:Methyl isobutyl ketone
{{Chembox
| Verifiedfields = changed
| Watchedfields = changed
| verifiedrevid = 433525327
| Name = Methyl isobutyl ketone
| ImageFile = MIBK.png
| ImageSize = 140
| ImageAlt = Skeletal formula of methyl isobutyl ketone
| ImageFile1 = Methyl isobutyl ketone 3D ball.png
| ImageSize1 = 160
| ImageAlt1 = Ball-and-stick model of the methyl isobutyl ketone molecule
| PIN = 4-Methylpentan-2-one
| OtherNames = 4-Methyl-2-pentanone, Isopropylacetone, Hexone, Isobutyl methyl ketone, 2-Methylpropyl methyl ketone, 4-Methyl-2-oxopentane, MIK, Isobutylmethyl ketone, MIBK, Isohexanone
|Section1={{Chembox Identifiers
| CASNo_Ref = {{cascite|correct|CAS}}
| CASNo = 108-10-1
| Abbreviations = MIBK
| ChEBI = 82344
| ChEMBL = 285323
| ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}
| ChemSpiderID = 7621
| EINECS = 203-550-1
| KEGG_Ref = {{keggcite|correct|kegg}}
| KEGG = C19263
| RTECS = SA9275000
| PubChem = 7909
| UNII_Ref = {{fdacite|correct|FDA}}
| UNII = U5T7B88CNP
| UNNumber = 1245
| SMILES = CC(C)CC(=O)C
| InChI = 1/C6H12O/c1-5(2)4-6(3)7/h5H,4H2,1-3H3
| InChIKey = NTIZESTWPVYFNL-UHFFFAOYAQ
| StdInChI_Ref = {{stdinchicite|changed|chemspider}}
| StdInChI = 1S/C6H12O/c1-5(2)4-6(3)7/h5H,4H2,1-3H3
| StdInChIKey_Ref = {{stdinchicite|changed|chemspider}}
| StdInChIKey = NTIZESTWPVYFNL-UHFFFAOYSA-N
}}
|Section2={{Chembox Properties
| Formula = C6H12O
| MolarMass = 100.16 g/mol
| Appearance = colorless liquid
| Density = 0.802 g/mL, liquid
| Solubility = 1.91 g/100 mL (20 °C)
| MeltingPtC = -84.7
| BoilingPtC = 117 to 118
| pKa =
| Viscosity = 0.58 cP at 20.0 °C
| RefractIndex = 1.3958
| VaporPressure = 16 mmHg (20 °C)
| MagSus = −70.05·10−6 cm3/mol
}}
|Section3={{Chembox Structure
| Dipole = 2.8 D
}}
|Section7={{Chembox Hazards
| ExternalSDS =
| NFPA-H = 2
| NFPA-F = 3
| NFPA-R =
| GHSPictograms = {{GHS02}}{{GHS07}}{{GHS08}}
| GHSSignalWord = Danger
| HPhrases = {{H-phrases|225|319|332|335|351}}
| PPhrases = {{P-phrases|210|233|240|241|242|243|261|264|271|280|303+361+353|304+312|304+340|305+351+338|312|337+313|370+378|403+233|403+235|405|501}}
| FlashPtC = 14
| AutoignitionPtC = 449
| IDLH = 500 ppm{{PGCH|0326}}
| REL = TWA 50 ppm (205 mg/m3) ST 75 ppm (300 mg/m3)
| PEL = TWA 100 ppm (410 mg/m3)
| ExploLimits = 1.2–8.0% (93 °C)
}}
|Section8={{Chembox Related
| OtherFunction_label = ketones
| OtherFunction = Methyl isopropyl ketone
2-Pentanone
Diisobutyl ketone
| OtherCompounds = 2-Methylpentan-4-ol
}}
}}
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.{{cite web|last1=United States Environmental Protection Agency | date = September 2016|title=Methyl Isobutyl Ketone (Hexone)|url=http://www3.epa.gov/airtoxics/hlthef/methyl-k.html|accessdate=2015-12-13}}
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,{{OrgSynth | last1= Conant|first1=J. B.|last2=Tuttle|first2=N. | Org. Synth. |doi=10.15227/orgsyn.001.0045 | title = Diacetone Alcohol | volume= 1 | page = 45| year = 1921}} which readily dehydrates to give 4-methylpent-3-en-2-one (commonly, mesityl oxide).{{OrgSynth | last1= Conant|first1=J. B.|last2=Tuttle|first2=N. | doi= 10.15227/orgsyn.001.0053| title = Mesityl Oxide | volume= 1 | page = 53 | year = 1921}} 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.{{cite web|last1=Uhde GmbH | date = 2005|title=Uhde Technology Profile: MIBK|url=http://www.uhde-ftp.de/cgi-bin/byteserver.pl/pdf/technologies/TP_MIBK_2005.pdf| archive-url = https://web.archive.org/web/20131203010302/http://www.uhde-ftp.de/cgi-bin/byteserver.pl/pdf/technologies/TP_MIBK_2005.pdf|accessdate=18 October 2021| archive-date = 2013-12-03}} 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, 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 used in tires. 6PPD is prepared by reductive coupling of MIBK with 4-aminodiphenylamine.Hans-Wilhelm Engels et al., "Rubber, 4. Chemicals and Additives" in Ullmann's Encyclopedia of Industrial Chemistry, 2007, Wiley-VCH, Weinheim. {{doi|10.1002/14356007.a23_365.pub2}}
=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 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. 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.{{cite journal | journal = BMJ | doi = 10.1136/bmj.321.7252.46 | url = http://bmj.bmjjournals.com/cgi/eletters/320/7233/458 | title = Is CS spray dangerous? : CS is a particulate spray, not a gas | format = Response to editorial | author = Peter J Gray | volume = 321 | pages = 26 | year = 2000 | pmid = 10939811 | last2 = Stark | first2 = MM | issue = 7252 | pmc = 1127688 | last3 = Gray | first3 = P. J | last4 = Jones | first4 = G R. N}}{{cite journal | author = Roger Eardley-Pryor | journal= Science History Institute | year = 2017 | title = A Tear Gas Tale | url = https://www.sciencehistory.org/distillations/a-tear-gas-tale#sources | accessdate = 2021-02-22 }}
References
External links
- [http://www.inchem.org/documents/icsc/icsc/eics0511.htm International Chemical Safety Card 0511]
- [https://web.archive.org/web/20051231141608/http://www.npi.gov.au/database/substance-info/profiles/58.html National Pollutant Inventory - Methyl isobutyl ketone fact sheet]
- [https://www.cdc.gov/niosh/npg/npgd0326.html NIOSH Pocket Guide to Chemical Hazards]
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