JPH0149148B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a novel halogen-substituted-ortho-benzenedithiol and a method for producing the same. That is, the compound of the present invention has the general formula (), A novel halogen represented by Substituted-ortho-benzenedithiols. Specifically, 1,
2,4-trichlorobenzene-5,6-dithiol, 1,4-dichlorobenzene-5,6-dithiol, 1-chlorobenzene-5,6-dithiol, 1,2,4-tribromobenzene-5, 6-
Dithiol, 1,4-dibromobenzene-5,6
-dithiol and 1-bromobenzene-5,6
- is a dithiol. The halogen-substituted-ortho-benzenedithiols of the present invention react with metal ions to form benzenedithiol metal complexes. This metal complex has superior compatibility with various resins compared to the conventionally known tetrachlorobenzenedithiol metal complex,
Even if the addition ratio is increased, crystallization from the resin does not occur during long-term use. already known, for example benzene-1,2-dithiol, 1-methylbenzene-3,4-dithiol, 1,2-dimethylbenzene-4,5-dithiol and 1,2,3,4-tetramethylbenzene-5 , 6-dithiol and other ortho-benzenedithiols have strong metal chelating abilities, reacting with metal ions to form benzenedithiol metal complexes, and these complexes have unique properties in the near-infrared region. It is known to exhibit an absorption spectrum (“Toluene-3,4-dithiol und verwan
dte1,2−Dithiolene als Chelatbildner fur
Metalle”, Monachieft Fire Hemy 102
Volume, pp. 308-320, 1971 and Characterization and Electronic Structures
of Metal Complexes Containing Benzene−
1,2-dithiolate and Related Ligands, Journal of the American Society 88
Vol., pp. 4870-4875, 1966). For this reason, ortho-benzenedithiols are important compounds as intermediates for the synthesis of near-infrared absorbers (Japanese Patent Publication No. 7454/1983, Japanese Patent Application Laid-open No. 13551/1983). However, conventionally known ortho-benzenedithiols, except for 1,2,3,4-tetrachlorobenzene-5,6-dithiol (Japanese Patent Publication No.
56-135463), which is obtained through a complex several-step synthesis reaction, is extremely expensive, and its use is naturally limited. In addition, tetrachlorobenzenedithiol is put into practical use because its production method is economically advantageous, and the metal complexes of tetrachlorobenzenedithiol derived from it have excellent performance as near-infrared absorbers. When kneaded into resin as a near-infrared absorber and used in films or plates, increasing the amount of tetrachlorobenzenedithiol metal complex added may cause the tetrachlorobenzenedithiol metal complex to crystallize from the resin after long-term use. . For example, this phenomenon becomes noticeable when 20% by weight or more is added to the acrylic resin. For this reason, if it is necessary to contain it in a resin at a high concentration,
For example, it is not suitable for imparting a high degree of near-infrared absorption ability with a thin film formed by a coating method. On the other hand, the metal complexes derived from the compounds of the present invention have high compatibility with resins, etc., and do not crystallize from the resin even after long-term use even if the addition ratio is increased. And, the intermediate of the present invention can be produced by the production method described below,
Since it can be produced industrially advantageously, metal complexes derived therefrom can also be produced at low cost and can be used for various purposes as economically advantageous near-infrared absorbers. That is, the novel halogen-substituted ortho-benzenedithiol of the present invention is extremely useful as a synthetic intermediate for near-infrared absorbers that have extremely excellent compatibility with resins. The present inventors investigated the industrially advantageous synthesis method for the above-mentioned useful novel halogen-substituted ortho-benzenedithiol. , from the known hexachlorobenzene to 1,2,3,4-tetrachlorobenzene-
A method for producing 5,6-dithiol, namely:
The hexachlorobenzene and sodium bisulfide described in the Journal of the American Society, Volume 88 cited above were mixed in the presence of iron powder using dimethyl formamide as a solvent.145
(2) To obtain the desired halogen-substituted-ortho-benzenedithiol from pentahalogenated benzene and lower halogenated benzene, For example, pentachlorobenzene, 1,2,3,4-tetrachlorobenzene, 1,2,3-trichlorobenzene,
from pentabromobenzene, 1,2,3,4-tetrabromobenzene or 1,2,3-tribromobenzene, respectively, to the corresponding new 1,2,4
-trichlorobenzene-5,6-dithiol,
1,4-dichlorobenzene-5,6-dithiol, 1-chlorobenzene-5,6-dithiol,
It has been found that 1,2,4-tribromobenzene-5,6-dithiol, 1,4-dibromobenzene-5,6-dithiol or 1-bromobenzene-5,6-dithiol can be obtained, and the present invention Completed the manufacturing method. That is, the method of the present invention is based on the general formula () (wherein, X represents a chlorine or bromine atom, Y and Z represent a hydrogen or chlorine atom when X is a chlorine atom, and represent a hydrogen or a bromine atom when X is a bromine atom) This is a method for producing a compound represented by the general formula () by heating and reacting benzene and hydrosulfide in a polar organic solvent in the presence of sulfur and iron powder or iron salts. Although it is not necessarily clear what mechanism of action the sulfur added in the method for producing halogen-substituted ortho-benzenedithiol in the present invention exerts its effect, it is possible to sufficiently increase the reaction yield of halogen-substituted ortho-benzenedithiol. Judging from the experimental results that the amount of sulfur added must be at least 5% by weight based on the hydrosulfide in order to improve the
It is thought that polysulfide is produced from sulfur and hydrosulfide, and this attacks the halogen-substituted benzene monothiol produced from the polyhalogenated benzene, facilitating the reaction to produce halogen-substituted-ortho-benzenedithiol. In the production method of the present invention, the raw material polyhalogenated benzene is represented by the general formula (),
Specifically, pentachlorobenzene, 1,2,3,
4-tetrachlorobenzene, 1,2,3-trichlorobenzene, pentabromobenzene, 1,2,
3,4-tetrabromobenzene and 1,2,3
- tribromobenzene. Further, as the hydrosulfide, an alkali metal or alkaline earth metal hydrosulfide, preferably sodium hydrosulfide or potassium hydrosulfide, is used. The amount of polyhalogenated benzene and hydrosulfide to be used is 2 to 5 moles, preferably 2.5 to 3.0 moles of hydrosulfide per 1 mole of polyhalogenated benzene.
It is a molar ratio. Furthermore, alcohols and amide solvents are suitable as the polar organic solvents used in the production method of the present invention. Alcohols include methanol, ethanol, n-propanol, isopropanol, n
-butanol, tert-butanol are good, and amide solvents include dimethylformamide, diethylformamide, dimethylacetamide, N-
Methylpyrrolidone, tetramethylurea, hexamethylphosphoramide are used. The amount of polar organic solvent used is 1 for polyhalogenated benzene.
~10 times by weight, preferably 2 to 5 times by weight. Further, as the iron powder or iron salt used in the production method of the present invention, any of iron powder, divalent or trivalent iron salts, that is, iron chloride, iron bromide, iron nitride, and iron phosphate may be used. The amount of powder or iron salts used is per mole of polyhalogenated benzene.
The proportion is between 0.25 and 2.0 mol, preferably between 0.5 and 1.0 mol. Further, the amount of sulfur used in the production method of the present invention is 3 to 30% by weight, preferably 5 to 30% by weight based on the hydrosulfide.
If the addition ratio is too small, the desired halogen-substituted ortho-benzenedithiol will not be produced or the yield will be extremely low. Also, if the amount added is too large, sulfur is likely to be liberated during post-treatment after the reaction.
Post-processing becomes complicated. Reaction temperature is 110-145℃, preferably 120-140℃
The reaction time varies depending on the type of reaction solvent and the addition ratio of hydrosulfide and sulfur, but 8 to 16 hours is usually sufficient. After the reaction under the above conditions, the reaction mixture is cooled, water is added to the reaction mixture, the resulting black solid is heated with zinc oxide in the presence of an alkali, and the resulting black solid is heated with zinc oxide in the presence of an alkali, then filtered, and then a mineral acid is added to the resulting leakage liquid. In addition, the desired liberated halogen-substituted-ortho-benzenedithiol can be obtained. The novel halogen-substituted ortho-benzenedithiol thus obtained has the ability to chelate metals, and nickel, palladium or platinum can be added to a solution in which the halogen-substituted ortho-benzenedithiol is dissolved or suspended in an appropriate solvent. A chemically stable organometallic complex can be obtained by further coordinating a quaternary ammonium salt to a halogen-substituted-ortho-benzenedithiol complex reacted with salts, which can be exposed to near-infrared rays. When used as an absorbent, conventional 1, 2, 3, 4
-Compared to organometallic complexes similarly derived from tetrachlorobenzene-5,6-dithiol, it has excellent compatibility with various resins, and can be incorporated in resins at high concentrations as a near-infrared absorber, making it suitable for coatings. It has become possible to provide a high degree of infrared absorption ability with a thin film made by the method. Examples are shown below. Note that parts in the examples indicate parts by weight. Example 1 150 parts of N,N-dimethyl formamide, 50 parts of pentachlorobenzene, 70% sodium bisulfide 38
1 part, 4 parts of sulfur, and 6 parts of iron powder were heated to 135°C and reacted for 10 hours while slowly passing nitrogen gas. After cooling and adding 500 parts of water, leakage was performed. The black solid was filtered out and air dried. Next, add 20 parts of zinc oxide to 250 parts of methanol.
and an aqueous solution of 50 parts of sodium hydroxide dissolved in 250 parts of water, and the mixture was heated for 1 hour at a temperature at which methanol refluxed. After cooling, leakage was performed and the leaked liquid was poured into sulfuric acid, which was a mixture of 500 parts of water and 250 parts of 98% sulfuric acid, and a pale yellow powder was precipitated. Filtration and air drying yielded 39 parts of pale yellow crystals (melting point 95-110°C).
This crystal was recrystallized from chloroform, and 1.
37 parts of pale yellow needle-shaped crystals of 2,4-trichlorobenzene-5,6-dithiol were obtained (yield: 75 mol%). Melting point 115-116℃ Elemental analysis value C(%) H(%) Cl(%) S(%) Calculated value 29.34 1.23 43.31 26.11 (as C ₆ H ₃ Cl ₃ S ₂ ) Analysis value 29.28 1.28 43.1726.31 NMR δCDCl ₃ 4.65 (2H, d), 7.34 (1H, S) Example 2 1,
43 parts of 2,3,4-tetrachlorobenzene, 35 parts of 70% sodium bisulfide, 3 parts of sulfur, 4 parts of ferrous chloride
Add 15 parts of aqueous salt, heat to 140℃ and react for 10 hours while slowly passing nitrogen gas, then cool, add 500 parts of water, and perform leakage to separate the black solid. and air-dried. Next, the entire amount of this solid was added to 250 parts of methanol together with an aqueous solution in which 20 parts of zinc oxide and 50 parts of sodium hydroxide were dissolved in 250 parts of water, and the mixture was heated for 1 hour at a temperature at which the methanol refluxed. After cooling, perform leakage and pour the leaked liquid into 500 parts of water.
When 250 parts of 98% sulfuric acid was added to the mixed sulfuric acid, a pale yellow powder was precipitated. Filtration and air drying gave 32 parts of pale yellow crystals (melting point 47-50°C). These crystals were recrystallized from chloroform, and pale yellow needle-like crystals of 1,4-dichlorobenzene-5,6-dithiol were obtained.
28 parts were obtained (yield 67 mol%). Melting point 57-58℃ Elemental analysis value C(%) H(%) Cl(%) S(%) Calculated value 34.13 1.91 33.59 30.37 (as C ₆ H ₄ Cl ₂ S ₂ ) Analysis value 33.78 1.95 33.33 30.51 NMR δCDCl ₃ 4.58 (2H, S), 7.52 (1H, S) Example 3 100 parts of methanol, 18.2 parts of 1,2,3-trichlorobenzene, 510 parts of 35% potassium hydrosulfide, 2 parts of sulfur, ferrous phosphate octahydrate Put 8.5 parts into a glass container, put the whole glass container into a stainless steel autoclave, and react at 135℃ for 12 hours.
Cool, take out the glass container, and add 300% of the reaction solution to water.
The black solid that precipitated in addition to the filtrate was filtered out and air-dried. Next, the entire amount of this solid was added to 125 parts of methanol together with an aqueous solution in which 10 parts of zinc oxide and 25 parts of sodium hydroxide were dissolved in 125 parts of water, and the mixture was heated for 1 hour at a temperature at which the methanol refluxed. After cooling, leakage was performed and the leaked liquid was poured into sulfuric acid, which was a mixture of 250 parts of water and 125 parts of 98% sulfuric acid, and an oily substance was separated. This oil was then extracted with 300 parts of benzene and concentrated to give a colorless semi-solid. This semi-solid was distilled under reduced pressure to collect a fraction at 108-110°C/1 mmHg, which was a colorless semi-solid of 1-chlorobenzene-5,6-diothyl.
8.5 parts were obtained (yield 48 mol%). Elemental analysis value C(%) H(%) Cl(%) S(%) Calculated value 40.79 2.85 20.07 36.30 (as C ₆ H ₅ ClS ₂ ) Analysis value 40.37 2.91 20.23 36.75 NMR δCDCl ₃ 4.70 (2H, d), 7.62~6.98 (3H,
m) Example 4 N,N-dimethylformamide of Example 1
The reaction was carried out in the same manner as in Example 1 except that 250 parts were used instead of 150 parts and 95 parts of pentabromobenzene was used instead of 50 parts of pentachlorobenzene.
After adding 500 parts, filtration was performed to obtain a blackish brown solid. Hereinafter, the same processing as in Example 1 was performed, 1,
33 parts of yellow needle-like crystals of 2,4-tribromobenzene-5,6-dithiol were obtained (yield: 43 mol%). Melting point 125-127℃ Elemental analysis value C(%) H(%) Cl(%) S(%) Calculated value 24.10 1.01 53.45 21.44 (as C ₆ H ₃ Br ₃ S ₂ ) Analysis value 23.98 1.13 52.11 21.82 NMR δCDCl ₃ 4.72 (2H, d), 7.20 (1H, S) Comparative Example 1 The reaction was carried out in the same manner as in Example 1 except that the reaction was carried out without adding 4 parts of sulfur, then cooled and 500 parts of water was added. was added, followed by filtration to obtain a black solid containing white crystals. Hereinafter, the same post-processing as in the example was performed, 1.
42 parts of colorless needle-like crystals of 2,4,5-tetrachlorobenzene-6-thiol were obtained (yield: 84 mol%). Melting point 109-111℃ Elemental analysis value C (%) H (%) Cl (%) S (%) Calculated value 29.34 0.70 57.21 12.88 (as C ₆ H ₂ Cl ₄ S) Analysis value 29.25 0.79 56.82 12.96 Application example Example Bis(1,2,
4-trichloro-5,6-dithiophenolate)
Nickel()tetra-n-butylammonium was synthesized by the method described below. That is, 1000 parts of methanol, 22 parts of 1,2,4-trichlorobenzene-5,6-dithiol, and nickel chloride hexahydrate.
10.7 parts of tetra-n-butylammonium bromide and 15.4 parts of tetra-n-butylammonium bromide were added thereto, and the mixture was reacted while blowing air to obtain the desired metal complex. In addition, by the same method, bis(1,4
-dichloro-5,6-dithiophenolate)nickel()tetra-n-butylammonium and bis(1-chloro-5,6-dithiophenolate)nickel()tetra-n-butylammonium were obtained. These obtained metal complexes strongly absorbed light in the near-infrared region, had good compatibility with resins, and exhibited extremely good performance as near-infrared absorbers. For comparison, known screws (1, 2,
The results obtained using nickel (3,4-tetrachloro-5,6-dithiophenolate) tetra-n-butylammonium are also shown.

【table】

【table】

Claims (1)

[Claims] 1 General formula (), Halogen substitution represented by Ortho-benzenedithiol. 2 General formula (), (wherein, X represents a chlorine or bromine atom, Y and Z represent a hydrogen or chlorine atom when X is a chlorine atom, and represent a hydrogen or a bromine atom when X is a bromine atom) General formula () characterized by reacting benzene and hydrosulfide in the presence of sulfur and iron powder or iron salts in a polar organic solvent Halogen substitution represented by Method for producing ortho-benzenedithiol.