Isoamyl acetate

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Isoamyl acetate
Isoamyl acetate
Isoamyl-acetate-3D-balls.png
Names
Preferred IUPAC name
3-Methylbutyl acetate
Systematic IUPAC name
3-Methylbutyl ethanoate
Other names
Isopentyl acetate
Isopentyl ethanoate
Isoamyl acetate
Banana oil
Pear essence
Identifiers
3D model (JSmol)
1744750
ChEBI
ChEMBL
ChemSpider
ECHA InfoCard 100.004.240
EC Number 204-662-3
101452
KEGG
RTECS number NS9800000
UNII
UN number 1104 1993
Properties
C7H14O2
Molar mass 130.19 g·mol−1
Appearance Colorless liquid
Odor Banana-like[1]
Density 0.876 g/cm3
Melting point −78 °C (−108 °F; 195 K)
Boiling point 142 °C (288 °F; 415 K)
0.3% (20 °C)[1]
Vapor pressure 4 mmHg (20 °C)[1]
−89.4·10−6 cm3/mol
1.4020 at 20°
Hazards
GHS pictograms The flame pictogram in the Globally Harmonized System of Classification and Labelling of Chemicals (GHS)The exclamation-mark pictogram in the Globally Harmonized System of Classification and Labelling of Chemicals (GHS)The health hazard pictogram in the Globally Harmonized System of Classification and Labelling of Chemicals (GHS)
GHS signal word Danger
H226, H315, H319, H335, H336, H372
P210, P233, P240, P241, P242, P243, P260, P261, P264, P270, P271, P280, P302+352, P303+361+353, P304+340, P305+351+338, P312, P314, P321, P332+313, P337+313, P362, P370+378, P403+233, P403+235
NFPA 704
Flammability code 3: Liquids and solids that can be ignited under almost all ambient temperature conditions. Flash point between 23 and 38 °C (73 and 100 °F). E.g., gasolineHealth code 1: Exposure would cause irritation but only minor residual injury. E.g., turpentineReactivity code 0: Normally stable, even under fire exposure conditions, and is not reactive with water. E.g., liquid nitrogenSpecial hazards (white): no codeNFPA 704 four-colored diamond
3
1
0
Flash point 25 °C (77 °F; 298 K)
Explosive limits 1.0% (100 °C) – 7.5%[1]
Lethal dose or concentration (LD, LC):
7422 mg/kg (rabbit, oral)
16,600 mg/kg (rat, oral)[2]
6470 ppm (cat)[2]
US health exposure limits (NIOSH):
PEL (Permissible)
TWA 100 ppm (525 mg/m3)[1]
REL (Recommended)
TWA 100 ppm (525 mg/m3)[1]
IDLH (Immediate danger)
1000 ppm[1]
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

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 colorless liquid that is only slightly soluble in water, but very soluble in most organic solvents. Isoamyl acetate has a strong odor which is also described as similar to both banana and pear.[3] Banana oil may be either pure isoamyl acetate, or flavorings that are mixtures of isoamyl acetate, amyl acetate, and other flavors.[4]

Production[edit]

Isoamyl acetate is prepared by the acid catalyzed reaction (Fischer esterification) between isoamyl alcohol and glacial acetic acid as shown in the reaction equation below. Typically, sulfuric acid is used as the catalyst. Alternatively, p-toluenesulfonic acid or an acidic ion exchange resin can be used as the catalyst.

Isoamylacetat.svg

Applications[edit]

Isoamyl acetate is used to confer banana flavor in foods. Banana oil commonly refers to a solution of isoamyl acetate in ethanol that is used as an artificial flavor.

It is also used as a solvent for some varnishes and nitrocellulose lacquers. As a solvent and carrier for materials such as nitrocellulose, it was extensively used in the aircraft industry for stiffening and wind-proofing fabric flying surfaces, where it and its derivatives were generally known as 'aircraft dope'. Now that most aircraft are all-metal, such use is now mostly limited to historically accurate reproductions and scale models.

Because of its intense, pleasant odor and its low toxicity, isoamyl acetate is used to test the effectiveness of respirators or gas masks. It is also used in thermometers.[citation needed]

Occurrence in nature[edit]

Isoamyl acetate occurs naturally in the banana plant[5] and it is also produced synthetically.[6]

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.[7]

References[edit]

  1. ^ a b c d e f g "NIOSH Pocket Guide to Chemical Hazards #0347". National Institute for Occupational Safety and Health (NIOSH). 
  2. ^ a b "Isoamyl acetate". Immediately Dangerous to Life and Health Concentrations (IDLH). National Institute for Occupational Safety and Health (NIOSH). 
  3. ^ "Iso-amyl acetate". chemicalland21.com. 
  4. ^ Karl-Georg Fahlbusch, Franz-Josef Hammerschmidt, Johannes Panten, Wilhelm Pickenhagen, Dietmar Schatkowski, Kurt Bauer, Dorothea Garbe, Horst Surburg "Flavors and Fragrances" in Ullmann's Encyclopedia of Industrial Chemistry, Wiley-VCH, Weinheim, 2002. doi:10.1002/14356007.a11_141.
  5. ^ McGee, Harold (2003). On Food and Cooking. New York: Scribner. 
  6. ^ Isoamyl Acetate Archived 2010-05-28 at the Wayback Machine., Occupational Safety and Health Administration
  7. ^ 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. England: Nature Publishing Group. 195 (4845): 1018–20. doi:10.1038/1951018b0. PMID 13870346.