ISOAMYL ALCOHOL

ISOAMYL ALCOHOL

Isoamyl alcohol is a colorless liquid with the formula C5H12O, specifically (H3C–)2CH–CH2–CH2–OH. It is one of several isomers of amyl alcohol (pentanol). It is also known as isopentyl alcohol, isopentanol, or (in the IUPAC recommended nomenclature) 3-methyl-butan-1-ol. An obsolete name for it was isobutyl carbinol.

CAS    123-51-3
EC (EINECS/ELINCS)    204-633-5
EC Index Number    603-006-00-7
EC Class    flammable, harmful

SYNONYMS: Isoamyl alcohol; 3-Methyl-1-butanol; Isopentyl alcohol; 3-Methylbutan-1-ol; Isopentanol; 123-51-3; 3-Methylbutanol; 1-Butanol, 3-methyl-; Isoamylol; Isobutylcarbinol; Iso-amyl alcohol; Iso-amylalkohol; Fusel Oil; 2-Methyl-4-butanol; Isobutyl carbinol; ISOAMYLALCOHOL; Alcool isoamylique; Fermentation amyl alcohol; Alcool amilico; Amylowy alkohol; Isoamyl alkohol; i-Amyl Alcohol; Primary isoamyl alcohol; 3-Metil-butanolo; isopentan-1-ol; Isoamyl alcohol (natural); isoamyl-alcohol; 3-Methyl-Butan-1-Ol; Isoamyl alcohol, primary; FEMA Number 2057; Isoamyl alkohol [Czech]; Alcool amilico [Italian]; Amylowy alkohol [Polish]; Iso-amylalkohol [German]; UNII-DEM9NIT1J4; 3-methyl-Butanol; NSC 1029; Alcool isoamylique [French]; 3-Metil-butanolo [Italian]; MFCD00002934; FEMA No. 2057; HSDB 605; Methyl-3-butan-1-ol; Butan-1-ol, 3-methyl; EINECS 204-633-5; DEM9NIT1J4; Fuseloel; AI3-15288; Huile de fusel; CHEBI:15837; 3-METHYL-BUTAN-(1)-OL; Magnesium bis(3-methylbutan-1-olate); Isoamyl alcohol (primary and secondary); 3-Methyl-1-butanol, ACS reagent; iso-pentanol; WLN: Q2Y1 & 1; 3-Methyl-1-butanol, 98%, pure; 1-Hydroxy-3-Methylbutane; 6423-06-9; Isopentyl alcohol (8CI); 3-Methyl-1-butanol, 99%, for biochemistry, AcroSeal(R); iso-amylalcohol; isopentylalcohol; Isopentylalkohol; CCRIS 8806; 3-methylbutanoI; 3-methyl butanol; 3-methyl 1-butanol; 3-methyl-1 butanol; 3-methylbutane-1-ol; Butanol, 3-methyl-; 3-Methylbutan-1-ol.; ACMC-1ADLL; DSSTox_CID_5469; EC 204-633-5; DSSTox_RID_77799; DSSTox_GSID_25469; KSC175S7D; 3-Methyl-1-butanol, 98%; CHEMBL372396; QSPL 002; DTXSID3025469; Isoamyl alcohol, >=98%, FG; CTK0H5971; NSC1029; NSC7905; 3-Methyl-1-butanol, for analysis; ZINC896830; Isoamyl alcohol (3-methyl butanol); NSC-1029; NSC-7905; 1-$l^{1}-oxidanyl-3-methylbutane; 3-Methylbutanol, analytical standard; EINECS 229-179-5; Tox21_302359; 7340AF; ANW-18132; LMFA05000108; STL282718; 3-Methyl-1-butanol A.C.S. Reagent; 3-Methyl-1-butanol, LR, >=98%; AKOS000118739; NATURAL ISOAMYL ALCOHOL P & F; DB02296; LS-2837; MCULE-7411270401; 3-Methyl-1-butanol, p.a., 99.8%; Isoamyl alcohol, natural, >=98%, FG; KS-00000X06; 3-Methyl-1-butanol, analytical standard; NCGC00255329-01; 3-Methyl-1-butanol, anhydrous, >=99%; CAS-123-51-3; 3-Methyl-1-butanol, reagent grade, 98%; 3-Methyl-1-butanol, technical grade, 95%; ISOAMYL ALCOHOL ULTRA PURE GRADE 1L; FT-0616032; I0289; NS00008204; 1973-EP2281899A2; 1973-EP2316937A1; 3-Methyl-1-butanol, ACS reagent, >=98.5%; 3-Methyl-1-butanol, biotech. grade, >=99%; 3-Methyl-1-butanol, ReagentPlus(R), >=99%; C07328; 74374-EP2269986A1; 74374-EP2308857A1; 74374-EP2380568A1; NATURAL ISOAMYL ALCOHOL - TECHNICAL GRADE; 117932-EP2287147A2; 117932-EP2298768A1; 3-Methyl-1-butanol, SAJ first grade, >=96.0%; Q223101; 3-Methyl-1-butanol, JIS special grade, >=98.0%; F0001-0367; Z955123582; UNII-2NK7O363Q6 component PHTQWCKDNZKARW-UHFFFAOYSA-N; 3-Methylbutanol, BioReagent, for molecular biology, >=98.5%; 3-Methylbutanol, puriss. p.a., ACS reagent, >=98.5% (GC); 3-Methylbutanol, BioUltra, for molecular biology, >=99.0% (GC); ISOAMYL ALCOHOL;3-methylbutan-1-ol;Isopentanol;Isopentyl alcohol; 3-Methyl-1-butanol, United States Pharmacopeia (USP) Reference Standard; 3-Methylbutanol, p.a., ACS reagent, reag. ISO, reag. Ph. Eur., 98.5%

Chemical formula: C5H12O
Molar mass: 88.148 g/mol
Appearance: Clear, colorless liquid
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)
Solubility in water: Slightly soluble, 28 g/L
Solubility: Very soluble in acetone, diethyl ether, ethanol
Vapor pressure: 28 mmHg (20°C)[3]
Magnetic susceptibility (χ): -68.96·10−6 cm3/mol
Viscosity: 3.692 mPa·s

Isoamyl alcohol is an ingredient in the production of banana oil, an ester found in nature and also produced as a flavouring in industry. It is a common fusel alcohol, produced as a major by-product of ethanol fermentation.

Occurrence
Isoamyl alcohol is one of the components of the aroma of Tuber melanosporum, the black truffle.

The compound has also been identified as a chemical in the pheromone used by hornets to attract other members of the hive to attack.

Isoamyl acetate is a component of the natural aroma of bananas, especially the Gros Michel variety.

Extraction from fusel oil
Isoamyl alcohol can be separated from fusel oil by either of two methods: shaking with strong brine 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 hot limewater, separating the oily layer, drying the product with calcium chloride, and distilling it, collecting the fraction boiling between 128 and 132 °C.

Synthesis
Isoamyl alcohol can be synthesized from isobutanol by conversion into isovaleraldehyde, which is subsequently reduced to isobutyl carbinol by means of sodium amalgam. 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. Amyl alcohol has an oral LD50 of 200 mg/kg in mice, suggesting that it is significantly more toxic than ethanol. On passing the vapour through a red-hot tube, it decomposes into acetylene, ethylene, propylene, and other compounds. It is oxidized by chromic acid to isovaleraldehyde, and it forms addition compounds crystals with calcium chloride and tin(IV) chloride.

Uses
Besides its use in the synthesis of banana oil, isoamyl alcohol is also an ingredient of Kovac's reagent, used for the bacterial diagnostic indole test.

It is also used as an antifoaming agent in the chloroform isoamyl alcohol reagent.

Isoamyl alcohol is used in a phenol–chloroform extraction mixed with the chloroform to further inhibit RNase activity and prevent solubility of RNAs with long tracts of poly-adenine.

PRODUCT IDENTIFICATION
Product Name    Isoamyl Alcohol
Empirical Formula    C5H12O
CAS Number    123-51-3
Synonyms    3-Methy-1-butanol, Isopentyl alcohol
Physical State    Colourless liquid
Odour    Pear drops, ester
Viscosity    7.2mPas (at 21°C)
Solubility in water    28g/L
Boiling Point    131-132°C

APPLICATIONS

Isoamyl alcohol is used as a solvent for the preparation of synthetic fruit flavours, such as apricot, banana, cheery, greengage, malt, orange, plum and whiskey flavours, and is a raw material in the production of synthetic banana oil. It is one of the components of the aroma of the black truffle. It is also used for estimation of fat in milk and milk products.

It is the main ingredient of Kovac’s Reagent used for the bacterial diagnostic Indole Test.

Its blend of properties makes it suitable for use as a foam suppressant, affecting the surface tension of micro-emulsions and causing foam breaking.

As a solvent, it is finding increasing use in a wide number of industrial applications. In solvency power, it falls between common hydrocarbon solvents and lower molecular weight ketones. Paraffin wax is soluble in hot isoamyl alcohol.

In formulation, some high molecular weight esters and polar plastics incorporate Isoamyl alcohol-based systems e.g. cellulose esters. Shellac and urea formaldehyde. It is a diluent in some printing inks, lacquers and gums.