4-Nitroaniline

p-Nitroaniline
Skeletal formula of p-nitroaniline
Ball-and-stick model of the p-nitroaniline molecule
Names
Other names
4-nitroaniline
1-amino-4-nitrobenzene
p-nitrophenylamine
Identifiers
100-01-6 YesY
ChEBI CHEBI:17064 N
ChEMBL ChEMBL14282 N
ChemSpider 13846959 N
Jmol interactive 3D Image
UNII 1MRQ0QZG7G YesY
Properties
C6H6N2O2
Molar mass 138.12 g/mol
Appearance yellow or brown powder
Odor faint, ammonia-like
Density 1.437 g/ml, solid
Melting point 146 to 149 °C (295 to 300 °F; 419 to 422 K) (lit.)
Boiling point 332 °C (630 °F; 605 K)
0.8 mg/ml at 18.5 °C (IPCS)
Vapor pressure 0.00002 mmHg (20°C)[1]
Hazards
Main hazards Toxic
Safety data sheet JT Baker
T N
R-phrases R23/24/25 R33 R52/53
S-phrases S28 S36/37 S45 S61
NFPA 704
Flammability code 1: Must be pre-heated before ignition can occur. Flash point over 93 °C (200 °F). E.g., canola oil Health code 2: Intense or continued but not chronic exposure could cause temporary incapacitation or possible residual injury. E.g., chloroform Reactivity code 0: Normally stable, even under fire exposure conditions, and is not reactive with water. E.g., liquid nitrogen Special hazards (white): no codeNFPA 704 four-colored diamond
1
2
0
Flash point 199 °C (390 °F; 472 K)
Lethal dose or concentration (LD, LC):
3249 mg/kg (rat, oral)
750 mg/kg (rat, oral)
450 mg/kg (guinea pig, oral)
810 mg/kg (mouse, oral)[2]
US health exposure limits (NIOSH):
TWA 6 mg/m3 (1 ppm) [skin][1]
TWA 3 mg/m3 [skin][1]
300 mg/m3[1]
Related compounds
Related compounds
 2-Nitroaniline, 3-Nitroaniline
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
N verify (what is YesYN ?)
Infobox references

4-Nitroaniline, p-nitroaniline or 1-amino-4-nitrobenzene is an organic compound with the formula C6H6N2O2. It is an organic chemical compound, consisting of a phenyl group attached to an amino group which is para to a nitro group. This chemical is commonly used as an intermediate in the synthesis of dyes, antioxidants, pharmaceuticals, and gasoline, in gum inhibitors, poultry medicines, and as a corrosion inhibitor.

Synthesis

It is produced industrially via the amination of 4-nitrochlorobenzene:[3]

ClC6H4NO2 + 2 NH3 → H2NC6H4NO2 + NH4Cl

Below is a laboratory synthesis of 4-nitroaniline from aniline. The key step in this reaction sequence is an electrophilic aromatic substitution to install the nitro group para to the amino group. After this reaction, a separation must be performed to remove 2-nitroaniline, which is also formed in a small amount during the reaction.[4]

Applications

4-Nitroaniline is mainly consumed industrially as a precursor to p-phenylenediamine, an important dye component. The reduction is effected using iron metal and by catalytic hydrogenation.[3]

It is a starting material for the synthesis of Para Red, the first azo dye:[5]

When heated, it polymerizes explosively into a rigid foam.

Laboratory use

Nitroaniline is a solvatochromic dye used for determining Kamlet-Taft solvent parameters. The position of its UV-visual peak changes with the balance of hydrogen bonding acceptors and donors in the solvent.

Toxicity

The compound is toxic by way of inhalation, ingestion, and absorption, and should be handled with care. Its LD50 in rats is 750 mg/kg when administered orally. 4-Nitroaniline is particularly harmful to all aquatic organisms, and can cause long-term damage to the environment if released as a pollutant.

See also

References

  1. 1 2 3 4 "NIOSH Pocket Guide to Chemical Hazards #0449". National Institute for Occupational Safety and Health (NIOSH).
  2. ↑ "p-Nitroaniline". Immediately Dangerous to Life and Health. National Institute for Occupational Safety and Health (NIOSH).
  3. 1 2 Gerald Booth "Nitro Compounds, Aromatic in Ullmann's Encyclopedia of Industrial Chemistry, 7th Ed.; Wiley-VCH: Weinheim, 2005. doi:10.1002/14356007.a17_411
  4. ↑ Mohrig, J.R.; Morrill, T.C.; Hammond, C.N.; Neckers, D.C. "Synthesis 5: Synthesis of the Dye Para Red from Aniline." Experimental Organic Chemistry. Freeman: New York, NY, 1997; pp 456-467.
  5. ↑ Williamson, Kenneth L. (2002). Macroscale and Microscale Organic Experiments, Fourth Edition. Houghton-Mifflin. ISBN 0-618-19702-8.

External links

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