Xylidine can refer to any of the six isomers of

xylene In organic chemistry, xylene or xylol (; IUPAC name: dimethylbenzene) are any of three organic compounds with the formula . They are derived from the substitution of two hydrogen atoms with methyl groups in a benzene ring; which hydrogens are s ...

amine In chemistry, amines (, ) are compounds and functional groups that contain a basic nitrogen atom with a lone pair. Amines are formally derivatives of ammonia (), wherein one or more hydrogen Hydrogen is the chemical element wi ...

, or any mixture of them. The chemical formula of xylidines is C₈H₁₁N or, more descriptively, (CH₃)₂C₆H₃NH₂. The CAS number for the isomer mixture is . They are colorless solids or liquids, although commercial samples can appear yellow or darker. They are miscible with

ethanol Ethanol (abbr. EtOH; also called ethyl alcohol, grain alcohol, drinking alcohol, or simply alcohol) is an organic compound. It is an alcohol with the chemical formula . Its formula can be also written as or (an ethyl group linked to a ...

and

diethyl ether Diethyl ether, or simply ether, is an organic compound in the ether class with the formula , sometimes abbreviated as (see Pseudoelement symbols). It is a colourless, highly volatile, sweet-smelling ("ethereal odour"), extremely flammable li ...

and slightly soluble in water. Xylidines are used in production of

pigment A pigment is a colored material that is completely or nearly insoluble in water. In contrast, dyes are typically soluble, at least at some stage in their use. Generally dyes are often organic compounds whereas pigments are often inorganic compou ...

s and dyestuffs, and various antioxidants, agrochemicals, pharmaceuticals, hypergolic propellants, and many other organic chemicals. In

World War II World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposing ...

, xylidine was an important

antiknock agent An antiknock agent is a gasoline additive used to reduce engine knocking and increase the fuel's octane rating by raising the temperature and pressure at which auto-ignition occurs. The mixture known as gasoline or petrol, when used in high comp ...

in very high performance aviation gasolines. Its purpose was to permit high levels of boost pressure in multiple-stage turbochargers, and thus high power at high altitudes, without causing detonation that would destroy the engine. The high pressures brought high temperatures of inlet air, making engines prone to knock. This use and storage stabilization methods were important military secrets.

Isomers of xylidine

Image:2,3-Xylidin.svg, 2,3-xylidine Image:2,4-Xylidin.svg, 2,4-xylidine Image:2,5-Xylidin.svg, 2,5-xylidine Image:2,6-Xylidin.svg, 2,6-xylidine Image:3,4-Xylidin.svg, 3,4-xylidine Image:3,5-Xylidin.svg, 3,5-xylidine

2,3-xylidine

2,3-xylidine, also called o-xylidine, 2,3-dimethylaniline, 2,3-xylylamine, or 2,3-dimethylphenylamine, is a liquid with melting point 2.5 °C and boiling point 222 °C, and flash point at 96 °C. It is used in production of

mefenamic acid Mefenamic acid is a member of the anthranilic acid derivatives (or fenamate) class of nonsteroidal anti-inflammatory drugs (NSAIDs), and is used to treat mild to moderate pain. Its name derives from its systematic name, dimethylphenylaminoben ...

, dyes, and pesticides.

2,4-xylidine

2,4-xylidine, also called 2-methyl-p-toluidine, 2,4-dimethylaniline, 2,4-xylylamine, or 2,4-dimethylphenylamine, is a liquid with melting point 16 °C, boiling point 217 °C, and flash point at 90 °C. It is used for production of pesticides, dyes, and other chemicals.

2,5-xylidine

2,5-xylidine, also called p-xylidine, 2,5-dimethylaniline, 2,5-xylylamine, or 2,5-dimethylphenylamine, is a liquid with melting point 11.5 °C and boiling point 215 °C. It is used for production of dyes and other chemicals.

2,6-xylidine

2,6-Xylidine, also called 2,6-dimethylaniline, 2,6-xylylamine, or 2,6-dimethylphenylamine, is a liquid with melting point 8.4 °C and boiling point 216 °C. It is used in production of some anesthetics and other chemicals.

3,4-xylidine

3,4-xylidine, also called 3,4-dimethylaniline, 3,4-xylylamine, or 3,4-dimethylphenylamine, is a crystalline solid with melting point 51 °C and boiling point 226 °C. It is used as a raw material for production of vitamin B₂, dyes, pesticides, and other chemicals.

3,5-xylidine

3,5-xylidine, also called 3,5-dimethylaniline, 3,5-xylylamine, or 3,5-dimethylphenylamine, is a liquid with melting point 9.8 °C and boiling point 220–221 °C. It is used for production of pesticides, dyes, and other chemicals.

Safety

The U.S.

Occupational Safety and Health Administration The Occupational Safety and Health Administration'' (OSHA ) is a large regulatory agency of the United States Department of Labor that originally had federal visitorial powers to inspect and examine workplaces. Congress established the agenc ...

(OSHA) has set the legal limit (

Permissible exposure limit The permissible exposure limit (PEL or OSHA PEL) is a legal limit in the United States for exposure of an employee to a chemical substance or physical agent such as high level noise. Permissible exposure limits are established by the Occupational ...

) for xylidine exposure in the workplace as 5 ppm (25 mg/m³) skin exposure over an eight-hour workday. The U.S.

National Institute for Occupational Safety and Health The National Institute for Occupational Safety and Health (NIOSH, ) is the United States federal agency responsible for conducting research and making recommendations for the prevention of work-related injury and illness. NIOSH is part of the C ...

(NIOSH) has set a

Recommended exposure limit A recommended exposure limit (REL) is an occupational exposure limit that has been recommended by the United States National Institute for Occupational Safety and Health. The REL is a level that NIOSH believes would be protective of worker safet ...

(REL) of 2 ppm (10 mg/m³) skin exposure over an eight-hour workday. At levels of 50 ppm, xylidine is immediately dangerous to life and health. Their hazard and precaution phrases are .

External links

CDC - NIOSH Pocket Guide to Chemical Hazards

References

{{Authority control Anilines Alkyl-substituted benzenes