CN111689866A - Preparation method of tower reaction RT base - Google Patents
Preparation method of tower reaction RT base Download PDFInfo
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- CN111689866A CN111689866A CN201910198931.XA CN201910198931A CN111689866A CN 111689866 A CN111689866 A CN 111689866A CN 201910198931 A CN201910198931 A CN 201910198931A CN 111689866 A CN111689866 A CN 111689866A
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- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C209/00—Preparation of compounds containing amino groups bound to a carbon skeleton
- C07C209/30—Preparation of compounds containing amino groups bound to a carbon skeleton by reduction of nitrogen-to-oxygen or nitrogen-to-nitrogen bonds
- C07C209/32—Preparation of compounds containing amino groups bound to a carbon skeleton by reduction of nitrogen-to-oxygen or nitrogen-to-nitrogen bonds by reduction of nitro groups
- C07C209/325—Preparation of compounds containing amino groups bound to a carbon skeleton by reduction of nitrogen-to-oxygen or nitrogen-to-nitrogen bonds by reduction of nitro groups reduction by other means than indicated in C07C209/34 or C07C209/36
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- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C209/00—Preparation of compounds containing amino groups bound to a carbon skeleton
- C07C209/30—Preparation of compounds containing amino groups bound to a carbon skeleton by reduction of nitrogen-to-oxygen or nitrogen-to-nitrogen bonds
- C07C209/38—Preparation of compounds containing amino groups bound to a carbon skeleton by reduction of nitrogen-to-oxygen or nitrogen-to-nitrogen bonds by reduction of nitroso groups
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- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C209/00—Preparation of compounds containing amino groups bound to a carbon skeleton
- C07C209/60—Preparation of compounds containing amino groups bound to a carbon skeleton by condensation or addition reactions, e.g. Mannich reaction, addition of ammonia or amines to alkenes or to alkynes or addition of compounds containing an active hydrogen atom to Schiff's bases, quinone imines, or aziranes
Abstract
The invention provides a RT base condensation method, which adopts a tower reactor to carry out condensation reaction, aniline and organic alkali are mixed and then part of water in the organic alkali is removed through azeotropic distillation, the aniline and the organic alkali are mixed and then are conveyed to a reaction tower with a sprayer, and the materials after being sprayed and dispersed are subjected to condensation reaction in the reaction tower, namely the tower reactor is adopted to carry out condensation reaction. Solves the problems of reducing the conversion rate of raw materials and the selectivity of target products caused by back mixing. The invention has the advantages of simplifying production flow, reducing the investment of reaction equipment, improving production efficiency and the like. The condensation reaction is carried out by adopting the process, the conversion rate of nitrobenzene is more than or equal to 99 percent, the selectivity of phenazine is less than or equal to 0.1 percent, and the selectivity of 2-aminodiphenylamine is less than or equal to 0.15 percent.
Description
Technical Field
The invention belongs to the field of fine chemical engineering, and relates to preparation of a rubber antioxidant intermediate RT base.
Background
RT base (p-aminodiphenylamine) is widely applied to the fields of rubber auxiliaries, dyes, textile, printing, pharmaceutical industry and the like, and is mainly used for producing rubber antioxidants IPPD, 6PPD and the like. At present, the yield of domestic RT base production is 200 kt/a. With the development of the rubber industry, the demand of rubber antioxidants is steadily increasing.
RT-sauce is produced mainly by the aniline method, the diphenylamine method, the formanilide method and the nitrobenzene method. The nitrobenzene process is an improvement of formanilide process, and uses nitrobenzene and aniline as raw materials, and makes them produce condensation reaction under the action of phase transfer catalyst to obtain 4-nitrosodiphenylamine and 4-nitrodiphenylamine, and makes the obtained condensation liquor undergo the process of hydrogenation reduction so as to obtain RT base. The nitrobenzene method process has the characteristics of less three wastes, high product yield, good quality and the like, is a green production process, has obvious advantages compared with other preparation methods, and the prior RT base production is mainly a nitrobenzene method.
The production of RT base by the nitrobenzene method can generate impurities such as 2-aminodiphenylamine, phenazine and the like, and particularly the boiling points of the two substances are close to that of the RT base, so that the rectification of the RT base is difficult, and the quality of the RT base is influenced. At present, RT base research mainly comprises the steps of optimizing a nitrobenzene method RT base process, improving the recovery efficiency of a phase transfer catalyst, reducing energy consumption and material consumption, inhibiting the generation of byproducts, improving the purity of RT base and the like.
The condensation reaction in the production of RT base is mainly carried out by adopting a kettle type continuous condensation process, but the kettle type process needs to be stirred vigorously, the fluid in the kettle can generate a back mixing phenomenon, the back mixing can cause the selectivity of a target product of the reaction to be reduced, impurities such as azobenzene, phenazine, o (sub) nitrodiphenylamine and the like in a condensation liquid can influence the purity of a finished product of the RT base, and the azobenzene can be reduced into aniline, but the energy consumption and the material consumption of the RT base production can be increased.
Disclosure of Invention
The invention provides an RT base condensation process, which comprises the steps of carrying out condensation reaction by adopting a tower reactor, mixing aniline and organic base, removing part of water in the organic base through azeotropic distillation, mixing the aniline and the organic base with nitrobenzene, conveying the mixed material to a reaction tower with a sprayer, carrying out condensation reaction on the sprayed and dispersed material in the reaction tower, wherein in the whole process, the material moves forward in a flat push mode, and the problems of reduction of raw material conversion rate and target product selectivity caused by back mixing in a kettle type process are solved.
The main technical scheme of the invention is as follows: the preparation method of the tower reaction RT base is characterized in that: mixing aniline and organic base, dehydrating, mixing the dehydrated material with nitrobenzene, dispersing by a sprayer, entering a tower reactor for condensation reaction, and reducing the reacted condensation liquid to prepare RT base.
Generally, the organic base is aqueous solution of tetramethylammonium hydroxide or aqueous solution of tetraethylammonium hydroxide, and the concentration of the organic base is 5-45%.
The molar ratio of the aniline to the organic base is 3: 1-20: 1.
The dehydration temperature is 50-90 ℃, and the vacuum degree is 0.080-0.099 MPa.
The water content in the dehydrated material is 5% -35%.
The molar ratio of the addition amount of the nitrobenzene to the tetramethyl ammonium hydroxide is 0.2: 1-1.1: 1.
The condensation reaction temperature is 60-90 ℃, and the vacuum degree is 0.080-0.099 MPa.
The invention has the advantages of
The invention provides an RT base condensation process, which comprises the steps of carrying out condensation reaction by adopting a tower reactor, mixing aniline and organic base, removing part of water in the organic base through azeotropic distillation, mixing the aniline and the organic base with nitrobenzene, conveying the mixed material to a reaction tower with a sprayer, carrying out condensation reaction on the sprayed and dispersed material in the reaction tower, wherein in the whole process, the material moves forward in a flat push mode, and the problems of reduction of raw material conversion rate and target product selectivity caused by back mixing in a kettle type process are solved.
The invention adopts a tower type condensation process, and has the advantages of simplifying production flow, reducing the investment of reaction equipment, improving production efficiency and the like. The condensation reaction is carried out by adopting the process, the conversion rate of nitrobenzene is more than or equal to 99 percent, the selectivity of phenazine is less than or equal to 0.1 percent, and the selectivity of 2-aminodiphenylamine is less than or equal to 0.15 percent.
Drawings
FIG. 1 is a schematic view of a tower condensation process according to an embodiment of the present invention.
FIG. 1-aniline base mixer; 2-a dehydrator; 3-condensation raw material mixer; 4-a tower reactor; and 5, a sprayer.
Detailed Description
The present invention will be described in detail below with reference to examples and the accompanying drawings.
The following example process flow refers to figure 1.
Example 1
150 parts of aniline and 120 parts of 25% tetramethylammonium hydroxide are mixed and dehydrated, the dehydration temperature is 70 ℃, the dehydration vacuum degree is 0.090MPa, and the water content in the dehydrated material is 16.42%. The materials are mixed with 40 parts of nitrobenzene, and then are sprayed and dispersed to enter a tower reactor for condensation reaction, wherein the reaction temperature is 65 ℃, and the vacuum degree is 0.092 MPa. The obtained condensation liquid is 180 parts, the condensed aniline water is 30 parts, the mass percentage of nitrobenzene in the condensation liquid is analyzed to be 0.06%, and the mass percentage of nitrobenzene in the condensed aniline water is 0.75%. Adding 80 parts of methanol into the obtained condensation liquid, and reducing to obtain 260 parts of reduction liquid, wherein the mass percent of the phenazine is 0.012%, and the mass percent of the 2-aminodiphenylamine is 0.017%. The conversion rate of nitrobenzene is calculated to be 99.17 percent, the selectivity of phenazine is 0.053 percent, and the selectivity of 2-aminodiphenylamine is 0.076 percent.
Example 2
200 parts of aniline and 120 parts of 25% tetramethyl ammonium hydroxide are mixed and dehydrated, the dehydration temperature is 65 ℃, the dehydration vacuum degree is 0.093MPa, and the water content in the dehydrated material is 12.44%. The materials are mixed with 40 parts of nitrobenzene, and then are sprayed and dispersed to enter a tower reactor for condensation reaction, wherein the reaction temperature is 80 ℃, and the vacuum degree is 0.092 MPa. 219 parts of the obtained condensation liquid, 41 parts of condensed aniline water, wherein nitrobenzene in the condensation liquid is not detected, and the mass percentage content of nitrobenzene in the condensed aniline water is 0.83%. Adding 80 parts of methanol into the obtained condensation liquid, and reducing to obtain 300 parts of reduced liquid, wherein the mass percent of the phenazine is 0.015%, and the mass percent of the 2-aminodiphenylamine is 0.021%. The conversion rate of nitrobenzene is calculated to be 99.15 percent, the selectivity of phenazine is calculated to be 0.076 percent, and the selectivity of 2-aminodiphenylamine is calculated to be 0.107 percent.
Example 3
600 parts of aniline and 1000 parts of 5% tetramethyl ammonium hydroxide are mixed and dehydrated, the dehydration temperature is 65 ℃, the dehydration vacuum degree is 0.093MPa, and the water content in the dehydrated material is 25.3%. Mixing the materials with 40 parts of nitrobenzene, spraying and dispersing the mixture, and feeding the mixture into a tower reactor for condensation reaction at the reaction temperature of 70 ℃ and the vacuum degree of 0.092 MPa. 285 parts of condensation liquid and 55 parts of condensed aniline water, wherein nitrobenzene in the condensation liquid is not detected, and the mass percentage content of nitrobenzene in the condensed aniline water is 0.70%. Adding 80 parts of methanol into the obtained condensation liquid, and reducing to obtain 365 parts of reduction liquid, wherein the mass percent of the phenazine is 0.015%, and the mass percent of the 2-aminodiphenylamine is 0.021%. The conversion rate of nitrobenzene is calculated to be 99.08 percent, the selectivity of phenazine is 0.068 percent, and the selectivity of 2-aminodiphenylamine is 0.093 percent.
Example 4
150 parts of aniline and 120 parts of 40% tetramethylammonium hydroxide are mixed and dehydrated, the dehydration temperature is 65 ℃, the dehydration vacuum degree is 0.091MPa, and the water content in the dehydrated material is 16.94%. The materials are mixed with 20 parts of nitrobenzene, and then are sprayed and dispersed to enter a tower reactor for condensation reaction, wherein the reaction temperature is 65 ℃, and the vacuum degree is 0.092 MPa. 180 parts of condensation liquid and 28 parts of condensed aniline water, wherein nitrobenzene in the condensation liquid is not detected, and the mass percentage content of nitrobenzene in the condensed aniline water is 0.53 percent. And adding 100 parts of methanol into the obtained condensation liquid, and reducing to obtain 292 parts of a reducing liquid, wherein the mass percent of the phenazine is 0.006 percent, and the mass percent of the 2-aminodiphenylamine is 0.008 percent. The conversion rate of nitrobenzene is 99.26 percent, the selectivity of phenazine is 0.060 percent, and the selectivity of 2-aminodiphenylamine is 0.080 percent.
Example 5
150 parts of aniline and 120 parts of 40% tetramethylammonium hydroxide are mixed and dehydrated, the dehydration temperature is 65 ℃, the dehydration vacuum degree is 0.091MPa, and the water content in the dehydrated material is 16.94%. The materials are mixed with 70 parts of nitrobenzene, and then are sprayed and dispersed to enter a tower reactor for condensation reaction, wherein the reaction temperature is 68 ℃, and the vacuum degree is 0.092 MPa. The obtained condensation liquid is 238 parts, the condensation aniline water is 32 parts, the mass percentage content of nitrobenzene in the condensation liquid is analyzed to be 0.17%, and the mass percentage content of nitrobenzene in the condensation aniline water is 0.91%. And adding 100 parts of methanol into the obtained condensation liquid, and reducing to obtain 338 parts of reduced liquid, wherein the mass percent of the phenazine is 0.006 percent, and the mass percent of the 2-aminodiphenylamine is 0.008 percent. The conversion rate of nitrobenzene is calculated to be 99.01 percent, the selectivity of phenazine is 0.049 percent, and the selectivity of 2-aminodiphenylamine is 0.069 percent.
Example 6
350 parts of aniline and 650 parts of tetraethyl ammonium hydroxide with the content of 15 percent are mixed and dehydrated, the dehydration temperature is 75 ℃, the dehydration vacuum degree is 0.089MPa, and the water content in the dehydrated material is 25.2 percent. The materials are mixed with 40 parts of nitrobenzene, and then are sprayed and dispersed to enter a tower reactor for condensation reaction, wherein the reaction temperature is 68 ℃, and the vacuum degree is 0.092 MPa. 258 parts of condensation liquid and 52 parts of condensed aniline water, wherein nitrobenzene in the condensation liquid is not detected, and the mass percentage content of nitrobenzene in the condensed aniline water is 0.70%. Adding 100 parts of methanol into the obtained condensation liquid, and reducing to obtain 358 parts of reduced liquid, wherein the mass percent of phenazine is 0.008%, and the mass percent of 2-aminodiphenylamine is 0.010%. Calculated to obtain the nitrobenzene conversion rate of 99.07 percent, the phenazine selectivity of 0.049 percent and the 2-aminodiphenylamine selectivity of 0.061 percent.
Example 7
150 parts of aniline and 150 parts of tetraethylammonium hydroxide with the content of 20 percent are mixed and dehydrated, the dehydration temperature is 75 ℃, the dehydration vacuum degree is 0.091MPa, and the water content in the dehydrated material is 26.80 percent. The materials are mixed with 27 parts of nitrobenzene, and then sprayed and dispersed to enter a tower reactor for condensation reaction, wherein the reaction temperature is 65 ℃, and the vacuum degree is 0.092 MPa. 180 parts of the obtained condensation liquid and 42 parts of condensed aniline water, wherein nitrobenzene in the condensation liquid is not detected, and the mass percentage content of the nitrobenzene in the condensed aniline water is 0.62%. And adding 100 parts of methanol into the obtained condensation liquid, and reducing to obtain 292 parts of a reducing liquid, wherein the mass percent of the phenazine is 0.008 percent, and the mass percent of the 2-aminodiphenylamine is 0.012 percent. The conversion rate of nitrobenzene is calculated to be 99.17 percent, the selectivity of phenazine is 0.057 percent, and the selectivity of 2-aminodiphenylamine is 0.085 percent.
Claims (7)
1. A preparation method of tower reaction RT base is characterized in that: mixing aniline and organic base, dehydrating, mixing the dehydrated material with nitrobenzene, dispersing by a sprayer, entering a tower reactor for condensation reaction, and reducing the reacted condensation liquid to prepare RT base.
2. The method of claim 1, wherein: the organic alkali is aqueous solution of tetramethyl ammonium hydroxide or aqueous solution of tetraethyl ammonium hydroxide, and the concentration of the organic alkali is 5-45%.
3. The method according to claim 1 or 2, characterized in that: the molar ratio of aniline to organic base is 3: 1-20: 1.
4. The method of claim 1, wherein: the dehydration temperature is 50-90 ℃, and the vacuum degree is 0.080-0.099 MPa.
5. The method of claim 1, wherein: the water content in the dehydrated material is 5% -35%.
6. The method of claim 1, wherein: the molar ratio of the addition amount of the nitrobenzene to the tetramethylammonium hydroxide is 0.2: 1-1.1: 1.
7. The method of claim 1, wherein: the condensation reaction temperature is 60-90 ℃, and the vacuum degree is 0.080-0.099 MPa.
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113402397A (en) * | 2021-06-15 | 2021-09-17 | 中石化南京化工研究院有限公司 | Preparation method of RT base by condensation and reflux |
| CN113816912A (en) * | 2021-08-30 | 2021-12-21 | 上海日异生物科技有限公司 | Preparation method of phenazine |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2003010126A1 (en) * | 2001-07-23 | 2003-02-06 | Flexsys America L.P. | Process for preparing 4-aminodiphenylamine |
| CN1506349A (en) * | 2002-12-11 | 2004-06-23 | 中国石油化工股份有限公司 | Prepn process of 4-amino diphenylamine |
| CN101906048A (en) * | 2009-06-02 | 2010-12-08 | 中国科学院过程工程研究所 | Synthesis method of 4-aminodiphenylamine |
| CN102060714A (en) * | 2010-06-25 | 2011-05-18 | 天津市有机化工一厂 | Method for preparing 4-aminodiphenylamine |
-
2019
- 2019-03-15 CN CN201910198931.XA patent/CN111689866A/en active Pending
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2003010126A1 (en) * | 2001-07-23 | 2003-02-06 | Flexsys America L.P. | Process for preparing 4-aminodiphenylamine |
| CN1506349A (en) * | 2002-12-11 | 2004-06-23 | 中国石油化工股份有限公司 | Prepn process of 4-amino diphenylamine |
| CN101906048A (en) * | 2009-06-02 | 2010-12-08 | 中国科学院过程工程研究所 | Synthesis method of 4-aminodiphenylamine |
| CN102060714A (en) * | 2010-06-25 | 2011-05-18 | 天津市有机化工一厂 | Method for preparing 4-aminodiphenylamine |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113402397A (en) * | 2021-06-15 | 2021-09-17 | 中石化南京化工研究院有限公司 | Preparation method of RT base by condensation and reflux |
| CN113816912A (en) * | 2021-08-30 | 2021-12-21 | 上海日异生物科技有限公司 | Preparation method of phenazine |
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Application publication date: 20200922 |