Isoamyl acetate

Chembox new
Name = Isoamyl acetate
ImageFile = Isoamyl_acetate.png ImageName = Isoamyl acetate
ImageFile2 = Isoamyl-acetate-3D-balls.png IUPACName = 3-methyl-1-butyl acetate
OtherNames = isopentyl acetate
banana oil
isopentyl ethanoate
pear essence
3-methylbutyl acetate
3-methylbutyl ethanoate
Section1 = Chembox Identifiers
CASNo = 123-92-2
SMILES = CC(C)CCOC(C)=O
Section2 = Chembox Properties
Formula = C₇H₁₄O₂
MolarMass = 130.19 g/mol
Density = 0.876 g/cm³
MeltingPt = -78 °C
BoilingPt = 142 °C
Section7 = Chembox Hazards
NFPA-H = 1
NFPA-F = 3
NFPA-R = 0
FlashPt = 25 °C 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. [cite journal | author = Boch R | coauthors = Shearer DA, Stone BC | date = September 8, 1962 | title = Identification of isoamyl acetate as an active component in the sting pheromone of the honey bee. | journal = Nature | volume = 195 | pages = 1018-20 | publisher = Nature Publishing Group | location = England | issn = 0028-0836 | pmid = 13870346 ]

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.

References