Allyl acetate

Allyl acetate

Names
IUPAC name 2-Propenyl acetate
Identifiers
CAS Number	591-87-7
ChemSpider	13862665
Jmol interactive 3D	Image
SMILES C=CCOC(C)=O
Properties
Chemical formula	C5H8O2
Molar mass	100.12 g·mol^−1
Appearance	Colorless liquid
Density	0.928 g/cm^3
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; 647 K)
Except where otherwise noted, 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

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

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

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

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.