JPS58162583A - Preparation of 2-benzothiazolone compound - Google Patents

Abstract

PURPOSE:To prepare the titled compound useful as a fungicide, sedative, agricultural chemicals, or their intermediates, in high purity and yield, in one step, by reacting o-halogenonitrobenzene with sulfur and carbon monoxide in the presence of a base and water. CONSTITUTION:The objective compound of formula II can be prepared by reacting the compound of formulaI X is halogen; Y is H or substituent group which does not participate in the reaction (e.g. halogen, alkyl, aryl, trihalomethyl, alkoxy, carboalkoxy, or substituted amino) with sulfur and carbon monoxide in the presence of a base, especially a tertiary amine, and water, under a CO pressure of usually 1-50kg/cm<2>, especially 5-20kg/cm<2>. The process has various advantages, i.e. the raw materials and the reaction reagents of the reaction are available easily at a low cost, the reaction proceeds under mild condition without necessitating particular reaction apparatus, the reaction operation and the post-treatment after the reaction are easy, and the recovered sulfur can be reused as it is.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing 2-benzothiazolones in 1 dollar volume, and more particularly to a method for producing the corresponding 2-benzothiazolones from 0-halogenonitrobenzenes in a single reaction.

2-Benzothiazolones themselves are used as fungicides and as intermediates for producing various pharmaceuticals and medicines, and have a wide range of industrial uses.

This unique method for producing 2-benzothiazolones is already well known. For example, Japanese Patent Publication No. 47-51341 describes a method in which 0-halogenonitrobenzenes are reacted with sodium sulfide and the resulting product is reacted with phosgene. However, this method involves a two-stage reaction in one culm as described above, and also uses toxic phosgene, which poses problems in terms of work safety and environmental protection, and is not satisfactory as an industrial method. . For this reason, as a method that does not use phosgene, Japanese Patent Application Laid-open No. 53-34772 discloses a method in which 0-halogenonitrobenzenes are reacted with a polyhydride metal to form the corresponding disulfide, and then a metal sulfide is reacted with the 0-halogenonitrobenzene. O-aminothiophenols are obtained, which are further reacted with chloroformic acid ester to form the corresponding 2-substituted thioanilines, and then ring-closed in the presence of an acid catalyst to obtain the desired 2-benzothiazolones. The method described here requires multiple steps, and chloroformic acid ester is expensive, so it is disadvantageous for industrial application.

On the other hand, JP-A No. 48-34875 describes a method for obtaining 2-benzothiazolone by reacting 0-nitrothiophenol with carbon monoxide using rhodium chloride and vanadium pentoxide as catalysts. This method is the same as the previous two methods in that a step for producing -nitrothiophenol from 0-halogenonitrobenzene is separately conducted, and 2-benzothiazolone is obtained from 0-halogenonitrobenzene through several steps. Furthermore, this method requires severe reaction conditions of high temperature and high pressure, and the noble metal catalyst used is also expensive.

In contrast to the above-mentioned method, it is possible to react in one step by reacting carbonyl sulfide in the presence of an organic phosphorus compound, an inorganic antimony compound, or sodium hydrogen sulfide with a nitrobenzene having a non-1W substitution at one 〇-grain position. A method for obtaining 2-benzothiazolones has also been proposed (U.S. Pat. No. 3,586).

No. 690 and No. 3,586,691], it is necessary to use carbonyl sulfide, which is toxic and difficult to handle, in large excess with respect to the raw material nitrobenzene, and the reaction conditions of Takada, a senior high school student, are required. , and the yield is extremely low.

The present invention was made in order to solve the various problems described above, and an object of the present invention is to provide a method for obtaining high-purity 2-benzothiazolones in high yield from the 0-halogenonitrobenzene angle in a single reaction. shall be.

The method for preparing 2-benzothiazolones according to the present invention involves converting 0-halogenonitrobenzenes represented by the general formula (where, X represents a halogen and Y represents hydrogen or a 'Pt substituent that does not participate in the reaction) into a base. and sulfur and -carbon oxide in the presence of water to obtain 2-benzothiazolones represented by the general formula (Y11 is the same as above).

In the raw material compound 0-halogenonitrobenzene m(I), halogen X includes fluorine, chlorine, chlorine, and iodine, and is preferably chlorine or bromine.

Y represents hydrogen or sludge that does not participate in the reaction. Examples of such substituents include halogen, such as fluorine, chlorine,
Bromine and iodine, alkyl groups, preferably 0l-CIO
Methyl, ethyl, propyl, butyl, hexyl, octyl, etc., aryl, such as evaphenyl, benzyl, etc., trihalomethyl, such as trichloromethyl, tribromomethyl, trifluoromethyl, dichlorobromomethyl, etc., alkoxy and allyloxy groups, Preferably C1-C
tO is methoxy, ethoxy, propoxy, butoxy, hexyloxy, octyloxy, phenoxy, etc., carboalkoxy group, preferably carbomethoxy, carboethoxy, carbopropoxy, carbobutoxy, etc. containing an alkyl group of 01' to CIO; W# cotton amide 7 groups, such as acetylamino, tosyl amino, etc. The substituents of O-halogenonitrobenzenes that can be used in the present invention are not limited to these examples, but do not substantially participate in the reaction and do not cause undesirable side reactions. For example, ring hydrocarbon groups, heterocyclic groups, and other polar groups can also serve as substituents, as long as they do not cause any of the following.

Preferred specific examples of O-halogenonitrobenzenes include 0-chloronitrobenzene, O-bromnitrobenzene, 2.3-dichloronitrobenzene, 2.5-dichloronitrobenzene, 2-chloro-3-nitrotoluene,
4-Chlor-3-nitrotoluene, 3-nitro-4-chlorobencitrichloride, 3-nitro-4-chlorobencitriflutlJ)', 4-chloro-3-nitroanisole, 4-chloro-3-di Trophenetol, 2-chloro-5-phenoxynitrobenzene, 4-chloro-3-
Examples include methyl triammonate, butyl 4-chloro-3-nitrobenzoate, and 5-acetylamino-2-chloronitrobenzene.

According to the method of the present invention, 2-benzothiazolone can be obtained from 0-halogenonitrobenzene, and 0-benzothiazolone can be obtained with any substituent.
-2-benzothiazolones having the corresponding a-substituted X are obtained from the halogenonitrobenzenes.

The sulfur used in the present invention is preferably sulfur, and commercially available sulfur can be used as is. The amount of sulfur used is 0-halogenonitrobenzene (1 to 10 moles per 121 moles, preferably 1 to 10 moles per 121 moles), considering whether the reaction proceeds quickly or the ease of post-treatment. The amount is 5 moles.There is no particular need to use as much as 10 moles.

Under the reaction conditions according to the present invention, the gap, which is not used in excess, reacts with carbon monochloride and water in the reaction system to form sulfides, and the resulting reaction mixture is (4 compound force λ
There is no need to remove it. However, it can also be recovered if necessary.

In this disclosure, as a base! fs3R amines are preferably used, and specific examples include tertiary amines such as trimethylamine, triethylamine, tripropylamine, aromatic tertiary amines such as N,N-dimethylaniline, N,N-diethylaniline, etc. pyridine, picoline,
N-aromatic tertiary amines such as lutidine, quinoline, pyrazine, pyrimidine, N-alkylpiperidines such as N-methylpyrrolidine, N-ethylpyrrolidine, N-methylpiperidine, N-ethylpiperidine, etc. f, KN
-alkylpiperidine, 1,4-diazabicyclo[2,
2,2]octane, 1,8-diazabicyclo[5,4,
0] Undecene-7 and other cyclic tertiary amines can be mentioned. Is the amount of base used not particularly controlled?
+￥lv,,0-halogenonitrobenzene 11(1)1
1 to 20 mol per mole, preferably 2 to 10 mol.

In the present invention, the reaction is preferably carried out in a solvent. The reaction solvent may be any solvent as long as it is not reduced in case F (e.g., ethers, amides, amines, aromatic hydrocarbons, aliphatic hydrocarbons, alicyclic hydrocarbons, etc.). One or a mixture of two or more of the following types can be used.

Preferably, one or a mixture of two or more of tetrahydrofuran, dioxane, diethyl ether, dimethylformamide, dimethylacetamide, triethylamine, pyridine, N-methylpiperidine, benzene, toluene, xylene, hexasan, cyclohexane, etc. is used.

In the present invention, as will be described later, the presence of water in the reaction solvent is required, so when using an organic solvent, it is desirable that it has water and resin solubility. , N,N-dimethylformamide, N,N-dimethylacetamide, N-methylpyrrolidone and the like are preferably used. As understood by Yojima, tertiary amines such as triethylamine and pyridine can serve both as base and solvent. Furthermore, water can also serve as a solvent.

Although the invention is not limited in any way by theory, the formation of a carbon-sulfur bond by substitution of an active halogen at the 0-position of a nitro group by the purifying action of a base in the presence of sulfur, carbon oxide, and water. , ・It is thought that the reduction of the nitro group and the ring-closing reaction to form the thiazolone ring occur in a controlled order to produce 2-benzothiazolones, and their exact function is not clear or there may be water present in the reaction system. That's 8 cents. In the present invention, water is usually used in a molar amount of 1 to 100 times the amount of the raw material 0-halogenonitrobenzene. Is it possible to use 100 times the molar amount?
Preferably it is 2 to 30 times the molar amount.

Carbon monoxide FF in the reaction is usually 1 to 5oKq/r
++1, preferably 5-20 i/crl. lO
Even at a low fF of less than /cd, the reaction proceeds sufficiently rapidly and smoothly, and does not require particularly high pressure. However, higher pressures can be used if necessary.

The reaction temperature may generally range from 0 to 300°C, but is preferably from 50 to 100°C, and the time required for the reaction depends on other reaction conditions, but is usually less than ten hours. In most cases, the reaction is completed in about 10 hours. The reaction is preferably carried out in an autoclave, in which case -carbon oxide may be replenished continuously or intermittently during the course of the reaction.

In the method of the present invention, the reaction system is usually substantially in a solution state. After the reaction is completed, the solvent is distilled off if necessary, water is added to the reaction mixture to precipitate any sulfur that may remain in the system, and then a sparingly soluble alcohol is added to the water for the reaction. After extracting the product and removing sulfur by filtration, the alcohol layer is separated and the alcohol is distilled off to obtain 2-benzothiazolones corresponding to the raw material compounds. As the extraction alcohol, for example, 0
A 4 to C9 aliphatic or alicyclic alcohol can be used, and specific examples include butanol, pentanol, hexanol, cyclohexanol, and the like.

Alternatively, as another simple post-treatment method, the solvent may be simply distilled off from the reaction mixture under reduced pressure. As mentioned above,
Usually, most of the sulfur used in the reaction reacts under the reaction conditions, and the reaction product is vaporized during the process of returning the autoclave to Tsuneta or distilling off the reaction solvent under reduced pressure after the reaction, and the resulting residue 7A1 is This is because virtually no sulfur remains.

As a method, the solvent is distilled off from the reaction mixture under reduced pressure, the residue is dissolved by adding an aqueous alkaline solution, and then filtered.
The corresponding 2-benzothiazolones can also be precipitated by acidifying the obtained p-liquid with a mineral acid.

According to the present invention, generally available 2-benzothiazolones have high purity, but 1 can be purified by crystallization depending on the required Cζ. As the recrystallization solvent, alcohol,
Water, aromatic hydrocarbons, etc. can be used.

The method of the present invention is to react 0-halogenonitrobenzenes with sulfur and carbon monoxide in the presence of a base and water to obtain the corresponding 2-benzothiazolones as described above. has advantages.

(a) Raw material compounds O-halogenonitrobenzenes, sulfur, -carbon oxide, bases, and all IQ materials and reaction reagents required for the reaction are readily available and inexpensive.

(b) Corresponding 2-benzothiazolones can be obtained from 0-halogenonitrobenzenes in a single reaction, and the benzothiazolones generally have a high yield of 4< and a high purity tr.

(Haλ) The reaction conditions are -sum, especially -carbon oxide powder is 1
Since the reaction proceeds quickly and smoothly even at 0)l/c- or less, no special reaction equipment is required. Furthermore, the reaction does not require high temperatures and the reaction time is relatively short.

(2) The reaction operation and post-treatment after the reaction are also simple.

(If necessary, the sulfur can be easily recovered after the reaction is completed and reused as is.

Examples of the present invention are shown below, but the present invention is not limited by these Examples.

'V Example 1 Add 0.9 of 2.5-dichloronitrobenzene to a 100Wle capacity stainless steel crepe equipped with a stirrer.
6 f (5 mmol), sulfur powder 0.8 f (
25 mm! ), 0.54 w/(30 mmol) of water and 2.8 m/(20 mmol) of triethylamine were charged together with 20 g of tetrahydrofuran, and -oxidation 1.
The inside of the autoclave was replaced with a mystery element, and the carbon oxide was adjusted to 9/cd to 10, and then the inside of the autoclave was heated to 80°C.
The mixture was heated to 80°C and reacted with stirring for 10 hours.

After the reaction was completed, the autoclave was cooled to room temperature and the interior of the autoclave was returned to normal operation. The solvent was distilled off from the resulting reaction mixture under reduced pressure to obtain a slightly brown solid as a residual liquid. This was recrystallized from toluene to yield 0.65 f of 5-chloro-2-benzothiazolone (yield 7'0%).
was obtained as white crystals.

``I? Clause 2 The reaction was carried out in the same manner as in Actual Example 1, except that 5 mmol of each of the 0-halogenonitrobenzenes shown in Table 1 was used instead of 2,5-dichloronitrobenzene as the 10-component compound. After that, the solid residue obtained was quantitatively analyzed by gas chromatography to determine the yield.The results are shown in Table 1.

Table 1 Example 3 3-nitro-4-chlorpenzotrifluoride 1.13F (5 m
The reaction was carried out in the same manner as in Example 1, except that mnl) was used. After the reaction was completed, the solvent was distilled off from the reaction mixture under reduced pressure, and a 5% aqueous solution of caustic soda was added to the obtained solid residue. Dissolved, filtered, and acidified the resulting precipitate by adding m salt misaki to precipitate crystals. Take one portion of the solution, wash with water, soften, and prepare 5-trifluoromethyl-2-benzothiazolone. .97F (yield 88%) was obtained.

Example 4 A reaction with 2,5-dichloronitrobenzene was carried out in exactly the same manner as in Example 1, except that the base shown in No. 2 was used as the base. After the reaction was completed, the solvent was distilled off from the resulting reaction mixture, and the solid nl fraction was quantitatively analyzed by gas chromatography to determine the yield of the obtained 5-chloro-2-benzothiazolone. The results are shown in Table 2.

Table 2 Patent applicant: Osaka City Same Sugai Chemical Industry Co., Ltd.

Claims (5)

[Claims] (1) General formula (where, X represents a halogen, and Y represents hydrogen or a fit substituent that does not participate in the reaction.0-halogenonitrobenzenes represented by A method for producing 2-benzothiazolones represented by the general formula (wherein, Y is the same as above), characterized by reacting with 2-benzothiazolones. (2) The method for producing 2-benzothiazolones as set forth in claim 1, wherein the base is a tertiary amine. (3) General formula (I) [where Y is hydrogen, halogen,
The method for producing 2-benzothiazolones according to claim j81, which is an alkyl group, an aryl group, a trihalomethyl group, an allyloxy group, an allyloxy group, a carbalkoxy group, or a substituted amino group. (4) A method for producing 2-benzothiazolones according to claim 1, characterized in that the reaction is carried out under a carbon monoxide pressure of 1 to 50 KIF/cd. (5) A method for producing 2-benzothiazolones according to Claim 11%IIJi, characterized in that the reaction is carried out under a -carbon oxide pressure of 5 to 20 Kf/e-.