Isoamyl acetate

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Isoamyl acetate
Isoamyl acetate
IUPAC name 3-methyl-1-butyl acetate
Other names isopentyl acetate
banana oil
isopentyl ethanoate
pear essence
3-methylbutyl acetate
Identifiers
CAS number [123-92-2]
SMILES CC(C)CCOC(C)=O
Properties
Molecular formula C7H14O2
Molar mass 130.19 g/mol
Density 0.876 g/cm3
Melting point

-78 °C

Boiling point

142 °C

Hazards
NFPA 704
3
1
0
 
Flash point 25 °C
Except where noted otherwise, data are given for
materials in their standard state
(at 25 °C, 100 kPa)

Infobox disclaimer and references

Isoamyl acetate, also known as isopentyl acetate, is an organic compound that is the ester formed from isoamyl alcohol and acetic acid. It is a clear colorless liquid that is only slightly soluble in water, but very soluble in most organic solvents.

Isoamyl acetate has a strong odor (similar to juicy fruit) which is also described as similar to both banana and pear. Banana oil is a term that is applied either to pure isoamyl acetate or to flavorings that are mixtures of isoamyl acetate, amyl acetate, nitrocellulose and other flavors. Pear oil commonly refers to a solution of isoamyl acetate in ethanol that is used as an artificial flavor.

Isoamyl acetate is also used to test the effectiveness of respirators or gas masks because it has a strong smell which is generally not experienced as unpleasant that can be detected at low concentrations, and has low toxicity.

It is also used as a solvent for some varnishes and nitrocellulose lacquers, as well as being a honey bee pheromone and can be used to attract large groups of honeybees to a small area.

Isoamyl acetate is released by a honey bee's sting apparatus where it serves as a pheromone beacon to attract other bees and provoke them to sting. [1]

[edit] Laboratory Synthesis

Isoamyl acetate can be prepared in the laboratory by the acid catalyzed Fischer esterification reaction between isoamyl alcohol and glacial acetic acid as shown in the reaction equation below. Typically, concentrated sulfuric acid is used as the catalyst. The reactants are refluxed in order to promote the reaction, the acid is neutralized and extracted, and the product is dried, then distilled.

[edit] References

  1. ^ Boch R; Shearer DA, Stone BC (September 8, 1962). "Identification of isoamyl acetate as an active component in the sting pheromone of the honey bee.". Nature 195: 1018-20. England: Nature Publishing Group. ISSN 0028-0836. PMID 13870346.