 | |
| Names | |
|---|---|
| Preferred IUPAC name 3-Methylbutan-1-ol | |
| Other names 3-Methyl-1-butanol Isopentyl alcohol Isopentanol Isobutylcarbinol | |
| Identifiers | |
| |
3D model (JSmol) | |
| ChEBI | |
| ChEMBL | |
| ChemSpider |
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| DrugBank |
|
| ECHA InfoCard | 100.004.213 |
| KEGG |
|
| UNII | |
| |
| |
| Properties | |
| C5H12O | |
| Molar mass | 88.148 g/mol |
| Appearance | Clear, colorless liquid |
| Odor | Disagreeable odor in high concentrations |
| Density | 0.8104 g/cm3 at 20 °C |
| Melting point | −117[2][3] °C (−179 °F; 156 K) |
| Boiling point | 131.1 °C (268.0 °F; 404.2 K) |
| Slightly soluble, 28 g/L | |
| Solubility | Very soluble inacetone,diethyl ether,ethanol |
| Vapor pressure | 28 mmHg (20 °C)[3] |
| −68.96·10−6 cm3/mol | |
| Viscosity | 3.692 mPa·s |
| Thermochemistry | |
| 2.382 J/g·K | |
Std enthalpy of formation(ΔfH⦵298) | −356.4 kJ/mol (liquid) −300.7 kJ/mol (gas) |
| Hazards | |
| Occupational safety and health (OHS/OSH): | |
Main hazards | Flammable, moderately toxic |
| GHS labelling: | |
   | |
| Danger | |
| H226,H302,H305,H315,H318,H332,H335 | |
| P210,P233,P240,P241,P242,P243,P261,P264,P270,P271,P280,P301+P312,P302+P352,P303+P361+P353,P304+P312,P304+P340,P305+P351+P338,P310,P312,P321,P330,P332+P313,P337+P313,P362,P370+P378,P403+P233,P403+P235,P405,P501 | |
| NFPA 704 (fire diamond) | |
| Flash point | 43 °C (109 °F; 316 K) |
| 350 °C (662 °F; 623 K) | |
| Explosive limits | 1.2–9% |
| Lethal dose or concentration (LD, LC): | |
LD50 (median dose) | 1453 mg/kg (rabbit, oral) 1300 mg/kg (rat, oral)[4] |
| NIOSH (US health exposure limits): | |
PEL (Permissible) | TWA 100 ppm (360 mg/m3)[3] |
REL (Recommended) | TWA 100 ppm (360 mg/m3), ST 125 ppm (450 mg/m3)[3] |
IDLH (Immediate danger) | 500 ppm[3] |
Except where otherwise noted, data are given for materials in theirstandard state (at 25 °C [77 °F], 100 kPa). | |
Isoamyl alcohol is a colorless liquid with the formulaC
5H
12O, specifically (H3C–)2CH–CH2–CH2–OH. It is one of severalisomers ofamyl alcohol (pentanol). It is also known asisopentyl alcohol,isopentanol, or (in theIUPAC recommended nomenclature)3-methyl-butan-1-ol. An obsolete name for it wasisobutyl carbinol.[5]
Isoamyl alcohol is an ingredient in the production ofbanana oil, anester found in nature and also produced as a flavouring in industry. It is a commonfusel alcohol, produced as a major by-product of ethanol fermentation.
Isoamyl alcohol is one of the components of the aroma ofTuber melanosporum, the black truffle.
Fusel alcohols like isoamyl alcohol are grain fermentation byproducts, and therefore trace amounts of isoamyl are present inmany alcoholic beverages.
The compound has also been identified as a chemical in thepheromone used byhornets to attract other members of the hive to attack.[6]
Isoamyl alcohol can be separated from fusel oil by either of two methods: shaking with strongbrine solution and separating the oily layer from the brine layer;distilling it and collecting the fraction that boils between 125 and 140 °C. Further purification is possible with this procedure: shaking the product with hotlimewater, separating the oily layer, drying the product withcalcium chloride, and distilling it, collecting the fraction boiling between 128 and 132 °C.[5]
Isoamyl alcohol can be synthesized by condensation ofisobutene andformaldehyde which producesisoprenol, thenhydrogenation. It is a colourless liquid of density 0.8247 g/cm3 (0 °C), boiling at 131.6 °C, slightly soluble in water, and easily dissolved in organic solvents. It has a characteristic strong smell and a sharp burning taste. On passing the vapour through a red-hot tube, it decomposes intoacetylene,ethylene,propylene, and other compounds. It isoxidized bychromic acid toisovaleraldehyde, and it formsaddition compoundscrystals with calcium chloride andtin(IV) chloride.[5]
Besides its use in the synthesis of banana oil, isoamyl alcohol is also an ingredient ofKovac's reagent, used for the bacterial diagnosticindole test.
It is also used as anantifoaming agent in the chloroform isoamyl alcohol reagent.[7]
Isoamyl alcohol is used in aphenol–chloroform extraction mixed with the chloroform to further inhibitRNase activity and prevent solubility of RNAs with long tracts of poly-adenine.[8]
IAA is also used as the reactant in the synthesis of the following list of drugs:
One or more of the preceding sentences incorporates text from a publication now in thepublic domain: Chisholm, Hugh, ed. (1911). "Amyl Alcohols".Encyclopædia Britannica. Vol. 1 (11th ed.). Cambridge University Press. p. 900.
