JP2007176812A - Method for producing 4-nitrosodiphenylamine and 4-nitrodiphenylamine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To produce 4-nitrosodiphenylamine and 4-nitrodiphenylamine at high selectivity from aniline and nitrobenzene. <P>SOLUTION: In the production method, aniline is reacted with nitrobenzene in the presence of a base and a hydrotalcite. As the hydrotalcite, one having a hydroxide ion or an alkoxide ion as an interlaminar anion or one subjected to a contact treatment with a quaternary ammonium compound is preferably used. As the base, an alkali metal hydroxide is used preferably. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a process for producing 4-nitrosodiphenylamine and 4-nitrodiphenylamine from aniline and nitrobenzene. Both 4-nitrosodiphenylamine and 4-nitrodiphenylamine can be converted to 4-aminodiphenylamine by hydrogenation. By alkylating this 4-aminodiphenylamine, it is useful as an antioxidant for natural rubber and synthetic rubber. 4-Alkylaminodiphenylamine can be obtained. 4-Nitrosodiphenylamine and 4-nitrodiphenylamine are also useful as raw materials for azo dyes.

  As a method for producing 4-nitrosodiphenylamine and 4-nitrodiphenylamine, JP-A-6-508630 (Patent Document 1) discloses reacting aniline with nitrobenzene in the presence of a base. . JP 2005-515163 A (Patent Document 2) discloses reacting aniline with nitrobenzene in the presence of a quaternary ammonium compound together with a base.

Japanese National Patent Publication No. 6-508630 JP 2005-515163 A

  In the conventional method, the selectivity of 4-nitrosodiphenylamine and 4-nitrodiphenylamine is not always sufficient. Accordingly, an object of the present invention is to provide a method capable of producing 4-nitrosodiphenylamine and 4-nitrodiphenylamine with high selectivity from aniline and nitrobenzene.

  As a result of intensive studies, the present inventors have found that the above object can be achieved by reacting aniline with nitrobenzene in the presence of a predetermined solid catalyst together with a base, and the present invention has been completed.

  That is, the present invention provides a method for producing 4-nitrosodiphenylamine and 4-nitrodiphenylamine by reacting aniline with nitrobenzene in the presence of a base and hydrotalcites.

  According to the present invention, 4-nitrosodiphenylamine and 4-nitrodiphenylamine can be produced from aniline and nitrobenzene with high selectivity.

  In the present invention, aniline and nitrobenzene are used as raw materials, and the use ratio is usually 1/10 to 10/1 in terms of the molar ratio of aniline / nitrobenzene. In general, the higher the use rate of aniline, the higher the production rate of 4-nitrosodiphenylamine, and the higher the use rate of nitrobenzene, the higher the production rate of 4-nitrodiphenylamine.

  When aniline is reacted with nitrobenzene, 4-nitrosodiphenylamine and 4-nitrodiphenylamine can be produced with high selectivity by allowing hydrotalcites to be present together with a base.

  Examples of the base include alkali metal and alkaline earth metal hydrides, hydroxides, alkoxides, etc. Among them, alkali metal hydroxides such as sodium hydroxide and potassium hydroxide are preferably used. The usage-amount of a base is 1-10 mol normally with respect to 1 mol of nitrobenzene, Preferably it is 2-5 mol.

  Hydrotalcite is hydrotalcite (see the following formula)

[Mg ₆ Al ₂ (OH) ₁₆ ] ²⁺ CO ₃ ^2-・ 4H ₂ O

A compound having a layered structure similar to the above, that is, a layered compound in which an exchangeable anion exists between layers having a positive charge made of a divalent metal and a hydroxide of a trivalent metal. Generally, it can be expressed by the following formula.

[M (II) _1-x M (III) _x (OH) ₂ ] ^{x +} A ^n- _{x / n} · mH ₂ O

Wherein, M (II) represents a divalent metal, M (III) represents a trivalent metal, A ^n-represents an n-valent interlayer anion, x is 0.1 to 0.5 Represents a number, and m represents a number from 0 to 4. ]

  Examples of the divalent metal represented by M (II) include magnesium, calcium, manganese, iron, cobalt, nickel, copper, zinc, palladium and the like. Of these, magnesium is preferable.

  Examples of the trivalent metal represented by M (III) include aluminum, titanium, vanadium, chromium, manganese, iron, cobalt, nickel, ruthenium, and rhodium. Among these, aluminum is preferable.

Examples of interlayer anion represented by A ^n-, hydroxide ion, alkoxide ion, carbonate ion, nitrate ion, phosphate ion, sulfate ion, chloride ion, fluoride ion, bromide ion, iodide ion, Examples include perchlorate ion, chlorate ion, tungstate ion, chromate ion, ferricyanide ion, ferrocyanide ion, and silicate ion. Of these, hydroxide ions and alkoxide ions are preferable.

  Note that x is preferably 0.2 to 0.4.

  Hydrotalcites can be prepared, for example, by mixing a solution containing a divalent metal, a trivalent metal, and an anion introduced between layers with a solution containing a hydroxide ion. In addition, hydrotalcites having hydroxide ions as interlayer anions can be suitably prepared by calcination and hydration of hydrotalcites having carbonate ions as interlayer anions. In addition, hydrotalcites having alkoxide ions as interlayer anions can be suitably prepared by contact-treating hydrotalcites having nitrate ions as interlayer anions with a solution containing alkoxides.

  It is also effective to contact hydrotalcites with a quaternary ammonium compound or a solution thereof, preferably an aqueous solution. Thereby, highly active hydrotalcites can be obtained and the conversion rate of aniline or nitrobenzene can be improved. Examples of the quaternary ammonium compound include quaternary ammonium chloride such as tetramethylammonium chloride, tetraethylammonium chloride, benzyltrimethylammonium chloride, benzyltriethylammonium chloride, benzyltributylammonium chloride, methyltrioctylammonium chloride, and trilaurylmethylammonium chloride. , Quaternary ammonium bromide such as tetra-n-butylammonium bromide, benzyltributylammonium bromide, hydroxide such as tetra-n-propylammonium hydroxide, tetra-n-butylammonium hydroxide, benzyltrimethylammonium hydroxide Examples thereof include quaternary ammonium, quaternary ammonium hydrogen sulfate such as tetrabutylammonium hydrogen sulfate, and the like. Among these, quaternary ammonium hydroxide is preferable, and tetraalkylammonium hydroxide is more preferable.

  The usage-amount of hydrotalcite is 1-10000g normally with respect to 1 mol of nitrobenzene, Preferably it is 10-1000g.

  Examples of the solvent that can be used in the reaction include dimethyl sulfoxide, dimethylformamide, N-methyl-2-pyrrolidone, N, N-dimethylformamide, tetrahydrofuran, t-butanol and the like. Of these, dimethyl sulfoxide is preferable. Alternatively, the raw material aniline or nitrobenzene may be used in excess and used as a raw material and solvent.

  The reaction temperature is usually 0 to 200 ° C, preferably 20 to 150 ° C. Moreover, reaction time is 0.1 to 24 hours normally. Increasing the reaction temperature promotes the reaction, but the selectivity of 4-nitrosodiphenylamine and 4-nitrodiphenylamine tends to decrease. Therefore, in order to improve the conversion of aniline or nitrobenzene, it is preferable to increase the reaction temperature. The reaction time should be extended.

  The post-treatment operation after the reaction is appropriately selected. For example, the reaction mixture is filtered to recover hydrotalcite as a filter residue, and the filtrate is neutralized if necessary, followed by distillation, distribution, and crystallization. It may be subjected to a separation and purification operation such as. The recovered hydrotalcites can be reused.

  Examples of the present invention will be shown below, but the present invention is not limited thereto.

  Nitrobenzene, 4-nitrosodiphenylamine and 4-nitrodiphenylamine were analyzed by high performance liquid chromatography. The conversion of nitrobenzene, the selectivity of 4-nitrosodiphenylamine and the selectivity of 4-nitrodiphenylamine are the number of moles of nitrobenzene used. Where X is X, the number of moles of unreacted nitrobenzene is Y, the number of moles of 4-nitrosodiphenylamine produced is Z1, and the number of moles of 4-nitrodiphenylamine is Z2.

Nitrobenzene conversion rate (%) = [(XY) / X] × 100
Selectivity of 4-nitrosodiphenylamine (%) = [Z1 / (XY)] × 100
Selectivity of 4-nitrodiphenylamine (%) = [Z2 / (XY)] × 100

In addition to hydrotalcite [Mg ₆ Al ₂ (OH) ₁₆ CO ₃ .4H ₂ O; Wako Pure Chemical Industries, Ltd.], the following were used as hydrotalcites.

[Hydrotalcite (A)]
10.00 g of hydrotalcite was calcined at 450 ° C. for 6 hours under a nitrogen flow, cooled to room temperature, and then hydrated for 18 hours under a flow of nitrogen bubbled in water. The hydrated product thus obtained was used as hydrotalcites (A). This hydrotalcite (A) has a hydroxide ion as an interlayer anion.

[Hydrotalcite (B)]
Magnesium nitrate hexahydrate [Mg (NO ₃ ) ₂ .6H ₂ O] 30.77 g (0.12 mol) and aluminum nitrate nonahydrate [Al (NO ₃ ) ₃ .9H ₂ O] 15.01 g (0.04 mol) was dissolved in 100 mL of water. To this solution, a 2 mol / L aqueous sodium hydroxide solution was added dropwise under a nitrogen atmosphere until the pH reached 10, and the mixture was stirred at room temperature for 2 hours. The obtained mixture was filtered, and the crystals remaining after filtration were washed with water and dried in vacuo at 80 ° C. overnight. The dried product was finely ground in a mortar, fired at 450 ° C. for 6 hours under an air flow, and then cooled to room temperature under a nitrogen flow.

  A 500 mL three-necked flask was charged with 13.20 g of potassium tert-butoxide (purity 85% by weight, 0.10 mol) and 300 mL of tetrahydrofuran, stirred under a nitrogen atmosphere, and then crystallized after the previous calcination and cooling. 50g was added and it stirred at 60 degreeC for 1 hour. The resulting mixture was filtered, and the residual crystals were washed with tetrahydrofuran and dried in vacuo. The dried product thus obtained was used as hydrotalcites (B). These hydrotalcites (B) have t-butoxide ions as interlayer anions.

[Hydrotalcite (C)]
To a 200 mL three-necked flask, 25.55 g of 39.8 wt% tetra-n-propylammonium hydroxide aqueous solution, 35.00 g of water, and 5.00 g of hydrotalcite were added, and the mixture was stirred at 60 ° C. for 5 hours. The resulting mixture was filtered, and the solid residue was washed with water and dried in vacuo. The dried product thus obtained was used as hydrotalcites (C).

Example 1
In a 50 mL three-necked flask, 0.50 g (4.0 mmol) of nitrobenzene, 2.26 g (24.2 mmol) of aniline, 0.79 g (12.0 mmol) of potassium hydroxide, 2.00 g of hydrotalcite, and dimethyl 10 mL of sulfoxide was charged, and the reaction was carried out for 1 hour while maintaining the temperature at 60 ° C. with stirring. The reaction mixture was filtered and the filtrate was analyzed. As a result, the conversion rate of nitrobenzene was 31.3%, the selectivity of 4-nitrosodiphenylamine was 79.9%, and the selectivity of 4-nitrodiphenylamine was 18.0% (total selection) The rate was 97.9%).

Example 2
The same operation as in Example 1 was performed except that 1.17 g of hydrotalcite (A) was used instead of hydrotalcite. The conversion of nitrobenzene was 47.4%, the selectivity of 4-nitrosodiphenylamine was 71.8%, and the selectivity of 4-nitrodiphenylamine was 25.3% (total selectivity 97.1%).

Example 3
The same operation as in Example 1 was performed except that hydrotalcite (B) was used instead of hydrotalcite. The conversion ratio of nitrobenzene was 60.0%, the selectivity of 4-nitrosodiphenylamine was 53.7%, and the selectivity of 4-nitrodiphenylamine was 37.6% (total selectivity 91.3%).

Example 4
The same operation as in Example 1 was performed except that 0.62 g of hydrotalcite (C) was used instead of hydrotalcite. The conversion of nitrobenzene was 51.9%, the selectivity of 4-nitrosodiphenylamine was 60.7%, and the selectivity of 4-nitrodiphenylamine was 35.4% (total selectivity 96.1%).

Comparative Example 1
The reaction was carried out in the same manner as in Example 1 except that hydrotalcite was not used. As a result of analyzing the reaction mixture, the conversion rate of nitrobenzene was 58.6%, the selectivity of 4-nitrosodiphenylamine was 28.3%, the selectivity of 4-nitrodiphenylamine was 45.4% (total selectivity 73.7%) )Met.

Comparative Example 2
The reaction was conducted in the same manner as in Example 1 except that 0.45 g (4.0 mmol) of tetramethylammonium chloride was used instead of hydrotalcite. As a result of analyzing the reaction mixture, the conversion rate of nitrobenzene was 80.7%, the selectivity of 4-nitrosodiphenylamine was 33.1%, the selectivity of 4-nitrodiphenylamine was 45.4% (total selectivity 78.5%) )Met.

Claims (7)

  A process for producing 4-nitrosodiphenylamine and 4-nitrodiphenylamine, which comprises reacting aniline and nitrobenzene in the presence of a base and hydrotalcites.   The method according to claim 1, wherein the hydrotalcite has a hydroxide ion or an alkoxide ion as an interlayer anion.   The method according to claim 1 or 2, wherein the hydrotalcite is contact-treated with a quaternary ammonium compound.   The process according to claim 3, wherein the quaternary ammonium compound is quaternary ammonium hydroxide.   The method according to claim 1, wherein the base is an alkali metal hydroxide.   The method according to any one of claims 1 to 5, wherein the reaction is carried out in an organic solvent. The process according to claim 6, wherein the organic solvent is dimethyl sulfoxide.