JPS6256495A - Novel production of tetrathiafulvalene derivative - Google Patents

Abstract

PURPOSE:To obtain the titled compound promising as a donor molecule of organic superconductors in high yield and good reproducibility, by reducing dithiapendione, reacting the resultant reduction product with a 3-halo-1-butyne and alkali metal alkoxide one after another, neutralizing the reaction product and treating the neutralization product with a weak acid. CONSTITUTION:Dithiapendione expressed by formula I is first reduced with an alkali metal alkoxide in, e.g. an alcoholic solvent and the resultant compound expressed by formula II is reacted with a 3-halo-1-butyne expressed by formula III (X is halogen) to give a compound expressed by formula IV, which is then reacted with an alkali metal alkoxide expressed by the formula (RO)<->M<+> (R is lower alkyl; M is alkali metal) to afford a compound expressed by formula V. An organic solvent incompatible with water is normally added to the reaction mixture, and acetic acid, etc., is used to neutralize the reaction mixture. The organic layer is separated and collected. A weak acid, e.g. p-toluenesulfonic acid, is then added to the above-mentioned organic layer and the resultant mixture is heat-treated, e.g. at 60-80 deg.C for several tens of min - several hr, to afford the aimed compound.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a novel method for producing tetrathiafulvalene (TTF), a J conductor, which is a promising donor molecule for organic superconductors.

[Background of the invention]

In the 1971s, Tetrathiafulvalene 7
゜7.8.8-tetracyanoquinodimethane complex (TTF
-TCNQ complex) was the first organic substance to exhibit one-dimensional metal conductivity, and the field of low-molecular, low-dimensional conductors blossomed all at once, and in the 1980s, tetramethyltetraselenafulvalene salt, a TTF derivative, developed. It has been discovered that there is superconductivity, and further research in the past 1.2 years has shown that bis(ethylene dithio)-tetrathiafulvalene (BEDT-T
TF) Concentrated in salt. One of the characteristics of this BEDT-TTF salt is that the eight sulfur atoms in one molecule interact with adjacent columns, increasing its two-dimensionality. One example of this is that materials that previously only exhibited high conductivity now also exhibit high conductivity in the direction perpendicular to the column. However, the main aim of this was to curve the Fermi surface by increasing its two-dimensionality, thereby suppressing the Beiers transition (metal-insulator transition), which is the fate of low-dimensional conductors. .

As BEDT-TTF salt, Re04 salt is 4Kbar
It has been discovered that superconductivity occurs at the following pressures, and more recently it has been discovered that halogen salts such as I3 salts and Br2I salts become superconducting even without applying pressure.

However, in this BEDT-TTF, both ends of the molecule are -
Because it is cH2-cH2-, it is not a planar molecule,
This is considered to be disadvantageous for the formation of the leading complex. Therefore, in order to form a complex with higher conductivity,
Bivalent bonds were introduced at both ends of BEDT-TTF to further increase planarity, and donor molecule bis (dimethylvinylene dithio) was introduced into the methyl group to increase solubility.
-Tetrathiafulvalene (hereinafter referred to as BDMVDT-TTF)
) has been proposed (R, R, Schumak
er et al., J. Phys. (Paris), 44.
C3-11! (1983)), there is a very simple description of its synthesis method. This synthetic route is roughly as follows.

However, the method of Schumaker et al. does not have detailed descriptions of the synthesis method such as reaction conditions, solvents, and reaction reagents in the literature, and also has problems with yield, reproducibility, etc. (the inventors et al. (According to a follow-up test, only trace amounts of the desired product were obtained.) Therefore, it cannot be said that the manufacturing method is completely satisfactory. Therefore, there is a current need for a method for producing DMVDT-TTF, which is extremely promising as a donor molecule for providing organic superconductors, with higher yield and better reproducibility.

[Purpose of the invention]

The present invention was made in view of the current situation as described above, and is extremely promising as a donor molecule for providing organic superconductors.
The purpose is to provide a new method for producing VDT-TTF with higher yield and better reproducibility.

[Structure of the invention]

The present invention provides 3-
It is reacted with halo-1-butyne, and then reacted with an alkali metal alkoxide represented by the formula (RO)-M'' (where R represents a lower alkyl group and M represents an alkali metal), and after neutralization, This is a method for producing bis(dimethylvinylene dithio)-tetrathiafulvalene represented by the formula, which is characterized by further heat-treating the product under mild conditions.

The synthetic route of the present invention is roughly as follows.

Examples of the reducing agent for dithiapenedione used in the production method of the present invention include alkali metal alkoxides represented by the formula (RO)-M'', which are the same as those used in the step [B]→[C1. (RO) Examples of R in the alkali metal alkoxide represented by "M" include lower alkali groups such as methyl, ethyl, propyl, and butyl; examples include sodium, potassium, and lithium. Examples include alkali metals.

The formula IC=C=C-C used in the production method of the present invention
Examples of the acids used for X in 3-halo-1-butyne represented by H3 include mineral acids such as hydrochloric acid and sulfuric acid, and organic acids such as acetic acid and P-)luenesulfonic acid. In these limiting steps, when an alkali metal alkoxide, for example, is used as a reducing agent, the reaction is usually carried out in an alcoholic solvent.

Therefore, it goes without saying that the same results can be obtained by using a metal alkali in an alcoholic solvent instead of using an alkali metal alkoxide, and the zero reaction is usually carried out under heating, preferably under reflux of the solvent. .

The reaction time varies slightly depending on the reaction temperature, but is usually 1
~A few hours is sufficient. Since the intermediate [AI] is unstable in air, an alcoholic solution of an alkali metal alkoxide (alcoholic solution of an alkali metal) must be used after deoxidizing bubbling. It goes without saying that the alcoholic solvent should be dehydrated. The amount of alkali metal alkoxide (or alkali metal) to be used for dithiapendione is 4 times the theoretical amount by mole of dithiapendione, so
There is no particular problem if it is 4 times the mole or more, but usually 4 to 5 times
Double molar ratio is preferably used.

As reducing agents for dithiapenedione, in addition to alkali metal alkoxides, for example, LiA IH4, LiB(C
2H5)3H, alkyl lithium, NaH, etc. may also be mentioned. In this case, the solvent used is an ether solvent such as tetrahydrofuran or diethyl ether.

Reaction product of dithiapennadione and reducing agent ([AI)
is subjected to the next reaction with 3-halo-1-butyne without q being isolated.

Reduction product [The reaction between AI and 3-halo-1-butyne is an exothermic reaction, and there is no need for particular heating, and if necessary, it is carried out under cooling, usually at a temperature below 40°C. The reaction time varies depending on the reaction temperature, but 30 minutes to several hours is usually sufficient. 3-/\Colo--butyne may be used as it is, but it is usually used after being dissolved in the same solvent used in the previous reaction, for example, in the case of reduction with an alkali metal alkoxide, in an alcoholic solvent. Needless to say, deoxygenation (bubbling) must be carried out in this case as well.The theoretical amount of 3-halo-l-butyne to be used is twice the mole of dithiapenedione, so if it is more than this, it must be used especially at the M1 limit. However, it is usually used in an amount of about 2 to 3 times the mole. The reduction product of dithiapendione and 3-
The reaction product ([B]) with halo-1-butyne is unstable and usually difficult to isolate, so it is directly subjected to the next reaction. That is, an alcoholic solution of an alkali metal alkoxide in an amount of at least 2 times the mole relative to the dithiapendione (an alcoholic solution of an alkali metal alkoxide in an amount equal to or more than 2 times the mole relative to the dithiabendione) was added to this reaction solution, and the mixture was heated at 50°C or under reflux of the solvent for 30 minutes.
After 0 minutes to several hours of reaction, the reaction solution is neutralized with water and an organic solvent that is incompatible with water, and the organic layer is separated.
If necessary, it can be purified by column chromatography etc. [
C] is obtained. Next, this is heated in a weak acid such as p-)luenesulfonic acid in a solvent such as benzene or toluene for several tens of minutes to several hours (e.g. 80 to 80
℃) to isomerize the target 6BDM.
VDT-TTF is obtained. If necessary, higher quality BDMVDT-TTF can be obtained by appropriately purifying it by a commonly used purification means such as recrystallization (for example, with acetonitrile) or column chromatography.

In the production method of the present invention, the dithiabeni/dione used as a starting material is, for example, J, Am, Che■.

According to the method described in Sac.
2-Bis(0-isopropyldithiocarbonyl)acetate can be easily treated with concentrated sulfuric acid, then treated with ice water, and then reacted with trialkyl phosphite under reflux in dehydrated benzene according to the method of the same document. You can get this.

Further, the 3-halo-1-butyne used in the present invention is 1, for example, J, -Am, Cbeya, Soc, 85.5
2 (1983), 3-butyne-
The 2-ol and the phosphorus trihalide are dehydrated in pyridine solvent and a mixture of these isomers is obtained. This mixture is also fully expected to be used in the same way as BDMVDT-TTF.

Reference Examples and Examples are listed below, but the present invention is not limited in any way by these Reference Examples and Examples.

〔Example〕

Reference example 1. Thiapendiono Synthesis 11.3 g of methyl dichloroacetate was added dropwise to a solution of 25 g of sodium isopropylxanthate in 300 g of acetone at room temperature with stirring, and after one drop was added, the mixture was further stirred for 2 hours. After filtering the reaction solution to remove the common salt, acetone was distilled off, n-hexane was added thereto, the precipitated common salt was further filtered and removed, and n-hexane was distilled off to obtain an oil. 4 in another container
00- concentrated sulfuric acid was added thereto and cooled to 0°C, and diethyl ether 14d was gradually added thereto with stirring. The above oil was added dropwise to this at 0 to 5°C, and stirring was continued until the temperature reached 18°C after the dropwise addition. Add this reaction solution little by little to about 1 kg of ice.
The white solid that floated to the surface was suctioned or filtered through a glass filter. This was washed once with water and twice with 50 d of water-cooled ethyl ether, dried under reduced pressure, and recrystallized from chloroform to obtain 7.6 g of white needle crystals. Yield 46%.

Reference example 2. Synthesis of dithiabendione 1.7 g of the thiabendione obtained in Reference Example 1 was added to dehydrated benzene 20- in a nitrogen atmosphere, and 8.2+ sl of trimethyl phosphite was added dropwise to this under stirring and reflux. 1 drop @ reflux stirring for 2 hours. After the completion of the reaction, the resulting precipitate was collected, washed several times with hot benzene, and then dried under reduced pressure to obtain 1.48 g of a pale green powder of dithiapendione. Yield 93
%.

Reference Example 3. Synthesis of 3-bromo-1-butyne Under a dry nitrogen atmosphere, 6.31 g of phosphorus tribromide was mixed with 0.0 g of dehydrated pyridine.
078 m/g was added at -15°C, and to this was added 4.44 g of 3-butyn-2-ol and 0.23 g of dehydrated pyridine under stirring.
The mixture of - was added dropwise over a period of 3 hours at -15°C. After stirring for another 2 hours at -15°C, the reaction solution was poured into ice water, and the resulting oily precipitate was collected at 200 wt. Extracted with diethyl ether.

The ether layer was washed twice with water, twice with aqueous sodium bicarbonate, and then twice with water, dried over calcium chloride, and 21-tyl was distilled off to give 3.5 g of a colorless transparent liquid of 3-bromo-1-butyne. I got it. Yield 41.4%.

Example 1゜ All reactions were conducted under a deoxygenated dry nitrogen atmosphere.

Reference example 2. Dithiabendione 144 mg (0,
374!11101), 35 mg of metallic sodium (
Dehydrated ethanol solution containing 1,52 mmol) 10
d was added dropwise after deoxidizing bubbling, and the mixture was refluxed for 2 hours with stirring. After the reaction, the temperature was returned to room temperature, and 100 g of 3-bromo-1-butyne obtained in Reference Example 3 (0,75
2 mmol) was diluted with 5 ml of dehydrated ethanol and added dropwise after deoxidizing bubbling.After adding 6 drops, stirring at room temperature for 1 hour, 5 ml of dehydrated ethanol solution containing 18 mg of sodium metal was further deoxidized and bubbling was carried out. The mixture was lowered and stirred under reflux for 1 hour. Return this to room temperature again, and add 100ml of water and 200ml of diethyl ether.
1 was added, and the mixture was neutralized with hydrochloric acid.

The ether layer was separated, dried over magnesium sulfate, the ether was distilled off, and the resulting product was subjected to column chromatography [filling material: Wakogel C-200 (manufactured by Wako Pure Chemical Industries, Ltd.), effluent: n-hexane: chloro]. *) Lm = 4:
1]. This was dissolved in benzene, 4 times the mole of p-1 toluenesulfonic acid was added, and the reaction mixture was refluxed for 2 hours. The reaction solution was returned to room temperature, washed twice with 100111 water, and the benzene layer was dried with sodium sulfate. Then, benzene was distilled off to obtain crude BDMVDT-TTFII. This was subjected to column chromatography [filling material Fuco-gel C-20].
0, effluent n-hexane:chloroform=4:l] to obtain 17 pale yellow peritectics of purified BDMVDT-TTF. Yield $10.4%, m, p, 240℃ rags
: 438m" NMR (CS2): 2.00 δ I R(am-') : y 2980.2920
．． 11300.1440° 1370.870,785° Elemental analysis value calculation value ($): C38,50, H2,77, S 5
8.73 Actual value ($): C38,18, H2,73,
S 59.10 Example 2゜Example 1. In , 3-promo l-butyne lQQmy
Example 1. instead of using 70 ml of 3-chloro-1-butyne. The reaction and treatment were carried out in the same manner as in Example 1.
Similar results were obtained.

Example 3゜Example 1. scaled up and dithiabenedione 2
．． Using 88g, react and treat L4B in the same manner as in Example 1.
38 g of DMVDT-TTF O was obtained.

Yield 11%, m, p, NMR, 11/3. I
R was exactly the same as that obtained in Example 1.

In addition, the experiment was repeated two more times on the same scale, but
Exactly the same results were obtained, indicating high reproducibility.

〔Effect of the invention〕

As described above, the present invention is directed to novel bis(dimethylvinylene dithio)-tetrathiafulvalene, which is extremely promising as a donor molecule for organic superconductors.

Moreover, the present invention has a remarkable effect in that it provides a manufacturing method with a higher yield and better reproducibility than conventional methods, and is an important invention that contributes to this industry.

Claims (1)

[Claims] Dithiapenedione represented by the formula ▲There are mathematical formulas, chemical formulas, tables, etc.▼ is reduced, and the dithiapendione is represented by the formula ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (However, x represents a halogen atom.) and then with an alkali metal alkoxide represented by the formula (RO)^-M^+ (wherein, R represents a lower alkyl group and M represents an alkali metal). A method for producing bis(dimethylvinylene dithio)-tetrathiafulvalene represented by the following formula: