JPS61143340A - Production of 1,4-diaminobenzene - Google Patents

Abstract

PURPOSE:The reaction between 4-bromoaniline and ammonia is effected using an acyclic saturated hydrocarbon and copper to enable simple and economical production of 1,4-diaminobenzene of high purity which is used as an intermediate of synthetic fibers, dyes and antioxidants. CONSTITUTION:The objective compound is obtained by reaction between 4- bromoaniline and ammonia, preferably in an acyclic hydrocarbon such as n- isoner, iso-isomer of a 4-16C hydrocarbons or mixture thereof, e.g., n-hexane or n-nonane, in the presence of copper powder or cuprous compound such as cuprous bromide at 70-160 deg.C under a pressure of 50-250 kg/cm<2>G. EFFECT:1,4-diamnobenzene hardly dissolves in acyclic saturated hydrocarbon, while 4-bromoaniline does, thereby enabling ready separation of the aimed compound. Also there hardly is, byproduct of high b.p. substance such as tar, and refining of the aimed compound is easy.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for producing 1,4-diaminobenzene, which is a Φ-mer used in synthetic fibers, dyes, antioxidants, and the like. In particular, the present invention relates to a novel method for producing 1,4-diaminobenzene from 4-bromoaniline and ammonia.

(Prior art) As a method for producing 1.4-diaminobenzene, the aminoazobenzene method starts from aniline and passes through diazobenzene nitrate, etc.
Publication No.-94349 and JP-A-57-122047
The Hofmann decomposition method starts from 1,4-benzenedicalzene iron and utilizes the Hofmann decomposition reaction (%
-131!5 Publication etc.). Nitroaniline process starting from acetanilide and passing through 4-nitroaniline [Kirk-Othmer Compiled Industrial Encyclopedia]
mer IIf4, Encyclope・dit o
fQchemical 7technology), 3rd
&, vol. 2, p. 311.365], the aminophenol process starting from nitrobenzene and passing through 4-aminophenol [Kirk-Othmer Encyclopedia of Chemical Industry (Kirk
-Othmer ring, 1iincyclopedia o
f Chemical Technology), %
3rd edition, 2 volumes, 371 negative and JP-A-1537-1537
No. 51], a hydroquinone method synthesized by amination of hydroquinone (Japanese Patent Application Laid-Open No. 1983-29176)
, direct amination method synthesized from aniline and ammonia (
U.S. Patent No. 3,919,155), the iodoaniline method synthesized from 4-iodoaniline and ammonia (U.S. Pat. No. 3,919,155);
U.S. Pat. No. 3,975,349), the dichlorobenzene method synthesized from 1,4-dichlorobenzene and ammonia (JP-A-51-59824, JP-A-Sho 53-
77023, JP 56-16449, JP 56-40145, JP 57-61263
(Japanese Patent Publication No. 55-33709), the chloroaniline method synthesized from 4-chloroaniline and ammonia (
% Publication No. 57-61262, Special Publication No. 57-6126
Publication No. 3) is known.

(Problems to be Solved by the Invention) Each of the conventional techniques for producing 1,4-diaminobenzene has serious problems.

The dichlorobenzene method requires high temperature and high pressure as reaction conditions, and also produces a large amount of tar-like high-boiling substances, making purification difficult and difficult to achieve high purity.

The method of Japanese Patent Publication No. 57-61263 teaches that amination of dichlorobenzene with aqueous ammonia hardly proceeds when the fi is lower than 175°C. The method disclosed in Japanese Patent Publication No. 56-40145 is based on aromatic
(All Examples are aromatic dichlorides) Amination with anthonia hardly proceeds below 160°C, so it should be carried out at 1To to 240°C. It teaches that ~7% of heavy materials are produced as by-products. Like the dichlorobenzene method, the chloroaniline method requires high temperatures and pressures, and heavy substances are produced as by-products. Both the dichlorobenzene method and the rialoaniline method are carried out in the coexistence of water, but the coexistence of water makes separation and recovery of diaminobenzene extremely difficult.

In other words, in order to separate diaminobenzene, it is necessary to add more than stoichiometric amount of sodium hydroxide to the reactant, precipitate the copper compound of the catalyst, and extract the diamine after converting the diamine salt into free diamine. do(%
Publication No. 55-33709). Other 1.4 below
Describe the problems of the diamine production method. The aminoazobenzene method requires a long process and the intermediate products are easily explosive and dangerous. The Hoffmann degradation method also requires a long process, and purification of both intermediates and products is complicated. In the nitroaniline method, the starting material acetanilide is expensive and the process is long. The amine phenol method is an electrolytic method in which the synthesis of the intermediate 4-aminophenol is complicated and requires expensive equipment, and 4-aminophenol is unstable and difficult to handle. The latter amination step not only requires high temperature and high pressure reaction conditions, but also produces a tar-like high-boiling substance as a by-product. In the no-hydroquinone method, the raw material, no-hydroquinone, is expensive and requires high temperature and high pressure reaction conditions. The direct amination method requires harsh conditions and has low yield and selectivity. The iodoaniline method uses an expensive and highly deceptive iodine compound, and also produces isomer 1,2-diaminobenzene as a by-product, making purification difficult.

(Means for Solving the Problems) As a result of intensive research into an improved production method for 1,4-diaminobenzene, the present inventors have found that 4-bromoaniline and ammonia are combined in the coexistence of an acyclic saturated hydrocarbon. and 1.4 by reacting in the presence of copper and/or a copper compound.
- It was discovered that diaminobenzene can be produced, and the present invention was completed.

That is, the present invention is a method for producing 1,4-diaminobenzene in which 4-bromoaniline and ammonia are reacted in the presence of an acyclic saturated hydrocarbon and in the presence of copper and/or a copper compound.

As the acyclic saturated hydrocarbon used in the method of the present invention,
It may be a normal form, an iso form, or a mixture of a normal form and an in form. The acyclic saturated hydrocarbon preferably has 4 to 16 carbon atoms, and most preferably 5 to 12 carbon atoms. If the number of carbon atoms is 4 or more, the pressure will not be too high;
If it is 6 or less, the reaction will proceed easily. Examples of acyclic saturated hydrocarbons used in the method of the present invention include n-butane,
i-butane, n-pentane, i-pentane, n-hexane, i-hexane, n-hebutane, i-hebutane, n-
Octane, i-octane, n-nonane, i-nonane, n
-deca/, i-decane, n-undecane, i-undecane, n-dodecane, 1-dodecane, n-) lysocane, 5-tridicane, n-tetradecane, i-tetradecane,
Examples include n-pentadecane, i-pentadecane, n-hexadecane, and l-hexadecane. The amount of acyclic hydrocarbon used is 1 to 100 per ton of 4-bromoaniline.
- is preferred, and 3 to 30 go is more preferred.

The copper and copper compounds used in the process of the invention have a catalytic effect in the process of the invention. The copper compound used in the method of the present invention may be either monovalent or divalent copper compound, but -
valent copper compounds are preferred.

Examples of copper compounds include bromide steel, copper chloride steel, copper oxide, hydroxide steel, organic acid copper such as copper succinate,
It is an ammine complex of a copper compound such as copper halide, or a combination of these copper compounds.

The amount of copper and/or copper compound used is preferably 0.001 to 5 gram atoms, more preferably 0.01 to 1 gram atom, in terms of copper atoms per gram mole of 4-bromoaniline.

In the method of the present invention, the reaction temperature is 7G to 160°C
is preferred, and 85 to 140°C is more preferred. 7
A temperature of 0°C or higher is preferable because the reaction is fast, and a temperature of 160°C or lower is preferable because the selectivity is high.

Further, the reaction pressure is preferably 50 to 250 #/ls"G.

(Effects of the Invention) The method of the present invention has the advantage that 1.4-/aminobenzene has little or no solubility in acyclic saturated hydrocarbons, whereas 4--
Bromoaniline is soluble. Therefore, 1,4-diaminobenzene and 4-bromoaniline can be easily separated. Furthermore, the method of the present invention hardly produces any high-boiling substances such as tar, and it is easy to purify 1,4-diaminobenzene. Due to these effects, the method of the present invention can easily and economically produce 1,4-diaminobenzene with bright equipment.

(Example) The present invention will be explained below with reference to Examples.

Example 1 4-bromoaniline 1.8F, cuprous bromide 0.6P.

N-Hexa 74011Ll was placed in a 5 stainless steel autoclave equipped with a stirrer having a content of 11R200d, and the autoclave was immersed in a dry ice methanol bath to introduce ammonia. Autoclave at 100℃, pressure 80Je
i/3"G for 4 hours with stirring.

The autoclave was returned to normal temperature and pressure, and the reaction product was analyzed by gas chromatography using the following procedure. When the reaction product was filtered and the liquid and the washing solution obtained by washing the product with n-nonane were analyzed, 1.539 4-bromoaniline was recovered. The solid after washing was extracted with tetrahydrofuran, and the liquid was analyzed by gas chromatography, and 0.17 F of 1,4-diaminobenzene was obtained. The gas chromatograph separation column was a PB020M 2 mm column at 20°C.

Example 2 4-bromoaniline 2.1f, cuprous bromide 0.7f.

After charging 40 grams of n-nonane into an autoclave and introducing ammonia, the temperature was 85°C and the pressure was 100 AiF/α2G.
It was kept for 5 hours. 4-bromoaniline charged with 1,4-diaminobenzene was obtained in a yield of 4-bromoaniline equivalent to 4-mol%.

Example 3 4-bromoaniline 2-5ts copper powder 0.8P, n-
Nonane 40- was charged into an autoclave, ammonia was added to the same amount, and then kept at 105°C and a pressure of 90#/cm"G for 5 hours. The yield of 1,4-diaminobenzene was 94 mol% based on the charged 4-bromoaniline. obtained at a rate.

Claims (3)

[Claims] (1) A method for producing 1,4-diaminobenzene characterized by reacting 4-bromoaniline and ammonia in the coexistence of an acyclic saturated hydrocarbon and in the coexistence of copper and/or a copper compound. (2) The method according to claim 1, wherein the acyclic saturated hydrocarbon has 4 to 16 carbon atoms. (3) The method according to claim 1 or 2, wherein the copper compound is a monovalent copper compound.