JP2969946B2 - 3.6-Diamino-2,5-pyrazinedicarbonitrile and method for producing the same - Google Patents

Description

Description: TECHNICAL FIELD The present invention is a novel pyrazine derivative 3,6-diamino-2,5-pyrazinedicarbonitrile (hereinafter abbreviated as the compound of the present invention) represented by the formula: and a method for producing the same.

The compound of the present invention is a yellow-green fluorescent dye with red crystals, and is used as a fluorescent dye and a light conversion material. It is also a synthetic intermediate useful for the synthesis of pteridine ring compounds and the like.

BACKGROUND ART Pyrazines, which occupy an important position among nitrogen-containing heterocyclic compounds, are a group of compounds widely used in agricultural medicines, fragrances, polymers, functional materials and the like. As the substituents, amino groups and cyano groups are particularly important and can be easily converted to other functional groups, respectively, and can be led to various derivatives by various reactions. It is expected to be a useful synthetic raw material.

It has been expected that methods for synthesizing such useful compounds from DAMN and its derivatives, which are industrial general-purpose raw materials, in a short process have been expanded.

A pyrazine derivative having an amino group and a cyano group is obtained by starting from diaminomaleonitrile (hereinafter abbreviated as DAMN) or a homolog thereof, and starting with 6-amino-2,3,5-pyrazinetricarbonitrile, 5,6-diamino- 2,3-Pyrazinedicarbonitrile, 3,5-diamino-2,6-pyrazinedicarbonitrile and the like have been synthesized. (J. Org. Chem., 39
Volume, p. 1235 (1974), Japanese Patent Application No. 63-75909, etc.) The compound of the present invention having a symmetric structure is disclosed in US Pat.
Figure 9 shows its structure as a raw material for a polymer. However, the polymer compound shown in the specification has a structure in which all imino groups are on the same side, and cannot be produced using the compound of the present invention as a raw material. Moreover, the specification does not show the physical properties of the compound of the present invention, nor its production method or an example using the same, and the existence of the compound of the present invention has not been confirmed at all.

DISCLOSURE OF THE INVENTION 2,3-Diamino-3- (phenylthio) acrylonitrile (hereinafter abbreviated as DAAN), which is an analog of DAMN, is a synthetic raw material that is easily derived from hydrocyanic acid and a disulfide compound. The present inventors have recognized the formation of a strong fluorescent substance in the course of research on a novel heterocyclic synthesis of DAAN, determined the structure of the product, devised an easy synthesis method, and reached the present invention.

That is, the present invention is a compound of the present invention which is a novel heterocyclic compound, and the following general formula [I] (wherein R is an optionally substituted aryl group, alkyl group, aralkyl Or a alkenyl group) under acidic conditions in the presence of oxygen.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in more detail.

The compound having the general formula [I] as a raw material can be easily synthesized by a method described in a patent. (WO88 / 01264) The reaction is carried out by (a) dissolving the compound represented by the general formula [I] in an acidic solution and reacting (b) dissolving an acidic salt of the compound represented by the general formula [1] in a solvent. Let react.

(A) The reaction is usually carried out in an organic solvent or in a mixed system of an organic solvent and water, in the presence of an acid or buffer for pH adjustment, and at about 0 to 30 ° C. for one hour to several hours while blowing air as necessary. Performed for hours at atmospheric pressure.

Examples of the reaction solvent include hydrocarbons such as benzene, toluene, and xylene; nitriles such as acetonitrile; halogenated hydrocarbons such as chloroform and methylene chloride; esters such as ethyl acetate; alcohols such as methanol and ethanol; and acetone. And ketones such as methyl ethyl ketone, ethers such as tetrahydrofuran, dioxane and 1,2-dimethoxyethane (DME), dimethylformamide and dimethylsulfoxide (DMSO), and may be used as a mixture.

The pH, which is an index of the acidity of the reaction solution, is suitably in the range of 1 to 5, preferably 2 to 4. At this time, any acid such as an inorganic acid or an organic acid can be used for pH adjustment, but it is preferable to use various buffers.

The reaction of the present invention is considered to be an oxidative dimerization condensation reaction. Therefore, it is necessary to put the system in an oxidizing atmosphere. Normally, it is only necessary to make contact with atmospheric oxygen, but it is desirable to actively blow air, oxygen, etc. into the reaction system.

(B) Reaction, that is, when an acid salt of the general formula [I] is used, a solvent capable of dissolving the acid salt, for example, a polar solvent such as acetonitrile, alcohols, dimethylformamide, dimethylsulfoxide, or the like; Dissolve and react in a mixed solvent. These solvents may include water.

The reaction is carried out at room temperature for 2 to 12 hours, but it is preferable to make the reaction system an oxidizing atmosphere by blowing air as in the case of the reaction (a).

Examples of the acidic salt include inorganic acid salts such as hydrochloride, sulfate and nitrate, and organic acid salts such as paratoluenesulfonate, oxalate and picrate. In addition, an acidic substance which hardly precipitates as an acidic salt, for example, trifluoroacetic acid, perchloric acid or the like can be reacted in the same manner as in the case of using an acidic salt.

In both cases of the reaction (a) and the reaction (b), after the reaction is completed, the desired product can be obtained by performing ordinary post-treatment.

The structure of the compound of the present invention was determined by comparing spectra such as IR, NMR, and Mass with known structural isomers.

Hereinafter, the present invention will be described more specifically with reference to examples.

Example 1 400 mg of DAAN was dissolved in 45 ml of DME, added to a solution containing 150 ml of 0.1 M citric acid-sodium citrate buffer (pH = 3.0) and 150 ml of water, and allowed to stand at room temperature for 5 hours. The precipitated red needle crystals were filtered and washed with 3 ml of n-hexane-ethyl acetate (3: 1).

7.5 mg (Yield: 45% assuming that one molecule of the compound of the present invention is formed from two molecules of DAAN) Melting point> 280 ° C. Mass spectrum: M ¹ = 160 Absorption spectrum: 223, 266, 458 nm (DME) Fluorescence spectrum: λem = 538 nm (λex = 460 nm) (DME) ¹³ C-NMR spectrum: 149.730, 115.115, 113.251 ppm (d ₆ -DMSO) High-resolution mass spectrum: measured value 160.0495 calculated value (C ₆ H ₄ N ₆ ) 160.0497 Example 2 Using 400 mg of 2,3-diamino-3- (4-chlorophenylthio) acrylonitrile instead of DAAN, the same reaction was carried out while blowing air, 57 mg of red crystals (41% yield).
I got

Example 3 In 120 g of DAAN, 1200 ml of acetonitrile and 285 m of xylene
l, 4800 ml of water was added to make a slurry. There, 0.1M citric acid aqueous solution 6235ml, 0.1M sodium citrate aqueous solution 508m
l was added to adjust the pH to 3.1. After that, while blowing air,
Stirred at C for 4 hours. After completion of the aging, the mixture was filtered, and the obtained red crystals were combined with 100 ml of water and n-hexane-ethyl acetate (1:
1) After washing with 150 ml, it was dried at 40 ° C. for 4 hours to obtain 38.0 g of the objective red crystal. (Y: 75.7%) Example 4 To 6.15 g of DAAN, 76 ml of DMA and 457 ml of water were added and dissolved.
Therefore, 70 ml of a 1M aqueous sodium acetate solution and 68
ml was added to adjust the pH to 3.7. Thereafter, the same operation as in Example 3 was carried out to obtain 1.81 g of the objective red crystal. (Y: 65.6%) Example 5 200 ml of chloroform was added to 2.05 g of DAAN to form a slurry. There, a 1N aqueous hydrochloric acid solution was added to adjust the pH to 3.0. Thereafter, the mixture was stirred at 20 ° C. for 4 hours while blowing air. still,
During the reaction, pH was adjusted to 3.0 with a 1N aqueous hydrochloric acid solution as appropriate. After aging, the same operation as in Example 3 was carried out to obtain 0.31 g of the target red crystal (Y: 36.2%). Example 6 76 ml of benzene and 245 ml of water were added to 6.15 g of DAAN to form a slurry. 320 ml of a 0.1 M aqueous citric acid solution and 26 ml of a 0.1 M aqueous sodium citrate solution were added thereto to adjust the pH to 3.0. Thereafter, the mixture was stirred at 20 ° C. for 4 hours while blowing air. After aging, the same operation as in Example 3 was carried out to obtain 1.93 g of the objective red crystal. (Y: 75.1%) Example 7 To 2.05 g of DAAN, 40 ml of acetonitrile and 82 ml of water were added and dissolved. Thereto, a 1N aqueous hydrochloric acid solution was added to adjust the pH to 3.1. Thereafter, the mixture was stirred at 20 ° C. for 4 hours while blowing air. After aging, the same operation as in Example 3 was carried out to obtain 0.57 g of the objective red crystal. (Y: 66.5%) Example 8 To 2.20 g of 2,3-diamino-3- (P-tolylthio) acrylonitrile, 25 ml of DME and 82 ml of water were added and dissolved. There, 107 ml of 0.1 M citric acid, 9 ml of 0.1 M sodium citrate
Was added to adjust the pH to 3.2. Thereafter, the mixture was stirred at 20 ° C. for 4 hours while blowing air. After aging, the same operation as in Example 3 was performed to obtain 0.60 g of a target red crystal. (Y: 70.1
% Example 9 2,3-diamino-3-ethylthioacrylonitrile 1.6
To 2 g, 26 ml of DME and 87 ml of water were added and dissolved. There, 0.1
113 ml of M citric acid and 9.5 ml of 0.1 M sodium citrate were added to adjust the pH to 3.2. After that, while blowing air,
Stirred at 4 ° C. for 4 hours. After aging, the same operation as in Example 3 was performed to obtain 0.44 g of the objective red crystal. (Y: 48.7%) Examples 10 to 15 Table 1 shows the results of the synthesis of the compound of the present invention under various conditions using DAAN and changing the solvent, buffer, pH and the like.

Example 16 75 ml of acetonitrile was added to and dissolved in 0.74 g of DAAN oxalate. The solution was reacted for 6 hours while blowing air into the solution. After completion of the reaction, acetonitrile was distilled off using an evaporator, water was added, the mixture was filtered, washed with water, and washed with n-hexane-ethyl acetate (3: 2). Further, the crystals were dried at 60 ° C. for 2 hours to obtain 0.10 g of the objective red crystals. (Y: 48.1
Example 17 191.0 g of DAAN and 68.7 g of picric acid were dissolved in 4800 ml of acetonitrile, and the mixture was stirred at room temperature for 2.5 hours. After completion of the reaction, the generated red crystals were filtered and washed with 300 ml of n-hexane-ethyl acetate (2: 1).

Drying was performed at 60 ° C. for 3 hours to obtain 59.2 g of a target red crystal. Example 18 0.53 g of trifluoroacetic acid was added at room temperature to a solution of 2.90 g of DAAN in 50 ml of acetonitrile, and the mixture was stirred for 3 hours. The precipitated red crystals were filtered and washed with 30 ml of n-hexane-ethylene acetate (2: 1). Drying was performed at 60 ° C. for 2 hours to obtain 0.79 of a target red crystal. Example 19 DAAN (2.90 g), oxalic acid (0.71 g) in acetonitrile (75 ml), water
Dissolved in 20 ml of the mixture and stirred for 3.5 hours at room temperature.
The precipitated red crystals were filtered and washed with 30 ml of n-hexane-ethyl acetate (2: 1). Drying was conducted at 60 ° C. for 3 hours to obtain 0.55 g of a target red crystal. (Yield: 45.4%) Industrial applicability: The compound of the present invention itself is a red dye, has strong yellow-green fluorescence, and can be used as a fluorescent dye or a light conversion material. It is also a synthetic intermediate useful for the synthesis of pteridines widely used as agricultural chemicals.

The production method of the present invention uses a 2,3-diaminoacrylonitrile derivative easily obtained from hydrocyanic acid, and in one step, the desired 3,6-diamino-2,5-pyrazinedicarboxy represented by the formula [II]. This is a method for obtaining nitrile in high yield, which is an industrially excellent production method.

Continued on the front page (72) Inventor Atsushi Yanagisawa 345 Yanagimachi, Takada, Odawara-shi, Kanagawa, Japan Inside Soda Co., Ltd. (72) Inventor Takakazu Kojima 345 Yanagimachi, Takada-shi, Odawara, Kanagawa, Japan Inside Soda Co., Ltd. 56) References JP-A-1-199954 (JP, A) JP-A-50-19761 (JP, A) JP-A-47-34373 (JP, A) (58) Fields studied (Int. Cl. ⁶ , DB name) C07D 241/26 CA (STN)

Claims (2)

(57) [Claims] (1) 3,6-diamino-2,5-pyrazinedicarbonitrile. 2. Formula (I) Wherein R represents an aryl group, an alkyl group, an aralkyl group or an alkenyl group which may have a substituent, wherein the compound is reacted under acidic conditions in the presence of oxygen. Of 6,6-diamino-2,5-pyrazinedicarbonitrile.