Methyl isobutyl ketone

Methyl isobutyl ketone
Names
	Preferred IUPAC name 4-Methylpentan-2-one
	Other names 4-Methyl-2-pentanone; Isopropylacetone; Hexone; Isobutyl methyl ketone; 2-Methylpropyl methyl ketone; 4-Methyl-2-oxopentane; Isobutylmethyl ketone; Isohexanone;
Identifiers
CAS Number	108-10-1 ;
3D model (JSmol)	Interactive image;
Abbreviations	MIBK
ChEBI	CHEBI:82344;
ChEMBL	ChEMBL285323;
ChemSpider	7621 ;
ECHA InfoCard	100.003.228
EC Number	203-550-1;
KEGG	C19263 ;
PubChem CID	7909;
RTECS number	SA9275000;
UNII	U5T7B88CNP ;
UN number	1245
CompTox Dashboard (EPA)	DTXSID5021889 ;
	InChI InChI=1S/C6H12O/c1-5(2)4-6(3)7/h5H,4H2,1-3H3 Key: NTIZESTWPVYFNL-UHFFFAOYSA-N ; InChI=1/C6H12O/c1-5(2)4-6(3)7/h5H,4H2,1-3H3 Key: NTIZESTWPVYFNL-UHFFFAOYAQ;
	SMILES CC(C)CC(=O)C;
Properties
Chemical formula	C6H12O
Molar mass	100.161 g·mol−1
Appearance	colorless liquid
Density	0.7965 g/mL
Melting point	−85 °C (−121 °F; 188 K)
Boiling point	115.7 °C (240.3 °F; 388.8 K)
Critical point (T, P)	575.4 K, 3.4 MPa
Solubility in water	1.91 g/100 mL (20.0 °C (68.0 °F; 293.1 K))
Solubility	miscible with acetone, benzene, ethanol, ether; soluble in chloroform;
log P	1.31
Vapor pressure	2.64 kPa
Magnetic susceptibility (χ)	−69.7×10−6 cm3/mol
Refractive index (nD)	1.3962
Viscosity	0.545 cP
Thermochemistry
Heat capacity (C)	213.3 J⋅mol−1·K-1
Enthalpy of vaporization (ΔfHvap)	40.61 kJ⋅mol−1
Hazards
	GHS labelling:
Pictograms
Signal word	Danger
Hazard statements	H225, H319, H332, H336, H351
Precautionary statements	P201, P202, P210, P233, P240, P241, P242, P243, P261, P264, P271, P280, P303+P361+P353, P304+P340+P312, P305+P351+P338, P308+P313, P337+P313, P370+P378, P403+P233, P403+P235, P405, P501
NFPA 704 (fire diamond)	2 3 1
Flash point	18 °C (64 °F; 291 K)
Autoignition; temperature	448 °C (838 °F; 721 K)
Explosive limits	1.2%–8.0%
Threshold limit value (TLV)	20 ppm (TWA), 75 ppm (STEL)
	Lethal dose or concentration (LD, LC):
LD50 (median dose)	2080 mg/kg (oral, rat)
LC50 (median concentration)	11.6 mg/L (4h, rat, vapor)
	NIOSH (US health exposure limits):
PEL (Permissible)	TWA 100 ppm (410 mg/m3)
REL (Recommended)	TWA 50 ppm (205 mg/m3); ST 75 ppm ppm (300 mg/m3);
IDLH (Immediate danger)	500 ppm
Related compounds
Related ketones	Acetone; Methyl isopropyl ketone; 2-Pentanone;
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). verify (what is ?) Infobox references

Methyl isobutyl ketone (MIBK, 4-methylpentan-2-one) is an organic compound with the condensed chemical formula (CH₃)₂CHCH₂C(O)CH₃. This ketone is a colourless liquid that is used as a solvent for gums, resins, paints, varnishes, lacquers, and nitrocellulose.^[5]

Production

At laboratory scale, MIBK can be produced via a three-step process using acetone as the starting material. Self-condensation, a type of aldol reaction, produces diacetone alcohol, which readily dehydrates to give 4-methylpent-3-en-2-one (commonly, mesityl oxide).^[6]^[7] Mesityl oxide is then hydrogenated to give MIBK.^{[citation needed]}

Industrially, these three steps are combined. Acetone is treated with a strongly acidic, palladium catalyst-doped cation exchange resin under medium pressure of hydrogen.^[8] Several million kilograms are produced annually.^{[citation needed]}

Uses

MIBK is used as a solvent for nitrocellulose, lacquers, and certain polymers and resins.^{[citation needed]}

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.^[9]

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. For example, the purification of tantalum from its ores often relies on MIBK extractions.^[10] It has a similar polarity to ethyl acetate, but greater stability towards aqueous acids and bases.^{[citation needed]}

It can be used to extract gold, silver and other precious metals from cyanide solutions, such as those used in gold mines, to determine the levels of those dissolved metals.^{[citation needed]}

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 American and British police forces.^[11]^[12]

References

^ ^a ^b ^c ^d ^e ^f Haynes, William M., ed. (2016). CRC Handbook of Chemistry and Physics (97th ed.). Boca Raton, Florida: CRC Press. pp. 3–386, 5–28, 5–158, 5–175, 6–77, 6–148, 6–246, 15–18. ISBN 9781498754293.
^ ^a ^b ^c Sigma-Aldrich Co., Methyl isobutyl ketone.
^ "Methyl isobutyl ketone". www.fishersci.com. ThermoFisher Scientific. Retrieved 13 May 2026.
^ "NIOSH Pocket Guide to Chemical Hazards".
^ United States Environmental Protection Agency (January 2000). "Methyl Isobutyl Ketone (Hexone)" (PDF). Retrieved 13 May 2026.
^ Conant, J. B.; Tuttle, N. (1921). "Diacetone Alcohol". Organic Syntheses. 1: 45. doi:10.15227/orgsyn.001.0045.
^ Conant, J. B.; Tuttle, N. (1921). "Mesityl Oxide". Organic Syntheses. 1: 53. doi:10.15227/orgsyn.001.0053.
^ Uhde GmbH (2005). "Uhde Technology Profile: MIBK" (PDF). Archived from the original (PDF) on 2013-12-03. Retrieved 18 October 2021.
^ Engels, H.-W.; Weidenhaupt, H.-J.; Pieroth, M.; Hofmann, W.; Menting, K.-H.; Mergenhagen, T.; Schmoll, R.; Uhrlandt, S. (2007). "Rubber, 4. Chemicals and Additives". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.a23_365.pub2. ISBN 978-3-527-30673-2.
^ Shikika, A.; Sethurajan, M.; Muvundja, F.; Mugumaoderha, M.C.; Gaydardzhiev, St. (2020). "A review on extractive metallurgy of tantalum and niobium". Hydrometallurgy. 198 105496. doi:10.1016/j.hydromet.2020.105496.
^ Peter J Gray; Stark, MM; Gray, P. J; Jones, G R. N (2000). "Is CS spray dangerous? : CS is a particulate spray, not a gas" (Response to editorial). BMJ. 321 (7252): 26. doi:10.1136/bmj.321.7252.46. PMC 1127688. PMID 10939811.
^ Roger Eardley-Pryor (2017). "A Tear Gas Tale". Science History Institute. Retrieved 2021-02-22.

[CRC-1] ^ ^a ^b ^c ^d ^e ^f Haynes, William M., ed. (2016). CRC Handbook of Chemistry and Physics (97th ed.). Boca Raton, Florida: CRC Press. pp. 3–386, 5–28, 5–158, 5–175, 6–77, 6–148, 6–246, 15–18. ISBN 9781498754293.

[Sigma-2] Sigma-Aldrich Co., Methyl isobutyl ketone.

[Fisher-3] "Methyl isobutyl ketone". www.fishersci.com. ThermoFisher Scientific. Retrieved 13 May 2026.

[4] "NIOSH Pocket Guide to Chemical Hazards".

[US_EPA_Hexone-5] United States Environmental Protection Agency (January 2000). "Methyl Isobutyl Ketone (Hexone)" (PDF). Retrieved 13 May 2026.

[6] Conant, J. B.; Tuttle, N. (1921). "Diacetone Alcohol". Organic Syntheses. 1: 45. doi:10.15227/orgsyn.001.0045.

[7] Conant, J. B.; Tuttle, N. (1921). "Mesityl Oxide". Organic Syntheses. 1: 53. doi:10.15227/orgsyn.001.0053.

[8] Uhde GmbH (2005). "Uhde Technology Profile: MIBK" (PDF). Archived from the original (PDF) on 2013-12-03. Retrieved 18 October 2021.

[9] Engels, H.-W.; Weidenhaupt, H.-J.; Pieroth, M.; Hofmann, W.; Menting, K.-H.; Mergenhagen, T.; Schmoll, R.; Uhrlandt, S. (2007). "Rubber, 4. Chemicals and Additives". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.a23_365.pub2. ISBN 978-3-527-30673-2.

[10] Shikika, A.; Sethurajan, M.; Muvundja, F.; Mugumaoderha, M.C.; Gaydardzhiev, St. (2020). "A review on extractive metallurgy of tantalum and niobium". Hydrometallurgy. 198 105496. doi:10.1016/j.hydromet.2020.105496.

[CS-11] Peter J Gray; Stark, MM; Gray, P. J; Jones, G R. N (2000). "Is CS spray dangerous? : CS is a particulate spray, not a gas" (Response to editorial). BMJ. 321 (7252): 26. doi:10.1136/bmj.321.7252.46. PMC 1127688. PMID 10939811.

[12] Roger Eardley-Pryor (2017). "A Tear Gas Tale". Science History Institute. Retrieved 2021-02-22.

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