O-XYLIDINE (2,3-DIMETHYLANILINE)

o-XYLIDINE

PRODUCT IDENTIFICATION

CAS NO.

87-59-2

o-XYLIDINE

EINECS NO.

201-755-0

FORMULA

(CH₃)₂C₆H₃NH₂

MOL WT.

121.18

H.S. CODE

2921.49

TOXICITY

Oral, rat: LD50 = 933 mg/kg

SYNONYMS

2,3-Dimethylaniline; 2,3-Dimethylphenylamine;

2,3-Xylidine; 2,3-Dimethylbenzenamine; 2,3-Xylylamine; 3-Amino-o-xylene; 2,3-Dimethylbenzeneamine;

CLASSIFICATION

PHYSICAL AND CHEMICAL PROPERTIES

PHYSICAL STATE

Yellow to red-brown liquid turns to darken when exposed to light and air

MELTING POINT

2.5 C

BOILING POINT

221 - 222 C

SPECIFIC GRAVITY

0.993

SOLUBILITY IN WATER

Slightly soluble

AUTOIGNITION

VAPOR DENSITY

4.2

NFPA RATINGS

REFRACTIVE INDEX

FLASH POINT

96 C

STABILITY

Stable under ordinary conditions

APPLICATIONS

Xylidine is the trivial name of dimethylaniline, (CH₃)₂C₆H₃NH₂. There are six structural isomers. The names of six compounds indicate methyl group positions relative to the amino on the benzene ring. They can be obtained from coal tar as by-products in the fractional distillation or can be prepared by heating aniline hydrochloride with methanol at 220 C. Xylidine is an aniline homologue and has similar properties of aromatic amine. Xylidines are brown liquids at room temperature except 3,4-Xylidine. They are sparingly soluble in water but miscible with ethanol and diethyl ether. They are sensitive to air and light and tend to darken on storage. They are toxic if inhaled, ingested, or absorbed through the skin. Xylidines and derivatives are widely used as raw materials to produce imaging chemicals like pigments and dyestuffs. All of these compounds are also used in the production of antioxidants, agricultural, pharmaceutical, rubber chemicals and other target organic molecules.

Xylidine	CAS #	Melting point C	Boiling point C
Isomer Mixture	1300-73-8
2,3-Xylidine	87-59-2	2.5	222
2,4-Xylidine	95-68-1	16	218
2,5-Xylidine	95-78-3	11.5	218
2,6-Xylidine	87-62-7	8.4	214
3,4-Xylidine	95-64-7	51	226
3,5-Xylidine	108-69-0	9.8	220 - 221

SALES SPECIFICATION

APPEARANCE

Yellow to red-brown liquid turns to darken when exposed to light and air

PURITY (GLC)

99.0%

CRYSTALLIZING POINT

2 C min

WATER

0.1% max

TRANSPORTATION

PACKING

200kgs in Drum

HAZARD CLASS

6.1

UN NO.

1711

GENERAL DESCRIPTION OF ANILINE

Aromatic amines are much weaker bases than the aliphatics. One of the most important aromatic amines is aniline, a primary aromatic amine replacing one hydrogen atom of a benzene molecule with an amino group. It is a pale brown liquid at room temperature; boiling at 184 C, melting at -6 C; slightly soluble in water and freely soluble in ether and alcohol. It causes serious industrial poisoning. The substance may have effects on the blood, resulting in formation of methaemoglobin. Repeated or prolonged exposures may be carcinogenic. Commercial aniline is obtained from nitrobenzene which is prepared from benzene with nitric acid by electrophilic substitution reaction or from chlorobenzene by heating with ammonia in the presence of copper catalyst. It is also obtained as a by-product of coal tar. In commerce the term of aniline oil blue refers to the pure one while aniline oil red indicates a mixture of aniline and toluidines with equimolecular weights.

Considerable quantity of aniline is converted into 4,4��-methylenedianiline (MDA) by the condensation reaction of formaldehyde with aniline in the presence of hydrochloric acid. MDA is is used as an epoxy curing agent, a corrosion inhibitor and molded plastics, and as an intermediate to prepare organic compounds used for polyurethane, spandex fibers, azo dyes, isocyanates and poly(amide-imide) resins. Other important aromatic amine compound as the starting material to produce polyurethane foam production is toluenediamine (TDA). TDA is the mixture of 2,4-diaminotoluene and 2,6-diaminotoluene, usually in a ratio of 80:20. Most of TDA is used in the manufacture of toluene diisocyanate (TDI), which is the predominant diisocyanate in the flexible foams and elastomers industries. TDI reacts with an alcohol to form urethane linkages. Other applications of TDA include to produce dyes, polyamides, antioxidants, hydraulic fluids, and fungicide stabilizers. Aniline is a starting moiety to prepare plant protecting agents. Examples include fenuron (CAS RN: 101-42-8), propham (CAS RN: 122-42-9), siduron (CAS RN: 1982-49-6), carboxin (CAS RN: 5234-68-4), fenfuram (CAS RN: 24691-80-3) and propachlor (CAS RN: 1918-16-7). Aniline is processed to produce a series of compounds being used in the rubber industry, e.g. diphenylguanidines, phenylenediamines mercaptobenzothiazoles, aniline ketones and etc. There are three isomers of phenylenediamine: ortho-, meta-, and para-phenylenediamine. They are low toxic diamines used as components of plastic composites and engineering polymers. They are used to produce aramid fibers, dyes including hair dyes, rubber chemicals (vulcanization accelerators and antioxidants), and pigments.

Aniline is the starting material in the dye manufacturing industry. It forms aniline colors when combined with other substances, particularly chlorine or chlorates. Aromatic amines are weaker bases reacting with strong acids to form amides. Anilide is an amide derived from aniline by substitution of an acyl group for the hydrogen of NH₂. Acetanilide is from acetic acid and aniline. Acetanilide is an odourless, white flake solid or crystalline powder (pure form); soluble in hot water alcohol, ether, chloroform, acetone, glycerol, and benzene;; melting point 114 C and boiling point 304 C; can undergo self-ignite at 545 C, but is otherwise stable under most conditions. Acetanilide which can be obtained by acetylation of aniline undergoes nitration at low temperature and yields highly the para-nitro products. Acetyl group can then be removed by acid-catalyzed hydrolysis to yield para-nitroaniline. Although the activating affection of the amino group can be reduced, the acetyl derivative remains an ortho/para-orientation and activating substituent. Aniline is converted into sulfanilic acid which is the parent compound of the sulfa drugs. Aniline is also important in the manufacture of rubber-processing chemicals, explosives, plastics, antioxidants and varnishes. Amines take part in many kinds of chemical reactions and offer many industrial applications.

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