Isoamyl acetate

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 described as similar to both banana and pear.[3] Pure isoamyl acetate, or mixtures of isoamyl acetate, amyl acetate, and other flavors may be referred to as banana oil.[4]

Isoamyl acetate
Isoamyl acetate
Isoamyl-acetate-3D-balls.png
Isopentyl acetate.jpg
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 Edit this at Wikidata
EC Number
  • 204-662-3
101452
KEGG
RTECS number
  • NS9800000
UNII
UN number 1104 1993
  • InChI=1S/C7H14O2/c1-6(2)4-5-9-7(3)8/h6H,4-5H2,1-3H3 checkY
    Key: MLFHJEHSLIIPHL-UHFFFAOYSA-N checkY
  • InChI=1/C7H14O2/c1-6(2)4-5-9-7(3)8/h6H,4-5H2,1-3H3
    Key: MLFHJEHSLIIPHL-UHFFFAOYAI
  • O=C(OCCC(C)C)C
Properties
C7H14O2
Molar mass 130.187 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 or 0.533 kPa (20 °C)[1]
−89.4·10−6 cm3/mol
1.4020 at 20°
Hazards
GHS pictograms GHS02: FlammableGHS07: Harmful
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 (fire diamond)
1
3
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]
NIOSH (US health exposure limits):
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).
checkY verify (what is checkY☒N ?)
Infobox references

ProductionEdit

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.

 

ApplicationsEdit

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.[5]

Occurrence in natureEdit

Isoamyl acetate occurs naturally in the banana plant[6] and it is also produced synthetically.[7]

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.[8]

ReferencesEdit

  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 or 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. ^ "Fit Testing Procedures (Mandatory). - 1910.134 App A | Occupational Safety and Health Administration". www.osha.gov. Retrieved 2020-02-04.
  6. ^ McGee, Harold (2003). On Food and Cooking. New York: Scribner.
  7. ^ Isoamyl Acetate Archived 2010-05-28 at the Wayback Machine, Occupational Safety and Health Administration
  8. ^ 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.