4-Nitroaniline

4-Nitroaniline
Skeletal formula of p-nitroaniline	Ball-and-stick model of the p-nitroaniline molecule
Names
	Preferred IUPAC name 4-Nitroaniline
	Systematic IUPAC name 4-Nitrobenzenamine
	Other names p-Nitroaniline; 1-Amino-4-nitrobenzene; p-Nitrophenylamine
Identifiers
CAS Number	100-01-6 ;
3D model (JSmol)	Interactive image;
Beilstein Reference	508690
ChEBI	CHEBI:17064 ;
ChEMBL	ChEMBL14282 ;
ChemSpider	13846959 ;
ECHA InfoCard	100.002.555
EC Number	202-810-1;
Gmelin Reference	27331
KEGG	C02126;
PubChem CID	7475;
RTECS number	BY7000000;
UNII	1MRQ0QZG7G ;
UN number	1661
CompTox Dashboard (EPA)	DTXSID8020961 ;
	InChI InChI=1S/C6H6N2O2/c7-5-1-3-6(4-2-5)8(9)10/h1-4H,7H2 Key: TYMLOMAKGOJONV-UHFFFAOYSA-N ; InChI=1/C6H6N2O2/c7-5-1-3-6(4-2-5)8(9)10/h1-4H,7H2 Key: TYMLOMAKGOJONV-UHFFFAOYAW;
	SMILES c1cc(ccc1N)N(=O)=O;
Properties
Chemical formula	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)
Solubility in water	0.8 mg/ml at 18.5 °C (IPCS)
Vapor pressure	0.00002 mmHg (20°C)[1]
Magnetic susceptibility (χ)	-66.43·10−6 cm3/mol
Hazards
Main hazards	Toxic
Safety data sheet	JT Baker
GHS pictograms
GHS Signal word	Warning
GHS hazard statements	H301, H311, H331, H373, H412
GHS precautionary statements	P260, P261, P264, P270, P271, P273, P280, P301+310, P302+352, P304+340, P311, P312, P314, P321, P322, P330, P361, P363, P403+233, P405, P501
NFPA 704 (fire diamond)	1 2 0
Flash point	199 °C (390 °F; 472 K)
	Lethal dose or concentration (LD, LC):
LD50 (median dose)	3249 mg/kg (rat, oral); 750 mg/kg (rat, oral); 450 mg/kg (guinea pig, oral); 810 mg/kg (mouse, oral)[2]
	NIOSH (US health exposure limits):
PEL (Permissible)	TWA 6 mg/m3 (1 ppm) [skin][1]
REL (Recommended)	TWA 3 mg/m3 [skin][1]
IDLH (Immediate danger)	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).
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	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 benzene ring in which an amino group is para to a nitro group. This chemical is commonly used as an intermediate in the synthesis of dyes, antioxidants, pharmaceuticals, gasoline, 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. The amino group can be easily protonated and become a meta director. Therefore, a protection of the acetyl group is required. 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 with sulfuric acid, it polymerizes explosively into a rigid foam.[6]

Synthesis of Para Red

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.

References

NIOSH Pocket Guide to Chemical Hazards. "#0449". National Institute for Occupational Safety and Health (NIOSH).
"p-Nitroaniline". Immediately Dangerous to Life and Health Concentrations (IDLH). National Institute for Occupational Safety and Health (NIOSH).
Gerald Booth (2007). Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.a17_411.
Mohrig, J.R.; Morrill, T.C.; Hammond, C.N.; Neckers, D.C. (1997). "Synthesis 5: Synthesis of the Dye Para Red from Aniline". Experimental Organic Chemistry. New York, NY: Freeman. pp. 456–467.
Williamson, Kenneth L. (2002). Macroscale and Microscale Organic Experiments, Fourth Edition. Houghton-Mifflin. ISBN 0-618-19702-8.
Poshkus, A. C.; Parker, J. A. (1970). "Studies on nitroaniline–sulfuric acid compositions: Aphrogenic pyrostats". Journal of Applied Polymer Science. 14 (8): 2049–2064. doi:10.1002/app.1970.070140813.

External links

[PGCH-1] NIOSH Pocket Guide to Chemical Hazards. "#0449". National Institute for Occupational Safety and Health (NIOSH).

[2] "p-Nitroaniline". Immediately Dangerous to Life and Health Concentrations (IDLH). National Institute for Occupational Safety and Health (NIOSH).

[Ullmann-3] Gerald Booth (2007). Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.a17_411.

[4] Mohrig, J.R.; Morrill, T.C.; Hammond, C.N.; Neckers, D.C. (1997). "Synthesis 5: Synthesis of the Dye Para Red from Aniline". Experimental Organic Chemistry. New York, NY: Freeman. pp. 456–467.

[5] Williamson, Kenneth L. (2002). Macroscale and Microscale Organic Experiments, Fourth Edition. Houghton-Mifflin. ISBN 0-618-19702-8.

[6] Poshkus, A. C.; Parker, J. A. (1970). "Studies on nitroaniline–sulfuric acid compositions: Aphrogenic pyrostats". Journal of Applied Polymer Science. 14 (8): 2049–2064. doi:10.1002/app.1970.070140813.