JP3370520B2 - Method for producing monosubstituted nitroguanidines - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for producing monosubstituted nitroguanidines. The method of the present invention is useful for synthesizing a compound or an intermediate thereof used in the field of agrochemicals (particularly pesticides). [0002] It is well known that certain nitroguanidines are useful as pesticides (especially insecticides) or intermediates thereof. In particular, it is known that an insecticide having a tetrahydrofuryl group has an extremely high activity. (JP-A-7-179448). [0003] A method of reacting S-methylnitroisothiourea (formula (1), sometimes abbreviated as NIU hereinafter) with (tetrahydrofuryl) methylamine when producing these compounds is known (see, for example, US Pat. Kaihei 7-1731
No. 57). [0004] In the above publication, solvents and conditions are listed, but in the description of Examples, ethanol is used as a solvent, and 4-N,
N-dimethylaminopyridine (hereinafter sometimes abbreviated as DMAP) is added as a catalyst, and the mixture is refluxed for 8 hours. NIU is a known compound and can be easily produced. For example, Am. Chem. So
c. , 76, 1877 (1954) describe a process for producing NIU and monosubstituted nitroguanidines. As an example of a method for producing monosubstituted nitroguanidines using general amines, the following method is described in the above-mentioned literature. A method of reacting NIU with a primary or secondary amine without solvent or in ethanol. At this time, it is described that when a solvent is used, ethanol is usually used. [0007] As another example, the following method is known. Methods obtained by reacting NIU and amine in various solvents (JP-A-2-288860, JP-A-3-1093)
No. 74, Japanese Patent Application Laid-Open No. 3-157308, Japanese Patent Application Laid-Open
-2007768, JP-A-3-279359, JP-A-4-59763, JP-A-5-1632.
42, JP-A-7-278094). [0008] The solvents used in these reactions are listed only in the text, and in the examples described, only ethanol or acetonitrile is used. Most of the reactions are carried out under reflux conditions, and the reaction time is as long as 4.5 to 17 hours. Further, in some reactions, bases such as potassium carbonate and metal compounds such as potassium hydrogen sulfate and cuprous iodide are used. [0009] JP-A-3-109374 and the like disclose that alcohol solvents are particularly preferred. [0010] Furthermore, NIU in the literature cited so far has been described.
Are all used as dried products. In the course of examining the properties of the starting material, NIU, the present inventors have found that NIU has a dust explosive property and is decomposed by a base to produce a nitrocyanamide derivative. Dust explosive compounds are very dangerous when dry and it is highly desirable to handle them under as dry a condition as possible. Therefore, in industrial production, it is desirable to handle in a solvent having as high a boiling point or non-volatile as possible, and a non-flammable solvent can be handled more safely. The present inventors have further found that NIU is unstable to certain bases, especially under heating conditions. For example, in the case of a base containing potassium such as potassium hydroxide and potassium carbonate, the compound represented by the formula (4) (Potassium nitrocyanamide). [0013] Potassium nitrocyanamide is a known compound. Am. Chem. Soc. , 74,2
077 (1952), Electrochemistry and Industrial Physical Chemistry 44,
803 (1976) and the like describe its production method. According to these documents, it is described that N-methyl-N'-nitro-N-nitrosoguanidine or N-methyl-N, N'-dinitroguanidine is obtained by treating with potassium hydroxide. Not listed. The inventors have found that potassium nitrocyanamide is sensitive to heating, is more intense than peroxide, and causes explosive combustion. The decomposition of NIU by a base is faster at a higher temperature, and gradually progresses with an organic base such as triethylamine or pyridine.
It has been found that the calorific value of IU and potassium nitrocyanamide by thermal analysis is larger than that of ordinary organic compounds. The problem to be solved by the present invention is that NI has a problem that it has a dust explosive property and decomposes or becomes unstable when reacted with a base.
It is an object of the present invention to provide a method for producing monosubstituted nitroguanidine safely and with a high selectivity, a high conversion, and a high yield by using U as a raw material in a mild reaction. Means for Solving the Problems The present inventors have conducted intensive studies on the reaction between (tetrahydrofuryl) methylamines and NIU. As a result, using water as a solvent, a catalyst such as a base or a metal salt can be obtained. It is not necessary to react with high yield, high conversion and high selectivity under mild temperature conditions compared to other solvents such as alcoholic solvents. Further, decomposition of NIU by (tetrahydrofuryl) methylamines Also found that it hardly occurred under mild conditions as in the present invention.
It has been confirmed that the reaction between IU and amines is advantageous for safety, and the present invention has been completed. That is, the present invention provides a compound of the formula (1) In water, S-methylnitroisothiourea represented by the formula (2) (Wherein, R ₁ and R ₂ each independently represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms). ) (Wherein R ₁ and R ₂ each independently represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms). DESCRIPTION OF THE PREFERRED EMBODIMENTS Typical examples of R ₁ and R ₂ of the amines represented by the formula (2) used in the present invention include a hydrogen atom,
Examples include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, and a t-butyl group. The equivalent of the amines used in the reaction of the present invention may be at least 1 equivalent, but usually 1 to 2 equivalents are used, and preferably 1 to 1 equivalent, since excess amine promotes the decomposition of NIU. 0.5 equivalent. As the raw material NIU, either a dried product or a hydrated product can be used, but from the viewpoint of safety, use of a hydrated product is preferred.
The water content is not limited, but is generally 0 to 90%, preferably 0 to 60%. Further, NIU obtained through the manufacturing process generally has an advantage that it can be used without drying since a water-containing product is first obtained. There are no restrictions on the order of charging the raw materials,
In order to avoid decomposition by amines, a method of dropping amines is preferable. Water is used as the solvent. Any amount can be used as long as stirring is possible, but usually 1 to 50 times the weight of NIU, preferably 1 to 10 times the weight. The reaction temperature is preferably low in terms of safety, and generally the reaction temperature is 0 to 50 ° C., preferably 0 to 3 ° C.
0 ° C. The reaction time can vary over a wide range but is generally between 0.01 and 50 hours, preferably between 0.1 and 24 hours. The treatment after the completion of the reaction can be carried out according to a conventional method. For example, it can be obtained as a wet solid by crystallization, and can be obtained as a solid if dried if necessary. It can also be extracted by extraction with an organic solvent. If necessary, such as recrystallization,
Higher purity can be obtained. Compounds having a nitroimino group such as formulas (1) and (3) are isomers (syn- and anti-isomers)
As well as tautomers. Equation (2),
When the compound has a tetrahydrofuryl group such as the formula (3), an asymmetric carbon is present in the tetrahydrofuran ring, and it may exist as an optically active isomer, a racemate, or a mixture at an arbitrary ratio. All such isomers and tautomers, and mixtures thereof, may be used in the present invention. EXAMPLES The contents of the present invention will be specifically described below with reference to examples and comparative examples. Example 1 27.72 g of dried NIU was suspended in 130 g of water, and 22.82 g of (3-tetrahydrofuryl) methylamine was added dropwise at 25 ° C. After completion of the dropwise addition, the mixture was stirred at the same temperature for 3 hours. After cooling to 0 ° C. and stirring for 1 hour, the crystals were collected by filtration. After washing with 100 g of cold water, 47.35 g of a wet cake of N- (3-tetrahydrofuryl) methyl-N'-nitroguanidine was obtained. Content 75%, 35.51 g,
Yield 92%. Conversion 99.8% Example 2 39.60 g of water-containing NIU (content 70%, 27.72 g)
Was suspended in 120 g of water, and 22.82 g of (3-tetrahydrofuryl) methylamine was added dropwise at 25 ° C. After completion of the dropwise addition, the mixture was stirred at the same temperature for 3 hours. After cooling to 0 ° C. and stirring for 1 hour, the crystals were collected by filtration. After washing with 100 g of cold water, 45.36 g of a wet cake of N- (3-tetrahydrofuryl) methyl-N'-nitroguanidine was obtained. Content 80%, 36.29 g, 94% yield. Conversion 99.8
%. Example 3 55.44 g of water-containing NIU (content: 50%, 27.72 g)
Was suspended in 110 g of water, and 22.82 g of (3-tetrahydrofuryl) methylamine was added dropwise at 25 ° C. After completion of the dropwise addition, the mixture was stirred at the same temperature for 3 hours. After cooling to 0 ° C. and stirring for 1 hour, the crystals were collected by filtration. After washing with 100 g of cold water, 40.87 g of a wet cake of N- (3-tetrahydrofuryl) methyl-N'-nitroguanidine was obtained. Content 85%, 34.74 g, yield 90%. Conversion 99.9
%. Example 4 55.44 g of water-containing NIU (content 50%, 27.72 g)
Was suspended in 110 g of water, and (2-methyl-4
-Tetrahydrofuryl) methylamine 25.99 g was added dropwise. After completion of the dropwise addition, the mixture was stirred at the same temperature for 3 hours. After cooling to 0 ° C. and stirring for 1 hour, the crystals were collected by filtration. Cold water 100
After washing with g, 42.86 g of a wet cake of N- (2-methyl-4-tetrahydrofuryl) methyl-N'-nitroguanidine was obtained. Content 90%, 38.58 g, 93% yield. 99.5% conversion. Example 5 55.44 g of hydrated NIU (content: 50%, 27.72 g)
Was suspended in 110 g of water and (2-ethyl-4
29.15 g of (tetrahydrofuryl) methylamine were added dropwise. After completion of the dropwise addition, the mixture was stirred at the same temperature for 3 hours. After cooling to 0 ° C. and stirring for 1 hour, the crystals were collected by filtration. Cold water 100
After washing with g, 45.83 g of a wet cake of N- (2-ethyl-4-tetrahydrofuryl) methyl-N'-nitroguanidine was obtained. Content 90%, 41.25 g, yield 93%. Conversion 99.7%. Example 6 55.44 g of water-containing NIU (content 50%, 27.72 g)
Are suspended in 110 g of water and (2-isopropyl-4-tetrahydrofuryl) methylamine 32.32 is added at 25 ° C.
g was added dropwise. After completion of the dropwise addition, the mixture was stirred at the same temperature for 3 hours.
After cooling to 0 ° C. and stirring for 1 hour, the crystals were collected by filtration. After washing with 100 g of cold water, 48.25 g of a wet cake of N- (2-isopropyl-4-tetrahydrofuryl) methyl-N′-nitroguanidine was obtained. Content 93%, 44.
87 g, 95% yield. 98.8% conversion. Example 7 55.44 g of hydrated NIU (content: 50%, 27.72 g)
Is suspended in 110 g of water and, at 25 ° C., 35.48 g of (2-t-butyl-4-tetrahydrofuryl) methylamine
Was dropped. After completion of the dropwise addition, the mixture was stirred at the same temperature for 3 hours. 0
After cooling to 0 ° C and stirring for 1 hour, the crystals were collected by filtration. Cold water 1
After washing with 00 g, 52.31 g of a wet cake of N- (2-t-butyl-4-tetrahydrofuryl) methyl-N′-nitroguanidine was obtained. Content 91%, 47.61
g, 95% yield. 99.2% conversion. Example 8 55.44 g of hydrated NIU (content: 50%, 27.72 g)
Is suspended in 110 g of water and, at 25 ° C, (2,2-dimethyl-4-tetrahydrofuryl) methylamine 29.15.
g was added dropwise. After completion of the dropwise addition, the mixture was stirred at the same temperature for 3 hours.
After cooling to 0 ° C. and stirring for 1 hour, the crystals were collected by filtration. After washing with 100 g of cold water, 44.41 g of a wet cake of N- (2,2-dimethyl-4-tetrahydrofuryl) methyl-N'-nitroguanidine was obtained. Content 85%, 37.
75 g, 91% yield. 99.5% conversion. Example 9 39.60 g of hydrated NIU (content: 70%, 27.72 g)
Was suspended in 120 g of water, and 22.82 g of (3-tetrahydrofuryl) methylamine was added dropwise at 0 ° C. After completion of the dropwise addition, the mixture was stirred at the same temperature for 3 hours, and the crystals were collected by filtration. Cold water 1
Wash with N- (3-tetrahydrofuryl) methyl-N'-nitroguanidine.
78 g were obtained. Content 82%, 35.90 g, 93% yield.
99.0% conversion. Example 10 39.60 g of water-containing NIU (content: 70%, 27.72 g)
Was suspended in 120 g of water, and 22.82 g of (3-tetrahydrofuryl) methylamine was added dropwise at 50 ° C. After completion of the dropwise addition, the mixture was stirred at the same temperature for 3 hours. After cooling to 0 ° C. and stirring for 1 hour, the crystals were collected by filtration. After washing with 100 g of cold water, 36.46 g of a wet cake of N- (3-tetrahydrofuryl) methyl-N'-nitroguanidine was obtained. Content 90%, 32.81 g, yield 85%. Conversion 99.9
%. Comparative Example 1 27.72 g of dry NIU was suspended in 210 g of dichloromethane, and 22.82 g of (3-tetrahydrofuryl) methylamine was added dropwise at 25 ° C. After completion of the dropwise addition, the mixture was stirred at the same temperature for 3 hours, and the crystals were collected by filtration. 100 g of cold dichloromethane
And washed with N- (3-tetrahydrofuryl) methyl-
A wet cake of N'-nitroguanidine was obtained. Drying under reduced pressure gave 34.06 g of a solid. Content 85%, 28.9
5 g, 75% yield. 78% conversion. Comparative Example 2 27.72 g of dry NIU was suspended in 100 g of methanol, and 22.82 g of (3-tetrahydrofuryl) methylamine was added dropwise at 25 ° C. After completion of the dropwise addition, the mixture was stirred at the same temperature for 3 hours. After cooling to 0 ° C. and stirring for 1 hour, the crystals were collected by filtration. After washing with 50 g of cold methanol, a wet cake of N- (3-tetrahydrofuryl) methyl-N′-nitroguanidine was obtained. Drying under reduced pressure gave 32.60 g of a solid.
Content 90%, 29.34 g, yield 76%. Conversion rate 88
%. Comparative Example 3 27.72 g of dry NIU was suspended in 100 g of ethanol, and 22.82 g of (3-tetrahydrofuryl) methylamine was added dropwise at 25 ° C. After completion of the dropwise addition, the mixture was stirred at the same temperature for 3 hours. After cooling to 0 ° C. and stirring for 1 hour, the crystals were collected by filtration. After washing with 50 g of cold ethanol, a wet cake of N- (3-tetrahydrofuryl) methyl-N′-nitroguanidine was obtained. Drying under reduced pressure gave 27.32 g of a solid.
Content 89%, 24.32 g, 63% yield. Conversion rate 75
%. Comparative Example 4 27.72 g of dry NIU was added to isopropyl alcohol 10
0-g, and (3-tetrahydrofuryl) methylamine 22.82g was dripped at 25 degreeC. After completion of the dropwise addition, the mixture was stirred at the same temperature for 3 hours. After cooling to 0 ° C. and stirring for 1 hour, the crystals were collected by filtration. After washing with 50 g of cold isopropyl alcohol, a wet cake of N- (3-tetrahydrofuryl) methyl-N′-nitroguanidine was obtained. Drying under reduced pressure gave 27.45 g of a solid. Content 90%, 24.71 g, yield 64%. 70% conversion. Comparative Example 5 27.72 g of dry NIU was added to isopropyl alcohol 10
The suspension was suspended at 0 ° C., and 22.82 g of (3-tetrahydrofuryl) methylamine was added dropwise at 50 ° C. After completion of the dropwise addition, the mixture was stirred at the same temperature for 3 hours. After cooling to 0 ° C. and stirring for 1 hour, the crystals were collected by filtration. After washing with 50 g of cold isopropyl alcohol, a wet cake of N- (3-tetrahydrofuryl) methyl-N′-nitroguanidine was obtained. The solid was dried under reduced pressure to obtain 26.01 g of a solid. Content 92%, 23.93 g, yield 62%. 73% conversion. [Table 1] As described above, according to the present invention, monosubstituted nitroguanidines useful as pesticides (especially insecticides) or intermediates thereof can be produced safely and in good yield. Manufacturing method Excellent as a manufacturing method.

────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Tatsuo Kaiho 30 Asamuta-cho, Omuta-shi, Fukuoka Prefecture Mitsui East Pressure Chemical Co., Ltd. (56) References JP-A-7-173157 (JP, A) (58) Survey Field (Int.Cl. ⁷ , DB name) CA (STN) REGISTRY (STN)

Claims (1)

(57) [Claims] [Claim 1] Formula (1) In water, S-methylnitroisothiourea represented by the formula (2) (Wherein, R ₁ and R ₂ each independently represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms). ) (Wherein, R ₁ and R ₂ each independently represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms).