JPS6140711B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a novel pyrrolopyrazine compound, a method for producing the same, and a pigment comprising the compound. The novel pyrrolopyrazine compound according to the present invention has the formula (In the formula, R represents a hydrogen atom or a methyl group, and
represents a carbocyclic aromatic residue or a heterocyclic aromatic residue). The novel compound of the present invention has the following general formula () (In the formula, R _represents a hydrogen atom or a methyl _group .) It can be obtained by condensation with a diamine (representing an aromatic residue) in an organic solvent. The pyrrolopyrazine represented by the general formula () used in the production of the compound according to the present invention can be obtained by various methods, but in particular 2,3-dicyanopyrazine obtained by dehydration condensation of diaminomaleonitrile with glyoxal or diacetyl or It can be produced in high yield by carrying out the addition reaction of ammonia on 2,3-dicyano-5,6-dimethylpyrazine in sodium alcoholate. The other raw material in the production of the compound, the diamine represented by the general formula (), includes various aromatic diamines, polycyclic diamines, heterocyclic diamines, and the like. In the production method according to the present invention, pyrrolopyrazine and diamine are mixed in an organic solvent. It is made by reacting as follows. Although this condensation reaction partially proceeds even at relatively low temperatures, it is desirable that the reaction temperature be 60°C or higher, particularly 100 to 200°C. The solvent used in this condensation reaction is an inert organic solvent that does not participate in the condensation, such as aromatic hydrocarbons such as benzene, toluene, and xylene, dichloroethane, trichloroethane, tetrachloroethane, monochlorobenzene, dichlorobenzene, and trichloroethane. Halogenated hydrocarbons such as benzene, nitrated hydrocarbons such as nitrobenzene, amides such as formamide and dimethylformamide, n
- Aliphatic alcohols such as propanol, isopropanol, n-butanol, sec-butanol, tert-butanol, ethylene glycol, and diethylene glycol. Note that it is advantageous to use a lower fatty acid as a solvent because ammonium produced as a by-product in the condensation reaction can be absorbed within the reaction system, and acetic acid is particularly preferably used. General formula thus produced The compound is a bright red-yellow to brown solid. Its decomposition point is about 400°C or higher, and its suitability as a pigment such as light resistance and solubility resistance is comparable to that of phthalocyanine compounds, which are widely used as pigments. Therefore, the compounds according to the present invention are useful as new organic pigments. The present invention will be further explained below with reference to Examples. Example 1 3.00 g of 7-amino-5-imino-5H-pyrrolo[3.4-b]pyrazine in a 200ml 4-necked flask,
2.50 g of paraphenylenediamine and 1200 ml of glacial acetic acid were added and heated at reflux temperature for 1 hour. The product was collected by filtration, washed with acetone, and dried to obtain 3.97 g of a red substance. Infrared spectrum of this product (KBr tablet method)
had characteristic absorptions at 3365, 1640, 1605, and 1545 cm ^-1 , and the elemental analysis was C% H% N% Analytical value 65.21 2.83 31.91 Calculated value 65.15 3.19 31.66 (as C ₂₄ H ₁₄ N ₁₀ ). From this, the product is It was recognized that This compound had excellent suitability as a pigment. Example 2 2.70 g of 7-amino-5-imino-5H pyrrolo[3,4-b]pyrazine, 2.00 g of metaphenylenediamine, and 50 ml of 1.2.4-trichlorobenzene were placed in a 100 ml 4-neck flask and heated at reflux temperature for 6 hours. .
The product was collected by filtration and washed with methanol and acetone to obtain 3.43 g of a reddish-brown material. The infrared spectrum of this product has characteristic absorption at 3390, 1645, 1595, and 1515 cm ^-1 , and the elemental analysis is C% H% N% Analytical value 65.19 2.97 31.44 Calculated value 65.15 3.19 31.66 (as C ₂₄ H ₁₄ N ₁₀ ) It was hot. This results in the product being It was recognized that This compound was suitable as a pigment. Example 3 3.60 g of 7-amino-5-imino-5H-pyrrolo[3.4-b]pyrazine in a 200ml 4-necked flask,
4.85 g of 3,6-diaminoacridine and 12 ml of nitrobenzene were added and heated at reflux temperature for 5 hours. The product was treated as in Example 2 to yield 7.52 g of reddish-brown material.
I got it. The infrared absorption of this thing is 3415, 1595,
At 1543 cm ^-1 , the elemental analysis was C% H% N% Analytical value 71.24 2.75 25.93 Calculated value 71.03 2.82 26.12 (as C ₃₈ H ₁₈ N ₁₂ ). From this, the product is It was recognized that This compound had excellent pigment suitability. In the reaction, the raw materials and reaction conditions were changed to obtain the products shown in the following table.

【table】

[Table] Furthermore, the compounds obtained in Examples 4 to 7 were subjected to a pigment suitability test according to the method of JISK-5101 (pigment test method), and the results were as shown in the table below.

【table】

【table】

Claims (1)

[Claims] 1 General formula () (wherein, R represents a hydrogen atom or a methyl group) and the general formula () H ₂ N—X—NH ₂ () (wherein, X is an unsubstituted or nitro group. Represents a divalent residue of a substituted carbocyclic aromatic compound having 1 to 3 rings or an N-containing heterocyclic aromatic compound having 1 to 3 rings. General formula characterized by reaction in a solvent A method for producing a pyrrolopyrazine compound represented by the formula (wherein R and X have the same meanings as above). 2. The method for producing a pyrolone pyrazine compound according to claim 1, wherein the organic solvent is a halogenated hydrocarbon, a nitrated hydrocarbon, an aliphatic alcohol, or a lower fatty acid.