Pinacolone

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 Ball-and-stick model
Names
Preferred IUPAC name 3,3-Dimethylbutan-2-one
Other names t-Butyl methyl ketone 1,1,1-Trimethylacetone
Identifiers
CAS Number	75-97-8 Y
3D model (JSmol)	Interactive image
Beilstein Reference	1209331
ChEBI	CHEBI:197349
ChemSpider	6176 Y
ECHA InfoCard	100.000.838
EC Number	200-920-4
MeSH	Pinacolone
PubChem CID	6416
RTECS number	EL7700000
UNII	3U1AAG3528 Y
UN number	1224
CompTox Dashboard (EPA)	DTXSID5021752
InChI InChI=1S/C6H12O/c1-5(7)6(2,3)4/h1-4H3 Y Key: PJGSXYOJTGTZAV-UHFFFAOYSA-N Y
SMILES CC(=O)C(C)(C)C
Properties
Chemical formula	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)
Magnetic susceptibility (χ)	−69.86·10−6 cm3/mol
Hazards
GHS labelling:
Pictograms
Signal word	Danger
Hazard statements	H225, H302, H315, H319, H332, H335, H412
Precautionary statements	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)	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). Y verify (what is YN ?) Infobox references

Preparation

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

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

• retrosynthetic analysis of vibunazole showed that it was derived from pinacolone.^{[original research?]}
• It is also used to prepare pinacidil, as well as naminidil.
• Stiripentol
• Tribuzone
• Pivaloylacetonitrile is used in the synthesis of Doramapimod.
• Triadimefon
• Diclobutrazole
• Paclobutrazol
• Valconazole
• Diethylstilbestrol pinacolone [18922-13-9].^[6]
• Some kind of Bisphenol A derivative also U.S. patent 4,599,463
• Thiofanox

See also

• Pinacol
• Pinacolyl alcohol
• Soman