Methyl vinyl ketone

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Methyl vinyl ketone[1]
Skeletal formula
Ball-and-stick model
Identifiers
CAS number 78-94-4 YesY
PubChem 6570
ChemSpider 6322 YesY
ChEBI CHEBI:48058 YesY
Jmol-3D images Image 1
Properties
Molecular formula C4H6O
Molar mass 70.09 g/mol
Density 0.8407 g/cm3
Melting point −7 °C
Boiling point 81.4 °C
kH 2.1×101 Allen et al. [1998]

4.4×101 Betterton [1991]

4.1×101 Iraci et al. [1998]

Hazards
NFPA 704
Flammability code 3: Liquids and solids that can be ignited under almost all ambient temperature conditions. Flash point between 23 and 38 °C (73 and 100 °F). E.g., gasoline) Health code 4: Very short exposure could cause death or major residual injury. E.g., VX gas Reactivity code 2: Undergoes violent chemical change at elevated temperatures and pressures, reacts violently with water, or may form explosive mixtures with water. E.g., phosphorus Special hazards (white): no codeNFPA 704 four-colored diamond
Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
 YesY (verify) (what is: YesY/N?)
Infobox references

Methyl vinyl ketone (MVK) (IUPAC name: Butenone) is the organic compound with the formula CH3C(O)CH=CH2. It is a reactive compound classified as an enone, in fact the simplest example thereof. It is a colorless, flammable, highly toxic liquid with a pungent odor. It is soluble in water and polar organic solvents. It is a useful intermediate in the synthesis of other compounds.[2]

Production[edit]

MVK has been prepared industrially by the condensation of acetone and formaldehyde, followed by dehydration. Similarly it is prepared by the Mannich reaction involving diethylammonium chloride and acetone, which produces the Mannich adduct:[2]

CH3C(O)CH3 + CH2O + [H2NEt2]Cl → [CH3C(O)CH2CH2N(H)Et2]Cl

Heating this ammonium salt releases the ammonium chloride and the MVK:

[CH3C(O)CH2CH2N(H)Et2]Cl → [CH3C(O)CH=CH2 + [N(H)Et2]Cl

Reactivity and applications[edit]

MVK can act as an alkylating agent because it is an effective Michael acceptor. It gained early attention for its use in the Robinson annulation, a method useful in the preparation of steroids:

Robinson annulation reaction

Its alkylating ability is both the source of its high toxicity and the feature that makes it a useful intermediate in organic synthesis. MVK will polymerize spontaneously. The compound is typically stored with hydroquinone, which inhibits polymerization.

As an electrophilic alkene, it forms an adduct with cyclopentadiene. The resulting norbornene is an intermediate in the synthesis the pesticide Biperiden. Via its cyanohydrin is also a precursor to Vinclozolin. It is also a precursor to synthetic vitamin A.[2]

Vinclozolin is a commercial fungicide prepared using MVK.

Safety[edit]

MVK is extremely hazardous upon inhalation causing coughing, wheezing and shortness of breath even at low concentrations. It will also readily cause irritation of the skin, eyes, and mucous membranes.

References[edit]

  1. ^ Merck Index, 11th Edition, 6052.
  2. ^ a b c Siegel, H.; Eggersdorfer, M. (2005), "Ketones", Ullmann's Encyclopedia of Industrial Chemistry, Weinheim: Wiley-VCH, doi:10.1002/14356007.a15_077 

External links[edit]