JP2717842B2 - Aminocarbonyl-substituted pyridinesulfinic acid or a salt thereof - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a novel amino compound which is a precursor of an aminosulfonyl-substituted pyridinecarboxylic acid amide compound (hereinafter abbreviated as APCA) useful as a raw material for agricultural chemicals, medicines and the like. The present invention relates to carbonyl-substituted pyridinesulfinic acid (hereinafter abbreviated as ACPS) or a salt thereof, and an industrially advantageous production method thereof.

`` Background of the Prior Art and the Present Invention '' The APCA is disclosed in JP-A-62-223180 and JP-A-63-1468.
No. 73 discloses the production method, but the production method has a low yield, a long reaction step, or requires isolation in each reaction step, or it is difficult to handle reaction raw materials. In addition, it is not always satisfactory for industrial implementation because it is an expensive reaction material.

The present inventors have conducted various studies to find an industrially advantageous production method of APCA, and found that the production method of the present invention via the ACPS or a salt thereof can achieve the desired effect,
The present invention has been completed.

"Disclosure of the Invention" The present invention provides a compound represented by the general formula (I): (Wherein, R ¹ and R ² are each a hydrogen atom or an alkyl group) or an aminocarbonyl-substituted pyridinesulfinic acid (ACPS) or a salt thereof.

As the alkyl group of R ¹ and R ^{2 in} the general formula (I),
Those having 1 to 6 carbon atoms, for example, a methyl group, an ethyl group, a propyl group, a butyl group and the like can be mentioned. Examples of the salts include alkali metal salts or alkaline earth metal salts such as lithium, sodium, potassium, magnesium, and calcium; amine salts with amines substituted with hydrocarbon groups such as triethylamine and dimethylamine; and ammonium salts with ammonia. And the like.

Among the ACPS or salts thereof, a compound represented by the following general formula (I ″) or a salt thereof is preferable. (Wherein R ¹ and R ² are the same as described above), and more preferably, a combination in which R ¹ is a hydrogen atom or a methyl group and R ² is a methyl group in the general formula (I ″). ACPS
Alternatively, among the salts, a salt is preferable, and among the salts, an alkali metal salt and an ammonium salt are preferable, and a sodium salt is more preferable.

The ACPS or a salt thereof of the present invention can be produced by the following method.

(Wherein R ¹ and R ² are as described above). The above-mentioned salt forming reaction and oxidation reaction will be described in detail.

(Salt-Forming Reaction) In this reaction, the mercapto-substituted pyridinecarboxylic acid amide-based compound (hereinafter abbreviated as MPCA) of the general formula (II) is usually reacted with a salt-forming substance in the presence of a solvent such as water. The amount of the solvent used is 100 to 1000% by weight based on MPCA. Examples of the salt-forming substance include hydroxides or carbonates of alkali metals or alkaline earth metals such as lithium, sodium, potassium, magnesium and calcium; amines such as triethylamine and dimethylamine; ammonia such as aqueous ammonia and ammonia gas. And the like. Of these, sodium hydroxide and ammonia are preferred. The amount of salt-forming substance used is at least a reaction equivalent to MPCA,
For example, when an alkali metal salt is used, it is 1 to 2 with respect to MPCA.
The molar amount is 4 times, and when ammonia is used, the molar amount is 4 to 20 times.

Although the reaction temperature cannot be specified unconditionally, it is generally 0 to 50 ° C, and the reaction time is generally 5 to 60 minutes.

The desired MPCA salt can be obtained by subjecting this reaction product to ordinary purification and separation operations, but this reaction product can be used as it is in the next oxidation reaction.

(Oxidation reaction) Hydrogen peroxide is dropped and reacted with the MPCA salt dissolved or suspended in a solvent such as water, or with the reaction product obtained in the above-described salt formation reaction. . Although the concentration of hydrogen peroxide is not particularly limited, it may be about 30%, and the amount of hydrogen peroxide is usually 1.8 to 1.8% based on MPCA salt.
It is 3 times mol. Although the reaction temperature cannot be specified unequivocally, it is generally 0 to 100 ° C, and the reaction time is generally 10 to 60 minutes.

As in the case of the salt formation reaction described above, this reaction product can be subjected to ordinary purification and separation operations to isolate the ACPS salt described in the above 4;
If this is further neutralized, ACPS can be obtained.

ACPS or a salt thereof obtained by this reaction can be easily derived into APCA by an amination reaction or an oxidation / condensation reaction described below.

In industrial practice, the ACPS salt obtained by the above reaction can be directly applied to an amination reaction or an oxidation / condensation reaction described below without isolation. Since the salts of ACPS that can be used in the oxidation / condensation reaction are limited to ammonium salts, when a salt other than the ammonium salt of ACPS is generated, it may be converted into an ammonium salt of ACPS once. Next, the salt conversion reaction will be described.

(Salt conversion reaction) ACPS obtained by dissolving or suspending an alkali metal salt, alkaline earth metal salt or amine salt of ACPS in a solvent such as water, or obtained by the above-described oxidation reaction
The reaction product containing an alkali metal salt, an alkaline earth metal salt or an amine salt is generally reacted by adding ammonia and then an acid. When using ammonia, specifically, an aqueous ammonia solution, ammonia gas, or the like is used. The amount of ammonia used is usually 4 to 4 with respect to the alkali metal salt, alkaline earth metal salt or amine salt of ACPS.
It is 20 times mol. As the acid, sulfuric acid, hydrochloric acid, nitric acid,
Examples thereof include inorganic acids and organic acids such as phosphoric acid and acetic acid, with sulfuric acid being preferred. The amount of the acid used is 1 to the alkali metal salt, alkaline earth metal salt or amine salt of ACPS.
４4 times mol. Although the reaction temperature cannot be specified unconditionally, it is generally 0 to 50 ° C, and the reaction time is generally 10 to 60 minutes.

As in the case of the above reaction, the reaction product can be subjected to ordinary purification and separation procedures to isolate the ammonium salt of ACPS, but can be used as it is in the oxidation and condensation reactions described below.

Further, the ACPS of the present invention or an alkali metal salt thereof,
It can also be produced by the following alternative method.

(Wherein R ¹ and R ² are as described above, M ′ is an alkali metal element, x is 2 to 8, and y is 1 to 8).

The above polysulfide conversion reaction and oxidation reaction will be described in detail.

(Polysulfide-forming reaction) In the polysulfide-forming reaction, a mixture of an alkali metal hydroxide and its hydrosulfide, or an alkali metal sulfide and 1 to 7 times, preferably 1 to 2 times, its mole of sulfur by a conventional method. Those obtained by reacting in advance may be used, but these may be used as the aminocarbonyl-substituted halogenopyridine compounds of the general formula (III) (hereinafter abbreviated as ACHP).
The reaction may be carried out in the co-presence of the above and may be used directly in the reaction system. Alkali metal hydroxide, hydrosulfide or sulfide alkali metal lithium, sodium,
Potassium and the like, among which sodium is preferred, the amount of the hydroxide, hydrosulfide or sulfide used is ACHP
Is 0.75 to 5 times mol, preferably 1 to 1.5 times mol. In this reaction, water is usually used as a solvent, but an organic solvent can also be used as long as it is miscible with polysulfide and water, for example, lower alcohols such as methanol, ethanol, and propanol;
Ethylene glycol, polyalcohols such as propylene glycol, ethers such as tetrahydrofuran,
Aprotic polar solvents such as dioxane and dimethyl sulfoxide, ketones such as methyl ethyl ketone, and nitriles such as acetonitrile can be used. The use amount of this solvent is usually 10 to 1000% by weight, preferably 10 to 100% by weight based on ACHP. The other reaction conditions of this reaction cannot be unequivocally defined, but the reaction temperature is usually 0 ° C. to reflux temperature, preferably 80 to 150 ° C., the pressure is normal pressure to several atmospheres, and the reaction time is generally 0.5 to 30 hours.

The alkali metal salt of pyridinecarboxylic acid amide (poly) sulfide of the general formula (IV) obtained by this reaction can be used as it is in the next oxidation reaction.

(Oxidation reaction) Here, the reaction can be performed in the same manner as in the case of the oxidation reaction of the reaction [A].

ACPS or an alkali metal salt thereof obtained by this reaction is
APCA can be easily derived by an amination reaction or a salt conversion reaction described below and an oxidation / condensation reaction described later.

Representative examples of the ACPS of the present invention or salts thereof obtained in the reactions [A] and [B] are shown in Table 1 below.

Next, MPCA of the general formula (II) used as a starting material for the reaction [A] can be produced by the following method.

(Wherein R ¹ , R ² , Hal, M ′, x and y are as described above) The above-mentioned polysulfide-forming reaction and acid treatment will be described in detail.

(Polysulfide formation reaction) The reaction can be carried out in the same manner as in the case of the polysulfide formation reaction of the above reaction [B].

(Acid treatment) The general formula (IV) obtained by the above polysulfide conversion reaction
When a conventional acid treatment is applied to a reaction product containing an alkali metal salt of pyridinecarboxylic acid amide (poly) sulfide, the desired MPCA is released, hydrogen sulfide gas is generated, and sulfur is generated. The acid treatment is carried out by adding a mineral acid having no oxidizing action such as concentrated hydrochloric acid or dilute sulfuric acid to the reaction product so that the pH becomes 3 or less, and then subjecting the reaction product to a usual purification and separation operation. Of MPCA can be isolated.

Further, the ACPS or a salt thereof of the present invention can be derived into an aminosulfonyl-substituted pyridinecarboxylic acid amide compound (APCA) of the following general formula (V) by the following amination reaction or oxidation / condensation reaction.

(In the formula, R ¹ and R ² are as described above.) (Amination reaction) The above-mentioned ACPS or a salt thereof dissolved or suspended in a solvent such as water, or the above-mentioned oxidation reaction Is reacted with hydroxylamine-O-sulfonic acids. It is desirable to further add a basic substance in this reaction. The order of addition of the hydroxylamine-O-sulfonic acid and the basic substance is not particularly limited, but it is preferable to add the hydroxylamine-O-sulfonic acid first, and then add the basic substance. As hydroxylamine-O-sulfonic acids,
Examples thereof include hydroxylamine-O-sulfonic acid and O-mesitylenesulfonylhydroxylamine, and among them, hydroxylamine-O-sulfonic acid is preferable. The amount of the hydroxylamine-O-sulfonic acids used was AC
It is 1 to 3 moles relative to PS or a salt thereof. Examples of the basic substance include sodium acetate, sodium carbonate, potassium carbonate, sodium hydrogen carbonate, sodium phosphate, sodium monohydrogen phosphate, sodium hydroxide, potassium hydroxide, ammonia, and triethylamine. Sodium and sodium hydroxide are preferred. The amount of the basic substance used is 0.5 to 4 times the reaction equivalent of ACPS or a salt thereof. Although the reaction temperature cannot be specified unconditionally, it is usually 0 to 100 ° C., and the reaction time is generally 10
Minutes to 24 hours.

If this reaction product is subjected to normal purification and separation operations, APCA
Can be obtained.

(In the formula, R ¹ and R ² are as described above.) (Oxidation / condensation reaction) ACPS ammonium salt is dissolved or suspended in a solvent such as water or oxidized or condensed. The reaction product containing the ammonium salt of ACPS obtained by the reaction or the salt conversion reaction is reacted with a hypochlorous acid or a halogen. Examples of hypochlorites include sodium hypochlorite, potassium hypochlorite, calcium hypochlorite, and the like.Halogen includes bromine, chlorine, iodine, and among others, sodium hypochlorite is desirable. The amount of the hypochlorous acid or halogen to be used is 1 to 4 moles per 1 mole of the ammonium salt of ACPS. Although the reaction temperature cannot be specified unconditionally, it is usually -10 to + 50 ° C, and the reaction time is generally 10 to 60 minutes.

APCA can be obtained by subjecting the reaction product to neutralization and ordinary purification and separation procedures.

In the reaction [b-2], the yield can be improved by adding an acid. The acid may be added at any time from the ammonium salt formation reaction step of MPCA or the salt conversion reaction step to the ammonium salt of ACPS to the oxidation / condensation reaction step.For example, after the ammonium salt formation reaction of MPCA and before the oxidation reaction, After oxidation reaction of ammonium salt of MPCA and before oxidation / condensation reaction. Examples of the acid include inorganic or organic acids such as sulfuric acid, hydrochloric acid, phosphoric acid, and acetic acid, with sulfuric acid being preferred. The amount of this acid used is MP
It is usually 1 to 5 moles per 1 mole of each reaction product of the ammonium salt formation reaction of CA, salt conversion reaction of ACPS to ammonium salt, oxidation reaction or oxidation / condensation reaction.

APCA obtained by the above reaction is described in, for example, JP-A-63-146873.
N-[(4,6-dimethoxypyrimidine-2) useful as a corn field herbicide described in
-Yl) aminocarbonyl] -3-dimethylaminocarbonyl-2-pyridinesulfonamide and salts thereof and the like can be easily derived.

"Examples" In order to describe the production method of the present invention in more detail, examples are described below, but these do not limit the method of the present invention.

Example 1 Preparation of Starting Material MPCA (Polysulfide Reaction and Acid Treatment) 55.4 g of 2-chloro-N, N-dimethylnicotinamide, 24 g of 70% pure sodium hydrosulfide, 9.6 g of sulfur, 12 g of sodium hydroxide and 15 ml of water Was heated to reflux with stirring for about 2 hours to produce the sodium salt of N, N-dimethylnicotinamide-2-polysulfide. 150 ml of water in this product
Then, 30 ml of a 50% aqueous sulfuric acid solution was added, and the mixture was stirred at 60 to 70 ° C. for 30 minutes, and the precipitated sulfur was filtered off while keeping the temperature. 100 ml of warm water
And the filtrate and the washing solution were combined to obtain a solution containing 2-mercapto-N, N-dimethylnicotinamide. The solution was cooled to 10 ° C., and the precipitated crystals were collected by filtration. The filtrate was further concentrated to about 1/3, and the precipitated crystals were collected by filtration. The crystals are combined and dried to a melting point of 20.
46.5 g of 2-mercapto-N, N-dimethylnicotinamide at 0 to 208 ° C. was obtained.

Preparation of ACPS Salt of the Present Invention (Salt Formation Reaction) In a 300 ml four-necked flask equipped with a thermometer, a dropping funnel and a stirrer, 18.2 g (0.1 mol) of 2-mercapto-N, N-dimethylnicotinamide and hydroxylation were added. 4.4g of sodium (0.11m
ol) and water (50 ml) were dissolved under stirring and reacted at room temperature for 10 minutes to obtain a reaction product containing sodium-N, N-dimethylnicotinamide-2-thiolate.

The reaction product obtained by performing the same reaction separately was concentrated, and the precipitated crystals were separated by filtration and dried, and sodium-N,
20.0 g of N-dimethylnicotinamide-2-thiolate were isolated. Its melting point was 260-268 ° C (slight decomposition).

(Oxidation reaction) 22.7 g (0.2 mol) of 30% aqueous hydrogen peroxide was stirred for about 30 minutes at a temperature of 10 to 20 ° C using the reaction product obtained in the above-mentioned salt formation reaction as it was while externally cooling. The reaction was performed dropwise to obtain a reaction product containing sodium N, N-dimethylnicotinamide-2-sulfinate.

The reaction product obtained by separately performing the salt formation reaction and the oxidation reaction is concentrated and dried to give 22.0 g of sodium N, N-dimethylnicotinamide-2-sulfinate (MPCA-based yield: 93.2% ) Was isolated. It has a melting point of 260-
The temperature was 265 ° C (discolored to brown, decomposed).

(Salt conversion reaction) The reaction product obtained in the above oxidation reaction was used as it was, and after adding 60.7 g (1.0 mol) of 28% aqueous ammonia to the product, at a temperature of 10 to 20 ° C, 12.3 g of concentrated sulfuric acid was added. (0.1
(25 mol) was added dropwise with stirring for 15 minutes to obtain a reaction product containing an ammonium salt of N, N-dimethylnicotinamide-2-sulfinic acid.

Separately, the reaction product obtained by conducting the salt formation reaction, oxidation reaction and salt conversion reaction in the same manner is concentrated and dried, the residue is extracted with methanol, and the extract is further dried to obtain N, N-dimethyl. 20.9 g of the ammonium salt of nicotinamide-2-sulfinic acid (MPCA standard yield: 90.5%) was isolated. Its melting point was 128-130 ° C.

Reference Example 1 Preparation of APCA (Oxidative Condensation Reaction) Using the reaction product obtained in the salt conversion reaction of Example 1 as it is, at a temperature of 10 to 20 ° C., 32 g of bromine (0.2 mol
l) was allowed to react dropwise with stirring for about 30 minutes. After stirring for 30 minutes, the mixture was neutralized with concentrated sulfuric acid to pH 3 to 6, and white crystals precipitated. After cooling the reaction product to around 20 ° C,
After filtration, washing with water and drying, 2-aminosulfonyl-N, N
-Dimethyl nicotinamide 16.2 g (yield; 70.7%, purity; 9
6.5%). The yield was determined based on the MPCA standard.

Example 2 Preparation of ACPS Salt of the Present Invention (Salt-Forming Reaction) 9.1 g (0.05 mol) of 2-mercapto-N, N-dimethylnicotinamide in a 300 ml four-necked flask equipped with a thermometer, a dropping funnel and a stirrer. And 45.5 g of 28% aqueous ammonia were dissolved under stirring and reacted at room temperature for 10 minutes to obtain a reaction product containing ammonium-N, N-dimethylnicotinamide-2-teolate.

The melting point of 9.7 g of this ammonium-N, N-dimethylnicotinamide-2-teolate was 198 to 201 ° C (partially decomposed).

(Oxidation reaction) 11.4 g (0.10 mol) of a 30% aqueous hydrogen peroxide solution was stirred at a temperature of 5 to 20 ° C for about 15 minutes while using the reaction product obtained in the above salt formation reaction as it was while cooling the outside. After reacting by dropping it underneath, 12.5 g of concentrated sulfuric acid (0.125mo
l) was added dropwise with stirring for about 20 minutes to give a reaction product containing the ammonium salt of N, N-dimethylnicotinamide-2-sulfinic acid.

The reaction product obtained by carrying out the ammonium salt forming reaction and the oxidation reaction in the same manner is separately concentrated and dried, the residue is extracted with methanol, and the extract is further dried to obtain N, N-dimethylnicotinamide. 10.8 g (yield based on MPCA: 93.5%) of ammonium salt of -2-sulfinic acid was isolated. Its melting point was 128-130 ° C.

Reference Example 2 Preparation of APCA (Oxidation / condensation reaction) 62 g (0.1 mol) of a 12% sodium hypochlorite solution at a temperature of 5 to 20 ° C using the reaction product obtained in the oxidation reaction of Example 2 as it is. Was added dropwise with stirring for about 30 minutes, and neutralized to pH 3 to 6 with concentrated sulfuric acid to precipitate white crystals. After cooling the reaction product to about 20 ° C., it was filtered, washed with water and dried to give 2-aminosulfonyl-
8.5 g of N, N-dimethylnicotinamide (yield: 74.2%, purity: 95.6%) was obtained. The yield was determined based on the MPCA standard.

Example 3 In Example 2, concentrated sulfuric acid 12.5 after completion of the oxidation reaction was used.
g (0.125 mol) was replaced with 24.5 g (0.125 mol) of 50% sulfuric acid, and the reaction was carried out in the same manner as in Example 2 to obtain N, N-dimethylnicotinamide-2-sulfinic acid. Ammonium salt 10.5g (MPCA standard yield: 90.9%)
I got

Reference Example 3 The same procedure as in Reference Example 2 was carried out except that the reaction product obtained by the oxidation reaction in Example 3 was used as it was, and 62 g of a 12% sodium hypochlorite solution was replaced with 28 g (0.175 mol) of bromine. The reaction was carried out in the same manner as in Example 2, and 6.98 g of 2-aminosulfonyl-N, N-dimethylnicotinamide (MPCA
Reference yield: 61.0%, purity: 98.6%).

Example 4 In Example 2, 12.5 g (0.125 mol) of concentrated sulfuric acid was added dropwise with stirring at a temperature of 5 to 20 ° C. after the completion of the oxidation reaction for about 20 minutes. Except for this, the reaction was carried out in the same manner as in Example 2 above,
10.3 g (yield based on MPCA: 89.2%) of ammonium salt of N, N-dimethylnicotinamide-2-sulfinic acid was obtained.

Reference Example 4 Using the reaction product obtained by the oxidation reaction of Example 4 as it was, the reaction was carried out in the same manner as in Reference Example 2, and 2
-Aminosulfonyl-N, N-dimethylnicotinamide 6.8
2 g (MPCA-based yield: 59.6%, purity: 93.8%) was obtained.

Example 5 Preparation of ACPS Salt of the Present Invention (Salt-Forming Reaction) 5.0 g (0.0275 mol) of 2-mercapto-N, N-dimethylnicotinamide in a 300 ml four-necked flask equipped with a thermometer, a dropping funnel and a stirrer. And 1.2 g of sodium hydroxide (0.0
3 mol) and 15 ml of water, dissolve with stirring, and add
After reacting for 1 minute, a reaction product containing sodium-N, N-dimethylnicotinamide-2-thiolate was obtained.

The reaction product obtained by performing the same reaction separately was concentrated, and the precipitated crystals were separated by filtration and dried, and sodium-N,
5.53 g of N-dimethylnicotinamide-2-thiolate were isolated. Its melting point was 260-268 ° C (slight decomposition).

(Oxidation reaction) 6.23 g (0.055 mol) of 30% aqueous hydrogen peroxide was stirred for about 30 minutes at a temperature of 10 to 20 ° C using the reaction product obtained in the above salt formation reaction as it was while externally cooling. The reaction was performed dropwise to obtain a reaction product containing sodium N, N-dimethylnicotinamide-2-sulfinate.

The reaction product obtained by separately performing the salt formation reaction and the oxidation reaction is concentrated and dried to give 6.05 g of sodium N, N-dimethylnicotinamide-2-sulfinate (MPCA standard yield: 93.2% ) Was isolated. It has a melting point of 260-
The temperature was 265 ° C (discolored to brown, decomposed).

Reference Example 5 Preparation of APCA (Amination Reaction) Using the reaction product obtained in the oxidation reaction of Example 5 as it is, sodium acetate 2.48 at a temperature of 10 to 30 ° C.
g (0.03 mol) and then hydroxylamine-O-
4.03 g (0.0357 mol) of sulfonic acid was added and reacted under stirring for about 5 hours. Crystals precipitated at about 20 ° C. were filtered, washed with water and dried to obtain 4.56 g of 2-aminosulfonyl-N, N-dimethylnicotinamide (yield; 72.4%, purity; 95.3%). The yield was determined based on the MPCA standard.

Reference Example 6 Same as Reference Example 5 except that 1.83 g (0.03 mol) of 28% aqueous ammonia was used instead of 2.48 g of sodium acetate, and that the reaction time was changed from 5 hours to 3 hours. To give 4.66 g of 2-aminosulfonyl-N, N-dimethylnicotinamide (MPCA-based yield; 74.0%, purity 98.2%).

Reference Example A reaction was carried out in the same manner as in Reference Example 5 except that 4.16 g (0.0412 mol) of triethylamine was used instead of 2.48 g of sodium acetate, and that the reaction time was changed from 5 hours to 3 hours. 4.35 g (yield based on MPCA; 69.1%, purity 97.1%) of 2-aminosulfonyl-N, N-dimethylnicotinamide were obtained.

Example 6 15 ml of water used for the salt formation reaction in Example 5 was used for 7.
The reaction was carried out in the same manner as in Example 5 except for changing the amount to 5 ml, to obtain 6.08 g of sodium N, N-dimethylnicotinamide-2-sulfinate (MPCA-based yield: 93.7%).

Reference Example 8 In Reference Example 5, the reaction product obtained in the oxidation reaction of Example 6 was directly used, and sodium acetate 2.48 was used.
g of hydroxylamine-O-sulfonic acid 4.0
Instead of adding 3 g, add hydroxylamine-O-sulfonic acid 4.03 g (0.0357 mol) and then add 1.83 g (0.03 mol) of 28% aqueous ammonia and change the reaction time from 5 hours to 3 hours. The reaction was carried out in the same manner as in Reference Example 5 to give 4-aminosulfonyl-N, N-dimethylnicotinamide (4.77 g, yield based on MPCA; 75.8%, purity 98.3).
%).

Example 7 In Example 5, instead of 1.2 g of sodium hydroxide used for the salt formation reaction, 1.8 g (0.03
mol), the reaction was carried out in the same manner as in Example 5 described above, and 5.90 g of ammonium salt of N, N-dimethylnicotinamide-2-sulfinic acid (MPCA-based yield: 9
2.9%).

Reference Example 9 In Reference Example 5, the reaction product obtained in the oxidation step of Example 7 was used as it was, and the reaction time was changed to 5 hours for 6 hours.
The reaction was carried out in the same manner as in Reference Example 5 except that the time was changed to 2.68 g of 2-aminosulfonyl-N, N-dimethylnicotinamide (MPCA-based yield; 74.3%, purity: 98.0 g).
%).

Example 8 Preparation of ACPS Salt of the Present Invention (Polysulfide Reaction) 55.4 g of 2-chloro-N, N-dimethylnicotinamide, 24 g of sodium hydrosulfide having a purity of 70%, 9.6 g of sulfur, 12 g of sodium hydroxide and 15 ml of water were prepared. The mixture was heated under reflux for about 2 hours with stirring to obtain a reaction product containing 68.7 g of a sodium salt of N, N-dimethylnicotinamide-2- (poly) sulfide.

(Oxidation reaction) 180 ml of water and 18 g of a 40% aqueous sodium hydroxide solution are added to the reaction product of the above step, and 75.8 g (0.78 mol) of 35% aqueous hydrogen peroxide is stirred at a temperature of 10 to 20 ° C for 30 minutes. To give a reaction product containing sodium N, N-dimethylnicotinamide-2-sulfinate.

The reaction product was filtered, free sulfur was filtered off, and the sulfur was washed with 60 ml of water to obtain a filtrate and a washing.

Separately similarly, free sulfur was removed from the reaction product obtained by performing the polysulfide reaction and the oxidation reaction,
Concentrate and dry to give N, N-dimethylnicotinamide 2-
65.0 g of sodium sulfinate (Yield based on ACHP: 91.8
%) Was isolated. Its melting point was 258 to 265 ° C (discoloration to brown, decomposition).

Reference Example 10 Preparation of APCA (Amination Reaction) 54.24 g (0.48 mol) of hydroxylamine-O-sulfonic acid was added to the filtrate and the washing solution in the above step while stirring at 10 ° C. or less, and after dissolution, 40% water was added. Sodium oxide aqueous solution
48 g (0.48 mol) was added dropwise, and the mixture was reacted at a temperature of 10 to 20 ° C. with stirring for 3 hours.

The reaction product was filtered to obtain crystals, and the crystals were washed with water and dried to obtain 52.5 g (purity: 96.5%) of 2-aminosulfonyl-N, N-dimethylnicotinamide. The yield based on ACHP is 76.4%.

[Effects of the Invention] The present invention provides a precursor of an aminosulfonyl-substituted pyridinecarboxylic acid amide-based compound (APCA), an aminocarbonyl-substituted pyridinesulfinic acid (ACPS) or a salt thereof, which is useful as a raw material for agricultural chemicals, medicines and the like. . In addition, the production method of the present invention is industrially advantageous in that ACPS or a salt thereof, and even APCA can be obtained from a mercapto-substituted pyridinecarboxylic acid amide-based compound (MPCA) or an aminocarbonyl-substituted halogenopyridine-based compound (ACHP) in an integrated process. Manufacturing method.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Shigeo Murai 2-3-1 Nishi-Shibukawa, Kusatsu-shi, Shiga Prefecture Central Research Laboratory of Ishihara Sangyo Co., Ltd. (72) Toshihiro Tanaka 2-3-3 Nishi-Shibukawa, Kusatsu-shi, Shiga Prefecture No. 1 Ishihara Sangyo Co., Ltd. Central Research Institute Examiner Megumi Saito (56) References JP-A-63-146873 (JP, A) JP-A-62-223180 (JP, A) JP-A-5-294936 (JP) , A)

Claims (3)

(57) [Claims] 1. A compound of the general formula (I): (Wherein R ¹ and R ² are each a hydrogen atom or an alkyl group) or an aminocarbonyl-substituted pyridinesulfinic acid or a salt thereof. (1) General formula (II): (Wherein, R ¹ and R ² are each a hydrogen atom or an alkyl group) by reacting a mercapto-substituted pyridine carboxylic acid amide compound with a salt-forming substance to obtain a salt of the carboxylic acid amide compound. (2) reacting a salt of the carboxylic acid amide compound with hydrogen peroxide to obtain a compound represented by the general formula (I): (Wherein R ¹ and R ² are as defined above), and a method for producing an aminocarbonyl-substituted pyridinesulfinic acid or a salt thereof, which comprises producing an aminocarbonyl-substituted pyridinesulfinic acid or a salt thereof. (1) General formula (III): (Wherein, R ¹ and R ² are each hydrogen atom or an alkyl group, Hal is a halogen atom) aminocarbonyl-substituted halogenopyridine compound represented by the M _'2 S
_x (wherein M 'is an alkali metal element and x is 2 to 8) to obtain an alkali metal salt of pyridinecarboxylic acid amide (poly) sulfide by reacting with a polysulfide represented by the formula (2) By reacting an alkali metal salt of sulfide with hydrogen peroxide, a compound represented by the general formula (I ′): (Wherein R ¹ , R ² and M ′ are as defined above), characterized by producing an aminocarbonyl-substituted pyridinesulfinic acid or an alkali metal salt thereof. A method for producing an alkali metal salt.