JPS58105960A - Novel halogen-substituted ortho-benzenedithiols and their production method - Google Patents

Abstract

NEW MATERIAL:The compound of formulaI(X is Cl or Br; when X is Cl, then Y and Z are H or Cl, and when X is Br, Y and Z are H or Br). EXAMPLE:1,2,4-Trichlorobenzene-5,6-dithiol. USE:Useful as a synthetic intermediate of near infrared absorbent. It has excellent compatibility to various resins, and can be incorporated in a resin in high concentration without causing the crystallization from the resin after the long-term use. PROCESS:The compound of formulaIis prepared by heating and reacting the polyhalogenated benzene of formula II (e.g. pentachlorobenzene, 1,2,3,4-tetrachlorobenzene, etc.) with a hydrosulfide (e.g. sodium hydrosulfide, potassium hydrosulfide, etc.) in the presence of sulfur and iron powder or iron salt, in a polar organic solvent (e.g. methanol, dimethylformamide, etc.) at 110-145 deg.C for 8- 16hr.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to novel halogen-substituted-ortho-benzenedithiols and processes for their production.

That is, the compound of the present invention has the general formula (I), (wherein X
represents a chlorine or bromine atom, Y and Z represent a hydrogen or chlorine atom when X is a chlorine atom, and a hydrogen or a bromine atom when X is a bromine atom). It is a dithiol. Specifically, 1,2゜4-) IJ Chlorobenzene-5,6
-dithiol, 1,4-dichlorobenzene-5,6-dithiol, 1-chlorobenzene-5,6-dithiol,
1°2.4-) lipcomobenzene-5,6-dithiol, 1,4-dibromobenzene-5,6-dithiol and 1-bromobenzene-5,6-dithiol.

The halogen-substituted-ortho-benzenedithiols of the present invention react with metal ions to form benzenedithiol metal complexes. This metal complex has better compatibility with various resins than the conventionally known tetrachlorobenzenedithiol metal complex, and does not crystallize from the resin during long-term use even if the addition ratio is increased.

already known, for example benzene-1,2-dithiol, 1
-methylbenzene-3,4-dithiol, 1,2-dimethylbenzene-4,5-dithiol and l,2,3.
Ortho-benzenedithiols such as 4-tetramethylbenzene-5,6-dithiol have strong metal chelating abilities and react with metal ions to form benzenedithiol metal complexes, and these complexes It is known to exhibit a unique absorption spectrum in the near-infrared region (
"Toluene -3,4-dithiol und
verwandte 1, 2-Dithiolen
e als Chelatbildnerfur Me
tal Ie l, Monacheft* 7 Ia 11
Hemy-102, pp. 308-320, 1971 and [Characterization and Ele
ctronic 5structures of Met
al Complexes ContainingBe
nzene-1, 2-dithiolate and
RelatedLigands, Journal Op.
The American Society Vol. 88, 4870-48.
75, 1966).

For this reason, ortho-benzenedithiols are important compounds as intermediates for the synthesis of near-infrared absorbers (Japanese Patent Publication No. 5
No. 2-7454, JP-A-56-13551).

However, the conventionally known ortho-benzenedithiols are 1,2,3,4-tetrachlorobenzene-5
, excluding 6-dithiol (JP-A-56-135463)
Because it is obtained through a complex several-step synthesis reaction, it 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, 20% for acrylic resin.
This phenomenon becomes noticeable when more than % by weight is added. For this reason, it is not suitable for cases where it is necessary to include it in a resin at a high concentration, for example, when imparting a high degree of near-infrared absorbing ability to 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. In addition, since the intermediate of the present invention can be produced industrially advantageously by the production method described below, the metal complex derived from it can also be produced at low cost, making it an economically advantageous near-infrared absorber. It can be used for various purposes.

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. Useful new halogen substitution
As a result of examining industrially advantageous synthetic methods for ortho-benzenedithiol, the novel halogen-substituted ortho-benzenedithiol of the present invention was found to be (1) 1.2,3.4-produced from the conventionally known hexachlorobenzene; A method for producing tetraclobenzene-5,6-dithiol,
That is, hexachlorobenzene and sodium hydrogen sulfide described in the Journal of the American Society, Vol. 488 cited earlier were reacted by heating to 1450C using dimethylformamide as a solvent in the presence of iron powder. (2) To obtain the desired halogen-substituted ortho-benzenedithiol from pentahalogenated benzene and lower halogenated benzene. , by further adding sulfur under the reaction conditions described above in the presence of iron powder or iron salts, e.g. pentachlorobenzene, 1,2,3,4-tetrachlorobenzene s 1+21.3 trichlorobenzene,
Pentabromobenzene, 1,2,3.4-tetrabromobenzene &! , 1, 2, 3-) from IJ dibromonzene, respectively the corresponding novel 1, 2, 4-)
IJ chlorobenzene-5,6-dithiol, 1゜4-dichlorobenzene-5,6-dithiol, 1-chlorobenzene-5,6-dithiol, 1,2゜4-tribromobenzene-5,6-dithiol, 1. 4-Shifcomobenzene-5,6-sitiolmata is 1-bromobenzene-5
, 6-dithiol was obtained, and the production method of the present invention was completed.

That is, the method of the present invention is based on the general formula (TL') (wherein, X
represents a chlorine or bromine atom, Y and Z represent a hydrogen or chlorine atom when X is a chlorine atom, and a hydrogen or a bromine atom when X is a bromine atom); This is a method for producing a compound represented by general formula (I) by carrying out a heating reaction with a compound represented by general formula (I) 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 Judging from the experimental results that sulfur needs to be added in an amount of 5 weight or more based on the amount of hydrosulfide in order to achieve sufficient improvement, the effect of sulfur is not a catalytic effect during the reaction, but rather
It is thought that polysulfides are generated from sulfur and hydrosulfides, and this attacks the 10-substituted benzene monothiols generated from the polyhalogenated benzenes, making it easier to cause the reaction that produces halogen-substituted-ortho-benzenedithiols. .

In the production method of the present invention, the raw material PoIJ/% rogenated benzene is represented by the general formula (1), and specific examples thereof include nihahentachlorobenzene, 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% of hydrosulfide per mol of polyhalogenated benzene.
~5 mol, preferably 2.5-3.0 mol.

Further, as the polar organic solvent used in the production method of the present invention, alcohols N and amide solvents are suitable. Alcohols include methanol, ethanol, n-propanol, isopropanol, n-butanol, tert-
Butanol is good; amide solvents include dimethylformamide, diethylformamide, dimethylacetamide, N-methylpyrrolidone, tetramethylurea,
Hexamethylphosphoramide is used. The amount of polar organic solvent used is 1 to 10% relative to polyhalogenated benzene.
The weight is preferably 2 to 5 times the weight.

Furthermore, iron powder or iron salts used in the production method of the present invention include iron powder, divalent or trivalent iron salts, i.e. iron salts,
Any of iron bromide, iron nitride, and iron phosphate may be used, and the amount of these iron powders or iron salts used is O25 to 2.0 mol, preferably 0 per 1 mol of polyhalogenated benzene.
．． The proportion is 5 to 1.0 moles.

Furthermore, the amount of sulfur used in the production method of the present invention is 3 to 30% by weight, preferably 5 to 15% by weight, based on the hydrosulfide. No dithiol is produced or the yield is extremely low. Furthermore, if the amount added is too large, sulfur is likely to be liberated in the post-treatment after the reaction (and the post-treatment will be complicated).

The reaction temperature is 110-145°C, preferably 120-1
At 40°C, the reaction time varied depending on the type of reaction solvent, hydrosulfide,
Although it varies depending on the addition ratio of sulfur, 8 to 16 hours is usually sufficient.

After the reaction under the above conditions, the reaction solution is cooled, water is added to the reaction solution, and the resulting black solid is heated with zinc oxide in the presence of an alkali, then concentrated, and then a mineral acid is added to the resulting leakage solution. In addition, it is possible to obtain the desired liberated ).logen-substituted-orthobenzenedithiols.

The novel halogen-substituted ortho-benzenedithiol obtained by (2) has the ability to chelate metals. Alternatively, a chemically stable organometallic complex can be obtained by further coordinating a quaternary ammonium salt with a halogen-substituted-ortho-benzenedithiol complex reacted with platinum salts. When used as a near-infrared absorber, it has superior compatibility with various resins compared to conventional organometallic complexes similarly derived from 1,2,3,4-tetrachlorobenzene-5,6-dithiol.
It is possible to incorporate it into a resin at a high concentration as a near-infrared absorber, and it has become possible to provide a high degree of infrared absorption ability with a thin film formed by a coating method or the like.

Examples are shown below. Note that parts in the examples indicate parts by weight.

Example I 50 parts of pentachlorobenzene, 38 parts of 70% sodium hydrogen sulfide, 4 parts of sulfur, and 6 parts of iron powder were added to 150 parts of N,N-dimethylformamide, and heated to 135°C while slowly passing nitrogen gas. After reacting for 10 hours,
After cooling and adding 500 parts of water, the mixture was concentrated to separate a black solid and air-dried. Next, the entire amount of this solid was hydroxylated with 20 parts of zinc oxide in 250 parts of methanol, and an aqueous solution of 50 parts of IJum dissolved in 250 parts of water was added thereto, and the mixture was heated for 1 hour at a temperature at which the methanol refluxed. After cooling, the mixture was concentrated and the leaked liquid was poured into sulfuric acid containing 500 parts of water and 250 parts of 98-thiosulfuric acid to precipitate a pale yellow powder.

Concentrate and air dry to obtain 39 parts of pale yellow colored crystals (melting point 95~
110'C) was obtained. This crystal was recrystallized from chloroform and 1,2.4-1lichlorobenzene-5,6-
37 parts of pale yellow needle-like crystals of dithiol were obtained (yield: 75
Mortgage).

Melting point 115-116°C Elemental analysis value CO2) H (%) C1 (%) 8
(H) Calculated value 29.34 1.23 43.31
26.11 (as C6H3CI382) Analysis value 29.28 1,28 43.17 26.
31st part MFLza CDCl34.65 (2H, d)
, 7.34 (IH,S) Example 2 1°2.3 to 210 parts of N,N-diethylformamide
．． 43 parts of 4-tetrachlorobenzene, 70 parts sulfurized)
35 parts of IJum, 3 parts of sulfur, 15 parts of ferrous chloride tetrahydrate
140° while slowly introducing nitrogen gas.
After heating to C and reacting for 10 hours, cool and add 50
After adding 0 parts, concentrate and filter out the black solid.
Air dried. Next, the entire amount of this solid was mixed with methanol 250
20 parts of zinc oxide and 50 parts of sodium hydroxide to 25 parts of water
The mixture was added together with an aqueous solution dissolved in 0 parts of methanoyl, and heated for 1 hour at a temperature at which methanomil was refluxed. After cooling, the mixture was concentrated and the leaked liquid was poured into a mixture of 500 parts of water and 250 parts of 98% sulfuric acid to precipitate a pale yellow powder. It was concentrated and air-dried to obtain 32 parts of pale yellow crystals (melting point 47-50'C). These crystals were recrystallized from loloform, and pale yellow needle-like crystals of 1,4-dichlorobenzene-5,6-dithiol were obtained.
8 parts were obtained (yield 67 mol%).

Melting point 57-58°C Elemental analysis C (chi) H (chi) CI (chi)
SoONMR, JCDCI34.58 (2H,S)
, 7.52 (IH,S) Example 3 100 parts of methanol, 18.2 parts of 1.2.3-trichlorobenzene, 510 parts of 35% trihydrium sulfide, 2 parts of sulfur, 8 parts of ferrous phosphate octahydrate .5 parts were placed in a glass container, the entire glass container was placed in a stainless steel autoclave, and reacted at 135°C for 12 hours, cooled, the glass container was taken out, and the reaction solution was added to 300 parts of water to precipitate. The black solid was concentrated 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, concentrate and collect the leaked liquid with 250 parts of water and 125 parts of 98% sulfuric acid.
When added to the mixed sulfuric acid, an oil 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 rrmHg to obtain 8.5 parts of a colorless semi-solid of 1-chlorobenzene-5,6-dithiol (yield: 48 mol). %).

Elemental analysis value C (%) H (chi) C1 (chi) 5 (
4) Analysis value 40.37 2.91 20,23 3
6,75 part MRSCDC134,70 (2H9d), 7
．． 62-6.98 (3H9m) Example 4 Example 1 except that 250 parts of N,N-dimethylformamide in Example 1 was replaced with 150 parts, and 95 parts of pentabromobenzene was replaced with 50 parts of pentachlorobenzene... After the reaction was carried out in the same manner as above, it was cooled, 500 parts of water was added, and then concentrated and filtered to obtain a blackish brown solid.

Below 1. The same treatment as in Example 1 was carried out, and 1,2.4-
33 parts of yellow needle-like crystals of tribromobenzene-5,6-)thiol were obtained (yield: 43 mol).

Melting point 125-127uC Elemental analysis value C (chi) H (chi) CI (%)
s (俤) Analysis value 23,98 1, 13 52.1
1 21.82 parts MR8CDC134,72 (2H9d
), 7.20 (IH9S) 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.
After adding 0 part, the mixture was concentrated and filtered to obtain a black solid containing white crystals.

Hereinafter, the same post-processing as in the example was performed, and 1, 2.4, 5
42 parts of colorless needle-like crystals of -tetrachlorobenzene-6-thiol were obtained (yield: 84 mol).

Melting point 109-111°C Elemental analysis value C (chi) H (chi) CI (%)
8 (%) Analysis box 29,25 0,79 56,8
2 12.96 Application Example 1,2,4-1-dichlorobenzene-5 obtained in Example 1
, 6-dithiol was used to synthesize bis(1+2+4-trichloro-5,6-sithioferto)nickel(I[)tetra-n-butylammonium by the method described below. That is, 1.2.4- to 100 parts of methanol
) Add 22 parts of dichlorobenzene-5,6-dithiol, 10.7 parts of nickel chloride hexahydrate, and 15.4 parts of tetra-n-butylammonium bromide, and react while blowing air to obtain the desired metal complex. Ta. In addition, the 1,4-dichlorobenzene-5,6-dithiol and 1-chlorobenzene-5,6-dithiol carabis (1,4-dichloro-5
,6-sithiofert)nickel(I[)tetra-n
-butylammonium and bis(1-chloro-5,6
-Sithiophel-)) Nickel (1) Tet5-n-butylammonium was 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, the known bis(1,2°3.4-tetrachloro-5,6-sithioferto)nickel (I[
) The results using tetra-n-butylammonium are also shown.

Claims (1)

[Claims] (1) General formula (I), (wherein, X represents a chlorine or bromine atom; Y and Z represent a hydrogen or chlorine atom when X is a chlorine atom; halogen-substituted-ortho-benzenedithiol represented by (In the formula, X represents a chlorine or bromine atom; Y and 2 represent hydrogen or a chlorine atom when X is a chlorine atom; and hydrogen or a bromine atom when X represents a bromine atom) General formula (I) characterized by reacting polyno-10-genated benzene and hydrosulfide in the presence of sulfur and iron powder or iron salts in a polar organic solvent. (Formula), X is a chlorine or bromine atom and Y and Z represent hydrogen or a chlorine atom when X is a chlorine atom, and hydrogen or a bromine atom when X is a bromine atom).