JPH04257553A - Production of diphenylamine derivative - Google Patents

Abstract

PURPOSE:To provide a method for efficiently producing a diphenylamine derivative having a p-trifluoromethyl group as a substituent and useful as a raw material for a recording material colorant. CONSTITUTION:A method for producing a diphenylamine derivative is characterized by reacting p-chlorobenzotrifluoride with an aromatic amine in the presence of a copper catalyst at a temperature above 190 deg.C in an autoclave.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing diphenylamine derivatives having a p-trifluoromethyl group as a substituent, which are useful as raw materials for dyes for recording materials.

0002

2. Description of the Related Art A reaction in which an aromatic amine and an aromatic halide are condensed at high temperature in the presence of a copper catalyst to synthesize a diphenylamine derivative is well known as the Ullmann reaction. However, when synthesizing a diphenylamine derivative having p-trifluoromethyl group as a substituent,
There is a problem in that the raw materials p-trifluoromethylaniline, p-bromobenzotrifluoride, and p-iodobenzotrifluoride are very expensive. In addition, when p-chlorobenzotrifluoride, which is available at a low price, is used, the reactivity is lower than that of the bromo and iodo forms, so the yield is low and unsatisfactory under normal reaction conditions.

0003

OBJECTS OF THE INVENTION An object of the present invention is to provide an efficient method for producing diphenylamine derivatives having a p-trifluoromethyl group as a substituent, which are useful as raw materials for dyes for recording materials. .

0004

[Means for Solving the Problem] The above object is to react p-chlorobenzotrifluoride and an aromatic amine at 190°C or higher in an autoclave in the presence of a copper catalyst, optionally using a deoxidizing agent. This problem was solved by developing a method for producing diphenylamine derivatives characterized by the following.

The aromatic amine used in the production method according to the present invention is preferably one represented by the following general formula (I). General formula (I)

[0006]

[Chemical formula 1]

In the above formula, Ar represents an aromatic ring, which may have one or more substituents. These substituents may be the same or different, and may be further substituted. Moreover, the substituents may be connected to each other to form a ring. Further, R1 represents a hydrogen atom, an alkyl group, an aralkyl group, an aryl group or an acyl group.

In the compound of general formula (I), Ullm
In order to use the diphenylamine derivative after the ann reaction as a raw material for a fluoran compound, those represented by the general formula (II) are preferred. General formula (II)

[0009]

[Case 2]

In the above formula, R2 is a hydrogen atom, an alkyl group,
It represents an aralkyl group, an aryl group, an alkylsulfonyl group, an arylsulfonyl group, etc., and these may be further substituted. Among these, hydrogen atoms, methyl groups,
Ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, t-butyl group, benzyl group, etc. are preferred. Moreover, R3 and R4 are hydrogen atoms, alkyl groups,
Aralkyl group, aryl group, alkoxy group, aryloxy group, halogen atom, cyano group, nitro group, dialkylamino group, amide group, alkoxycarbonyl group, alkylsulfonyl group, arylsulfonyl group, alkylsulfonyloxy group, arylsulfonyloxy group , an alkylthio group, an arylthio group, a sulfo group, a carboxyl group, etc., and these may be the same or different. These may be further substituted. R3 and R4 are preferably hydrogen atoms, alkyl groups, alkoxy groups, halogen atoms, etc., particularly hydrogen atoms, methyl groups, ethyl groups, n-propyl groups, isopropyl groups, n-butyl groups,
Isobutyl group, t-butyl group, methoxy group, ethoxy group, n-propyloxy group, isopropyloxy group, n-
Preferred are butoxy group, isobutyloxy group, t-butyloxy group, fluorine atom, chlorine atom, and the like. Further, R1 represents a hydrogen atom, an alkyl group, an aralkyl group, an aryl group or an acyl group, and an acetyl group is particularly preferred.

In the compound of general formula (I), Ullm
In order to use the diphenylamine derivative after the ann reaction as a triphenylmethane phthalide compound, a raw material for a photoconductor, etc., those represented by the general formula (III) are preferable. General formula (III)

0012

[Chemical formula 3]

In the above formula, R5 and R6 represent a hydrogen atom, an alkyl group, an aralkyl group, or an aryl group, which may be the same or different, and may be further substituted. Furthermore, R5 and R6 may be connected to form a ring. R5 and R6 are preferably alkyl groups, particularly preferably methyl, ethyl, propyl, butyl, pentyl, and hexyl groups, which may be branched. Moreover, R1, R3, and R4 represent the same substituents as in the compound of general formula (II).

Specific examples of compounds of general formula (I) include:
Aniline, acetanilide, 4-chloroacetanilide, 3-methylacetanilide, 4-nitroacetanilide, 3-cyanoacetanilide, 2-phenylbenzoylaniline, p-anisidine, 4-methoxyacetanilide, p-phenetidine, 4-ethoxyacetanilide, 4- n-propyloxyacetanilide, 4-butoxybenzoylaniline, 3-benzyloxyacetanilide, 4-methoxy-2-methylacetanilide, 4-
Hydroxyacetanilide, 4-ethoxy-2-chloroacetanilide, 4-methoxy-2,6-dimethylacetanilide, 4-ethoxy-2-fluoro-6-methylacetanilide, 4-hydroxy-2-methoxybenzoylaniline, 2-N, N-dimethylaminoacetanilide, 3-N,N-diethylaminoacetanilide, 2
-N-ethyl-N-isobutyl-3-methylacetanilide, 4-methoxydiphenylamine, 2-methyl-4
-methoxydiphenylamine and the like, but are not limited to these.

As the copper catalyst used in the production method according to the present invention, any of zero-valent copper compounds, monovalent copper compounds, and divalent copper compounds can be used. Specific examples of these copper catalysts include metallic copper, bronze copper, cuprous chloride, cuprous bromide, cuprous iodide, cuprous cyanide, cuprous oxide, cupric chloride, and acetic acid. Examples include copper, cupric cyanide, cupric oxide, copper thiocyanide, and the like. Further, in order to increase the activity of the catalyst, the copper catalyst may be subjected to ultrasonic treatment, or prepared copper may be used. Preferably cuprous chloride, cuprous bromide,
These include cuprous iodide, cupric chloride, metallic copper, and bronze copper.

As the deoxidizing agent used in the production method according to the present invention, those used in general Ullmann reactions can be used. Specifically, potassium carbonate, sodium carbonate, potassium hydroxide, sodium hydroxide, potassium hydrogen carbonate, sodium hydrogen carbonate, sodium hydride, magnesium oxide, calcium oxide,
Pyridine, trimethylamine, triethylamine, tripropylamine, tributylamine, DBN, DBU,
Examples include N,N-dimethylaminopyridine. Preferred examples include potassium carbonate and sodium carbonate.

[0017] In the production method according to the present invention, additives used for increasing the reaction activity in ordinary Ullmann reactions may be used in combination. Examples of these additives include phase transfer catalysts such as polyethylene glycol, crown ether, and quaternary ammonium salts, as well as potassium iodide, sodium iodide, and iodine. Also,
A high boiling point solvent such as nitrobenzene, chlorobenzene, or o-dichlorobenzene may be used in combination.

The p-chlorobenzotrifluoride used in the present invention is preferably used in an amount of 0.5 to 10.0 equivalents, particularly preferably 1.0 to 3.0 equivalents, of the aromatic amine compound. In addition, the deoxidizer is an aromatic amine with a concentration of 1.0 to 5
．． It is preferable to use 0 equivalent, especially 1.2 to 3.0
Equivalent amounts are preferred. Further, the copper catalyst is preferably used in an amount of 0.01 to 5.0 equivalents, particularly preferably 0.1 to 0.5 equivalents, of the aromatic amine compound. Further, it is preferable to use the additive in an amount of 0.01 to 5.0 equivalents of the aromatic amine compound. The reaction temperature is preferably 190°C or higher, particularly preferably 200°C to 240°C. Further, in order to suppress the oxidation reaction caused by oxygen, it is preferable to carry out the reaction under an inert gas atmosphere such as argon or nitrogen.

[0019]

[Examples] Examples are shown below, but the present invention is not limited thereto. Unless otherwise specified in the examples, weight % is expressed. Example-1 In an autoclave with a capacity of 500 ml, 33.0 g (0.2 mol) of p-methoxyacetanilide, 72.0 g (0.4 mol) of p-chlorobenzotrifluoride,
20.8 g (0.15 mol) of potassium carbonate and 12.4 g (0.62 mol) of cuprous iodide were added, and the atmosphere was replaced with nitrogen gas. The mixture was stirred at a reaction temperature of 240°C for 6 hours. The stirring speed was 500r. p. m. And so. After cooling the reaction vessel to room temperature, the reaction mixture was analyzed by HPLC, and the conversion rate of p-methoxyacetanilide to the corresponding diphenylamine derivative was 68%.

Example 2 Instead of cuprous iodide, 4.0 g of bronze copper (0.62
mol) and 4.0 g (0.16 mol) of iodine,
The reaction was carried out in the same manner as in Example-1, except that the mixture was stirred at 240°C for 16 hours. After cooling the reaction vessel to room temperature, the reaction mixture was analyzed by HPLC, and the conversion of p-methoxyacetanilide to the corresponding diphenylamine derivative was 60%.

Comparative Example In a 300 ml three-necked flask, 33.0 g (0.2 mol) of p-methoxyacetanilide, 72.0 g (0.4 mol) of p-chlorobenzotrifluoride, 20.8 g (0.15 mol) of potassium carbonate, and bronze Copper 4.0g
(0.62 mol), iodine 4.0 g (0.16 mol)
and heated and stirred at an external temperature of 240°C for 30 hours (500°C
r. p. m. ). Analysis of the reaction mixture by HPLC showed that the conversion of p-methoxyacetanilide to the corresponding diphenylamine derivative was 5%.

[0022]

Effects of the Invention As is clear from the examples, the present invention enables the production of the desired diphenylamine derivative by setting specific conditions in the Ullmann reaction with an aromatic amine compound using p-chlorobenzotrifluoride. We were able to improve the yield.

Claims (2)

[Claims] 1. A method for producing a diphenylamine derivative, which comprises reacting p-chlorobenzotrifluoride and an aromatic amine in an autoclave at 190° C. or higher in the presence of a copper catalyst. [Claim 2] Claim 1, wherein the aromatic amine is an acylanilide which may have a substituent.
A method for producing a diphenylamine derivative.