O-Anisidine

o-Anisidine (2-anisidine) is an organic compound with the formula CH₃OC₆H₄NH₂. A colorless liquid, commercial samples can appear yellow owing to air oxidation. It is one of three isomers of the methoxy-containing aniline derivative.

o-Anisidine

Names
Preferred IUPAC name 2-Methoxyaniline[1]
Other names ortho-Anisidine 2-Anisidine ortho-Aminoanisole o-Methoxyaniline 2-Methoxy-1-aminobenzene 2-Methoxyphenylamine
Identifiers
CAS Number	90-04-0 Y
3D model (JSmol)	Interactive image
ChEBI	CHEBI:82288
ChEMBL	ChEMBL1612004 Y
ChemSpider	13860775 Y
ECHA InfoCard	100.001.785
EC Number	201-963-1
KEGG	C19191 Y
PubChem CID	7000
RTECS number	BZ5410000
UNII	NUX042F201
UN number	2431
CompTox Dashboard (EPA)	DTXSID5023877
InChI InChI=1S/C7H9NO/c1-9-7-5-3-2-4-6(7)8/h2-5H,8H2,1H3 Y Key: VMPITZXILSNTON-UHFFFAOYSA-N Y InChI=1/C7H9NO/c1-9-7-5-3-2-4-6(7)8/h2-5H,8H2,1H3
SMILES Nc1ccccc1OC
Properties[2]
Chemical formula	C7H9NO
Molar mass	123.155 g·mol−1
Appearance	Yellow liquid, turns brown upon exposure to air
Density	1.0923 g/cm3
Melting point	6.2 °C (43.2 °F; 279.3 K)
Boiling point	224 °C (435 °F; 497 K)
Solubility in water	1.5 g/100 ml
Solubility	soluble in ethanol, diethyl ether, acetone, benzene
Magnetic susceptibility (χ)	−80.44·10−6 cm3/mol
Hazards
Occupational safety and health (OHS/OSH):
Main hazards	potential occupational carcinogen[3]
GHS labelling:
Pictograms
Signal word	Danger
Hazard statements	H301, H311, H331, H341, H350
Precautionary statements	P201, P202, P261, P264, P270, P271, P280, P281, P301+P310, P302+P352, P304+P340, P308+P313, P311, P312, P321, P322, P330, P361, P363, P403+P233, P405, P501
NFPA 704 (fire diamond)	2 1 0
Flash point	118 °C (244 °F; 391 K) (open cup)
Autoignition temperature	415 °C (779 °F; 688 K)
Lethal dose or concentration (LD, LC):
LD50 (median dose)	2000 mg/kg (rat, oral) 1400 mg/kg (mouse, oral) 870 mg/kg (rabbit, oral)[4]
NIOSH (US health exposure limits):
PEL (Permissible)	TWA 0.5 mg/m3 [skin][3]
REL (Recommended)	: Ca TWA 0.5 mg/m3 [skin][3]
IDLH (Immediate danger)	50 mg/m3[3]
Related compounds
Related compounds	m-Anisidine p-Anisidine
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). N verify (what is YN ?) Infobox references

Production and use

It is prepared via methanolysis of 2-chloronitrobenzene:^[5]

NaOCH₃ + ClC₆H₄NO₂ → CH₃OC₆H₄NO₂ + NaCl

The resulting o-nitroanisole is reduced to o-anisidine.

o-Anisidine is used in the manufacture of dyes. It is nitrated to give 4-nitroanisidine. It is also a precursor to o-dianisidine.

One special use is as a heartwood indicator. An acid solution of o-anisidine is diazotized by adding a sodium nitrite solution. This mixture is applied to the wood and by reaction with polyphenols in the heartwood a reddish brown azo dye is formed.

Direct Blue 15 is an azo dye produced from o-anisidine

Safety and environmental aspects

o-Anisidine is a dangerous pollutant from the production of dyes. It is listed as RCRA hazardous waste, with the code K181.^[6] The International Agency for Research on Cancer (IARC) has classified o-anisidine as a Group 2B, possible human carcinogen.^[7]