JPH0662538B2 - Method for producing naphthoquinone compound - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial field of application> The present invention is useful for near infrared light adjusting filters and the like.
-An improved process for the preparation of dicyanonaphthoquinone compounds.

<Prior Art> General Formula (I) (In the formula, R ¹ and R ² each represent an aromatic group which may have a substituent, and R ¹ and R ² may be the same or different.) Compounds are colored compounds that have an absorption band in the visible to near infrared region, and are a group of useful compounds that have applications such as near-infrared control filters and recording layers for optical disks. Was not known.

Previously, "Dyes and Chemicals", (1984), Vol.29, NO.4, No. 12-
As shown on page 22, the formula (IV) A naphthoquinone compound represented by the formula: and an aromatic amine represented by the general formula (III ′) NH ₂ —R (III ′) (wherein R represents an aromatic group which may have a substituent) To react with the general formula (I
I ′) (Wherein R represents the above-mentioned meaning) General formula (I ′) slightly by-produced when a naphthoquinone compound represented by (In the formula, R represents the above-mentioned meaning) A naphthoquinone compound was obtained by separation and purification.

<Problems to be Solved by the Invention> However, in this method, the amount of the aromatic amine represented by the general formula (III ′) is increased in an attempt to increase the yield of the naphthoquinone compound represented by the general formula (I ′). Even if it is made, the general formula (V) (In the formula, R represents the above-mentioned meaning) The reaction by-product represented by the formula increases, but the yield of the target naphthoquinone compound represented by the general formula (I ′) hardly increases.

In addition, this method can only synthesize compounds having the same R ¹ and R ^{2 in} the general formula (I).

Furthermore, even if the naphthoquinone compound represented by the general formula (II ′) and the aromatic amine represented by the general formula (III ′) are heated in a solvent such as alcohol to react with each other, the compound represented by the general formula (I The target naphthoquinone compound represented by ′) is hardly formed.

<Means for Solving the Problem> The present inventors have found that the above-mentioned reaction operation can be carried out in the presence of an acid to obtain the desired naphthoquinone compound represented by the general formula (I) in good yield. The invention was reached.

That is, the present invention is represented by the general formula (II) (In the formula, R ¹ represents an aromatic group which may have a substituent), and a naphthoquinone compound represented by the general formula (III) NH ₂ —R ² (III) (wherein R ² Represents an aromatic group which may have a substituent) and a general formula (I) characterized by reacting with an aromatic amine represented by Wherein R ¹ and R ² each represent an aromatic group which may have a substituent, and R ¹ and R ² may be the same or different. It is a method for producing a compound.

In the present invention, the aromatic group represented by R ¹ and R ² is, for example, a phenyl group, a naphthyl group, an anthranyl group or the like, and the substituent which R ¹ and R ² may have is an aromatic compound. Are any groups common to, for example, alkyl group, alkoxy group, phenyl group, phenoxy group, halogen atom, nitro group, cyano group, hydroxyl group, substituted or unsubstituted amino group, acylamino group, mercapto group, thioether. Group, carboxy group or ester or amide group thereof, alkyl or phenylsulfonyl group, sulfonic acid group or ester or amide group thereof, and the like, and the number and position of substituents are arbitrary. Further, it does not matter if different substituents are present on the same aromatic group.

A wide range of acids can be used, for example, carboxylic acids such as formic acid, acetic acid, propionic acid, lactic acid, glycolic acid, oxalic acid, succinic acid, maleic acid, citric acid, tartaric acid, phthalic acid, benzoic acid, and methanesulfonic acid. Sulfonic acids such as benzene sulfonic acid, toluene sulfonic acid, sulfuric acid,
Examples thereof include inorganic acids such as phosphoric acid and hydrochloric acid, and acidic esters thereof. Among these, formic acid, acetic acid, propionic acid and other carboxylic acids which are liquid at room temperature can be used particularly well when used as a reaction solvent.

As the reaction solvent, various solvents can be used in addition to the above acids, for example, lower alcohols such as methanol, ethanol, propanol, butanol, ethylene glycol,
In addition to polyhydric alcohols such as glycerin, glycol ethers such as polyethylene glycol or esters thereof, ethers such as tetrahydrofuran and dioxane, aromatic solvents such as toluene, dimethylformamide, sulfolane, dimethylsulfoxide and the like can be used.

The amount of the acid added to the solvent is effective even if it is 1 to 2% of the solvent, but generally it is more effective to use a large amount, and the reactivity of the aromatic amine represented by the general formula (III) to be used is particularly high. When it is low, the effect is particularly great when the acid itself is used as a solvent.

As specific reaction conditions, a solvent and an acid sufficient to form a slurry of at least a naphthoquinone compound represented by the general formula (II) are added, and then an aromatic amine represented by the general formula (III) is added thereto. After the addition, the temperature is raised and the reaction is carried out by heating for 15 minutes to several hours. Alternatively, after the temperature is raised, the aromatic amine represented by the general formula (III) is added all at once or in portions or continuously in small portions to carry out the reaction.

The reaction temperature may be in the range of room temperature to about 200 ° C., but is generally more preferably 60 ° C. to 150 ° C. If the boiling point of the solvent is within this range, the reaction is usually carried out under reflux. Good.

The amount of the aromatic amine represented by the general formula (III) with respect to the naphthoquinone compound represented by the general formula (II) may be equal to or more than the molar ratio, and the use of a large excess amount does not affect the reaction. If there is no problem in separation after the reaction, it is preferable to use an excess amount of about 2 to 10 molar ratio because the reaction is easy.

<Effects of the Invention> As described above, according to the method of the present invention, a naphthoquinone compound represented by the general formula (III), which has not been known for a good synthetic method, can be obtained in good yield.

<Examples> Specific examples will be described below. In the examples, "parts" means "parts by weight" unless otherwise specified.

Example 1 Formula (1) in 270 parts of acetic acid 6.9 parts of the compound represented by and p-phenetidine 13.1 parts were added, and the mixture was heated under reflux for 2 hours. After cooling to room temperature,
And then washed with methanol to give formula (2) Thus, 9.0 parts of the target compound represented by

Physical properties of the compound represented by the formula (2): M ^{+ by} FD-MS, melting point: 261 to 263 ° C. (recrystallized from chloroform) λmax 798 nm (in chloroform) Example 2 In Example 1, 270 parts of acetic acid was used. Methanol 3
00 parts and 60 parts of acetic acid were used and it heated under reflux for 6 hours.
9.2 parts of the compound of formula (2) are obtained.

Example 3 In Example 1, ethanol 3 was used instead of 270 parts of acetic acid.
00 parts and p-toluenesulfonic acid 15 parts were used and it heated under reflux for 4 hours.

8.7 parts of a compound of formula (2) was obtained.

Example 4 To 200 parts of acetic acid were added 4.3 parts of the compound of the formula (1) used in Example 1 and 3.86 parts of p-toluidine, and the mixture was heated under reflux for 3 hours. After cooling to room temperature, pass, then wash with methanol to give formula (3) Thus, 3.8 parts of the target compound represented by

Physical property values of the compound represented by the formula (3): M ^{+ by} FD-MS, melting point: 288 to 290 ° C. (recrystallized from chloroform) λmax 798 nm (in chloroform), Example 5: Formula (4) in 70 parts of acetic acid 2.8 parts of a compound represented by and p-phenetidine (3.2 parts) were added, and the mixture was heated under reflux for 1 hour. After cooling to room temperature,
And wash with methanol to obtain formula (5) 2.1 parts of the target compound shown by are obtained.

Physical properties of the compound represented by the formula (5) M ^{+ by} FD-MS = 478 λmax 799 nm (in chloroform) In the same manner as in Example 1, the corresponding naphthoquinone compound represented by the general formula (II) and the general formula ( When the aromatic amine represented by III) is used, the naphthoquinone compound represented by the general formula (I) shown in Table 1 is obtained. However, in Table-1, R ¹ and R ² are Represents the meaning of.

Claims (1)

[Claims] 1. A general formula (I) (In the formula, R ¹ represents an aromatic group which may have a substituent), and a naphthoquinone compound represented by the general formula (III) NH ₂ —R ² (III) (wherein R ² Represents an aromatic group which may have a substituent) and a general formula (I) characterized by reacting with an aromatic amine represented by (In the formula, R ¹ and R ² each represent an aromatic group which may have a substituent, and R ¹ and R ² may be the same or different.) Method for producing compound.