Methyl isobutyl ketone

Methyl isobutyl ketone
IUPAC name	4-Methylpentan-2-one
Other names	Isopropylacetone, Hexone, Isobutyl methyl ketone, 4-Methylpentan-2-one, 4-methyl-2-pentanone, 4-methylpentan-2-one, 2-methyl-4-pentanone, 2-methylpropyl methyl ketone, 4-methyl-2-oxopentane, MIK, isobutylmethyl ketone, MIBK, isohexanone
Identifiers
CAS number	108-10-1 Y
RTECS number	SA9275000
SMILES	CC(C)CC(=O)C
Properties
Molecular formula	C6H12O
Molar mass	100.2 g/mol
Appearance	colorless liquid
Density	0.80 g/ml, liquid
Melting point	−84.7 °C
Boiling point	117-118 °C
Solubility in water	1.91 g/100 ml (20 °C)
Viscosity	0.58 cP at 20.0 °C
Structure
Dipole moment	4.2 D
Hazards
EU classification	Flammable (F) Harmful (Xn)
R-phrases	R11, R20, R36/37, R66
S-phrases	(S2), S9, S16, S29
NFPA 704	3 2 0
Flash point	14 °C
Related compounds
Related ketones	Methyl isopropyl ketone 2-Pentanone Diisobutyl ketone
Related compounds	2-Methylpentan-4-ol
Y (what is this?)  (verify) Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

Methyl isobutyl ketone (MIBK) is the organic compound with the formula (CH₃)₂CHCH₂C(O)CH₃. This colourless liquid, a ketone, is widely used as a solvent.

Production

Methyl isobutyl ketone is manufactured from acetone via a three-step process. Firstly acetone undergoes an aldol condensation to give diacetone alcohol, which readily dehydrates to give mesityl oxide. Mesityl oxide can then be hydrogenated to give MIBK:

Several million kilograms are produced annually.^[1]

Uses

MIBK is used as a solvent for nitrocellulose, lacquers, and certain polymers and resins.^[1]

Precursor to 6PPD

Another major use is as a precursor to N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylene diamine (6PPD), an antiozonant used in tires. 6PPD is prepared by reductive coupling of MIBK with 4-aminodiphenylamine.^{[citation needed]}

Solvent and niche applications

Unlike the other common ketone solvents, acetone and MEK, MIBK has quite low solubility in water, making it useful for liquid-liquid extraction. It has a similar polarity to ethyl acetate, but greater stability towards aqueous acid and base. It can be used to extract gold, silver and other precious metals from cyanide solutions, such as those found at 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. When mixed with water or isopropyl alcohol MIBK serves as a developer for PMMA electron beam lithography resist. MIBK is used as a solvent for CS in the preparation of the CS spray used currently by British police forces.^[2]

References

1. ^ ^{a b} Stylianos Sifniades, Alan B. Levy, “Acetone” in Ullmann’s Encyclopedia of Industrial Chemistry, Wiley-VCH, Weinheim, 2005.
2. ^ Peter J Gray (2000). "CS gas is not CS spray - formulation is important" (Response to editorial). BMJ 321: 26. doi:10.1136/bmj.321.7252.46. PMID 10939811. http://bmj.bmjjournals.com/cgi/eletters/320/7233/458. 

External links

• International Chemical Safety Card 0511
• National Pollutant Inventory - Methyl isobutyl ketone fact sheet
• NIOSH Pocket Guide to Chemical Hazards