Allyl acetate
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| Names | |
|---|---|
| IUPAC name
2-Propenyl Ethanoate
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| Identifiers | |
| ECHA InfoCard | 100.008.851 |
CompTox Dashboard (EPA)
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| Properties | |
| C5H8O2 | |
| Molar mass | 100.12 g/mol |
| Appearance | Colorless liquid |
| Density | 0.928 g/cm3 |
| Boiling point | 103 °C (217 °F; 376 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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Allyl acetate is an organic compound with formula C3H5OC(O)CH3. This colourless liquid is a precursor to many useful compounds, especially allyl alcohol.
Preparation
Allyl acetate used to be commonly produced by the reaction of allyl bromide with zinc oxide in acetic acid.[1] Currently is it generated by the gas phase reaction of propene, acetic acid, and oxygen over a palladium catalyst.
C3H6 + CH3COOH + ½ O2 → CH2=CHCH2OCOCH3 + H2O
Vinyl acetate is produced similarly, using ethylene in place of propene. Each of these reactions is an acetoxylation, The mechanism of the acetoxylation of ethylene has been explored in detail.[2] Addition of the olefin to palladium is followed by C-O bond formation between the ethylene and acetate on the metal center and a beta hydrogen elimination. At this point reductive elimination of the acetate and ethylene yields the product, vinyl acetate. The palladium center is then reoxidized by the O2 present. The mechanism for the acetoxylation follows a similar pathway, with propene forming a π-allyl bond on the palladium.[3]
Main reactions
Allyl Alcohol
Allyl acetate can be hydrolyzed to allyl alcohol:
CH2=CHCH2OCOCH3 + H2O → CH2=CHCH2OH + CH3COOH
Allyl alcohol is a precursor for some specialty polymers, mainly polyallyl alcohol which is used for drying oils. Other polymers are used for flame-resistant foams.
Allyl alcohol is also a precursor to synthetic glycerol. Epoxidation by hydrogen peroxide to produce glycidol followed by hydrolysis yields 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.[4]
Substitutions
Substitution of the acetate group in allyl acetate using hydrogen chloride yields allyl chloride. Reaction with hydrogen cyanide over copper catalyst yields allyl cyanide.[5]
CH2=CHCH2OCOCH3 + HCl → CH2=CHCH2Cl + CH3COOH
CH2=CHCH2OCOCH3 + HCN → CH2=CHCH2CN + CH3COOH
Although allyl chloride is generally produced directly by the chlorination of propene and allyl cyanide has no industrial uses. Allyl alcohol is also produced primarily from allyl chloride, but the allyl acetate route avoids the use of chlorine so is increasing in use.
References
- ^ K. N. Gurudutt, B. Ravindranath, P. Srinivas (1982). "Solvolytic displacement of alkyl halides by metal salts. Preparative procedures for allyl-, benzyl-, and tertiary alkyloxy derivatives using the zinc salts". Tetrahedron. 38: 1843–1846.
{{cite journal}}: CS1 maint: multiple names: authors list (link) - ^ J. J. Plata; et al. (2009). "Vinyl Acetate Synthesis on Homogeneous and Heterogeneous Pd-Based Catalysts: A Theoretical Analysis on the Reaction Mechanisms". J. Phys. Chem. 113: 11758–11762.
{{cite journal}}: Explicit use of et al. in:|author=(help) - ^ M. R. Churchill, R. Mason (1964). "Molecular Structure of π-allyl-palladium Acetate". Nature. 4960: 777.
- ^ H. A. Wittcoff, B. G. Reuben, J. S. Plotkin (2004). Industrial Organic Chemicals. pp. 195–214.
{{cite book}}: Unknown parameter|Chapter=ignored (|chapter=suggested) (help)CS1 maint: multiple names: authors list (link) - ^ Ludger Krahling; et al. "Allyl Compounds. Ullmann's Encyclopedia of Industrial Chemistry". Ullmann’s Encyclopedia of Industrial Chemistry. doi:10.1002/14356007.a01_425.
{{cite journal}}: Explicit use of et al. in:|author=(help)