4-Nitrotoluene

4-Nitrotoluene or para-nitrotoluene is an organic compound with the formula CH₃C₆H₄NO₂. It is a pale yellow solid. It is one of three isomers of nitrotoluene.

4-Nitrotoluene

Names
Preferred IUPAC name 1-Methyl-4-nitrobenzene
Other names p-nitrotoluene p-mononitrotoluene, p-methylnitrobenzene
Identifiers
CAS Number	99-99-0 Y
3D model (JSmol)	Interactive image
ChemSpider	13863774
ECHA InfoCard	100.002.553
PubChem CID	7473
UNII	E88IMG14EX Y
CompTox Dashboard (EPA)	DTXSID5023792
InChI InChI=1S/C7H7NO2/c1-6-2-4-7(5-3-6)8(9)10/h2-5H,1H3 Key: ZPTVNYMJQHSSEA-UHFFFAOYSA-N
SMILES O=[N+]([O-])c1ccc(C)cc1
Properties
Chemical formula	C7H7NO2
Molar mass	137.138 g·mol−1
Appearance	crystalline solid[1]
Odor	weak, aromatic[1]
Density	1.1038 g·cm−3 (75 °C) [2]
Melting point	51.63 °C (124.93 °F; 324.78 K)[2]
Boiling point	238.3 °C (460.9 °F; 511.4 K)[2]
Solubility in water	0.04% (20°C)[1]
Vapor pressure	0.1 mmHg (20°C)[1]
Magnetic susceptibility (χ)	−72.06·10−6 cm3/mol
Hazards
Occupational safety and health (OHS/OSH):
Main hazards	moderately toxic
Flash point	106 °C; 223 °F; 379 K[1]
Explosive limits	1.6%–?[1]
Lethal dose or concentration (LD, LC):
LD50 (median dose)	1231 mg/kg (mouse, oral) 1330 mg/kg (rat, oral) 1450 mg/kg (rabbit, oral)[3]
NIOSH (US health exposure limits):
PEL (Permissible)	TWA 5 ppm (30 mg/m3) [skin][1]
REL (Recommended)	TWA 2 ppm (11 mg/m3) [skin][1]
IDLH (Immediate danger)	200 ppm[1]
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Synthesis and reactions

Together with other isomers, 4-nitrotoluene is prepared by nitration of toluene,^[4] commonly using titanium(IV) nitrate.^[5] It undergoes the reactions typical for nitrobenzene derivatives, e.g. hydrogenation gives p-toluidine.

Oxidation of the methyl substituent of 4-nitrotoluene has been extensively investigated. Depending on the conditions, oxidation yields 4-nitrobenzaldehyde diacetate,^[6] 4-nitrobenzenoic acid,^[7] and 4,4'-dinitrobibenzyl.^[8] Treatment of 4-nitrotoluene with bromine gives the 4-nitrobenzyl bromide.^[9]

Applications

The principal application involves its sulfonation to give the 4-nitrotoluene-2-sulfonic acid (with the –SO₃H group adjacent to methyl). This species can be oxidatively coupled to produce stilbene derivatives,^[10] which are used as dyes.^[11] Representative derivatives include the molecular and salt forms of 4,4'-dinitroso- and the 4,4'-dinitro-2,2'-stilbenedisulfonic acids, e.g. disodium 4,4'-dinitrostilbene-2,2'-disulfonate.^[12]

Safety

Evidence exists for toxicity and carcinogenicity in mice.^[13]