p-Toluidine p-Toluidine
Structural formula
| Business number | 02TM |
|---|---|
| Molecular formula | C7H9N |
| Molecular weight | 107.15 |
| label |
p-methylaniline, 4-methylaniline, Para-aminotoluene, 4-Aminotoluene, p-Methylaniline, 4-Methylaniline, Nitrogen-containing compound solvents, aromatic compounds, Dye raw materials |
Numbering system
CAS number:106-49-0
MDL number:MFCD00007906
EINECS number:203-403-1
RTECS number:XU3150000
BRN number:471281
PubChem ID:None
Physical property data
1. Properties: The pure product is colorless flaky crystals. [1]
2. Melting point (℃): 44.5[2]
3. Boiling point (℃): 200.4 [3]
4. Relative density (water = 1): 1.05[4]
5. Relative vapor density (Air=1): 3.90[5]
6. Saturated vapor pressure (kPa): 0.0346[6]
7. Heat of combustion (kJ/mol): -4006.1[7]
8. Critical pressure (MPa): 4.4[8]
9. Octanol/water partition coefficient: 1.39[9]
10. Flash point (℃): 86 (CC)[10 ]
11. Ignition temperature (℃): 482[11]
12. Explosion upper limit (%): 6.6[12]
13. Lower explosion limit (%): 1.1[13]
14. Solubility: slightly soluble in water , soluble in ethanol, ether, benzene and hydrochloric acid. [14]
15. Viscosity (mPa·s, 45ºC): 1.945
16. Viscosity (mPa·s, 55ºC): 1.557
17. Heat of evaporation (KJ/mol, b.p.): 41.20
18. Heat of fusion (KJ/mol): 17.29
19. Heat of generation (KJ/ mol): -27.63
20. Heat of combustion (KJ/mol, constant pressure): 4014
21. Specific heat capacity (KJ/(kg·K), 20ºC, constant pressure) : 1.16
22. Boiling point rising constant: 4.14
23. Conductivity (S/m, 100ºC): 6.2×10-8
24. Thermal conductivity (W/(m·K), liquid): 0.164
25. Thermal conductivity (W/(m·K), 50ºC): 0.1640
26. Volume expansion coefficient (K-1, 0~30ºC): 0.000815
Toxicological data
1. Acute toxicity[15]
LD50: 336mg/kg (rat oral); 890mg/kg (rabbit transdermal)
LC50: >640mg/m3 (rat inhalation, 1h)
2. Irritation [16]
Rabbit transdermal: 500mg (24h), severe stimulation.
Rabbit eye: 20mg (24h), moderate irritation.
3. Mutagenicity[17] DNA inhibition: Mouse oral administration: 200mg/kg. DNA damage: 35 mg/kg in mouse abdominal cavity. Unprogrammed DNA synthesis: rat liver 100 μmol/L.
Ecological data
1.The thing��It may be harmful to the environment and it is recommended not to let it enter the environment.
2. Ecotoxicity[18] EC50: 0.6mg/L (48h) (Daphnia)
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3. Biodegradability No data yet
4. Non-biodegradability[19] In the air, when the concentration of hydroxyl radicals is 5.00×105/cm3, the degradation half-life is 2.9h (theoretical).
Molecular structure data
1. Molar refractive index: 35.31
2. Molar volume (cm3/mol): 107.9
3. Isotonic specific volume (90.2K ): 270.7
4. Surface tension (dyne/cm): 39.5
5. Polarizability: 13.99
Compute chemical data
1. Reference value for hydrophobic parameter calculation (XlogP): None
2. Number of hydrogen bond donors: 1
3. Number of hydrogen bond acceptors: 1
4. Number of rotatable chemical bonds: 0
5. Number of tautomers: none
6. Topological molecule polar surface area 26
7. Number of heavy atoms: 8
8. Surface charge: 0
9. Complexity: 62.8
10. Number of isotope atoms: 0
11. Determine the number of atomic stereocenters: 0
12. Uncertain number of atomic stereocenters: 0
13. Determine the number of chemical bond stereocenters: 0
14. Number of uncertain chemical bond stereocenters: 0
15. Number of covalent bond units: 1
Properties and stability
1. Chemical properties: Alkaline, forming salt with acid. When recrystallized with water or water-containing alcohol, even when left in the air, crystals containing 1 molecule of crystal water are obtained, with a melting point of 42°C. When oxidized with manganese dioxide or chromic acid, 4,4′-dimethylazobenzene is generated.
2. Stability[20] Stable
3. Incompatible substances[21] Strong oxidants, acids, acid chlorides, acid anhydrides, chloroform
4. Conditions to avoid contact [22] Light
5. Polymerization hazard[23] No polymerization
6. Decomposition products[24 ] Ammonia
Storage method
Storage Precautions[25] Store in a cool, ventilated warehouse. Keep away from fire and heat sources. The packaging must be sealed and must not come into contact with air. They should be stored separately from oxidants, acids, and food chemicals, and avoid mixed storage. Equipped with the appropriate variety and quantity of fire equipment. Suitable materials should be available in the storage area to contain spills.
Synthesis method
1. Prepare p-toluidine by reducing p-nitrotoluene with sodium sulfide at 124-126°C and 0.2MPa gauge pressure. The reaction solution is allowed to stand and separated into layers. The water layer is separated, and then distilled under reduced pressure. Condensation, crystallization, and drying produce the finished product.
Refining method: Generally, it can be refined by the method of refining aniline. Fractional crystallization from its melt allows the separation of p-toluidine from its ortho- and meta-isomers. The p-toluidine used for fractional crystallization is recrystallized with hot water (activated carbon), ethanol, benzene, petroleum ether or a mixture of ethanol and water (1:4) and vacuum dried. It can also be sublimated and refined at 30°C under reduced pressure. For further purification it can be prepared as oxalate, sulfate or acetyl derivatives. For example, p-toluidine that has been distilled three times and sublimed twice at 30°C is dissolved in 5 times the amount of diethyl ether, and an equivalent amount of oxalic acid dissolved in diethyl ether is added to precipitate the oxalate of p-toluidine. After filtering, it is recrystallized three times with distilled water. , then add sodium carbonate aqueous solution, recrystallize the free p-toluidine three times with distilled water, and then repeatedly recrystallize with ethanol to obtain the pure product.
2. Toluene is reduced to methylaniline after nitration. Its isomers can be separated by 40% formaldehyde aqueous solution, obtained by distillation under reduced pressure, and then recrystallized in petroleum ether.
Purpose
1. Used for the preparation of red base GL, methylamine red lake, basic fuchsin, acid green P-3B, tolyl periphosphate, 4-aminotoluene-3-sulfonic acid, and triphenylmethane dyes and oxazine dyes, etc.
2. Used as analytical reagent. Used in organic synthesis and preparation of dyes.
3. Used as an intermediate for dyes and pharmaceuticals such as pyrimethamine. [26]
