Pinacolone (3,3-dimethyl-2-butanone) is an important ketone in organic chemistry. It is a colorless liquid with a slight peppermint or camphor odor. It is a precursor to triazolylpinacolone in the synthesis of the fungicide triadimefon and in synthesis of the herbicide metribuzin. The molecule is an unsymmetrical ketone. The α-methyl group can participate in condensation reactions. The carbonyl group can undergo the usual reactions (hydrogenation, reductive amination, etc.). It is a Schedule 3 compound under the Chemical Weapons Convention 1993, due to being related to pinacolyl alcohol, which is used in the production of soman.[2] It is also a controlled export in Australia Group member states.[3]

Pinacolone
Skeletal formula of pinacolone
Skeletal formula of pinacolone
Names
Preferred IUPAC name
3,3-Dimethylbutan-2-one
Other names
t-Butyl methyl ketone
1,1,1-Trimethylacetone
Identifiers
3D model (JSmol)
1209331
ChEBI
ChemSpider
ECHA InfoCard 100.000.838 Edit this at Wikidata
EC Number
  • 200-920-4
MeSH Pinacolone
RTECS number
  • EL7700000
UNII
UN number 1224
  • InChI=1S/C6H12O/c1-5(7)6(2,3)4/h1-4H3 checkY
    Key: PJGSXYOJTGTZAV-UHFFFAOYSA-N checkY
  • CC(=O)C(C)(C)C
Properties
C6H12O
Molar mass 100.161 g·mol−1
Appearance Colorless liquid
Density 0.801 g cm−3
Melting point −52[1] °C (−62 °F; 221 K)
Boiling point 103 to 106 °C (217 to 223 °F; 376 to 379 K)
-69.86·10−6 cm3/mol
Hazards
GHS labelling:
GHS02: FlammableGHS07: Exclamation mark
Danger
H225, H302, H315, H319, H332, H335, H412
P210, P233, P240, P241, P242, P243, P261, P264, P270, P271, P273, P280, P301+P312, P302+P352, P303+P361+P353, P304+P312, P304+P340, P305+P351+P338, P312, P321, P330, P332+P313, P337+P313, P362, P370+P378, P403+P233, P403+P235, P405, P501
NFPA 704 (fire diamond)
NFPA 704 four-colored diamondHealth 1: Exposure would cause irritation but only minor residual injury. E.g. turpentineFlammability 4: Will rapidly or completely vaporize at normal atmospheric pressure and temperature, or is readily dispersed in air and will burn readily. Flash point below 23 °C (73 °F). E.g. propaneInstability 0: Normally stable, even under fire exposure conditions, and is not reactive with water. E.g. liquid nitrogenSpecial hazards (white): no code
1
4
0
Flash point 5 °C (41 °F; 278 K)
Safety data sheet (SDS) External MSDS
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Preparation

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Most famously, at least in the classroom, pinacolone arises by the pinacol rearrangement, which occurs by protonation of pinacol (2,3-dimethylbutane-2,3-diol).[4]

 

Industrially pinacolone is made by the hydrolysis of 4,4,5-trimethyl-1,3-dioxane, which is the product of isoprene and formaldehyde via the Prins reaction. It also is generated by ketonization of pivalic acid and acetic acid or acetone over metal oxide catalysts. 3-Methylbutanal is a starting material for 2,3-dimethyl-2-butene, which in turn is converted to pinacolone. Pinacolone can also be produced from 2-methy-2-butanol when reacted with C5 alcohols.[5]

Uses

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Pinacolone is produced in large amounts for use in fungicides, herbicides, and pesticides. Some derivatives include:

See also

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References

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  1. ^ "Pinacolone | C6H12O | ChemSpider".
  2. ^ Handbook of chemical and biological warfare agents (2nd ed.). CRC Press. 24 August 2007. ISBN 9780849314346.
  3. ^ "Export Control List: Chemical Weapons Precursors". Australia Group. australiagroup.net. Retrieved 7 April 2017.
  4. ^ G. A. Hill and E. W. Flosdorf (1941). "Pinacolone". Organic Syntheses; Collected Volumes, vol. 1, p. 462.
  5. ^ Siegel, H; Eggersdorfer (2012). Ketones. 5. Vol. 20. doi:10.1002/14356007.a15_077. ISBN 9783527306732. {{cite book}}: |journal= ignored (help)
  6. ^ Oda, T; Sato, Y; Kodama, M; Kaneko, M (July 1993). "Inhibition of DNA topoisomerase I activity by diethylstilbestrol and its analogues". Biological & Pharmaceutical Bulletin. 16 (7): 708–10. doi:10.1248/bpb.16.708. PMID 8401407.