JPH06116232A - Aminobenzothiazole compound, aniline compound and their production - Google Patents

Abstract

PURPOSE:To provide the novel aminobenzothiazole compound extremely useful as a pigment raw material for optical recording media. CONSTITUTION:A compound of formula I [R is CnHmF2n-m+1 (n) is 2, 3; (m) is 0-2n); X<1>, X<2> are H, Cl, CH3], e.g. 2-amino-6-(pentafluoroethylthio) benzothiazole. The compound is obtained by reacting an aniline compound of formula II with a thiocyanic acid salt. The compound of formula II is a new compound. and i obtained by reacting an aminothiophenol compound of formula III with an alkyl halide compound of formula: CnHmF2n-m+1]Y (Y is Br I) in the presence of an alkali. The compound of formula I as a starting raw material can give a compound of formula V useful as a laser light-absorbing colorant for optical recording media through a compound of formula IV (Z<1>, Z<2> are 2-6C alkyl; Z<3> is H, 1-6C alkyl, 1-6C alkoxy).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel aminobenzothiazole compound, aniline compound and a method for producing them. More specifically, the present invention relates to compounds that are extremely useful as starting materials for dye intermediates, especially dyes for optical recording media such as optical disks, and methods for producing them.

[0002]

2. Description of the Related Art In recent years, optical recording using a laser has been particularly developed because it enables high density information recording, storage and reproduction. An optical disc can be given as an example of the optical recording medium. In general, an optical disc has a thin recording layer provided on a circular substrate,
A high-density information recording is performed by irradiating a laser beam focused to about μm. The recording is performed by the absorption of the irradiated laser light energy, which causes thermal deformation such as decomposition, evaporation, and dissolution in the recording layer at that location. The recorded information is reproduced by reading the difference in reflectance between the portion where the laser light is deformed and the portion where the laser light is not deformed. Therefore, as the optical recording medium, it is necessary to efficiently absorb the energy of laser light, and a laser absorbing dye is used.

Various types of optical recording media have been proposed. For example, a dye using a cyanine dye or a phthalocyanine dye as a laser absorbing dye has been proposed, but these dyes have problems such as low sensitivity, high decomposition point, and difficulty in vapor deposition. However, it has a problem that it cannot be used for coating by coating, and also has a problem that it has poor light resistance.

Recently, in order to solve these problems, there has been proposed a compound using an azo compound, particularly an azo metal chelate compound of a benzothiazole compound and a metal, as a laser absorbing dye. However, some of these azo metal chelate compounds, such as fluorine-substituted compounds, are difficult to synthesize.

[0005]

DISCLOSURE OF THE INVENTION An object of the present invention is to provide a novel intermediate useful for producing the azo metal chelate compound, a compound useful for producing the intermediate, and a method for producing them. In particular, the present invention provides a fluorothioalkyl group-substituted benzothiazole compound, a fluorothioalkyl group-substituted aniline compound, and methods for producing them.

[0006]

DISCLOSURE OF THE INVENTION The inventors of the present invention have previously described the following general formula (4) as a laser absorbing dye for an optical recording medium.
It was found that the compound represented by

[0007]

[Chemical 6]

(In the general formula (4), R is C _n H _2n F _{2n-m + 1.}
(Wherein n is 2 or 3, m is an integer from 0 to 2n), X ¹ and X ² each independently represent a hydrogen atom, a chlorine atom or a methyl group, and Z ¹ and Z ² Each independently represent an alkyl group having 2 to 6 carbon atoms, Z ³ is a hydrogen atom, an alkyl group having 1 to 6 carbon atoms or 1 to 6 carbon atoms.
Represents an alkoxy group. As a result of further diligent studies, the present inventor has found that the compound represented by the general formula (4) can be easily produced by the following reaction, and arrived at the present invention.

That is, the compound represented by the general formula (4) has the following general formula (3) (in the formula, X ¹ and X ² each independently represent a hydrogen atom, a chlorine atom or a methyl group). Using the indicated aminothiophenol compounds as raw materials,
The following general formula (2) (wherein R is C _n H _m F _{2n-m + 1} (where n is 2 or 3, m is an integer from 0 to 2n,
X ¹ and X ² each independently represent a hydrogen atom, a chlorine atom or a methyl group. ) Of the present invention represented by the following general formula (1) (wherein R is C _n H _m F _{2n-m + 1)}
(Wherein n is 2 or 3 and m is an integer from 0 to 2n), and X ¹ and X ² each independently represent a hydrogen atom, a chlorine atom or a methyl group. ) Via the aminobenzothiazole compound of the present invention represented by the following general formula (5) (wherein R is C _n H _m F _{2n-m + 1} (where n is 2 or 3, m is an integer from 0 to 2n), X ¹ and X ² each independently represent a hydrogen atom, a chlorine atom or a methyl group, and Z ¹ and Z ² each independently have 2 to 2 carbon atoms. Represents an alkyl group having 6 carbon atoms, Z ³ represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or 1 to 6 carbon atoms.
Represents an alkoxy group. ) Is obtained via a benzothiazole compound.

[0010]

[Chemical 7]

The above reaction can be represented by the following synthetic route.

[0012]

[Chemical 8]

Next, the present invention will be described in detail. The aniline-based compound represented by the general formula (2) is obtained by adding C to the aminothiophenol-based compound represented by the general formula (3).
_n H _m F _{2n-m + 1} Y (where n is 2 or 3 and m is 0 to 2)
It is an integer up to n, and Y represents a bromine atom or an iodine atom. ) Is obtained by reacting the halogenated alkyl compound.

The above reaction is preferably carried out in a solvent, and the solvent is not particularly limited, but a polar solvent is preferably used, for example, dimethylformamide, tetrahydrofuran, alcohol and the like. In these solvents, the aminothiophenol compound represented by the general formula (3) and C _n H _m F _{2n-m + 1} Y (in the formula, n, m and Y
Is as defined above. ) Is reacted with an alkyl halide compound represented by the formula (1) in the presence of a suitable alkali such as potassium carbonate, sodium carbonate sodium hydroxide, potassium hydroxide or triethylamine. The reaction is -10 ° C to 4
It can be carried out at 0 ° C., preferably at 20 ° C. or lower, particularly preferably at 5 ° C. to 10 ° C. Further, a catalyst such as a crown ether or a phase transfer catalyst may be added to the reaction system.

Before adding the alkyl halide compound,
A method in which an aminothiophenol compound is previously reacted with sodium hydride, metallic sodium, sodium alcoholate, sodium amide or the like to form a thioalcoholate, and then a halogenated alkyl compound is reacted is preferable because of high synthetic yield. From the viewpoint of reactivity, the method using sodium hydride is particularly preferable. Further, an alkali compound such as potassium hydroxide or sodium hydroxide can be used instead of sodium hydride or metallic sodium.

The aminobenzothiazole compound represented by the general formula (1) can be synthesized by using the aniline compound represented by the general formula (2) as a raw material. As a synthesizing method, ORGANIC REACTIONS
VOL 3 CHAPTER 6, John Will
ey and Sons, Inc. (1946) New
York and Organic Synthesis C
collective Volume 2 P76-78
Although various methods such as the method described in 1) can be used, the method of reacting bromine in the presence of thiocyanates in an acetic acid solvent is particularly preferable because the production method is simple and the yield is good.

Examples of thiocyanates include K and N.
Salts of a, Li, NH _{4 and} the like are preferably used.

[0018]

EXAMPLES The present invention will be specifically described below with reference to examples. Example 1 Under a nitrogen stream, 1.92 g of 60% sodium hydride was dispersed in 40 ml of dimethylformamide (DMF), and 5.0 g (0.04 mol) of p-aminothiophenol represented by the following structural formula (6) was obtained. ) Was dissolved in 60 ml of DMF, and the solution was added dropwise at 10 ° C. over about 20 minutes.

[0019]

[Chemical 9]

Then, after cooling the reaction solution to 5 ° C., C
A solution prepared by dissolving 25 g (2.5 mol ratio) of F ₃ CF ₂ I (boiling point 11 to 12 ° C.) in 60 ml of DMF was added dropwise over about 15 minutes. After stirring at 5 ° C. to 10 ° C. for 5 hours, the mixture was allowed to stand overnight and released in 400 ml of water.

The precipitated oily substance was added with 200 ml of chloroform.
The extract was washed with water, washed with water and dried by adding anhydrous sodium sulfate. Oily substance obtained by distilling off chloroform under reduced pressure 15.
Distilled 02 g under reduced pressure and boiling point at 5-6 mmHg at 35-93 ° C.
After separating 2.38 g of the first fraction of
7.51 g (yield: 77.3%) of (5-6 mmHg) p-aminophenylpentafluoroethyl sulfide of the following structural formula (7) was obtained. The IR spectrum of the obtained compound is shown in FIG.

[0022]

[Chemical 10]

Example 2 Under a nitrogen stream, 1.92 g of 60% sodium hydride was added to D
A solution obtained by dispersing 5.0 g (0.04 mol) of p-aminothiophenol in 60 ml of DMF dispersed in 40 ml of MF was added dropwise at 10 ° C. over about 20 minutes. Then
After cooling the reaction solution to 5 ° C., CF ₃ CF ₂ I (boiling point 3
9 ° C) 17.75 g (1.5 mol ratio) of DMF 60 ml
The solution dissolved therein was added dropwise over about 15 minutes. 5 ° C
After stirring at -10 ° C for 5 hours, the mixture was left standing overnight and 400m of water was added.
It was released in 1

200 ml of chloroform was added to the precipitated oily substance.
The extract was washed with water, washed with water and dried by adding anhydrous sodium sulfate. 3. The oily substance obtained by distilling off chloroform under reduced pressure was distilled under reduced pressure and the initial fraction having a boiling point of 35 to 95 ° C. at 3 to 4 mmHg was obtained.
After separating 50 g, boiling point 95-98 ° C (3-4 mmH
6.25 g of p-aminophenylheptafluoro-n-propyl sulfide represented by the following structural formula (8) of g).
(Yield 53.3%) was obtained. The IR spectrum of the obtained compound is shown in FIG.

[0025]

[Chemical 11]

Example 3 A solution of 7.30 g (30 mmol) of p-aminophenylpentafluoroethyl sulfide, 9.13 g (120 mmol) of ammonium thiocyanate in 75 ml of acetic acid and 3.8 ml of water was mixed with bromine at 10.degree. 0 g (37.5
A solution of 15 mmol of acetic acid in 15 ml was slowly added dropwise. Three
After stirring for an hour, leave it overnight and then at 70-80 ° C for 3
The mixture was heated and stirred for an hour. The insoluble matter was removed by filtration under heat, the filtrate was poured into 300 ml of hot water, and the insoluble matter was removed again by filtration under heat. Sodium carbonate was added to the filtrate while cooling with ice.
g to bring the pH to 5. After filtering the precipitated crystals,
When washed with water and dried, it is represented by the following structural formula (9).
-Amino-6- (pentafluoroethylthio) benzothiazole, 6.94 g (yield 7
7.1%) was obtained. MASS spectrum M ⁺ = 30
The melting point was 0 and the melting point was 111 to 113 ° C. The IR spectrum is shown in FIG.

[0027]

[Chemical 12]

Example 4 5.86 g (20 mmol) of p-aminophenylheptafluoro-n-propyl sulfide, 6.09 g (80 mmol) of ammonium thiocyanate in 50 ml of acetic acid,
A solution of 4.0 g (25 mmol) of bromine in 10 ml of acetic acid was slowly added dropwise to a solution of 2.5 ml of water at 10 ° C. After stirring for 5 hours, the mixture was allowed to stand overnight and further heated and stirred at 70 to 80 ° C. for 4 hours. The insoluble matter was removed by filtration while hot, the filtrate was poured into 200 ml of hot water, and the insoluble matter was removed by filtration again while hot. While cooling with ice, 44 g of sodium carbonate was added to the filtrate.
In addition, the pH was set to 6. The precipitated crystals are filtered, washed with water and dried to give a compound represented by the following structural formula (10).
-Amino-6- (heptafluoro-n-propylthio)
Benzimidazole, 5.88g as pale yellow crystals
(Yield 83.9%) was obtained. MASS spectrum M ⁺
= 350, melting point 152-154 ° C. The IR spectrum is shown in FIG.

[0029]

[Chemical 13]

[0030]

The compound of the present invention is extremely useful as a raw material for a dye for an optical recording medium. It is also extremely useful as an intermediate for dyes used for purposes other than optical recording media, such as dyes for liquid crystals, dyes for thermal transfer, and dyes for fibers.

[Brief description of drawings]

1 is an IR spectrum of the compound obtained in Example 1. FIG.

2 is an IR spectrum of the compound obtained in Example 2. FIG.

3 is an IR spectrum of the compound obtained in Example 3. FIG.

FIG. 4 is an IR spectrum of the compound obtained in Example 4.

Claims (5)

[Claims] 1. The following general formula (1) (wherein R is C _n H _m
F _{2n-m + 1} (where n is 2 or 3, and m is an integer from 0 to 2n), X ¹ and X ² are each independently a hydrogen atom, a chlorine atom or a methyl group. Represent ) The aminobenzothiazole type compound shown by these. [Chemical 1] 2. The following general formula (2) (wherein R is C _n H _m
F _{2n-m + 1} (where n is 2 or 3, and m is an integer from 0 to 2n), X ¹ and X ² are each independently a hydrogen atom, a chlorine atom or a methyl group. Represent The method for producing an aminobenzothiazole compound according to claim 1, wherein the compound represented by the formula (1) is reacted with thiocyanates. [Chemical 2] 3. General formula (2), wherein R is C _n H _m F
_{2n-m + 1} (where n is 2 or 3 and m is an integer from 0 to 2n), and X ¹ and X ² each independently represent a hydrogen atom, a chlorine atom or a methyl group. . ) An aniline compound. [Chemical 3] 4. The following general formula (3) (in the formula, X ¹ and X ²
Each independently represent a hydrogen atom, a chlorine atom or a methyl group. ) C in the aminothiophenol compound
_n H _m F _{2n-m + 1} (where n is 2 or 3 and m is 0 to 2n
Up to Y, and Y represents a bromine atom or an iodine atom. 4. The method for producing an aniline-based compound according to claim 3, wherein the halogenated alkyl compound represented by the formula 4) is reacted. [Chemical 4] 5. An aminothiophenol compound represented by the general formula (3) (wherein X ¹ and X ² each independently represents a hydrogen atom, a chlorine atom or a methyl group) as a starting material. Formula (2) (where R is C _n H _m F
_{2n-m + 1} (where n is 2 or 3, m is an integer from 0 to 2n, and X ¹ and X ² each independently represent a hydrogen atom, a chlorine atom or a methyl group). General formula (1) (wherein R is C _n H _m F _{2n-m + 1} (where n is 2 or 3 and m is an integer from 0 to 2n). And X ¹ and X ² each independently represent a hydrogen atom, a chlorine atom or a methyl group.). [Chemical 5]