JPH01146855A - 2,5-substituted-cyclohexane-1,4-bis(dicyanomethylene) and production thereof - Google Patents

Abstract

NEW MATERIAL:A 2,5-bis[2-(dialkylcarbamoyl)ethyl]-cyclohexane-1,4-bis (dicyanomethylene) expressed by formula I(R is alkyl). USE:A synthetic intermediate for tetracyanoquinodimethane derivatives useful as an organic semiconductor. PREPARATION:A 2,5-bis[2-(dialkylcarbamoyl)ethyl-1,4-cyclohexanedione expressed by formula II is reacted with malononitrile expressed by the formula NC-CH2- CN in a solvent, such as water-alcohol, in the presence of a catalyst (e.g., beta- alanine or glycine) at 40-60 deg.C to afford the aimed compound expressed by formula I. The malononitrile is used in an amount of 2mol based on 1mol compound expressed by formula II.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a novel compound useful as an intermediate for tetracyanoquinodimethane derivatives, which can be expected to be used as an organic semiconductor.

[Conventional technology]? , 7,8.8-tetracyanoquinodimethane (TCNQ
) is a yellow crystal with a melting point of 293.5-296°C. This compound easily accepts one electron to form a stable anion radical, and its derivatives exhibit extremely low electrical resistance. This compound is reduced with thiophenol, mercaptoacetic acid, hydrogen iodide, etc. to become phenylene dimalononitrile, which is oxidized with N-bromosuccinimide to return to TCNQ. Chemical capacitors are a practical application of TCNQ.

For example, TCNQ can be synthesized by condensing malononitrile and 1,4-cyclohexanedione!
, 4-bis(dicyanomethylene)cyclohexane is solubilized in pyridine using N-bromosuccinimide or bromine.

[Problems to be solved by the invention] As mentioned above, although TCNQ is an organic compound, it has conductivity. (F) is important for research, development, and further practical application of this type of organic conductive compound.

The present invention can be expected to be used as an organic semiconductor.
The object of the present invention is to provide a novel compound useful as an intermediate for Q derivatives.

[Means for Solving the Problems] The compound of the present invention is represented by the following general formula (fV): 25-bis[2-(dialkylcarbamoyl)ethyl]-
It is cyclohexane-1,4-bis(dicyanomethylene), and is a new compound that has not been described in any literature.

賎　　　　　　　　　 In the formula, R represents an alkyl group.

The alkyl group may be any one such as a methyl group, ethyl group, propyl group, butyl group, hexyl group, octyl group, decyl group, or cyclohexyl group.

Next, a method for producing the compound of the present invention represented by the above formula (IV) will be described.

The above compound is 2,5-bis[2-(dialkylcarbamoyl)ethyl)-1,4 represented by the general formula [wherein R represents an alkyl group]
-Produced by reacting cyclohexanedione with malononitrile represented by the formula %.

The reaction is usually carried out in a solvent such as water, alcohol, water/alcohol.

During the reaction, a small amount of a catalyst such as β-alanine, glycine, ammonium acetate, etc. is allowed to coexist.

It is sufficient to carry out the reaction under heating (for example, 40 to 60°C) for about 1 to 5 hours.

ml, the molar ratio of 4-cyclohexanedione (III) and malononitrile used is usually 2 moles of the latter to 1 mole of the former, but there is no problem even if the latter is used in excess.

After the reaction is completed, the precipitated crystals may be collected and purified by a conventional method.

When the compound thus obtained (1%') is oxidized with bromine or N-bromosuccinimide, it has the following formula: 2,5-bis[2-(dialkylcarbamoyl)ethyl)-7,7 , 8,8-tetracyanoquinodimethane can be obtained.

Compound (DI), which is a starting material, can be produced according to the following formula.

(1) (n) (n)
+ CH,=CHC011R,-'-→(1)
The first step is a reaction in which compound (I), that is, 1,4-cyclohexanedione, is enaminated with pyrrolidine to obtain compound (ff), that is, I, 4-dipyrrolidinocyclohexane-1,3-diene. It is.

Benzene, toluene, xylene, etc. are used as the solvent.

The reaction temperature is preferably reflux, and the reaction is allowed to proceed while water produced as a by-product during the reaction is removed from the system. A catalyst is not particularly required, but an acid such as p-toluenesulfonic acid can be used.

In order to prevent the oxidation of the generated dienamine, the reaction system is
It is advantageous to keep it under a nitrogen atmosphere.

The amount of pyrrolidine used is 2 to 1 mole of compound (■).
-4 moles.

The reaction time is suitably 1 to 3 hours.

After removing the solvent and residual pyrrolidine from the reaction product solution of the first stage reaction, a reaction with N,N-dialkyl acrylamide is carried out in the second stage reaction.

As the solvent, dioxane, dimethylformamide, ethanol, methanol, acetonitrile, etc. are used.

N,N-dialkyl acrylamide is compound (r)1
It is used in a ratio of 2 to 4 moles per mole.

A time window of about 3 to 24 hours is carried out under reflux, and then about 2 molar equivalents of water to cyclohexanedione are added to give 1
When the hydrolysis reaction is continued under reflux for about 2 hours, the desired product is obtained.

The alkyl group of N,N-dialkylacrylamide may be any one such as methyl group, ethyl group, propyl group, butyl group, hexyl group, octyl group, decyl group, and cyclohexyl group.

The compound (■) of the present invention is useful as an intermediate for producing a tetracyanoquinodimethane (TCNQ) derivative as an organic semiconductor.

[Function] As mentioned earlier, when the compound (■) of the present invention is oxidized using an oxidizing agent such as bromine or N-bromosuccinimide, the compound (V), that is, 2.5-bis[ 2-(Dialkylcarbamoyl)ethyl)-7,7,8,8-tetracyanoquinodimethane can be obtained.

The series of reactions detailed above can be summarized as follows. Compound (IV) corresponds to the compound of the present invention, and reaction (2) corresponds to the method of the present invention.

■ (1) + pyrrolidine → (II)
■ (I [) + CHt=CH-CONR, - foot → (If) ■ (III) + IC-CHg
CN-? (IV)■ (■) -”-p
(V) Compounds (III) and (V) themselves are also new compounds, and the reactions of (1), (2) and (2) to obtain the compounds (III) and (V) are also new methods. Therefore, the applicant filed a separate patent application in parallel with the patent application for the present invention.

[Example] Next, the present invention will be further explained with reference to Examples.

Example 1 112 g (1.0 mol) of 1,4-cyclohexanedione
, pyrrolidine 2139 (3.0 mol), toluene 450
ml was mixed and the reaction was carried out under reflux and dehydration while introducing nitrogen gas into the system. After reacting for 1.5 hours, toluene and remaining pyrrolidine were removed from the system, and 400ml of dioxane was added.
1SN.

N-dimethylacrylamide 297y (3.0 mol) was added.

After reacting under reflux for 3 hours, 100111 of water was added and the reaction was further carried out under reflux for 1 hour. After the reaction was completed, the reaction solution was cooled, residual N,N-dimethylacrylamide and dioxane were removed, and 500 ml of water was added, followed by extraction with chloroform.

The chloroform layer was washed with a 10% aqueous hydrochloric acid solution, further washed with water, and then dehydrated with sodium sulfate. Chloroform was distilled off from the extract to obtain crystals of 729.

The above product was recrystallized from methanol/acetone.

The melting point of this colorless crystal is 157-158°C, and NM
As a result of analysis of the R spectrum, mass spectrum, and IR spectrum, it was identified as the target 2,5-bis[2-(dimethylcarbamoyl)ethyl)-1,4-cyclohexanedione.

Compound (I [[a) 11.29 (36.2 mmol) obtained above, 38.3 g of water, 22.3 g of methanol and β
- 112 mg of alanine was mixed and warmed. Internal temperature 40
When the temperature reaches ℃, add 4.8 g of malononitrile to 16 g of methanol in advance! A solution containing M (73.5 mmol) was added dropwise, and the mixture was reacted at 40 to 50°C for 1.5 hours.

After the reaction was completed, it was cooled to room temperature, the crystals were separated by filtration, washed with water and methanol, and then dried under reduced pressure to obtain white powder crystals of 8.929.

The obtained crystals had the following characteristic values, and the compound (R'a)
In other words, it was confirmed to be 2,5-bis[2-(dimethylcarbamoyl)ethyltwocyclohexane-1,4-bis(dicyanomethylene). In addition, the compound (I[
The yield based on Ia) was 60.7% by weight.

Melting point 196-197℃am-'
2930.2240, 1645, 1500.1415
,1370゜IR″KBr 1340,1265,
1125.10106ON Q5su,, 2.93(
S, 611), 2.80 (S, 6H), 3.7-1.5
(m, 1411) Mass M" 406
dialkylcarbamoyl)ethyl-cyclohexane-
Since 1,4-bis(dicyanomethylene) can be provided,
Tetracyanoquinodimethane (TCN) as an organic semiconductor
Q) Routes for obtaining intermediates of derivatives will be expanded.

Claims (2)

[Claims] (1) General formula ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ 2,5-bis [2
-(Dialkylcarbamoyl)ethyl]-cyclohexane-1,4-bis(dicyanomethylene) (2) The compound according to claim 1, which is 2,5-bis[2-(dimethylcarbamoyl)ethyl]-cyclohexane-1,4-bis(dicyanomethylene). ▲There are mathematical formulas, chemical formulas, tables, etc.▼ 2,5-bis[2
General formula characterized by reacting -(dialkylcarbamoyl)ethyl]-1,4-cyclohexanedione with malononitrile represented by the formula NC-CH_2-CN▲There are mathematical formulas, chemical formulas, tables, etc.▼ [In the formula, R is an alkyl group] 2,5-bis[2
A method for producing -(dialkylcarbamoyl)ethyl]-cyclohexane-1,4-bis(dicyanomethylene).