol monomethyl ether solution of glyoxime and chlorine at −5 to 0 ° C. The injection molar ratio of glyoxime and chlorine in the solution becomes 1: 3. Were injected at the same time. After the reaction for 10 hours, the dissolved hydrogen chloride was deaerated under reduced pressure using a vacuum pump until the reaction mixture no longer smoked to obtain 250 kg of a pale yellow liquid. When the dichloroglyoxime content was analyzed by HPLC, it was 11.1% (yield: 88.4%). The pH of this dichloroglyoxime solution (1% purified aqueous solution) was 2.1, and the hydrogen chloride produced as a by-product was sufficiently removed. However, after the chlorination reaction was completed, the hydrogen chloride was sufficiently removed (hydrogen chloride). It took about 5 days to obtain a light yellow liquid of dichloroglyoxime (without smoking). During the deaeration work, problems such as clogging of the alkali trap and a decrease in the suction capacity of the vacuum pump, which seems to be caused by hydrogen chloride that could not be captured by the alkali trap, were observed.

  In Examples 1 to 6, the time for dehydrochlorination after the chlorination reaction is remarkably shortened as compared with Comparative Example 1 or 2, and dichloroglyoxime or an organic solvent solution of dichloroglyoxime can be obtained efficiently. You can see that

The present invention relates to a method for safely and more efficiently producing dichloroglyoxime used as an industrial disinfectant, preservative, slime control agent, etc., and harmful microorganisms such as water treatment and paper industry are problematic. It is used in the industrial field. In particular, in the present invention, the time for completing the production of dichloroglyoxime can be significantly shortened, and dichloroglyoxime can be produced efficiently.

Claims (8)

Dichloroglyoxime is prepared by reacting glyoxal with hydroxylamine or a salt thereof to prepare a glyoxime solution containing a water-miscible organic solvent, and simultaneously injecting the glyoxime solution and the chlorinating agent into a reaction vessel. A process for producing dichloroglyoxime comprising the following steps:
(A) A step of containing a low-boiling organic solvent that is immiscible with water and has a boiling point at 760 mmHg of 200 ° C. or lower.
(B) The water content in the reaction vessel after completion of chlorination is adjusted to 20 to 90% by weight in the reaction mixture, and the organic layer and the aqueous layer are separated into two layers, and then the organic layer is separated. Process.
(C) A step of removing the low-boiling organic solvent (a) from the organic layer (b).   The glyoxime solution is characterized by containing a water-miscible organic solvent in a glyoxime reaction solution obtained by reacting a glyoxal aqueous solution with an hydroxyl acid inorganic acid salt or organic acid salt and an alkali. The manufacturing method of the dichloroglyoxime of Claim 1.   2. The dichloroglycol solution according to claim 1, wherein the glyoxime solution is a glyoxime reaction solution obtained by reacting an aqueous solution of glyoxal with hydroxylamine under acidity and containing a water-miscible organic solvent. A method for producing oximes.   The glyoxime solution contains a water-miscible organic solvent having a boiling point higher than that of water in a glyoxime reaction solution obtained by reacting an aqueous glyoxal solution with hydroxylamine inorganic acid salt or organic acid salt and alkali, followed by distillation. The method for producing dichloroglyoxime according to claim 1, wherein water is removed by filtration, and then the precipitated salt is removed by filtration.   The glyoxime solution is obtained by adding water-miscible organic solvent having a boiling point higher than water to a glyoxime reaction solution obtained by reacting an aqueous solution of glyoxal with hydroxylamine under acidity, and then removing water by distillation. The method for producing dichloroglyoxime according to claim 1.   The glyoxime solution contains a water-miscible organic solvent in a glyoxime reaction solution obtained by reacting an aqueous solution of glyoxal with an inorganic acid salt of hydroxylamine or an organic acid salt with an alkali. The method for producing dichloroglyoxime according to claim 1, which is an organic layer obtained by liquid-liquid extraction (separation) with the low-boiling organic solvent described above.   The glyoxime solution contains a water-miscible organic solvent in a glyoxime reaction solution obtained by reacting an aqueous glyoxal solution with hydroxylamine under acidity, and then the liquid is added with the low-boiling organic solvent according to claim 1 (a). The method for producing dichloroglyoxime according to claim 1, which is an organic layer obtained by liquid extraction (separation).   The method for producing dichloroglyoxime according to any one of claims 1 to 7, wherein the chlorinating agent is chlorine or sulfuryl chloride.