JPH0517430A - Drying method of benzenesulfonamide derivative - Google Patents

Abstract

PURPOSE:To substantially mitigate the load on the drying equipment for the subject compound by injecting steam into a wet form of a benzenesulfonamide derivative produced, followed by making a drying operation. CONSTITUTION:Steam at <=150 deg.C is injected into a wet form of a compound of formula I (R<1>-R<4> are each H, 1-4C alkyl, 1-4C alkylthio, F, Ci, CF3 or SCF3), for example, N-(2-chloro-4-nitrophenyl)-3-methylbenzenesulfonamide produced through its production process to replace or evaporate the solvent contained to raise the solid content of the wet form, followed by drying the form through vacuum drying, aeration drying, air stream drying or fluidization drying technique. The compound of the formula I can be obtained by condensation between a benzenesulfonyl chloride of formula II and an aniline of formula III in an organic solvent in the presence of a basic substance. After completion of the reaction, if necessary, a diluting solvent is added to the reaction liquor and then cooled to effect deposition of the compound of the formula I, which is then put to solid/liquid separation and subjected to the above drying process.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to an improved method for drying benzenesulfonamide derivatives. More specifically, the present invention provides a method for shortening the time and efficiently drying.

[0002]

2. Description of the Related Art JP-A-61-1197553, 61-2
No. 00959, 61-200960, 61-2052.
47, 61-205248, or JP-A-2-21.
Certain compounds of the benzenesulfonamide series are useful as agricultural fungicides, such as those found in 2467, 2-231465, and the like.

In particular, the following equations (4) (formula 5), (5)
(Chemical formula 6)

[0004]

[Chemical 5]

[0005]

[Chemical 6]

N- (2-chloro-4-nitrophenyl) -3-methylbenzenesulfonamide and N-
(2-chloro-4-nitrophenyl) -4-chloro-3
-Trifluoromethylbenzenesulfonamide is known to be a compound showing a very excellent effect against root-knot disease fungi occurring on cross vegetables such as cabbage and Chinese cabbage.

By the way, a method for producing a benzenesulfonamide derivative is generally based on a condensation reaction between corresponding benzenesulfonyl chlorides and anilines. More specifically, JP-A-61-197553 and JP-A-63-5756.
As shown in No. 5, benzenesulfonyl chlorides and anilines are heated and reacted in a solvent inert to the reaction in the presence of a basic substance such as pyridine to produce benzenesulfonylanilides. The benzenesulfonamide produced in the reaction is usually cooled by directly cooling the reaction solution or by adding a diluting solvent and then cooling to precipitate the benzenesulfonamide. The precipitated benzenesulfonamide is separated by solid-liquid separation operation, and the obtained wet body is washed with a solvent and then made into a product through a drying operation such as vacuum drying, aeration drying, air stream drying, or fluidized drying. .

[0008]

In this operation, the wetted benzenesulfonamide derivative obtained before the drying operation usually contains 30 to 50% of the solvent. Therefore, it took a long time to dry the benzenesulfonamide derivative.

[0009]

DISCLOSURE OF THE INVENTION The present inventors have studied to shorten the drying time, that is, to reduce the content of the solvent contained in the benzenesulfonamide derivative. as a result,
Focusing on the fact that benzenesulfonamide derivatives generally have a high melting point and almost no solubility in water, the moisture content is replaced by aeration or evaporation of the solvent contained in the wet body to change the solid content of the wet body. The inventors have found that it can be increased and reached the present invention. That is, the present invention provides formula (1)

[0010]

[Chemical 7]

[In the formula, R ¹ , R ² , R ³ and R ⁴ are each independently a hydrogen atom, an alkyl group having 1 to 4 carbon atoms or an alkylthio group, a fluorine atom, a chlorine atom, a nitro group, a cyano group, and a trialkyl group. A fluoromethyl group or a trifluoromethylthio group is shown. ] It is a benzene sulfonamide derivative represented by these.

As described above, the benzenesulfonamide derivative of the formula (1) used in the method of the present invention is usually a condensation reaction of corresponding benzenesulfonyl chlorides and anilines in the presence of a basic substance in an organic solvent. It can be obtained by carrying out, but it may be one produced by a reaction using another raw material. After the reaction, the reaction solution is diluted with a diluting solvent if necessary and then cooled to precipitate crystals of a benzenesulfonamide derivative.

As the solvent used in the reaction, aromatic hydrocarbons such as toluene, xylene, chlorobenzene and o-dichlorobenzene can be used, and as the diluting solvent, the above solvents, alcohols such as methanol and ethanol, and water can be used. it can.

The resulting benzenesulfonamide derivative slurry liquid is filtered to obtain a benzenesulfonamide derivative wet body, and the benzenesulfonamide derivative wet body is washed with a washing solvent such as alcohols, aromatic hydrocarbons and water. . The wetted benzenesulfonamide derivative thus obtained usually contains 30 to 50% of a washing solvent.

In the prior art, the benzenesulfonamide derivative is dried to obtain a product of the benzenesulfonamide derivative, but in the present invention, steam is aerated through the benzenesulfonamide wet body. The operating pressure for aeration of steam is preferably normal pressure, but since the benzenesulfonamide derivative is normally stable up to 150 ° C in the presence of water, it can be operated up to the vapor pressure of water corresponding to 150 ° C.

There is no particular limitation on the aeration time and the aeration amount of the water vapor, but it is better to carry out until the temperature of the water or water vapor distilled from the wet body of the benzenesulfonamide derivative becomes almost equal to the boiling point of the operating pressure of benzene. This is advantageous because it has a large effect of removing the cleaning solvent attached to the wet body of the sulfonamide derivative and also reduces the amount of condensed water attached.

When water vapor is passed through the wet body of the benzenesulfonamide derivative for 30 to 40 minutes under normal pressure, the solid content of 50 to 70% before aeration increases to about 90%. This significantly reduces the load of the subsequent benzenesulfonamide derivative drying step.

As described above, in order to ventilate water vapor into the wet body of the benzenesulfonamide derivative, it is structurally better to filter the benzenesulfonamide derivative with a pressure filter or a vacuum filter than with a centrifugal separator. Although it is easy to deal with, the structure of the filtering device is not particularly limited as long as water vapor can be passed through the wet body of the benzenesulfonamide derivative.

Thus, the wet body of the benzenesulfonamide derivative having a reduced solid content is dried. Since the washing solvent has already been replaced by water, a drying method using air as a medium can also be used. For example, vacuum drying, aeration drying, flash drying or fluidized drying can be used. There is no other limitation as long as the drying temperature is 150 ° C. or lower.

Specific examples of the benzenesulfonamide derivative used in the method of the present invention include the following compounds, but of course the present invention is not limited to these compounds.

That is, N-phenylbenzenesulfonamide, N- (4-nitrophenyl) -benzenesulfonamide, N- (2-chloro-4-nitrophenyl)-
Benzenesulfonamide, N- (2-chloro-4-trifluoromethyl) benzenesulfonamide, N- (2-
Methyl-4-nitrophenyl) benzenesulfonamide, N- (4-trifluoromethylphenyl) benzenesulfonamide, N- (2-chloro-4-trifluoromethylphenyl) -4-chlorobenzenesulfonamide, N- (4 -Trifluoromethylphenyl) -4-chlorobenzenesulfonamide, N- (4-trifluoromethylphenyl) -2-chlorobenzenesulfonamide, N- (2-chloro-4-trifluoromethylphenyl) -2-chlorobenzenesulfonamide , N- (4
-Trifluoromethylphenyl) -2,4-dichlorobenzenesulfonamide, N- (2-chloro-4-trifluoromethylphenyl) -2,4-dichlorobenzenesulfonamide, N- (2-chloro-4-tri) Fluoromethylphenyl) -3-trifluoromethylbenzenesulfonamide, N- (2-chloro-4-trifluoromethylphenyl) -4-chloro-3-trifluoromethylbenzenesulfonamide, N- (2-chloro-4) -Trifluoromethylphenyl) -2-chloro-5-trifluoromethylbenzenesulfonamide, N- (2-chloro-
4-nitrophenyl) -4-chloro-3-trifluoromethylbenzenesulfonamide, N- (2-chloro-4
-Nitrophenyl) -2-chloro-5-trifluoromethylbenzenesulfonamide, N- (2-chloro-4-
Nitrophenyl) -2-chlorobenzenesulfonamide, N- (2-chloro-4-nitrophenyl) -4-chlorobenzenesulfonamide, N- (2-chloro-4-
Nitrophenyl) -3-methylbenzenesulfonamide, N- (2-chloro-4-nitrophenyl) -3-nitrobenzenesulfonamide, N- (2-chloro-4-)
Nitrophenyl) -4-methylbenzenesulfonamide, N- (2-chloro-4-nitrophenyl) -3,4
-Dimethylbenzenesulfonamide, N- (2-chloro-4-nitrophenyl) -2,5-dimethylbenzenesulfonamide, N- (2-chloro-4-nitrophenyl) -2,5-dichlorobenzenesulfonamide, N-
(2-chloro-4-nitrophenyl) -3,4-dichlorobenzenesulfonamide, N- (2-chloro-4-trifluoromethylphenyl) -3-trifluoromethylbenzenesulfonamide, N- (2-chloro -4-Trifluoromethylphenyl) -4-chloro-3-trifluoromethylbenzenesulfonamide, N- (2-chloro-4-trifluoromethylphenyl) -2-chloro-5
-Trifluoromethylbenzenesulfonamide, N-
(2-Methyl-4-nitrophenyl) -3-cyanobenzenesulfonamide, N- (2-methyl-4-nitrophenyl) -4-chloro-3-cyanobenzenesulfonamide, N- (2-methyl-4) -Nitrophenyl) -4-
Chlorobenzenesulfonamide, N- (2-methyl-4)
-Nitrophenyl) -3,4-dichlorobenzenesulfonamide, N- (2-methyl-4-nitrophenyl)-
4-chloro-3-trifluoromethylbenzenesulfonamide, N- (2-methyl-4-nitrophenyl) -3
-Trifluoromethylbenzenesulfonamide, N-
(2-chloro-4-trifluoromethylphenyl) -3
-Cyanobenzenesulfonamide, N- (2-chloro-
4-nitrophenyl) -2,4-dimethylbenzenesulfonamide, N- (2-chloro-4-trifluoromethylphenyl) -2,5-dimethylbenzenesulfonamide, N- (2-chloro-4-trifluoro) Methylphenyl) -4-trifluoromethylbenzenesulfonamide, N- (2-chloro-4-trifluoromethylphenyl) -3-chloro-4-trifluoromethylbenzenesulfonamide, N- (3-trifluoromethylphenyl ) -4-Trifluoromethylthiobenzenesulfonamide, N- (4-trifluoromethylthiophenyl)-
4-chloro-3-trifluoromethylbenzenesulfonamide and the like can be mentioned.

[0022]

Industrial Applicability According to the present invention, the load on the benzenesulfonamide derivative drying equipment can be significantly reduced, and the drying equipment can be downsized and the drying time can be shortened.

[0023]

EXAMPLES The present invention will be described in more detail with reference to examples. Example 1 In a 500 ml glass four-necked flask equipped with a thermometer, a stirrer and a reflux condenser, 72 g of o-chloro-p-nitroaniline and p-chloro-m-trifluoromethylbenzenesulfonyl chloride 129 were placed.
g, 30 g of xylene and 8 g of β-picoline,
Heated at 160 ° C. for 10 hours. After cooling to 140 ° C., 34 g of xylene was added, the temperature was cooled to room temperature, and 220 g of water was added. This slurry liquid was filtered with a stainless steel pressure filter having a filter cloth surface diameter of 10 cm, and 148 g of this filter cake was filtered.
Of methanol and then 94 g of water.
Subsequently, after blowing with compressed nitrogen of 1 kg / cm ² G for 5 minutes, steam was aerated from the upper part of the filter for 15 minutes. 1
The temperature on the outlet side of the filter after aeration for 5 minutes was 100 ° C. Remove the filter cake from the filter and press under reduced pressure to 100
Dry at 6 ° C for 6 hours. N- (2-chloro-4 after drying
-Nitrophenyl) -4-chloro-3-trifluoromethylbenzenesulfonamide weighs 148 g,
The solid content of the filter cake before drying was 91%.

Comparative Example 1 By the same operation as in Example 1, a filter cake blown with compressed nitrogen for 5 minutes was obtained. This was dried under reduced pressure at 100 ° C. for 6 hours. The weight of N- (2-chloro-4-nitrophenyl) -4-chloro-3-trifluoromethylbenzenesulfonamide after drying was 148 g, and the solid content of the filter cake before drying was 66%.

Example 2 By the same operation as in Example 1, a filter cake blown with compressed nitrogen for 5 minutes was obtained. Steam is added to this from the top of the filter 6
Aerated for 0 minutes. The temperature on the outlet side of the filter was 100 ° C. from 10 minutes after the start of the aeration of steam. The filter cake was taken out from the filter and dried at 130 ° C. for 3 hours with a warm air dryer. N- (2-chloro-4-nitrophenyl) after drying
The weight of -4-chloro-3-trifluoromethylbenzenesulfonamide was 146 g, and the solid content of the filter cake before drying was 90%.

Example 3 88.2 g of m-methylbenzenesulfonyl chloride, o
72 g of -chloro-p-nitroaniline, 30 g of o-dichlorobenzene, and 7 g of pyridine were charged, and the mixture was reacted at 160 to 165 ° C for 8 hours under a gentle nitrogen stream. The reaction mass was then cooled to 110 ° C. The obtained slurry liquid was filtered with a stainless steel pressure filter having a filter cloth surface diameter of 10 cm, and the filter cake was washed with 100 g of methanol and further with 90 g of water. Then 1 kg / cm
After blowing with ² G compressed nitrogen for 5 minutes, 120 ° C
The steam of was aerated for 15 minutes from the upper part of the filter. The temperature on the outlet side of the filter after aeration for 15 minutes was 100 ° C. Remove the filter cake from the filter and remove it under reduced pressure at 100 ° C for 6
Dried for hours. The weight of N- (2-chloro-4-nitrophenyl) -3-methylbenzenesulfonamide after drying was 117 g, and the solid content of the filter cake before drying was 92.
%Met.

Comparative Example 2 By the same operation as in Example 3, a filter cake blown with compressed nitrogen for 5 minutes was obtained. This was dried with a warm air dryer at 130 ° C. for 3 hours. The weight of N- (2-chloro-4-nitrophenyl) -4-chloro-3-trifluoromethylbenzenesulfonamide after drying was 149 g, and the solid content of the filter cake before drying was 61%.

Comparative Example 3 The solid content of the filter cake after blowing with compressed nitrogen for 5 minutes in Example 3 was 67%.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Ryuichi Mita             30 Asamu-cho, Omuta City, Fukuoka Prefecture Mitsui Toatsu Chemical             Within the corporation

Claims (4)

[Claims] 1. Formula (1) (Formula 1) [In the formula, R ¹ , R ² , R ³ and R ⁴ are each independently a hydrogen atom, an alkyl group having 1 to 4 carbon atoms or an alkylthio group, a fluorine atom, a chlorine atom, a nitro group, a cyano group, a trifluoromethyl group. Alternatively, it represents a trifluoromethylthio group. ] In the method for drying the benzenesulfonamide derivative represented by the formula (1) obtained through the production process
A method for drying a benzenesulfonamide derivative of the formula (1), characterized in that the wet operation of the benzenesulfonamide derivative is carried out and then a drying operation is carried out. 2. Formula (2) (Formula 2) [In the formula, R ¹ and R ² each independently represent a hydrogen atom, an alkyl group or an alkylthio group having 1 to 4 carbon atoms, a fluorine atom, a chlorine atom, a nitro group, a cyano group, a trifluoromethyl group or a trifluoromethylthio group. Show. ] Benzenesulfonyl chlorides of the formula (3) (Chemical Formula 3) [In the formula, R ³ and R ⁴ are each independently a hydrogen atom, an alkyl group or an alkylthio group having 1 to 4 carbon atoms, a fluorine atom, a chlorine atom, a nitro group, a cyano group, a trifluoromethyl group or a trifluoromethylthio group. Show. ] Aniline is condensed in an organic solvent in the presence of a basic substance, a diluting solvent is added if necessary, and the compound is cooled by cooling to precipitate (1) (Chemical Formula 4) [In formula, R < ¹ >, R < ² >, R < ³ > and R < ⁴ > shows the same meaning as that of Formula (2) and Formula (3). ] The method for drying a benzenesulfonamide derivative of the formula (1), characterized in that the benzenesulfonamide derivative is isolated by a solid-liquid separation operation, steam is passed through the wet body, and then the drying operation is performed. 3. The method according to claim 1, wherein the steam to be aerated is steam in a temperature range of 150 ° C. or lower. 4. The method according to claim 1 or 2, wherein the drying operation is vacuum drying, aeration drying, flash drying or fluidized drying.