JPH0987261A - Production of 3-(3-fluoropropyl)-2-iminothiazoline - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently obtain 3-(3-fluoropropyl)-2-iminothiazoline useful as an intermediate for highly active herbicides from industrially inexpensive raw material by reacting a specific thiazole with a specific propane under prescribed conditions. SOLUTION: (A) 2-Aminothiazole of formula I is reacted with (B) 1-chloro-3- fluoropropane of formula II in the presence of a metal bromide (e.g. potassium bromide), a metal iodide (e.g. potassium iodide) or a phase transfer catalyst (e.g. tetra-normal-butylammonium bromide) and then, the resultant product is reacted with a base (e.g. potassium carbonate) to provide the objective compound of formula III. Furthermore, a sulfonic acid fluoropropyl ester of formula IV (R is metyl, para-tolyl or trifluoromethyl) is reacted with the component A and the resultant 3-(3-fluoropropyl)-2-iminothiazoline sulfonic acid salt of the formula V is reacted with a base to preferably provide the objective compound.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a fluoropropylthiazoline derivative useful as a herbicide (JP-A-7-24266).
(Described in No. 5), and a synthetic intermediate thereof.

[0002]

2. Description of the Related Art As a technique prior to the present invention, 3- (3-fluoro) obtained via 3- (3-fluoropropyl) -2-iminothiazoline hydrobromide salt described in JP-A-7-242665. There is the synthesis of propyl) -2-iminothiazoline. However, 1-bromo-3 described in the document
-The manufacturing method using fluoropropane is not always satisfactory as a manufacturing method of 3- (3-fluoropropyl) -2-iminothiazoline, and the degree of freedom in selection of raw materials is expanded, and further industrial An advantageous manufacturing method using inexpensive raw materials is desired. US Patent 4,237,30
No. 2 and WO9300336 disclose a method for synthesizing 3-alkyl-2-iminothiazoline using 2-aminothiazole and an alkyl halide of the following scheme 1, but the alkyl used in the literature is disclosed. Halide is bromide or iodide, and there is no disclosure about alkyl chloride. Those skilled in the art will appreciate that the disclosures of these prior art indicate that highly reactive alkyl bromide or alkyl iodide is suitable for the alkylation reaction of 2-aminothiazole, and that the reaction using alkyl chloride is difficult. You can easily infer what you are doing. Also, Scheme 2
The intermediate shown in 3- (3-fluoropropyl) -2-
Iminothiazoline sulfonates and trifluoromethanesulfonic acid fluoropropyl ester are novel compounds that have hitherto not been known at all.

[0003]

Means for Solving the Problems The inventors of the present invention have diligently studied a method for producing a 3-fluoropropylthiazoline derivative (described in JP-A-7-242665) which is useful as a herbicide, and as a result, used a cheaper raw material. , Scheme 1 described below
The present invention has been completed by finding a method for producing 3- (3-fluoropropyl) -2-iminothiazoline represented by Scheme 2 and Scheme 2.

[0004]

Embedded image (In the formula, X represents a halogen atom.) That is, in the method of Scheme 1, 2-aminothiazole (1) and 1-chloro-3-fluoropropane (2) are added to a metal bromide or a metal iodide, or a phase transfer catalyst. By reacting the resulting intermediate 3- (3-fluoropropyl) -2-iminothiazoline / hydrogen halide with a base to give 3- (3-fluoropropyl) -2-iminothiazoline. This is a method of obtaining (3).

[Chemical 12]

(In the formula, R represents a methyl group, a paratoluyl group or a trifluoromethyl group.) That is, the method of Scheme 2 involves the reaction of sulfonic acid fluoropropyl ester (4) with 2-aminothiazole (1). Three
-(3-Fluoropropyl) -2-iminothiazoline
In this method, a sulfonate (5) is obtained, which is further converted to 3- (3-fluoropropyl) -2-iminothiazoline (3) by using a base.

BEST MODE FOR CARRYING OUT THE INVENTION The reaction of 2-aminothiazole (1) with 1-chloro-3-fluoropropane (2) in Scheme 1 is carried out by reacting 1 mol of 2-aminothiazole (1) with 1-chloro- It is carried out using 0.5 to 3 molar amount of 3-fluoropropane (2), more preferably 0.75 to 2.0 molar amount. Examples of the additive include metal halides such as potassium iodide, sodium iodide, potassium bromide and sodium bromide, phase transfer catalysts such as tetranormal butyl ammonium bromide and tetra normal butyl ammonium iodide, or 18-crown. Crown ethers such as -6-ether are used in a catalytic amount based on 1-chloro-3-fluoropropane (2) to 2.
Add 0 molar equivalents. These additives may be used alone or as a mixture. For example, to metal halides such as potassium bromide and sodium bromide, 18-crown-6-
Crown ethers such as ether may be further added and used. The reaction temperature can be arbitrarily selected from the range of -30 ° C to 150 ° C, but is preferably 0 ° C to 100 ° C.
It is in the range of ° C. As the solvent for this reaction, a solvent inert to this reaction, for example, aromatic hydrocarbons such as benzene, toluene, xylene, halogenated aromatic hydrocarbons such as chlorobenzene and dichlorobenzene, dichloromethane, chloroform, ethylene dichloride, Halogenated hydrocarbons such as carbon tetrachloride, ethers such as ethyl ether, isopropyl ether, dioxane and tetrahydrofuran,
Alcohols such as methanol, ethanol, normal propyl alcohol and isopropyl alcohol, nitriles such as acetonitrile and propionitrile, amides such as dimethylformamide, dimethylacetamide, N-methylpyrrolidone and hexamethylphosphoric triamide,
Cyclic ureas such as 1,3-dimethyl-2-imidazolidinone and 1,3-dimethyl-1,3-diazacyclohexane-2-one; sulfoxides such as dimethyl sulfoxide; sulfones such as sulfolane; Examples thereof include ketones such as acetone and methyl ethyl ketone, esters such as ethyl acetate, hydrocarbons such as petroleum ether, petroleum benzine, hexane and heptane, and water solvents. These solvents may be used alone or as a mixture. After completion of the reaction, a usual post treatment is carried out to give an intermediate 3- (3-
Fluoropropyl) -2-iminothiazoline / hydrogen halide salt (6) can be obtained. This reaction can also be carried out under pressure using an autoclave or the like.
The reaction of 3- (3-fluoropropyl) -2-iminothiazoline hydrogen halide (4) with a base is 3- (3-
Fluoropropyl) -2-iminothiazoline / hydrogen halide salt (6) per 1 mol of base 0.2 to 3.0
It is carried out using a molar amount. Preferably 0.5 to 1.5
It is carried out in a molar amount range. Examples of the base include inorganic bases such as potassium carbonate, sodium carbonate, potassium hydroxide, sodium hydroxide, potassium hydrogen carbonate and sodium hydrogen carbonate, organic bases such as triethylamine, pyridine and DBU, sodium methoxide and sodium ethoxide. And metal hydrides such as sodium hydride. Preferred are inorganic bases and organic bases. Reaction temperature is -30 ° C to 10
It can be arbitrarily selected from the range of 0 ° C, but is preferably -20.
It is in the range of 40 ° C to 40 ° C. As a solvent for this reaction, a solvent inert to this reaction, for example, methanol, ethanol,
Alcohols such as normal propyl alcohol and isopropyl alcohol, amides such as dimethylformamide, dimethylacetamide, N-methylpyrrolidone and hexamethylphosphoric triamide, aromatic hydrocarbons such as benzene, toluene and xylene, ethyl ether and isopropyl ether. , Ethers such as dioxane and tetrahydrofuran, and water solvents. These solvents may be used alone or as a mixture. Preferably, a water solvent,
And when alcohols are used. After the completion of the reaction, 3- (3-fluoropropyl) -2-iminothiazoline (3) can be obtained by performing a usual treatment. The structure can be confirmed by IR, NMR and MS spectra. Intermediate (6) in this production method
Is reacted with a base as it is without isolation and purification to give the desired 3- (3-fluoropropyl)-
It is also possible to obtain 2-iminothiazoline (3).

2-aminothiazole (1) of scheme 2
The reaction of sulfonic acid fluoropropyl ester (4) with sulfonic acid fluoropropyl ester (4) is 0.5 to 3.
It is carried out using 0 molar amount, but it is more preferable to use 0.75 to 2.0 molar amount. The reaction temperature can be arbitrarily selected from the range of -30 ° C to 150 ° C, but is preferably 0.
It is in the range of 100 ° C to 100 ° C.

As the solvent for this reaction, solvents inert to this reaction, for example, aromatic hydrocarbons such as benzene, toluene and xylene, halogenated aromatic hydrocarbons such as chlorobenzene and dichlorobenzene, dichloromethane, chloroform, Halogenated hydrocarbons such as ethylene dichloride and carbon tetrachloride, ethyl ether, isopropyl ether,
Ethers such as dioxane, tetrahydrofuran, methanol, ethanol, normal propyl alcohol,
Alcohols such as isopropyl alcohol, nitriles such as acetonitrile and propionitrile, amides such as dimethylformamide, dimethylacetamide, N-methylpyrrolidone and hexamethylphosphoric triamide, 1,
Cyclic ureas such as 3-dimethyl-2-imidazolidinone, 1,3-dimethyl-1,3-diazacyclohexane-2-one, sulfoxides such as dimethyl sulfoxide, sulfones such as sulfolane, acetone, Examples thereof include ketones such as methyl ethyl ketone, esters such as ethyl acetate, hydrocarbons such as petroleum ether, petroleum benzine, hexane and heptane, and water solvents.

These solvents may be used alone or as a mixture. After completion of the reaction, the compound (5) of the present invention can be obtained by performing a usual post-treatment. 3-
The reaction of (3-fluoropropyl) -2-iminothiazoline sulfonate (5) with a base is based on 1 mol of 3- (3-fluoropropyl) -2-iminothiazoline sulfonate (5), It is carried out using 0.5 to 3.0 molar amounts of base. It is preferably carried out in the range of 0.9 to 1.2 molar amount.

Examples of the base include inorganic bases such as potassium carbonate, sodium carbonate, potassium hydroxide, sodium hydroxide, potassium hydrogen carbonate and sodium hydrogen carbonate, organic bases such as triethylamine, pyridine and DBU, sodium methoxide, Examples thereof include metal alkoxides such as sodium ethoxide and metal hydrides such as sodium hydride. Preferred are inorganic bases and organic bases.

The reaction temperature can be arbitrarily selected from the range of -30 ° C to 100 ° C, but is preferably -20 ° C to 40 ° C.
Range. As a solvent for this reaction, a solvent inert to this reaction, for example, alcohols such as methanol, ethanol, normal propyl alcohol, isopropyl alcohol, dimethylformamide, dimethylacetamide,
Amides such as N-methylpyrrolidone and hexamethylphosphoric triamide, aromatic hydrocarbons such as benzene, toluene and xylene, ethers such as ethyl ether, isopropyl ether, dioxane and tetrahydrofuran,
Examples include water solvents.

These solvents may be used alone or as a mixture. It is preferable to use a water solvent and alcohols. After the completion of the reaction, 3- (3-fluoropropyl) -2-iminothiazoline (3) can be obtained by performing a usual treatment. Structure is IR, NMR
And MS spectrum etc. can confirm.

3-Fluoropropyl trifluoromethanesulfonate used in this reaction is also a novel compound. The intermediate sulfonic acid 3-fluoropropyl ester (4) used in this reaction can be obtained by a method known from the literature,
Alternatively, it can be produced by a method commonly used per se. A known technique is US Pat. No. 5,035,740.
No. 4,913,724, Journal of Medicinal Chemistry (J. Med. Che
m) 35, 2221 (1992), journal
Of the Chemical Society (J. Chem. So
c. 2574 (1957), Angewhem Chem. 98, 264 (1).
986), Hemische Berichte (Chem.Be
r. ) 126, 779 (1993), Tetrahedron Letters.
21; page 2991 (1980).

3-fluoropropyl methanesulfonate (4: R = Me), 3-fluoropropyl p-toluenesulfonate (4: R = p-MeC ₆ H ₄ ) and 3-fluoropropyl trifluoromethanesulfonate (4). : R
= The synthesis scheme of CF ₃₎ in Scheme 1, 2 and 3. [Reaction formula 1]

[0014]

Embedded image

[Reaction Formula 2]

[0016]

Embedded image

[Reaction Formula 3]

[0018]

[Chemical 15]

Further, 1-chloro-3-fluoropropane, which is a starting material used in this reaction, is used in Journal of Organic Chemistry (J. Org. Che).
m. 15), 425 pages (1950), JP-A-64-
It can be easily synthesized from 1-bromo-3-chloropropane with reference to the literature such as 45321. Also,
3-Fluoro-1-propanol is the Journal of
Organic Chemistry (J. Org. Che)
m. ) Vol. 15, page 425 (1950), etc., and can be easily synthesized from 3-chloro-1-propanol.

EXAMPLES In the following, in the present invention, the intermediate and the production method shown in Scheme 1 are used as examples, and the production method of various starting materials used in the production method of the present invention, and 3- (3-fluoropropyl) -2 -Production of a herbicide using iminothiazoline will be specifically described as a reference example, but the present invention is not limited thereto. [Reference Example 1] Synthesis of 1-chloro-3-fluoropropane

Embedded image 157 g of 1-bromo-3-chloropropane (1 mo
l), propylene glycol 206 g (2.7 mol)
A mixture of water and 36 ml of water was heated to 100 ° C., and a mixture of 87 g (1.5 mol) of potassium fluoride and 78 ml of water was added dropwise thereto. 114.65 g of a fraction obtained by heating the reaction mixture to 120 ° C. was dried with anhydrous sodium sulfate and then distilled again to obtain 15.24 g of 1-chloro-3-fluoropropane. Boiling point 73-75 ° C. Example 1 Synthesis of 3- (3-fluoropropyl) -2-iminothiazoline

Embedded image A) 2-aminothiazole 1 g (10 mmol), 1-
Chloro-3-fluoropropane 0.97 g (10 mmo
A mixture of l), sodium iodide 1.5 g (10 mmol) and DMF 1.2 ml was stirred at 80 ° C. for 10 hours. The reaction mixture was washed 3 times with 50 ml of ethyl acetate, and 2.14 g of precipitated crystals were collected by filtration. 2.14 g of this crystal
Was dissolved in 14 ml of water, and 1.02 g (7.
4 mmol) was added. After stirring for 10 minutes, the mixture was extracted 3 times with 20 ml of chloroform, the organic layer was washed with saturated brine and dried over anhydrous sodium sulfate. The solvent was distilled off under reduced pressure to obtain 0.84 g of 3- (3-fluoropropyl) -2-iminothiazoline as a pale yellow oily substance. B) 0.5 g (5 mmol) of 2-aminothiazole, 1
-Chloro-3-fluoropropane 0.48 g (5 mmo
l), 0.83 g (5 mmol) of potassium iodide and D
A mixture of MF 0.6 ml was stirred at 80 ° C. for 8 hours. The reaction mixture was washed with 50 ml of ethyl acetate three times, and 1.31 g of precipitated crystals were collected by filtration. 1.31 g of this crystal is added to water 1
Dissolved in 1 ml, 0.63 g potassium carbonate (4.6 mm
ol) was added. After stirring for 10 minutes, chloroform 20m
It was extracted 3 times with 1 and the organic layer was washed with saturated saline and dried over anhydrous sodium sulfate. The solvent was distilled off under reduced pressure to obtain 0.46 g of 3- (3-fluoropropyl) -2-iminothiazoline as a pale yellow oily substance. C) 2-aminothiazole 1 g (10 mmol), 1-
Chloro-3-fluoropropane 0.97 g (10 mmo
A mixture of l), 1.03 g (10 mmol) of sodium bromide and 1.2 ml of DMF was stirred at 80 ° C. for 16 hours. The reaction mixture was washed with 50 ml of ethyl acetate three times, and 1.34 g of precipitated crystals were collected by filtration. 1.34g of this crystal
Was dissolved in 14 ml of water, and 0.77 g (5.
6 mmol) was added. After stirring for 10 minutes, the mixture was extracted 3 times with 20 ml of chloroform, and the organic layer was washed with saturated saline,
It was dried over anhydrous sodium sulfate. The solvent is distilled off under reduced pressure,
0.28 g of 3- (3-fluoropropyl) -2-iminothiazoline was obtained as a pale yellow oil. D) 2-aminothiazole 0.5 g (5 mmol), 1
-Chloro-3-fluoropropane 0.48 g (5 mmo
l), potassium bromide 0.6 g (5 mmol) and DMF
0.6 ml of the mixture was stirred at 80 ° C. for 19 hours. The reaction mixture was washed 3 times with 50 ml of ethyl acetate, the obtained crude product was dissolved in 13 ml of water, and then 0.69 g of potassium carbonate was added.
(5 mmol) was added. After stirring for 10 minutes, the mixture was extracted 3 times with 20 ml of chloroform, the organic layer was washed with saturated brine and dried over anhydrous sodium sulfate. The solvent was distilled off under reduced pressure to give 3- (3-fluoropropyl) -2 as a pale yellow oily substance.
-0.11 g of iminothiazoline was obtained. E) 2-aminothiazole 0.5 g (5 mmol), 1
-Chloro-3-fluoropropane 0.48 g (5 mmo
l), tetranormal butyl ammonium bromide 1.61
80 g of a mixture of g (5 mmol) and DMF 0.6 ml.
The mixture was stirred at ° C for 14 hours. The reaction mixture is ethyl acetate 50m
After washing 3 times with 1 and dissolving the obtained crude purified product in 13 ml of water, 0.69 g (5 mmol) of potassium carbonate was added.
After stirring for 10 minutes, extract 3 times with 20 ml of chloroform,
The organic layer was washed with saturated brine and dried over anhydrous sodium sulfate. The solvent was distilled off under reduced pressure to give 3- (3
-Fluoropropyl) -2-iminothiazoline 0.21
g was obtained. F) 0.5 g (5 mmol) of 2-aminothiazole, 1
-Chloro-3-fluoropropane 0.48 g (5 mmo
A mixture of 1), potassium bromide 0.6 g (5 mmol), 18-crown-6 (catalytic amount) and DMF 0.6 ml was stirred at 80 ° C. for 19 hours. The reaction mixture was mixed with ethyl acetate 5
After washing with 0 ml three times, the obtained crude product was dissolved in 13 ml of water, and 0.69 g (5 mmol) of potassium carbonate was added. After stirring for 10 minutes, the mixture was extracted 3 times with 20 ml of chloroform, the organic layer was washed with saturated brine and dried over anhydrous sodium sulfate. The solvent was distilled off under reduced pressure to give a pale yellow oily substance 3-
(3-Fluoropropyl) -2-iminothiazoline 0.
18 g was obtained. Reference Example 2 Synthesis of 1- {3- (3-fluoropropyl) thiazoline-2-imino-sulfonyl}-(4,6-dimethoxytriazin-2-yl) urea

Embedded image 0.62 g of 2-amino-4,6-dimethoxytriazine
(4 mmol) was suspended in 40 ml of dry tetrahydrofuran, and chlorosulfonyl isocyanate 0.5 was added at room temperature.
7 g (4 mmol) was added dropwise. After stirring for 30 minutes at room temperature, 0.64 g (4 mmol) of 3- (3-fluoropropyl) -2-iminothiazoline, triethylamine.
45 g (4.4 mmol) and tetrahydrofuran 4 m
1 of the mixture was added dropwise. After stirring at room temperature for 30 minutes, the solvent was evaporated under reduced pressure, 200 ml of water was added to the obtained residue, and the precipitated crystals were collected by filtration to obtain the desired 1-
0.7 g of {3- (3-fluoropropyl) thiazoline-2-iminosulfonyl} -3- (4,6-dimethoxytriazin-2-yl) urea was obtained. Then, in the present invention, the intermediate shown in Scheme 2 and the production method are used as examples, and the production method of various starting materials used in the production method of the present invention and 3- (3-fluoropropyl) -2-iminothiazoline are used. The production of the herbicide mentioned above is specifically described as a reference example, but the present invention is not limited thereto. [Reference Example 3] Synthesis of 3-fluoro-1-propanol 3-chloro-1-propanol 18.9 g (0.2 mo
1), a mixture of 17.4 g (0.3 mol) of potassium fluoride and 25 g of ethylene glycol, with vigorous stirring, are heated to 175 to 180 ° C. and have a boiling point of 125 to 135.
8.31 g of a fraction at a temperature of ℃ was obtained. By distilling this again, 3.28 g of 3-fluoro-1-propanol was obtained. Boiling point 126-130 ° C. [Reference Example 4] Synthesis of 3-fluoropropyl methanesulfonate

Embedded image 1.95 g of 3-fluoro-1-propanol (25 mm
ol), 3.83 g of triethylamine (37.9 mmo)
l), and a mixture of 25 ml of methylene chloride are cooled to -40 ° C., and 3.15 g of methanesulfonyl chloride are added thereto.
(27.5 mmol) was added. The reaction solution was returned to room temperature over 30 minutes, 20 ml of water was added, the organic layer was separated, and the aqueous layer was extracted 3 times with 50 ml of methylene chloride. The organic layers were combined, washed successively with diluted hydrochloric acid, saturated aqueous sodium hydrogen carbonate and saturated brine, and dried over anhydrous sodium sulfate. After distilling off the solvent under reduced pressure, 2.90 g of 3-fluoropropyl methanesulfonate was obtained by distillation under reduced pressure. Boiling point 73-74 ° C / 0.60
Torr. [Reference Example 5] Synthesis of 3-fluoropropyl p-toluenesulfonate

[0020]

Embedded image

3-Fluoro-1-propanol 2.34
g (30 mmol), triethylamine 4.55 g (4
5 mmol) and methylene chloride (30 ml) at room temperature, 6.29 g (3
3 mmol) was added and the mixture was stirred for 4 hours. Water 30
ml was added, the organic layer was separated, and the aqueous layer was methylene chloride 50 m.
Extract 3 times with 1. The organic layers were combined, washed successively with diluted hydrochloric acid, saturated aqueous sodium hydrogen carbonate and saturated brine, and dried over anhydrous sodium sulfate. After evaporating the solvent under reduced pressure, the residue was purified by silica gel column chromatography (chloroform) to obtain 3.4 g of 3-fluoropropyl p-toluenesulfonate. n _D ^20.3 1.5043. [Example 2] Synthesis of 3-fluoropropyl trifluoromethanesulfonate

[0022]

[Chemical 21]

3-Fluoro-1-propanol 2.34
A mixture of g (30 mmol), 2,4,6-trimethylpyridine 4 g (33 mmol) and methylene chloride 30 ml was cooled to −40 ° C., and trifluoromethanesulfonic anhydride 9.31 g (33 mmol) was added thereto. After returning the reaction solution to room temperature over 30 minutes, 30 ml of water was added,
The organic layer was separated, and the aqueous layer was extracted 3 times with 50 ml of methylene chloride. The organic layers were combined, washed successively with saturated aqueous sodium hydrogen carbonate, diluted hydrochloric acid and saturated brine, and dried over anhydrous sodium sulfate. After distilling off the solvent under reduced pressure, distillation under reduced pressure gave 3.29 g of 3-fluoropropyl trifluoromethanesulfonate.
Boiling point 62-63 ° C / 19 Torr. [Example 3] Synthesis of 3- (3-fluoropropyl) -2-iminothiazoline methanesulfonate

[0024]

Embedded image

A mixture of 2.57 g (16.5 mmol) of 3-fluoropropyl methanesulfonate, 1.5 g (15 mmol) of 2-aminothiazole and 30 ml of isopropyl alcohol was heated under reflux for 72 hours. The solvent was distilled off under reduced pressure, ethyl ether and ethanol were poured, and the insoluble material was filtered off. The filtrate was concentrated, ethyl acetate was added, and the precipitated crystals were collected by filtration to obtain 2.22 g of 3- (3-fluoropropyl) -2-iminothiazoline methanesulfonate. 81-83 ° C. [Example 4] Synthesis of 3- (3-fluoropropyl) -2-iminothiazoline / p-toluenesulfonate

[0026]

Embedded image

A mixture of 3.05 g (16 mmol) of 3-fluoropropyl p-toluenesulfonic acid, 1.28 g (12.8 mmol) of 2-aminothiazole and 7.5 ml of N, N-dimethylformamide at 80 ° C. was used for 32.
Heat for 5 hours. After washing the reaction solution with ethyl acetate and ethyl ether, the solvent was distilled off under reduced pressure to give 3
-(3-Fluoropropyl) -2-iminothiazoline
1.49 g of p-toluenesulfonate was obtained. (Brown viscous oil) [Example 5] 3- (3-fluoropropyl) -2-iminothiazoline / trifluoromethanesulfonate

[0028]

Embedded image

1.12 g of 2-aminothiazole (11.
2 mmol) and N, N-dimethylformamide 1.7
The mixture (ml) was ice-cooled, and to this was added 2.94 g (14 mmo) of 3-fluoropropyl trifluoromethanesulfonate.
l) was added. After stirring at room temperature for 1.5 hours, the reaction solution was washed with ethyl ether and the solvent was evaporated under reduced pressure to give 3- (3-fluoropropyl) -2-iminothiazoline / trifluoromethanesulfonate (3.42 g). Got (Light yellow oily substance) [Example 6] Synthesis of 3- (3-fluoropropyl) -2-iminothiazoline

[0030]

Embedded image

A) 3- (3-Fluoropropyl) -2-
Iminothiazoline methanesulfonate 1.02 g (4
mmol) in 10 ml of water, and potassium carbonate 0.5
5 g (4 mmol) was added. After stirring for 10 minutes, the reaction solution was extracted three times with 10 ml of chloroform, the organic layer was washed with saturated saline and then dried over anhydrous sodium sulfate. The solvent was distilled off under reduced pressure to obtain 0.56 g of 3- (3-fluoropropyl) -2-iminothiazoline as a pale yellow oily substance. Boiling point 77 ° C / 0.52 Torr. B) 3- (3-Fluoropropyl) -2-iminothiazoline / p-toluenesulfonate 0.87 g (3 mmo
l) was dissolved in 7.5 ml of water and 0.41 g of potassium carbonate was added.
(3 mmol) was added. After stirring for 10 minutes, the reaction solution was extracted three times with 10 ml of chloroform, the organic layer was washed with saturated saline and then dried over anhydrous sodium sulfate. The solvent was distilled off under reduced pressure to obtain 0.26 g of 3- (3-fluoropropyl) -2-iminothiazoline as a pale yellow oily substance. C) 3- (3-Fluoropropyl) -2-iminothiazoline trifluoromethanesulfonate 2.49 g (8
mmol) in 20 ml of water and potassium carbonate 1.1
1 g (8 mmol) was added. After stirring for 10 minutes, the reaction solution was extracted three times with 20 ml of chloroform, the organic layer was washed with saturated brine and dried over anhydrous sodium sulfate. The solvent was distilled off under reduced pressure to obtain 0.84 g of 3- (3-fluoropropyl) -2-iminothiazoline as a pale yellow oily substance. [Reference Example 6] Synthesis of 1- {3- (3-fluoropropyl) thiazoline-2-imino-sulfonyl}-(4,6-dimethoxytriazin-2-yl) urea

312 mg (2 mmol) of 2-amino-4,6-dimethoxytriazine was suspended in 20 ml of dry tetrahydrofuran, and 284 mg (2 mmol) of chlorosulfonyl isocyanate was added dropwise at room temperature. 3 at room temperature
After stirring for 0 minutes, a mixture of 320 mg (2 mmol) of 3- (3-fluoropropyl) -2-iminothiazoline, 222 mg (2.2 mmol) of triethylamine and 2 ml of tetrahydrofuran was added dropwise. After stirring at room temperature for 30 minutes, the solvent was distilled off under reduced pressure, and the resulting residue was mixed with 100 parts of water.
ml was added, and the precipitated crystals were collected by filtration to give the desired 1- {3- (3-fluoropropyl) thiazoline-2.
566 mg of -iminosulfonyl} -3- (4,6-dimethoxytriazin-2-yl) urea was obtained.

[0033]

INDUSTRIAL APPLICABILITY According to the present invention, 3- (3-fluoropropyl) -2-iminothiazoline, which is useful as an intermediate for highly active herbicides, can be efficiently produced from industrially inexpensive raw materials.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Toshimasa Hamada, Toshimasa Hamada, 722 Tsuboi-cho, Funabashi-shi, Chiba 1 Nissan Chemical Industry Co., Ltd. Central Research Laboratory (72) Takashi Mizukoshi 722, Tsuboi-cho, Funabashi, Chiba Kogyo Co., Ltd. Central Research Laboratory (72) Inventor Jun Sato 1 722, Tsuboi-cho, Funabashi City, Chiba Nissan Chemical Co., Ltd. Central Research Laboratory

Claims (5)

[Claims] (1) Formula (1): 2-aminothiazole represented by the formula (2): 1-chloro-3-fluoropropane represented by the formula (3), which is characterized by reacting with a base after reacting with 1-chloro-3-fluoropropane in the presence of a metal bromide, a metal iodide, or a phase transfer catalyst. A method for producing 3- (3-fluoropropyl) -2-iminothiazoline represented by: 2. Formula (4): (Wherein R represents a methyl group, a paratoluyl group or a trifluoromethyl group), and a sulfonic acid fluoropropyl ester represented by the formula (1): A compound of formula (5) characterized by reacting with 2-aminothiazole represented by: (In the formula, R represents a methyl group, a paratoluyl group or a trifluoromethyl group.) A method for producing 3- (3-fluoropropyl) -2-iminothiazoline sulfonate represented by the formula: 3. Formula (5): embedded image (In the formula, R represents a methyl group, a paratoluyl group or a trifluoromethyl group.) 3- (3-fluoropropyl) -2-iminothiazoline sulfonate is reacted with a base. Equation (3): A method for producing 3- (3-fluoropropyl) -2-iminothiazoline represented by: 4. Formula (5): embedded image (In the formula, R represents a methyl group, a paratoluyl group or a trifluoromethyl group.) 3- (3-fluoropropyl) -2-iminothiazoline sulfonate. 5. The following formula: The trifluoromethanesulfonic acid 3-fluoropropyl ester represented by.