JPH05117225A - Production of o-benzenedithiol compound - Google Patents

Abstract

PURPOSE:To industrially obtain the title high-purity compound at a low cost by charging a polar solvent with a halogen-substituted benzene compound, sulfur, iron powder or an iron salt followed by successive addition of a hydrosulfide to carry out reaction. CONSTITUTION:A polar solvent such as N,N-dimethylformamide is charged with (A) a halogen-substituted benzene compound of formula I (X is Cl or Br; R1 to R4 are such that when X is Br, they are each H, Cl, Br, alkyl, alkenyl, alkoxy, aryl, etc., and when X is Cl, they are each H, Cl, alkyl, alkenyl, alkoxy, aryl, etc.) (e.g. pentachlorobenzene), (B) sulfur, and (C) iron powder or an iron salt, followed by successive addition of a hydrosulfide like sodium hydrosulfide pref. at 60-140 deg.C for >= one hour to carry out reaction, thus obtaining the objective orthobenzenethiol compound of formula II (e.g. 1,2,4- trichlorobenzenedithiol). This method can yield the objective dithiol compound useful as an intermediate for synthesizing near-infrared light absorbers, with no need for any purification processes such as recrystallization or distillation.

Description

Detailed Description of the Invention

[0001]

The present invention relates to a method for producing orthobenzenedithiols. More specifically, the general formula (2)

[0002]

[Chemical 3]

[In the formula, R _{1 to} R ₄ may each have the same or independently a hydrogen atom, a chlorine atom, a bromine atom, an alkyl group having 1 to 9 carbon atoms, an alkenyl group, an alkoxy group, or a substituent. Aryl group, or R ₁ and R ₂ , R ₂ and R ₃ , R
₃ and R ₄ may combine with each other to form a condensed ring. ] It is related with the manufacturing method of the orthobenzene dithiols represented by these.

[0004]

Orthobenzenedithiols react with metal ions to form benzenedithiol metal complexes,
It is known that these complexes show a unique absorption spectrum in the near infrared region. Therefore, orthobenzenedithiols are important synthetic intermediates for near infrared absorbers [(Tluene-3,4-dithiol und
rerwan die 1,2-Dithioen a
ls Chelatbildner fur Meta
lle), Monacheft Fear Chemie Vol. 102,
Pages 308-320, 1971, and (Chara
ctarization and Electroni
c Structures of MetalCompl
exs Contining Benzen-1,
2-dithiolate and Related
Ligandos) Journal of American Society, 88, 4870-4875, 19
1966; Japanese Patent Publication No. 52-7454, Japanese Patent Publication No. 56-1355.
1].

Various methods are known to date for synthesizing these intermediates. For example, a method of reacting sulfonyl chloride benzene with disulfide and once obtaining dithiol via bis (orthohalogenated sulfonylbenzene) dithioether (Pol, PL 12539).
8), a method in which p-halogenated benzenethiol is treated with methyl iodide and then reacted with sulfonic acid chloride to obtain dithiol (JP-A-51-70740), and a method in which ortho-disulfonylbenzene is reduced (JP-A-Sho). 63-1859
55) and the like are disclosed.

[0006] However, these methods have to undergo complicated multi-step synthetic reactions, so that the reaction yield is low, and thus the cost is naturally high.

First, we have prepared halogenated benzene as iron powder,
A method for obtaining dithiol by treating with sulfur or hydrosulfide and once passing through an iron complex is disclosed (JP-A-58-1059).
60). This method gives dithiols with improved yield and quality compared to the above method, but since various impurities are contained therein, the quality of the near-infrared absorber derived therefrom is as follows: It is not a satisfactory product yet, and when it is used as a synthetic intermediate for a near-infrared absorber, it is necessary to recrystallize or distillate the obtained dithiol in advance.

[0008]

DISCLOSURE OF THE INVENTION The inventors of the present invention have earnestly studied a method for obtaining dithiols in a higher yield and a higher purity than halogen-substituted benzenes. That is, the present invention, halogen-substituted benzenes and hydrosulfide, in the presence of sulfur, iron powder or iron salts, in a polar solvent, in a method of obtaining orthobenzenedithiols, halogen-substituted benzenes, sulfur, This is a method for producing orthobenzenedithiols in which iron powder or iron salts are charged in a polar solvent, and then hydrosulfides are sequentially added and reacted.

An object of the present invention is to industrially and inexpensively obtain a substantially high-purity dithiol which does not require purification such as recrystallization and distillation and is satisfied as a synthetic intermediate for a near infrared absorber. A manufacturing method is provided.

The method of the present invention will be described in detail below. The halogen-substituted benzenes used in the present invention are represented by the following formula (1),

[0011]

[Chemical 4]

[Wherein, X represents a chlorine atom or a bromine atom, and R _{1 to} R ₄ are the same or independently of each other when X is a bromine atom, a hydrogen atom, a chlorine atom, a bromine atom, and a carbon number of 1 to 9]. An alkyl group, an alkenyl group, an alkoxy group, an aryl group which may have a substituent, or R ₁ and R ₂ , R ₂ and R ₃ ,
R ₃ and R ₄ may combine with each other to form a condensed ring. Further, when X is a chlorine atom, R _{1 to} R ₄ are the same or independently of each other, a hydrogen atom, a chlorine atom, an alkyl group having 1 to 9 carbon atoms,
An alkenyl group, an alkoxy group, an aryl group which may have a substituent, or R ₁ and R ₂ , R ₂ and R ₃ , and R ₃ and R ₄ may be bonded to each other to form a condensed ring. ]

Specifically, hexachlorobenzene, pentachlorobenzene, 1,2,3,4-tetrachlorobenzene, 1,2,3,5-tetrachlorobenzene, 1,
2,4,5-tetrachlorobenzene, 1,2,3-trichlorobenzene, 1,2,4-trichlorobenzene,
1,2-dichlorobenzene, hexabromobenzene, pentabromobenzene, 1,2,3,4-tetrabromobenzene, 1,2,3,5-tetrabromobenzene, 1,
2,4,5-tetrabromobenzene, 1,2,3-tribromobenzene, 1,2,4-tribromobenzene,
Halogenated benzenes such as 1,2-dibromobenzene,
1,2-dichloro-3-methylbenzene, 1,2-dichloro-3-ethylbenzene, 1,2-dichloro-3-propylbenzene, 1,2-dichloro-3-isopropylbenzene, 1,2-dichloro- 3-butylbenzene,
1,2-dichloro-3-sec butylbenzene, 1,2
-Dichloro-3-tertbutylbenzene, 1,2-dichloro-3-octylbenzene, 1,2-dichloro-6
-Nonylbenzene, and positional isomers of these alkyl groups, 1,2,3-trichloro-4-methylbenzene,
1,2,3-trichloro-4-ethylbenzene, 1,
2,3-trichloro-4-propylbenzene, 1,2,
3-trichloro-4-isopropylbenzene, 1,
2,3-trichloro-4-butylbenzene, 1,2,3
-Trichloro-4-sec butylbenzene, 1,2,3
-Trichloro-4-tertbutylbenzene, 1,2,
3-trichloro-4-octylbenzene, 1,2,3-
Trichloro-4-nonylbenzene, and positional isomers of these alkyl groups, 1,2,3,4-tetrachloro-5-
Methylbenzene, 1,2,3,4-tetrachloro-5-
Ethylbenzene, 1,2,3,4-tetrachloro-5-
Propylbenzene, 1,2,3,4-tetrachloro-5
-Isopropylbenzene, 1,2,3,4-tetrachloro-5-butylbenzene, 1,2,3,4-tetrachloro-5-sec butylbenzene, 1,2,3,4-tetrachloro-5 -Tert butylbenzene, 1,2,
3,4-tetrachloro-5-octylbenzene, 1,
2,3,4-tetrachloro-5-nonylbenzene, and positional isomers of these alkyl groups, 1,2,3,4,5-
Pentachloro-6-methylbenzene, 1,2,3,4
5-pentachloro-6-ethylbenzene, 1,2,3
4,5-pentachloro-6-propylbenzene, 1,
2,3,4,5-pentachloro-6-isopropylbenzene, 1,2,3,4,5-pentachloro-6-butylbenzene, 1,2,3,4,5-pentachloro-6-
alkyl group-substituted halogenated benzenes such as sec-butylbenzene, 1,2,3,4,5-pentachloro-6-octylbenzene, 1,2,3,4,5-pentachloro-6-nonylbenzene, 1,2 -Dichloro-3-ethenylbenzene, 1,2-dichloro-3- (2-propenyl)
Benzene, 1,2-dichloro-3- (2-isopropenyl) benzene, 1,2-dichloro-3- (2-butenyl) benzene, and positional isomers of these alkenyl groups,
1,2,3-trichloro-4-ethenylbenzene, 1,
2,3-trichloro-4- (2-propenyl) benzene, 1,2,3-trichloro-4- (2-isopropenyl) benzene, 1,2,3-trichloro-3- (2-
Butenyl) benzene, and positional isomers of these alkenyl groups, 1,2,3,4-tetrachloro-5-ethenylbenzene, 1,2,3,4-tetrachloro-5- (3-propenyl) benzene, 1,2,3,4-tetrachloro-
5- (2-propenyl) benzene, 1,2,3,4-tetrachloro-5- (2-butenyl) benzene, and positional isomers of these alkenyl groups, 1,2,3,4,5-pentachloro- 6-ethenylbenzene, 1,2,3,4
5-pentachloro- (3-propenyl) benzene, 1,
2,3,4,5-pentachloro-6- (2-propenyl) benzene, 1,2,3,4,5-pentachloro-6
Alkenyl group-substituted halogenated benzenes such as-(2-butenyl) benzene, 1,2-dichloro-4-methoxybenzene, 1,2-dichloro-4-ethoxybenzene,
Alkoxy group-substituted halogenated benzenes such as 1,2-dichloro-3,4,5-trimethoxybenzene, 2,3-
Aryl group-substituted halogenated benzenes such as dichlorobiphenyl and 3,4-dichlorobiphenyl, condensed ring-substituted halogenated benzenes such as 2,3-dichloronaphthalene and 1,2-dichloro-4,5- (methyleneoxy) benzene Etc.

The iron powder or iron salt used in the present invention may be any of, for example, iron powder, iron halides such as iron chloride and iron bromide, and iron nitrate and iron phosphate. In addition, the amount thereof used is 0.4 to 2.0 times the molar amount of the halogen-substituted benzenes, of which 0.5 to 1.1 times.
A molar ratio is preferable. If it is less than 0.4 mol, the yield is remarkably reduced, and if it exceeds 2.0 mol, it is economically disadvantageous.

Although the mechanism that acts on the reaction of sulfur used in the present invention is not clear, the experimental effect that the reaction yield of orthobenzenedithiols depends on the amount of sulfur added makes the effect of sulfur merely catalytic. It is presumed that polysulfide is produced from sulfur and hydrosulfide, which is not effective, and attacks the halogen-substituted benzene monothiol produced from halogenated benzene, facilitating the production reaction of orthobenzenedithiols. The amount of sulfur used is 1 to 20% by weight, preferably 3 to 10% by weight with respect to the halogen-substituted benzene.
% By weight. If the amount used is less than 1% by weight, the yield of desired orthobenzenedithiols decreases, and conversely 20% by weight.
If it exceeds, sulfur is liberated after the reaction, which makes post-treatment difficult.

The hydrosulfide used in the present invention is an alkali metal or alkaline earth metal hydrosulfide, and sodium hydrosulfide which is industrially inexpensive and easily available is more preferable. The amount used is 1.5 to 4.0 mol times, and preferably 1.8 to 2.5 mol times, relative to 1 mol of halogenated benzenes. Incomplete reaction product (monothiol compound) when the amount used is less than 1.5 mol times
If the number of halogen-substituted benzenes in the raw material is 3 or more when the amount of hydrogen chloride is increased to more than 4.0 mol times, by-products such as trithiol and tetrathiol compounds are increased, and yield and purity are increased. Is reduced.

Further, as a method for charging the hydrosulfide, a method of sequentially adding it as a solid, a method of dissolving it in a polar solvent used for the reaction once and adding it dropwise, or a method of dispersing it in a solvent and sequentially adding it as a slurry are available. Any method may be used, and there is no limitation on the method as long as the hydrosulfide is sequentially added to the reaction system.

The addition time of hydrosulfide is 0.5 to
It is 8.0 hours, preferably 1 to 4 hours. If the addition time is short, the heterogeneous reaction between halogenated benzene and hydrosulfide will proceed, and in the case of halogenated benzene as described above, by-products such as trithiol will be produced, resulting in a decrease in yield and purity. To do.

The temperature at which the hydrosulfide is added is preferably 40 ° C. or higher, preferably 60 to 140 ° C. If the reaction temperature is low, the reaction rate of hydrosulfide will be slow, so when unreacted raw materials are recovered or once the reaction starts to proceed, the temperature of the reaction solution rises due to its self-heating, making temperature control difficult and controlling the reaction. Various problems occur, such as being unable to do so and the risk of bumping.

The polar solvent used in the present invention is preferably a solvent such as alcohols, esters and amides. As alcohols, methanol, ethanol,
Propanol, iso-propanol, butanol, t
Examples include ert-butanol and the like. As the esters, ethyl acetate and butyl acetate, and as the amides,
Examples thereof include dimethylformamide, diethylformamide, dimethylacetamide, N-methylpyrrolidone, tetramethylurea, hexamethylphosphoramide, dimethylimidazolidinone, and the like, preferably dimethylformamide, N-methylpyrrolidone, dimethylimidazolidinone. Is used. The amount of the polar solvent used is 1 to 10 times by weight, preferably 1 to 5 times by weight that of the halogen-substituted benzenes.

In order to obtain orthobenzenedithiols, water is added to the reaction mass obtained under the above-mentioned reaction conditions and filtered, and the black solid obtained is heat treated with zinc oxide in the presence of alkali. To do. Next, this is filtered, and a mineral acid is added to the filtrate to precipitate crystals, whereby a desired orthobenzenedithiol compound can be obtained.

The orthobenzenedithiols thus obtained are dissolved or dispersed in an appropriate solvent, reacted with salts such as nickel, palladium and platinum, and further coordinated with an alkyl quaternary ammonium to give a chemical compound. It can be used as a near-infrared absorber.

[0023]

EXAMPLES The present invention will be specifically described with reference to the following examples. In addition, the part in an Example shows a weight part. Example 1 To 200 parts of N, N-dimethylformamide (DMF) were added 100 parts of pentachlorobenzene, 12.0 parts of iron powder and 6.0 parts of sulfur, and the temperature was raised to 90 ° C. while slowly passing nitrogen. Add 70% of 70% -NaSH to DMF20
The solution dissolved in 0 part was added dropwise over 2 hours. After dropping, the mixture was aged for 2 hours and then cooled, 1000 parts of water was added, and the precipitated black solid was separated by filtration and dried. Next, 700 parts of methanol, 50 parts of zinc oxide, 125 parts of NaOH, and 500 parts of water were added to this solid, and the mixture was heated under reflux for 1 hour, cooled, and filtered, and the obtained filtrate was 1000 parts of water and 98% -H ₂ SO _4. 5
00 parts was added dropwise to the mixed solution to precipitate pale yellow crystals. This was separated by filtration, washed with water and dried, and 93.7 parts of 1,2,4-trichlorobenzenedithiol (yield 95.5%,
Purity 98.0%) was obtained.

Examples 2 to 8 The same conditions as in Example 1 were used except that the conditions shown in Table 1 were changed. The yield and purity of the obtained orthobenzenedithiol compound are shown in Table 1 together with the reaction conditions. The results of Example 1 are also shown in Table 1.

Comparative Example 1 To 300 parts of N, N-dimethylformamide (DMF) was added 100 parts of pentachlorobenzene, 12.0 parts of iron powder, 6.0 parts of sulfur and 77 parts of 70% NaSH, and nitrogen was slowly passed through. While raising the temperature to 90 ° C. After further aging for 2 hours, the mixture was cooled, 1000 parts of water was added, and the precipitated black solid was separated by filtration and dried. Then 700 parts of methanol was added to this solid,
Zinc oxide (50 parts), NaOH (125 parts) and water (500 parts) were added, and the mixture was heated under reflux for 1 hour, cooled, filtered, and the obtained filtrate was added dropwise to a mixed solution of water (1000 parts) and 98% -H ₂ SO _{4 (} 500 parts). Then, pale yellow crystals were precipitated. This was separated by filtration, washed with water and dried, and 66.8 parts of 1,2,4-trichlorobenzenedithiol (yield 65.7%, purity 83.1).
%) Was obtained.

Comparative Example 2 The same procedure as in Comparative Example 1 was carried out except that the reaction conditions shown in Table 2 were changed, and the results shown in Table 2 were obtained. The orthobenzenedithiol products obtained in Comparative Examples 1 and 2 were inferior in yield and purity as compared with those obtained in Examples 1 to 8.

Application Example 1 To 9.0 parts of the dithiol obtained in Example 1 was added 250 parts of methanol.
Parts, nickel chloride hexahydrate 4.7 parts, and tetra-n-butylammonium bromide 6.7 parts were added and reacted while blowing air to obtain 13.8 parts of the corresponding metal complex (purity 9
9.9%, molar extinction coefficient 15000) was obtained.

Application Examples 2 to 6 The same procedures as in Application Example 1 were carried out except that the conditions shown in Table 2 were changed to obtain metal complexes corresponding to orthobenzenedithiol compounds. The yield, purity, and molar absorption coefficient of the metal complex are shown in Table 2 together with the results of Application Example 1.

[0029]

[Table 1]

[0030]

[Table 2]

[0031]

As can be seen from the examples, the method of the present invention makes it possible to obtain the desired product with a high yield and high purity by a simple operation and without purification as an intermediate of the near infrared absorber. Can be used.

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[Procedure amendment]

[Submission date] August 25, 1992

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] 0025

[Correction method] Change

[Correction content]

Comparative Example 1 To 300 parts of N, N-dimethylformamide (DMF) was added 100 parts of pentachlorobenzene, 12.0 parts of iron powder, 6.0 parts of sulfur and 77 parts of 70% NaSH, and nitrogen was slowly passed through. While raising the temperature to 90 ° C. After further aging for 2 hours, the mixture was cooled, 1000 parts of water was added, and the precipitated black solid was separated by filtration and dried. Then 700 parts of methanol was added to this solid,
50 parts of zinc oxide, NaOH125 parts, 500 parts of water was added, after cooling by heating to reflux for 1 hour, filtered, added dropwise to the resulting filtrate to the liquid obtained by mixing 1000 parts of _98% -H ₂ SO 4 500 parts of water Then, pale yellow crystals were precipitated. This was separated by filtration, washed with water and dried to give 74.3 parts of 1,2,4-trichlorobenzenedithiol (yield 75.7%, purity 83.1).
%) Was obtained.

[Procedure Amendment 2]

[Document name to be amended] Statement

[Name of item to be corrected] 0029

[Correction method] Change

[Correction content]

[0029]

[Table 1]

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location C07C 323/20 7419-4H 323/21 7419-4H // C07B 61/00 300 (72) Inventor Yasushi Fukuiri 30 Mitsui Toatsu Chemical Co., Ltd. 30 Asamu-cho, Omuta-shi, Fukuoka (72) Inventor Masahiro Ota 30 Asamu-cho, Omuta-shi, Fukuoka Mitsui Toatsu Chemical Co., Ltd.

Claims (7)

[Claims] 1. A method for obtaining orthobenzenedithiols by reacting a halogen-substituted benzene represented by the general formula (1) with hydrosulfide in a polar solvent in the presence of sulfur and iron powder or iron salts, Of orthobenzenedithiols represented by the general formula (2), characterized in that halogen-substituted benzenes, sulfur, iron powder or iron salts are mixed in a polar solvent in advance, and then hydrosulfides are sequentially added and reacted. Production method. [Chemical 1] [Chemical 2] [In the formula, X represents a chlorine atom or a bromine atom, R _{1 to} R ₄ are the same or independently hydrogen atoms when X is a bromine atom,
A chlorine atom, a bromine atom, an alkyl group having 1 to 9 carbon atoms, an alkenyl group, an alkoxy group, an aryl group which may have a substituent, or R ₁ and R ₂ , R ₂ and R ₃ , R ₃ and R. They may combine with each other at ₄ to form a condensed ring. Further, when X is a chlorine atom, R _{1 to} R ₄ are the same or independent and each independently have a hydrogen atom, a chlorine atom, an alkyl group having 1 to 9 carbon atoms, an alkenyl group, an alkoxy group, or an aryl which may have a substituent. A group, or R ₁ and R ₂ , R ₂ and R ₃ , and R ₃ and R ₄ may combine with each other to form a condensed ring. ] 2. The method according to claim 1, wherein the temperature in the reaction system is 60 to 140 ° C. when the hydrosulfide is added in the reaction system. 3. The method according to claim 1, wherein when the hydrosulfide is charged into the reaction system, the addition time is 1 hour or more. 4. The hydrosulfide when adding hydrosulfide to the reaction system is sodium hydrosulfide.
The method described. 5. The method according to claim 1, wherein the polar solvent is N, N-dimethylformamide. 6. The method according to claim 1, wherein the amount of the polar solvent used is in the range of 1 to 5 times by weight based on the halogen-substituted benzene. 7. The method according to claim 1, wherein the amount of sulfur used is in the range of 1 to 10% by weight based on the halogen-substituted benzene.