Methyl isobutyl ketone (MIBK, 4-methylpentan-2-one) is an

organic compound Some chemical authorities define an organic compound as a chemical compound that contains a carbon–hydrogen or carbon–carbon bond; others consider an organic compound to be any chemical compound that contains carbon. For example, carbon-co ...

with the condensed chemical formula (CH₃)₂CHCH₂C(O)CH₃. This

ketone In organic chemistry, a ketone is an organic compound with the structure , where R and R' can be a variety of carbon-containing substituents. Ketones contain a carbonyl group (a carbon-oxygen double bond C=O). The simplest ketone is acetone ( ...

is a colourless liquid that is used as a

solvent A solvent (from the Latin language, Latin ''wikt:solvo#Latin, solvō'', "loosen, untie, solve") is a substance that dissolves a solute, resulting in a Solution (chemistry), solution. A solvent is usually a liquid but can also be a solid, a gas ...

for gums, resins, paints, varnishes, lacquers, and nitrocellulose.

Production

At laboratory scale, MIBK can be produced via a three-step process using

acetone Acetone (2-propanone or dimethyl ketone) is an organic compound with the chemical formula, formula . It is the simplest and smallest ketone (). It is a colorless, highly Volatile organic compound, volatile, and flammable liquid with a charact ...

as the starting material. Self-condensation, a type of

aldol reaction The aldol reaction (aldol addition) is a Chemical reaction, reaction in organic chemistry that combines two Carbonyl group, carbonyl compounds (e.g. aldehydes or ketones) to form a new β-hydroxy carbonyl compound. Its simplest form might invol ...

, produces

diacetone alcohol Diacetone alcohol is an organic compound with the formula CH3C(O)CH2C(OH)(CH3)2, sometimes called DAA. This colorless liquid is a common synthetic intermediate used for the preparation of other compounds, and is also used as a solvent. Synthesi ...

, which readily dehydrates to give 4-methylpent-3-en-2-one (commonly, mesityl oxide). Mesityl oxide is then hydrogenated to give MIBK. : Industrially, these three steps are combined. Acetone is treated with a strongly acidic, palladium catalyst-doped cation exchange resin under medium pressure of hydrogen. Several million kilograms are produced annually.Stylianos Sifniades, Alan B. Levy, "Acetone" in ''Ullmann’s Encyclopedia of Industrial Chemistry'', Wiley-VCH, Weinheim, 2005.

Uses

MIBK is used as a solvent for

nitrocellulose Nitrocellulose (also known as cellulose nitrate, flash paper, flash cotton, guncotton, pyroxylin and flash string, depending on form) is a highly flammable compound formed by nitrating cellulose through exposure to a mixture of nitric acid and ...

, lacquers, and certain polymers and resins.

Precursor to 6PPD

Another major use is as a precursor to ''N''-(1,3-dimethylbutyl)-''N-phenyl-''p''-phenylene diamine ( 6PPD), an

antiozonant An antiozonant, also known as anti-ozonant, is an organic compound that prevents or retards damage caused by ozone. The most important antiozonants are those which prevent degradation of elastomers like rubber. A number of research projects stud ...

used in tires. 6PPD is prepared by reductive coupling of MIBK with 4-aminodiphenylamine.

Solvent and niche applications

Unlike the other common ketone solvents,

and MEK, MIBK has quite low solubility in water, making it useful for liquid-liquid extraction. It has a similar polarity to

ethyl acetate Ethyl acetate commonly abbreviated EtOAc, ETAC or EA) is the organic compound with the formula , simplified to . This flammable, colorless liquid has a characteristic sweet smell (similar to pear drops) and is used in glues, nail polish removers, ...

, but greater stability towards

aqueous An aqueous solution is a solution in which the solvent is water. It is mostly shown in chemical equations by appending (aq) to the relevant chemical formula. For example, a solution of table salt, also known as sodium chloride (NaCl), in wat ...

acid An acid is a molecule or ion capable of either donating a proton (i.e. Hydron, hydrogen cation, H+), known as a Brønsted–Lowry acid–base theory, Brønsted–Lowry acid, or forming a covalent bond with an electron pair, known as a Lewis ...

and base. It can be used to extract gold, silver and other precious metals from

cyanide In chemistry, cyanide () is an inorganic chemical compound that contains a functional group. This group, known as the cyano group, consists of a carbon atom triple-bonded to a nitrogen atom. Ionic cyanides contain the cyanide anion . This a ...

solutions, such as those used in gold mines, to determine the levels of those dissolved metals. Diisobutyl ketone (DIBK), a related lipophilic ketone, is also used for this purpose. Methyl isobutyl ketone is also used as a denaturing agent for

denatured alcohol Denatured alcohol, also known as methylated spirits, metho, or meths in Australia, Ireland, New Zealand, South Africa, and the United Kingdom, and as Rectified spirit, denatured rectified spirit, is ethanol that has additives to make it poisonou ...

. When mixed with water or isopropyl alcohol MIBK serves as a developer for PMMA

electron beam lithography Electron-beam lithography (often abbreviated as e-beam lithography or EBL) is the practice of scanning a focused beam of electrons to draw custom shapes on a surface covered with an electron-sensitive film called a resist (exposing). The electron ...

resist A resist, used in many areas of manufacturing and art, is something that is added to parts of an object to create a pattern by protecting these parts from being affected by a subsequent stage in the process. Often the resist is then removed. For ...

. MIBK is used as a solvent for CS in the preparation of the CS spray used currently by American and British police forces.

References

External links

International Chemical Safety Card 0511

* ttps://www.cdc.gov/niosh/npg/npgd0326.html NIOSH Pocket Guide to Chemical Hazards {{Authority control Hexanones Ketone solvents Commodity chemicals IARC Group 2B carcinogens