Aniline Aniline
Structural formula
| Business number | 01CE |
|---|---|
| Molecular formula | C6H7N |
| Molecular weight | 93.13 |
| label |
anilin, anillin oil, aminobenzene, aniline oil, Anilin oil, Aminobenzene, Phenylamine, Benzenamine, Aromatic nitrogen-containing compounds and their derivatives, organic insulating materials |
Numbering system
CAS number:62-53-3
MDL number:MFCD00007629
EINECS number:200-539-3
RTECS number:BW6650000
BRN number:605631
PubChem number:24854547
Physical property data
1. Properties: colorless to light yellow transparent liquid with strong odor. Turns brown when exposed to air or sunlight. [1]
2. pH value: about 8 (2% solution) [2]
3. Melting point ( ℃): -6.2[3]
4. Boiling point (℃): 184.4[4]
5. Relative Density (water=1): 1.02[5]
6. Relative vapor density (air=1): 3.22[6]
7. Saturated vapor pressure (kPa): 2.00 (25℃)[7]
8. Heat of combustion (kJ/mol): -3389.8 [8]
9. Critical temperature (℃): 425.6[9]
10. Critical pressure (MPa): 5.30[10]
11. Octanol/water partition coefficient: 0.94[11]
12. Flash point (℃) : 70[12]
13. Ignition temperature (℃): 615[13]
14. Explosion upper limit (%): 11.0[14]
15. Lower explosion limit (%): 1.2[15]
16. Solubility: Slightly soluble in water, soluble in ethanol, ether and benzene. [16]
17. Refractive index (20ºC): 1.5860
18. Viscosity (mPa·s, 20ºC): 4.423~4.435
19. Heat of evaporation (KJ/kg): 476.8
20. Heat of fusion (KJ/mol): 10.54
21. Heat of formation (KJ/mol, 25ºC , liquid): 31.28
22. Heat of formation (KJ/mol, 25ºC, gas): 87.09
23. Heat of combustion (KJ/mol, 25ºC, constant pressure): 3395.33
24. Heat of combustion (KJ/mol, 25ºC, constant volume): 3392.23
25. Specific heat capacity (KJ/(kg·K), 20~25ºC, constant pressure): 2.17
26. Boiling point rising constant: 3.69
27. Conductivity (S/m, 25ºC): 2.4×10-8
28. Thermal conductivity (W/(m·K),): 0.19971
29. Solubility (%, 25ºC, water): 3.5
30. Volume expansion Coefficient (K-1): 0.000855
31.pKa (20ºC): 4.60
Toxicological data
1. Acute toxicity[17]
LD50: 250mg/kg (rat oral); 1400mg/kg (rat transdermal); 1000mg/kg (rabbit oral); 820mg/kg (rabbit transdermal)
LC50: 665mg/m3(mouse inhalation, 7h)
2.�Nitrobenzene hydrogenation reduction method: Nitrobenzene is subjected to gas phase hydrogenation and reduction in a fluidized bed reactor in the presence of a copper catalyst, and the reaction product is condensed and distilled under reduced pressure to obtain the product.
3. Catalytic addition of nitrobenzene Hydrogen method: The commonly used catalyst is Cu-SiO2. This catalyst has good selectivity and can smoothly reduce nitrobenzene to aniline and is not prone to hydrogenation on the benzene nucleus. The reaction is carried out in a fluidized bed reactor. After the hydrogen is purified, it is heated to 350-400°C by a heater and then enters the evaporator. At the same time, nitrobenzene enters the evaporator from the high-level tank and is vaporized in contact with the hot hydrogen. And superheated to 180~223℃, the mixed gas enters from the bottom of the fluidized bed, and contacts and reacts with the copper catalyst mounted on silica gel installed in the fluidized bed. The generated crude aniline and water vapor are discharged from the top of the bed. The crude aniline is cooled by a condenser, separated, and then distilled to obtain the finished product aniline. Nowadays, the production of aniline has been continuous, and the reduction reaction is carried out under normal pressure boiling reflux conditions, realizing large-scale production with small equipment. Refining method: Depending on the preparation method, aniline may contain impurities such as nitrobenzene, toluidine, benzene, and sulfide. If aniline is dissolved in dilute hydrochloric acid to obtain a colorless and transparent liquid, it generally does not contain hydrocarbons and nitrobenzene. During refining, dissolve aniline in dilute hydrochloric acid or dilute sulfuric acid. If there is insoluble matter, remove it with steam distillation. Add sodium hydroxide to the residual liquid to make it alkaline. Steam distillation again can obtain aniline. Dry the steamed aniline with solid sodium hydroxide, add zinc powder, boil and reflux, and then distill. Then dry with solid sodium hydroxide, and then distill under reduced pressure under nitrogen flow to obtain a high-purity product. Aniline can also be converted into its derivatives, such as aniline hydrochloride and acetanilide, and then recrystallized and refined.
4. Add nitrobenzene, ferrous chloride solution (or ammonium chloride solution) and crushed iron powder into the reaction kettle, stir continuously, and perform reduction reaction to obtain it. Or it can be obtained by reducing nitrobenzene with hydrogen.
5. Take industrial aniline directly as The finished reagent can also be obtained by distilling the raw materials in a nitrogen atmosphere through the same distillation process. The finished product must be stored in a sealed brown bottle. To prepare chromatographically pure aniline, nitrogen can be used as the carrier gas, and industrial aniline is injected into a preparative gas chromatograph equipped with an Apiezon L or SE30/white diatomite carrier stationary phase column, and its main peak components are separated and collected, and then put into glass Just seal it in the bottle.
6. Nitrobenzene is reduced by catalytic hydrogenation or reduction with iron powder:
The generated aniline can react with oxalic acid to form aniline oxalate, which is then purified and treated with alkali, and then collected by distillation under a nitrogen atmosphere at 183~185℃ Interdistillate.
7. Phenol ammoniation method: In the presence of acidic alumina catalyst, phenol and ammonia are reacted at 370°C and 1.6MPa pressure. The raw materials of this process are easy to obtain, the production method is simple, the catalyst is cheap, the product quality is good, and it does not produce gases or large amounts of water that cause air pollution. The phenol conversion rate is greater than 99%, and the aniline yield is over 96%. The catalyst has good stability, does not need to be regenerated, and can co-produce diphenylamine. Therefore, this method is suitable for large-scale continuous production and can co-produce diphenylamine as needed. However, its cost is affected by phenol. This method can only be used when phenol is in sufficient supply and cheap, and requires higher quality aniline and less investment.
Purpose
1. Used as a weak base, it can precipitate trivalent and tetravalent elements in the form of hydroxides (Fe3+, Al3+, Cr3+) easily hydrolyzable salts are separated from salts of divalent elements that are difficult to hydrolyze (Mn2+). In microcrystalline analysis, it is used to detect elements (Cu, Mg, Ni, Co, Zn, Cd, Mo, W, V). Tests for halogens, chromates, vanadates, nitrites and carboxylic acids. Solvent. Organic synthesis, dye manufacturing.
2. It is one of the most important intermediates in the dye industry and the main raw material for medicine, rubber accelerators and antioxidants. It can also be used to make spices, varnishes and explosives. Aniline is an important raw material for the production of pesticides. N-alkyl aniline, alkyl aniline, o-nitroaniline, o-phenylenediamine, phenylhydrazine, cyclohexylamine, etc. can be derived from aniline. It can be used as a fungicide, sodium dichloride, and seed dressing. spirit, methylprofen, fenfosamine, carbendazim, azoxystrobin, benomyl, insecticides triazophos, pyridazinathion, quinalphos, herbicides alachlor, acetochlor, Intermediates of butachlor, cyclazinone, imidazoquinclorac, etc. Used in synthetic amino resins, epoxy resin curing agents, polymerization catalysts, solvents, metal preservatives, and lubricating oil additives.
3. Nitric acid pickling corrosion inhibitor can be configured with potassium thiocyanate and methenamine. It can also be directly used as a corrosion inhibitor for inorganic acids such as hydrochloric acid and sulfuric acid.
4. Used as analytical reagent. It is also used in the synthesis of dyes, medicines, resins, rubber, spices, etc.
5. Used in the synthesis of amino resins, epoxy resin curing agents, polymerization catalysts, solvents, metal preservatives, and lubricating oil additives. It is an important raw material for manufacturing MDI and dye intermediates. It is also commonly used to manufacture medicines, spices, herbicides, insecticides, insect repellents, photographic developers, rubber vulcanizers, antioxidants, anti-aging agents and other products.
6. It can be used to determine the aniline point of oil products, and is also used as a raw material for dye intermediates, pesticides, rubber additives and other organic synthesis. [29]
It is an important raw material for the body and is also commonly used to manufacture medicines, spices, herbicides, insecticides, insect repellents, photographic developers, rubber vulcanizers, antioxidants, anti-aging agents and other products.
6. It can be used to determine the aniline point of oil products, and is also used as a raw material for dye intermediates, pesticides, rubber additives and other organic synthesis. [29]