CN1022483C - Process for preparing 2, 4-dimethylaniline and 2, 6-dimethylaniline - Google Patents
Process for preparing 2, 4-dimethylaniline and 2, 6-dimethylaniline Download PDFInfo
- Publication number
- CN1022483C CN1022483C CN 90102390 CN90102390A CN1022483C CN 1022483 C CN1022483 C CN 1022483C CN 90102390 CN90102390 CN 90102390 CN 90102390 A CN90102390 A CN 90102390A CN 1022483 C CN1022483 C CN 1022483C
- Authority
- CN
- China
- Prior art keywords
- dimethyl nitrobenzene
- xylidine
- alcohol
- dimethyl
- dimethylaniline
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Landscapes
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
Abstract
The present invention relates to a method for preparing 2, 4-dimethylaniline and 2, 6-dimethylaniline, which comprises: alcohol is used as solvent, and nickel catalysts are adopted; 2, 4-dimethylnitrobenzene and 2, 6-dimethylnitrobenzene are respectively hydrogenated, and then, products are rectified to obtain 2, 4-dimethylaniline and 2, 6-dimethylaniline in high yield. The method has the advantages of low energy consumption, high yield, little pollution, easy operation, etc., and cheap nickel catalysts are adopted. The method can satisfy requirements for industrialized production and has obvious social and economic benefits.
Description
The invention belongs to the preparation method of xylidine, especially 2,4-xylidine and 2, the preparation method of 6-xylidine.
Before the present invention makes, present 2,4-xylidine and 2,6-xylidine suitability for industrialized production are to be the reductive agent reductase 12 with the iron powder, 4-dimethyl nitrobenzene and 2, the 6-dimethyl nitrobenzene makes, it is per ton 2 that this method prepares, and 4-xylidine or 2,6-dimethyl benzene amine product produce three tons of iron mud and more than 20 ton and contain amine waste water, three-waste pollution is serious, and yield is low, energy consumption is big; Newer report is to be that catalyzer, temperature are at 40～80 ℃, pressure hydrogenating reduction 2 under 0.6～10MPa with the palladium, 4-dimethyl nitrobenzene or 2,6-dimethyl nitrobenzene preparation 2,4-xylidine and 2,6-xylidine, this preparation method has that reaction pressure is not high, temperature is lower, the liquid phase reaction energy-saving advantages, but, cost an arm and a leg the source difficulty because of palladium catalyst is a precious metal, be difficult to satisfy need of industrial production, and production cost is higher.
Task of the present invention is with 2 of m-xylene preparation, 4-dimethyl nitrobenzene and 2, the 6-dimethyl nitrobenzene is a raw material, provides that a kind of energy consumption is low, yield is high, pollution is little, avoid using 2 of noble metal catalyst, 4-xylidine and 2, the preparation method of 6-xylidine.
The present invention is with 2 of m-xylene preparation, 4-dimethyl nitrobenzene and 2, the 6-dimethyl nitrobenzene, 2, the preparation method of 4-xylidine, with 2,4-dimethyl nitrobenzene and hydrogen are raw material, and adopting alcohol is solvent and nickel catalyzator, adds 2 in reactor, the 4-dimethyl nitrobenzene, alcohol, nickel catalyzator, behind air in the hydrogen exchange reactor, add the excess hydrogen controlled temperature at 60～120 ℃, pressure is at 0.25～2MPa, stirring velocity be under 200～1500 rev/mins of conditions with 2, the 4-dimethyl nitrobenzene fully reacts, the rectifying hydrogenation products promptly obtains 2, the 4-xylidine.Control 2, the 4-dimethyl nitrobenzene is 1: 0.3～2.2 with the weight ratio of alcohol, the preparation method of 6-xylidine, with 2,6-dimethyl nitrobenzene and hydrogen are raw material, adopting alcohol is solvent and nickel catalyzator, in reactor, add 2,6-dimethyl nitrobenzene, alcohol, nickel catalyzator, behind air in the hydrogen exchange reactor, add the excess hydrogen controlled temperature 60～120 ℃, pressure 0.25～2MPa, stirring velocity be under 200～1500 rev/mins of conditions with 2, the 6-dimethyl nitrobenzene fully reacts, the rectifying hydrogenation products promptly obtains 2, the 6-xylidine.Control 2, the 6-dimethyl nitrobenzene is 1: 0.3～2 with the weight ratio of alcohol.
Of the present invention 2,4-xylidine and 2, the preparation method of 6-xylidine is compared with prior art, it is not high to have reaction pressure, and temperature of reaction is lower, and energy consumption is low, the yield height, three-waste pollution is little and use advantages such as more cheap nickel catalyzator is easy to implement, and economic results in society are remarkable.
Embodiment 1:
Present method used 2,4-dimethyl nitrobenzene and 2,6-dimethyl nitrobenzene raw material can be with the preparation of following method.Be mixed with nitration mixture with 28～32 parts of nitric acid, 52～60 parts of sulfuric acid, 12～16 parts of water, in 500 liter nitration reaction stills, drop into 100 kilograms and contain 98% m-xylene, control reaction temperature is 15～20 ℃, stirring velocity is 150 rev/mins, in one hour, evenly drip 100 kilograms of nitration mixture, then under same speed stirs, control reaction temperature is at 25～30 ℃, continuation evenly dripped 100 kilograms of nitration mixture in one hour, continue stirring reaction half an hour then, discard lower floor's spent acid after waiting to leave standstill,, wash with water to neutrality again with the washing of 6% aqueous sodium carbonate.To be washed till in the about 240.8 kilograms of input rectifying tower of neutral m-xylene itrated compound, control rectifying reflux ratio is 6: 1; The about 0.087MPa of the serious reciprocal of duty cycle of control tower, collecting 108 ℃ of fore-runnings mainly is about 0.8 kilogram of m-xylene, wherein 2,4-dimethyl nitrobenzene and 2,6-dimethyl nitrobenzene content is all less than 0.1%; The top vacuum degree is brought up to 0.099MPa, collect 108～110 ℃ of section of heating up in a steamer content and be 97.48% 2, about 23.8 kilograms of 6-dimethyl nitrobenzene, wherein 2,4-dimethyl nitrobenzene content is less than 010%; Collect about 38.0 kilograms of 110～120 ℃ of sections of heating up in a steamer, wherein 2, the 6-dimethyl nitrobenzene contains 28.27%, 2, and the 4-dimethyl nitrobenzene contains 70.75%; Raffinate is about 173.5 kilograms in the tower, and wherein 2, the 4-dimethyl nitrobenzene contains 91.61%, 2, and 6-dimethyl nitrobenzene content is less than 0.10%.0.8 kilogram fore-running product is again as nitrated raw material, 110～120 ℃ of section of heating up in a steamer product rectifying again in next batch, 108～110 ℃ of section of heating up in a steamer products are as 2,6-dimethyl nitrobenzene raw material, raffinate is as 2 in the tower, 4-dimethyl nitrobenzene raw material is respectively applied for hydrogenation preparing 2,6-xylidine and 2,4-xylidine.
Embodiment 2:
To contain 91.61% 2,115 kilograms of 4-dimethyl nitrobenzenes, 49.6 kilograms of ethanol, nickel catalyzator drop into reactor for 3 kilograms in the lump, behind air in three displacement stills of hydrogen, hydrogenation reaction is 2 hours under pressure 1MPa, 80～110 ℃ of temperature, 300 rev/mins of conditions of stirring velocity, the rectifying hydrogenation products promptly obtain content be 98.37% 2, about 78.7 kilograms of 4-xylidine, yield is 91.7%.
Embodiment 3:
To contain 97.48% 2,6-dimethyl nitrobenzene 105 kg, 42 kilograms of ethanol, nickel catalyzator drop into reactor for 3 kilograms in the lump, behind air in three displacement stills of hydrogen, hydrogenation reaction is 2 hours under pressure 1MPa, 60～80 ℃ of temperature, 300 rev/mins of conditions of stirring velocity, the rectifying hydrogenation products promptly obtain content be 98.77% 2, about 76.8 kilograms of 6-xylidine, yield is 92.5%.
Claims (4)
1, a kind of 2, the preparation method of 4-xylidine, with 2,4-dimethyl nitrobenzene and hydrogen are raw material, adopting alcohol is solvent, it is characterized in that adopting nickel catalyzator, in reactor, add 2,4-dimethyl nitrobenzene, alcohol, nickel catalyzator, behind air in the hydrogen exchange reactor, add the excess hydrogen controlled temperature 60～120 ℃, pressure 0.25～2MPa, stirring velocity be under 200～1500 rev/mins of conditions with 2, the 4-dimethyl nitrobenzene fully reacts, the rectifying hydrogenation products promptly obtains 2, the 4-xylidine.
2, preparation method as claimed in claim 1 is characterized in that controlling 2, and the 4-dimethyl nitrobenzene is 1: 0.3～2 with the weight ratio of alcohol.
3, a kind of 2, the preparation method of 6-xylidine, with 2,6-dimethyl nitrobenzene and hydrogen are raw material, adopting alcohol is solvent, it is characterized in that adopting nickel catalyzator, in reactor, add 2,6-dimethyl nitrobenzene, alcohol, nickel catalyzator, behind air in the hydrogen exchange reactor, add the excess hydrogen controlled temperature 60～120 ℃, pressure 0.25～2MPa, stirring velocity be under 200～1500 rev/mins of conditions with 2, the 6-dimethyl nitrobenzene fully reacts, the rectifying hydrogenation products promptly obtains 2, the 6-xylidine.
4, preparation method as claimed in claim 3 is characterized in that controlling 2, and the 6-dimethyl nitrobenzene is 1: 0.3～2 with the weight ratio of alcohol.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 90102390 CN1022483C (en) | 1990-04-21 | 1990-04-21 | Process for preparing 2, 4-dimethylaniline and 2, 6-dimethylaniline |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 90102390 CN1022483C (en) | 1990-04-21 | 1990-04-21 | Process for preparing 2, 4-dimethylaniline and 2, 6-dimethylaniline |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN1055922A CN1055922A (en) | 1991-11-06 |
| CN1022483C true CN1022483C (en) | 1993-10-20 |
Family
ID=4877506
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 90102390 Expired - Fee Related CN1022483C (en) | 1990-04-21 | 1990-04-21 | Process for preparing 2, 4-dimethylaniline and 2, 6-dimethylaniline |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN1022483C (en) |
Families Citing this family (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1087970C (en) * | 1997-08-06 | 2002-07-24 | 湖南化工研究院 | Preparation and use method of catalyst for synthesis of 2,6-dimethylaniline |
| CN100436403C (en) * | 2004-12-28 | 2008-11-26 | 浙江工业大学 | Method for preparing o-chloroaniline |
| CN100436404C (en) * | 2004-12-28 | 2008-11-26 | 浙江工业大学 | Method for preparing aniline |
| CN100509750C (en) * | 2006-06-05 | 2009-07-08 | 甘肃银光化学工业集团有限公司 | Process for continuously preparing nitro-xylene isomer monomer |
| CN101863777B (en) * | 2010-05-23 | 2013-08-21 | 青岛科技大学 | Preparation method for solvent-free 2, 4-dimethylaniline and 2, 6-dimethylaniline |
| CN103288608B (en) * | 2013-05-29 | 2016-03-30 | 扬州大学 | The novel method of nano-nickel oxide catalyzing alcohols matter selective oxidation |
| CN109776332A (en) * | 2019-02-22 | 2019-05-21 | 中海油天津化工研究设计院有限公司 | A kind of method that continous way adds hydrogen to prepare 2,4- dimethylaniline |
-
1990
- 1990-04-21 CN CN 90102390 patent/CN1022483C/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| CN1055922A (en) | 1991-11-06 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN113620813B (en) | Preparation method of N, N-dimethyl-1, 3-propanediamine | |
| CN108101850A (en) | A kind of method for improving 5-acetoacetamido benzimidazolone quality | |
| CN100594210C (en) | Process for synthesizing p-aminophenol by nitrobenzene catalytic hydrogenation | |
| CN113563201B (en) | Method for continuously and efficiently synthesizing 3, 4-dichloroaniline based on fixed bed microreactor | |
| CN1022483C (en) | Process for preparing 2, 4-dimethylaniline and 2, 6-dimethylaniline | |
| CN113402395A (en) | Method for continuously and efficiently synthesizing m-phenylenediamine based on fixed bed microreactor | |
| CN111217712A (en) | Method for preparing o-phenylenediamine from aniline | |
| CN110756198A (en) | Ruthenium-aluminum oxide catalyst for selective hydrogenation of 4, 4' -diaminodiphenylmethane and preparation method and application thereof | |
| CN113024385B (en) | Preparation method of 2,2 '-bis (trifluoromethyl) -4, 4' -diaminobiphenyl | |
| CN102020568A (en) | Method for preparing 1,5-diaminonaphthalene and 1,8-diaminonaphthalene | |
| CN113200876A (en) | Synthesis process of p-aminophenol | |
| CN102010340A (en) | Method of catalytic preparation of 4-aminodiphenylamine by Ni-B amorphous alloy-loaded catalyst | |
| CN101440040A (en) | Process for synthesizing p-aminophenol by catalytic hydrogenation of nitrobenzene | |
| CN1462740A (en) | Method for preparing o-phenylendiamine and m-phenylene diamine by catalysis of mixed dinitro benzene and reduction with hydrogen being added | |
| CN111689866A (en) | Preparation method of tower reaction RT base | |
| CN114478262B (en) | Continuous flow high-efficiency production method of 2-amino-4-nitrotoluene | |
| CN113666830B (en) | Preparation process of 1, 3-cyclohexanediamine | |
| CN1594278A (en) | Method for producing p-p-phenylene diamine by p-nitroaniline hydrogenation | |
| CN111377820B (en) | Preparation method of 2-methylpentanediamine | |
| CN110841647B (en) | Method for recycling waste skeleton nickel catalyst | |
| CN1098852C (en) | Process for preparing 1,8-diazadicyclo [5,4,0] undecene | |
| CN112939784A (en) | Industrial preparation method of hexamethylene diamine | |
| CN1800143A (en) | 2,4,6-trimethylaniline synthesis method | |
| CN1075488C (en) | Production method for preparing mono-alkyl dimethyl tertiary amine by use of aliphatic nitrile | |
| CN105949076B (en) | A kind of preparation method of 3,5 diaminobenzoic acid |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C06 | Publication | ||
| PB01 | Publication | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| C19 | Lapse of patent right due to non-payment of the annual fee | ||
| CF01 | Termination of patent right due to non-payment of annual fee |