Allyl acetate

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Allyl acetate
Allyl acetate.png
Identifiers
CAS number 591-87-7 YesY
ChemSpider 13862665 YesY
Jmol-3D images Image 1
Properties
Molecular formula C5H8O2
Molar mass 100.12 g mol−1
Appearance Colorless liquid
Density 0.928 g/cm3
Boiling point 103 °C (217 °F; 376 K)
Solubility in water slightly soluble
Hazards
R-phrases R11 R21 R23 R25 R36
S-phrases S16 S26 S45 S36
Autoignition temperature 374 °C (705 °F)
Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
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Infobox references

Allyl acetate is an organic compound with formula C3H5OC(O)CH3. This colourless liquid is a precursor to especially allyl alcohol, which is a useful industrial intermediate. It is the acetate ester of allyl alcohol.

Preparation[edit]

Allyl acetate is produced industrially by the gas phase reaction of propene in the presence of acetic acid using a palladium catalyst:[1]

C3H6 + CH3COOH + ½ O2 → CH2=CHCH2OCOCH3 + H2O

This method is advantageous because propene is inexpensive and "green." Allyl alcohol is also produced primarily from allyl chloride, but production via the hydrolysis of allyl acetate route avoids the use of chlorine, and so is increasing in use.

Vinyl acetate is produced similarly, using ethylene in place of propene. These reactions are examples of acetoxylation. The palladium center is then re-oxidized by the O2 present. The mechanism for the acetoxylation follows a similar pathway, with propene forming a π-allyl bond on the palladium.[2]

Catalytic cycle for the production of Allyl Acetate.


Reactions and applications[edit]

Allyl acetate can be hydrolyzed to allyl alcohol:

CH2=CHCH2OCOCH3 + H2O → CH2=CHCH2OH + CH3COOH

Allyl alcohol is a precursor for some specialty polymers, mainly for drying oils. Allyl alcohol is also a precursor to synthetic glycerol. Epoxidation by hydrogen peroxide produces glycidol, which undergoes hydrolysis to glycerol.

CH2=CHCH2OH + HOOH → CH2OCHCH2OH + H2O
CH2OCHCH2OH + H2O → C3H5(OH)3

Synthetic glycerol tends to be used in cosmetics and toiletries whereas glycerol from the hydrolysis of fats is used in food.[3]

Substitution reactions[edit]

Substitution of the acetate group in allyl acetate using hydrogen chloride yields allyl chloride. Reaction with hydrogen cyanide over copper catalyst yields allyl cyanide.[4]

CH2=CHCH2OCOCH3 + HCl → CH2=CHCH2Cl + CH3COOH
CH2=CHCH2OCOCH3 + HCN → CH2=CHCH2CN + CH3COOH

Allyl chloride is generally produced directly by the chlorination of propene.

References[edit]

  1. ^ Harold Wittcoff, B. G. Reuben, Jeffrey S. Plotkin (2004). Industrial organic chemicals (Google Books excerpt). p. 212. ISBN 0-471-54036-6. 
  2. ^ M. R. Churchill, R. Mason (1964). "Molecular Structure of π-allyl-palladium acetate". Nature 4960 (4960): 777. doi:10.1038/204777a0. 
  3. ^ H. A. Wittcoff, B. G. Reuben, J. S. Plotkin (2004). "Chemicals and Polymers from Propylene". Industrial Organic Chemicals. pp. 195–214. ISBN 0-471-44385-9. 
  4. ^ Ludger Krahling, et al (2000). "Allyl Compounds. Ullmann’s Encyclopedia of Industrial Chemistry". Ullmann’s Encyclopedia of Industrial Chemistry. doi:10.1002/14356007.a01_425.