RU2293723C1 - Method of production of 4-aminodiphenylamine - Google Patents

Abstract

FIELD: chemical industry; methods of production of 4-aminodiphenylamine.

SUBSTANCE: the invention is pertaining to the method of production of 4-aminodiphenylamine, which is used as the basic raw in production of the stabilizing agents and antioxidants for the tire, cable and other rubbers of engineering designation as well as the colorants. The method provides, that conduct condensation of the nitrobenzol and phenylamine with utilization of the tetramethylammonium hydroxide and the subsequent catalytic hydrogenation of the produced semi-finished products. At that after the termination of the condensation reaction the reaction mixture is added with the hydrochloric acid till gaining pH 6÷7 and remove the gained water solution of the tetramethylammonium chloride and subject the remained 4- nitroso diphenylamine and 4-nitro diphenylamine to the catalytical hydrogenation up to 4-aminodiphenylamine in the medium of the mixture of aniline, toluene and water at the temperature of 80÷120°C. The method allows to increase the level of conversion of the semi-finished products up to 100 % and to conduct purification of the recycle water solution of the tetramethylammonium hydroxide without application of the electrolyzers.

EFFECT: the invention ensures the increased level of conversion of the semi-finished products up to 100 %, realization of the purification of the recycle water solution of the tetramethylammonium hydroxide without application of the electrolyzers.

2 cl, 2 ex

Description

The invention relates to a method for producing 4-aminodiphenylamine (ADPA), which is used as the main raw material in the production of stabilizers and antioxidants for bus, cable and other technical rubbers, as well as dyes.

A known method of producing ADPA by nitrosation of diphenylamine, rearrangement of the obtained N-nitrosodiphenylamine, followed by catalytic hydrogenation of the obtained 4-nitrosodiphenylamine to ADPA (US Pat. RF RU 2223259 C1. Martynov N.V. and others). The disadvantage of this method is the formation of a larger number of low-value mineral salts and a low yield of ADPA, which does not exceed 82%, based on the consumed diphenylamine. Also known modern low- process for preparing ADPA condensation of aniline with nitrobenzene in the presence of tetramethylammonium hydroxide (GTMA) followed by catalytic hydrogenation of the resulting mixture tetramethylammonium salt of 4-nitrosodiphenylamine (4-NO · TMA) and tetramethylammonium salt of 4-nitrodiphenylamine (4-NO ₂ · TMA) to ADFA (US No. 5117063, May 26, 1992; US No. 5453541, September 26, 1995; US No. 5608111, Mar. 1997; US No. 5623088, Apr. 22 1997; RU 2102381, 01.20.1998; US No. 5739403, 14.04 .1998. US No. 6388136, May 4, 2002; US No. 6395933, may 2002; US No. 6538320, Jun 24 2003; RU 2224741, 02.27.2004; RU 2247712, 03/10/2005). An experimental justification of the mechanism of direct interaction of nitrobenzene with aniline with the participation of GTMA is given in the article (see Michael K. Stern, Frederick D. Hileman, and Jemes K. Bashkin. Direct Coupling of Aniline and Nitrobenzene: A New Exemple of Nucleophilic Aromatic Substitution for Hydrogen. J. Am. Chem. Soc. 1992, 114, 9237-9238).

The closest analogue of the invention is the method for producing ADPA described in patent RU 2102381 (class C 07 C 209/36, 209/38, 211/55, 211/56, publ. 20.01.98 Bull. No. 2). The method of producing ADPA according to the prototype is as follows (see Example 1A). Nitrobenzene is condensed with aniline using GTMA to give a suspension of a mixture of 4-NO · TMA and 4-NO ₂ · TMA salts. Water (16 ml) was added to this mixture, and then the entire reaction mixture was charged into a 300 cm ³ autoclave for hydrogenation. A catalyst is added to the autoclave - 1% Pt on carbon (0.5 g dry weight). The reaction mixture is heated to 80 ° C. under a hydrogen pressure of 10.5 · 10 ³ Pa (150 psig). The absorption of hydrogen is completed within 30 minutes The HPLC analysis showed that 35.9 mmol of ADPA was formed, which corresponds to the conversion of 4-NO · TMA and 4-NO ₂ · TMA in 97% ADPA.

The disadvantage of the method for producing ADFA according to the prototype is that hydrogenation of a mixture of salts of 4-NO · TMA and 4-NO ₂ · TMA at temperatures above 80 ° C leads to the decomposition of expensive GTMA according to the scheme (see Chemical encycl., T 1, ed., Soviet encyclopedia M., 1988, pp. 279, 280):

(CH ₃ ) ₄ HOH → (CH ₃ ) ₃ H + CH ₃ OH.

At a temperature of 80 ° C and lower, the hydrogenation process slows down and does not proceed to the end, which leads to a decrease in the conversion of 4-NO · TMA and 4-NO ₂ · TMA salts to ADPA to 97%. After catalytic hydrogenation, it is recommended to isolate GTMA from the reaction mixture in the form of an aqueous solution and reuse it in subsequent syntheses (see US No. 5739403). However, after several cycles of reuse of the aqueous GTMA solution, by-products accumulate in this solution, the solution loses its catalytic activity and special cleaning is required. Such cleaning is carried out by electrolysis using special electrolytic cells with membranes made of expensive porous plastic polytetrafluoroethylene (polytetrafluoroethylene) type Na-fion DuPont. However, these membranes withstand no more than 50 cycles of work, after which their replacement is required. This significantly increases the cost of the purified aqueous solution of GTMA, which is the second disadvantage of the prototype method (see application United States Patent Application 20020079233 Kind Code Al, Giatti Anna et al. June 27, 2002).

The objective of the invention is to create such a method for producing ADPA by condensation of nitrobenzene with aniline using GTMA followed by catalytic hydrogenation of the obtained intermediates, in which the degree of conversion of intermediates to ADFA reaches 100%, and the return of an aqueous solution of GTMA will be purified without the use of electrolyzers.

This problem is solved by the proposed method for producing ADPA, by condensation of nitrobenzene with aniline using tetramethylammonium hydroxide and subsequent catalytic hydrogenation of the obtained intermediates, in which according to the invention, after completion of the condensation reaction, hydrochloric acid is added to the reaction mixture to a pH of 6–7, the resulting aqueous solution of tetramethylammonium chloride is removed and catalytically hydrogenate the remaining 4-nitrosodiphenylamine and 4-nitrodiphenylamine to 4-aminodiphenylamine in a mixture of aniline, toluene and ode at 80 ÷ 120 ° C. An aqueous solution of tetramethylammonium chloride, isolated from the reaction mixture, is purified by treatment with active carbon, neutralized with potassium hydroxide, excess (precipitated) potassium chloride is removed, and the resulting aqueous solution of tetramethylammonium hydroxide is used in the condensation step.

The invention consists in the following:

- prepare an aqueous solution of GTMA;

- aniline is added to the resulting solution, tetramethylammonium anilide is obtained, nitrobenzene is added dropwise to it, while water is distilled off, and a mixture of 4-NO-TMA and 4-N02-TMA salts is obtained;

- in the obtained reaction mixture, water distilled off earlier is loaded, and hydrochloric acid is added dropwise to a pH value of 6.0-7.0, the mass is heated to a temperature of 60-65 ° C and the aqueous XMA solution is separated from the organic;

- the extracted aqueous solution of XTMA is purified with activated carbon, concentrated, transferred with a KOH solution to GTMA, filtered off with KCl and the resulting GTMA solution is reused at the condensation stage;

- the remaining mixture of 4-NO · DFA (4-nitrosodiphenidamine) with 4-NO ₂ · DFA (4-nitrodiphenylamine) is catalytically hydrogenated to ADPA in aniline and toluene and water at a temperature of 80 ÷ 120 ° C.

An advantage of the method for producing ADFA according to the invention is that the complete removal of GTMA from the reaction mixture immediately after the completion of the condensation reaction allows the catalytic hydrogenation of a mixture of 4-NO · DFA and 4-NO ₂ · DFA at temperatures above 80 ° and thereby increase the degree of conversion 4-NO · DFA and 4-NO ₂ · DFA in ADFA up to 100%, and also reduce the duration of hydrogenation.

An advantage is also that the purification of the used aqueous solution of GTMA (in the form of HTMA) is carried out without the use of electrolyzers. Removing excess (precipitated) potassium chloride simplifies the transportation and reuse of the purified GTMA solution, in which only (residual) dissolved potassium chloride works.

The ability to obtain ADFA according to the invention is demonstrated by the following examples.

Example 1

In a glass beaker with a capacity of 500 cm ³ with a stirrer and a thermometer, 0.625 moles of ХТМА, 161 cm ^{3 of} water are loaded, the stirrer is turned ^on , and at a temperature of 20 ÷ 30 ° С, exposure is made until the complete dissolution of ХТМА. 0.625 moles of a 47-50% KOH solution are added to the solution and stirred for 10 minutes. The resulting suspension is filtered off from excess precipitated KCl. The filtrate (aqueous solution of GTMA) is loaded into a flask with a capacity of 500 cm ³ with a stirrer, thermometer, capillary, dropping funnel and a refrigerator with a receiver, add 275 cm ^{3 of} aniline (99.4% - 3,000 mol.) And with stirring and a temperature of 60 ÷ 77 ° C, the azeotrope of water with aniline is distilled off under reduced pressure of 55 ÷ 65 mm Hg. with air supply through the capillary into the gas phase above the surface of the reaction mixture. Water is distilled off until it stops appearing in the distilled aniline (visually). The distilled aniline is separated from the water and returned to the flask. 51.5 cm ^{3 of} nitrobenzene are added dropwise (61.95 g of 99.4% - 0.500 mol) into the resulting reaction mixture with stirring and a temperature of 65 ÷ 78 ° C. In this case, air is continuously supplied through the capillary into the gas space above the surface the reaction mixture. The azeotrope of water with aniline is distilled off with vigorous stirring and the temperature of the reaction mixture is 70 ÷ 78 ° C. The condensation reaction of nitrobenzene with aniline proceeds with the release of heat, therefore, the rate of addition of nitrobenzene should be such that the temperature of the reaction mixture does not exceed 78 ° C. All nitrobenzene is charged for ~ 90 minutes. After the loading of nitrobenzene into the flask through the capillary continues to supply air for 120 minutes with stirring and a temperature of 70 ÷ 75 ° C. At the end of the exposure, a sample of the reaction mixture is taken to determine the absence of nitrobenzene by TLC (thin layer chromatography). If there is no nitrobenzene in the sample, the shutdown is stopped, the distilled aniline is loaded back into the flask and a sample of the reaction mixture is taken to determine the ratio of 4-NO · TMA, 4-NO ₂ · TMA, by-products and impurities by high-precision liquid chromatography (HPLC analysis). Then, GTMA is removed from the reaction mixture. At the beginning, 120 cm ^{3 of} water are charged into the flask (water previously distilled from the stages of obtaining TMA-anilide and the condensation of nitrobenzene with aniline is used), stirred for 15-20 minutes. In this case, the hydrolysis of the residual TMA anilide with the formation of GTMA and aniline and dissolution of the KCl precipitate resulting from the azeotropic distillation of water and aniline occur. Next, sensors are placed in the flask to measure the activity index of hydrogen ions (glass and silver chloride electrodes from a pH meter) and, when stirred under a layer of reaction mass, a 28-30% hydrochloric acid solution is added dropwise from a dropping funnel to reach a pH value of 6.5-7, 0. The resulting reaction mixture with stirring is heated in a water bath to 60 ÷ 70 ° C and maintained at this temperature for 20-30 minutes until the mixture of crystals of 4-NO- and 4-NO ₂ · DFA is completely dissolved. Then the two-layer mass is transferred to a heated dividing funnel and the lower aqueous layer containing CTMA is separated from the upper organic one.

5 g of (technical) activated carbon of the OU-B grade are added to the removed HTMA solution, heated to a temperature of 80-85 ° С, maintained at this temperature and stirring for 30 minutes, and filtered from coal. The filtrate was evaporated until KCl crystals appeared at a temperature no higher than 80 ° С, cooled to 20 ÷ 30 ° С and a 47-50% KOH solution was added, as many moles as how many moles of hydrochloric acid were previously charged when GTMA was removed from the reaction mixture.

The resulting suspension of KCl in a GTMA solution is filtered, the filtrate-regenerated GTMA is reused in the next synthesis.

8 g of Raney nickel (34% Raney nickel) is added to the upper organic layer containing a total of 0.4855 mol of a mixture of 4-NO- and 4-NO ₂ · DMF and the resulting suspension (with a temperature of 60-70 ° C) is transferred to an autoclave with a capacity of 500 cm ³ 150 cm ^{3 of} toluene are loaded there. The autoclave is sealed, a pressure of 2 MPa is created with hydrogen, the mass is stirred at a temperature of 105 ÷ 115 ° C until the absorption of hydrogen ceases, which lasts about 4 hours. The end of the hydrogenation process is determined by the absence of 4-NO · DPA in the hydrogenate sample by TLC. The hydrogenate in an autoclave is cooled to 20-30 ° C, filtered from a catalyst (Raney nickel). The organic phase is separated from the aqueous phase (reaction water). The analysis shows the content of ADPA in the hydrogenate 89.44 g (0.4855 mol), that is, the conversion of 4-NO · DFA and 4-NO ₂ · DFA in ADPA was 100%. Toluene and aniline are distilled off from the hydrogenate and reused. ADPA raw is purified by known methods, for example, by fractional distillation or distillation at a pressure of 4 ÷ 20 mm Hg.

Example 2. This example illustrates the reuse of an isolated purified aqueous solution of GTMA (return HTMA).

In a flask with a capacity of 500 cm ³ with a stirrer, a thermometer, a capillary, a dropping funnel and a refrigerator with a receiver, the returning GTMA is loaded, the GTMA content in it is adjusted to 0.625 mol by adding fresh aqueous solution of GTMA, 275 cm ^{3 of} aniline (99.4%, 3,000 mol ) and with stirring and a temperature of 60 ÷ 77 ° C, the azeotrope of water with aniline is distilled off under reduced pressure (55-65 mm Hg) with air supply through the capillary into the gas phase above the surface of the reaction mixture. Water is distilled off until it stops appearing in the distilled aniline (visually). The distilled aniline is separated from the water and returned to the flask. 51.5 cm ^{3 of} nitrobenzene are added dropwise (61.95 g, 99.4%, 0.500 mol) into the resulting reaction mixture with stirring and a temperature of 65-78 ° C. The process is then carried out as described in Example 1. The isolation of GTMA from the reaction mixture is carried out after the completion of the condensation reaction, diluting the reaction mixture with water and neutralizing with hydrochloric acid. Then the flask with a two-layer mass is heated in a water bath with stirring to 60 ÷ 70 ° C. After complete dissolution of the crystals of 4-NO · DFA and 4-NO ₂ · DFA, the reaction mixture is transferred to a dividing funnel heated to a temperature of 60-70 ° C, an aqueous solution of XMA, which is purified by charcoal, is separated, transferred to GTMA, as described in example 1, and reused in the next synthesis. The upper layer (organic phase) containing a total of 0.4855 moles of a mixture of 4-NO · DFA and 4-NO ₂ · DFA was transferred to an autoclave and hydrogenated as described in Example 1. After filtration from the catalyst (Raney nickel), the analysis showed the ADFA content 89.43 g (0.4855 mol) in the filtrate. Thus, the conversion of 4-NO · DFA and 4-NO ₂ · DFA to ADPA was almost 100%.

Claims (2)

1. The method of producing 4-aminodiphenylamine by condensation of nitrobenzene with aniline using tetramethylammonium hydroxide and subsequent catalytic hydrogenation of the obtained intermediates, characterized in that after the completion of the condensation reaction, hydrochloric acid is added to the reaction mixture to pH 6-7, the resulting aqueous solution of tetramethylammonium chloride is removed and catalytically hydrogenate the remaining 4-nitrosodiphenylamine and 4-nitrodiphenylamine to 4-aminodiphenylamine in a mixture of aniline, toluene and water at a temperature of 80 ÷ 120 ° C. 2. The method according to claim 1, characterized in that the aqueous solution of tetramethylammonium chloride isolated from the reaction mixture is purified by treatment with active carbon, neutralized with potassium hydroxide, excess potassium chloride is removed and the resulting aqueous solution of tetramethylammonium hydroxide is used in the condensation step.