ISOAMYL ALCOHOL

Table of Contents

ISOAMYL ALCOHOL

Isoamyl alcohol is a primary alcohol, a volatile organic compound and an alkyl alcohol. Isoamyl alcohol derives from a hydride of an isopentane.

 

ISOAMYL ALCOHOL = ISOPENTYL ALCOHOL = ISOPENTANOL = 3-METHYLBUTANOL = ISOAMYLOL = ISOBUTYLCARBINOL = 3-METHYLBUTAN-1-ol = IAA

EC / List no.: 204-633-5

CAS no.: 123-51-3

Mol. formula: C5H12O

Isoamyl alcohol is a colorless liquid with a mild, choking alcohol odor. 

Isoamyl alcohol is less dense than water, soluble in water. Hence Isoamyl alcohol floats on water. 

Isoamyl alcohol produces an irritating vapor. 

Isoamyl alcohol is a specialty solvent that finds extensive use for flavours and fragrances and is used in the production of many synthetic flavours. 

Its relatively low eco-tox profile finds it use growing in other areas. 

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. 

ISOPENTYL ALCOHOL is one of the components of the aroma of the black truffle. 

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

Isoamylol is an primary alcohol that is butan-1-ol in which a hydrogen at position 3 has been replaced by a methyl group. 

Isoamylol has a role as a xenobiotic metabolite, a Saccharomyces cerevisiae metabolite and an antifungal agent. 

Isoamylol is a primary alcohol, a volatile organic compound and an alkyl alcohol. Isoamylol derives from a hydride of an isopentane.

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). 

Isoamyl alcohol is also known as isopentyl alcohol, isopentanol, or (in the IUPAC recommended nomenclature) 3-methyl-butan-1-ol. 

An obsolete name for Isoamyl alcohol was isobutyl carbinol.

Isoamyl alcohol is an ingredient in the production of banana oil, an ester found in nature and also produced as a flavouring in industry. 

Isoamyl alcohol is a common fusel alcohol, produced as a major by-product of ethanol fermentation.

Isoamyl Alcohol is one of the flavour and fragrance chemicals. 

Isoamyl Alcohol is a speciality solvent often noted for its distinctive odour – which smells like pear drops.

Isoamyl alcohol is a speciality solvent that finds extensive use for flavours and fragrances and is used in the production of many synthetic flavours. 

Its relatively low eco-tox profile finds it use growing in other areas.

Isoamyl alcohol or Isopentanol, also known as isopentyl alcohol or iso-amylalkohol, belongs to the class of organic compounds known as primary alcohols. 

Primary alcohols are compounds comprising the alcohol functional group, attached to a primary carbon, with the general structure RCOH (R=alkyl, aryl). 

Isoamyl alcohol is a very hydrophobic molecule, practically insoluble in water but readily soluble in organic solvents such as methanol, ethanol and ethyl acetate. 

Thus, isopentanol is considered to be a fatty alcohol lipidic molecule. 

Isopentyl alcohol is one of several isomers of amyl alcohol. 

It is a by-product of gut microbial fermentation (PMID: 17452087). 

Isopentanol is an alcoholic, banana, and burnt tasting compound. 

Due to its flavour and aroma, it is an ingredient in the production of banana oil, an ester found in nature and also produced as a flavouring in industry. 

Isoamyl alcohol can be produced by 3-methylbutanal reductase (EC 1.1.1.265) from 3-methylbutanal. 

In alcoholic beverages, isopentyl alcohol is also the major higher chain alcohol and it is present in cider, mead, beer, wine, and spirits to varying degrees, being a product of the fermentation of starches. 

Isopentanol has been shown to induce expression of CYP3A and CYP2E1 in human liver (PMID: 7574728).

Isoamyl Alcohol (Isopentanol)

Isoamyl Alcohol, also known as Isopentanol is a clear, colorless, liquid organic compound that is one of several isomers of amyl alcohol. It is a principal ingredient in the production of banana oil, a natural ester used in the flavoring industry. It is also used as an antifoaming agent in the Chloroform: Isomyl Alcohol reagent.

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. 

Isoamyl alcohol is one of the components of the aroma of the black truffle. Isoamyl alcohol is also used for estimation of fat in milk and milk products.

Isoamyl alcohol 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, Isoamyl alcohol is finding increasing use in a wide number of industrial applications. 

In solvency power, Isoamyl alcohol 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.

Isoamyl alcohol is a diluent in some printing inks, lacquers and gums.

In pharmaceuticals, Isoamyl alcohol is the initial raw material for a number of drug preparations such as Barbamil, Validol, Corvalol and amyl nitrite.

A derivative of Isoamyl alcohol, the p-methoxycinnamate is used as a UV absorber in some cosmetic formulations, and the product itself finds application as a cosmetic flavouring and in perfume.

Isoamyl alcohol is used in the following products: lubricants and greases, polishes and waxes, anti-freeze products, washing & cleaning products, adhesives and sealants, coating products, finger paints, perfumes and fragrances and cosmetics and personal care products.

Isoamyl alcohol is routinely used in molecular biology, especially in the purification of DNA. 

Isoamyl alcohol is widely used in conjunction with phenol and chloroform (25:24:1 phenol : chloroform : isoamyl alcohol) for the removal of proteins from the nucleic acid solutions by extraction. 

Isoamyl alcohol is added to the phenol solution to help inhibit RNase activity and to help prevent the solubilization in the phenol phase of long RNA molecules with long poly(A) portions. 

Isoamyl alcohol will also help in reducing the foaming during the extraction process.

Isoamyl alcohol is also used in the extraction of ethidium bromide from DNA solutions and in the radiolabeling of RNA transcripts in nuclei that have been isolated from tissue. 

Isoamyl alcohol has various miscellaneous uses which include HPLC analysis of various pharmaceuticals and metabolites, analysis of oxidized and reduced pyridine nucleotides and adenylates in organic phenol extracts from mitochondria, isolation of mRNA from a thermophilic cyanobacterium, Solvent for fats, resins, alkaloids, Manufacturing isoamyl (amyl) compounds, isovaleric acid, mercury fulminate, pyroxylin, artificial silk, lacquers, smokeless powders, for dehydrating celloidin solutions, for determining fat in milk etc.

Isoamyl alcohol is a colorless, clear liquid with the chemical formula (CH3)2CHCH2CH2OH and the CAS # 123-51-3. The nontoxic compound has a mild, choking disagreeable odor. It is less dense than water, soluble in water, and floats on water. Its main use in industry is as a food additive and flavoring agent. It is manufactured from light petroleum by fractional distillation.

Isoamyl alcohol is used as a solvent in the manufacture of photographic and pharmaceutical chemicals.

Uses: Synthetic flavor, intermediate in preparation of pharmaceuticals, for isoamyl acetate and other esters, for dithiophosphate esters (lubricating oil additive and hydraulic fluid additive).

Isoamyl alcohol (also known as isopentyl alcohol) is a colorless liquid with the formula (CH3)2CHCH2CH2OH. It is one of several isomers of amyl alcohol. It 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. It is also an ingredient of Kovac’s reagent, used for the bacterial diagnostic indole test.

Isoamyl alcohol is a cyanobacterial volatile organic compound that has been identified as one of the main aroma/flavor constituents in banana fruit, karanda fruits and in whey spirit.

Preferred IUPAC name: 3-Methylbutan-1-ol

Other names: 

3-Methyl-1-butanol

Isopentyl alcohol

Isopentanol

Isobutylcarbinol

Identifiers

CAS Number: 123-51-3 

Properties

Chemical formula: C5H12O

Molar mass: 88.148 g/mol

Appearance: Clear, colorless liquid

Density: 0.8104 g/cm3 at 20 °C

Melting point: −117 °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)

Magnetic susceptibility (χ): −68.96·10−6 cm3/mol

Viscosity: 3.692 mPa·s

Thermochemistry

Heat capacity (C): 2.382 J/g·K

Std enthalpy of formation (ΔfH⦵298): 

−356.4 kJ/mol (liquid)

−300.7 kJ/mol (gas)

Hazards

Flash point: 43 °C (109 °F; 316 K)

Autoignition temperature: 350 °C (662 °F; 623 K)

Explosive limits: 1.2–9%

Lethal dose or concentration (LD, LC): LD50 (median dose): 3438 mg/kg (rabbit, oral) 1300 mg/kg (rat, oral)

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 of Isoamyl alcohol 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 of Isoamyl alcohol

Isoamyl alcohol can be synthesized by condensation of isobutene and formaldehyde which produces isoprenol and hydrogenation. 

Isoamyl alcohol 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. 

Isoamyl alcohol 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 of Isoamyl alcohol :

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.

Isoamyl alcohol 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.

Uses: Isoamyl alcohol is used as a solvent, paint stripper, and intermediate in the photographic and pharmaceutical industries; [ACGIH]

1-Butanol, 3-methyl-

IUPAC names

3-Methyl-1-butanol

3-methyl-1-butanol

3-methylbut-1-ol

3-METHYLBUTAN-1-OL

3-Methylbutan-1-ol

3-methylbutan-1-ol

3-methylbutanol

3-metil-1-butanolo

Iso-Amyl alcohol

isoamyl alcohol

Isoamyl alcohol

isoamyl alcohol

Isoamyl alcohol, Isopentyl alcohol

Methyl-1-butanol

Trade names

1-Butanol, 3-methyl-(9CI)

2-Methyl-4-butanol

3-Methyl-1-butanol

IAA

iso-Amyl alcohol

iso-Pentanol

Isoamyl alcohol

Isoamylol

Isobutyl carbinol

Isopentanol

Isopentyl alcohol (8CI)

SYNONYMS :

Isoamyl alcohol

3-Methyl-1-butanol

Isopentyl alcohol

3-Methylbutan-1-ol

123-51-3

Isopentanol

3-Methylbutanol

1-Butanol, 3-methyl-

Isoamylol

Isobutylcarbinol

Iso-amylalkohol

Fusel Oil

Iso-amyl alcohol

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

MFCD00002934

Isoamyl alcohol (natural)

isoamyl-alcohol

3-Methyl-Butan-1-Ol

Isoamyl alcohol, primary

UNII-DEM9NIT1J4

3-methyl-Butanol

NSC 1029

Methyl-3-butan-1-ol

Butan-1-ol, 3-methyl

DEM9NIT1J4

Fuseloel

Huile de fusel

CHEBI:15837

3-METHYL-BUTAN-(1)-OL

3-Methyl-1-butanol, ACS reagent

iso-pentanol

WLN: Q2Y1 & 1

3-Methyl-1-butanol, 98%, pure

FEMA Number 2057

Isoamyl alkohol [Czech]

Alcool amilico [Italian]

Amylowy alkohol [Polish]

Iso-amylalkohol [German]

1-Hydroxy-3-Methylbutane

Alcool isoamylique [French]

3-Metil-butanolo [Italian]

FEMA No. 2057

HSDB 605

EINECS 204-633-5

Isopentyl alcohol (8CI)

3-Methyl-1-butanol, 99%, for biochemistry, AcroSeal(R)

iso-amylalcohol

isopentylalcohol

Isopentylalkohol

AI3-15288

CCRIS 8806

3-methylbutanoI

3-methyl butanol

3-methyl 1-butanol

3-methyl-1 butanol

3-methylbutane-1-ol

Butanol, 3-methyl-

Isoamyl alcohol (primary and secondary)

ACMC-1ADLL

6423-06-9

DSSTox_CID_5469

EC 204-633-5

DSSTox_RID_77799

DSSTox_GSID_25469

3-Methyl-1-butanol, 98%

CHEMBL372396

QSPL 002

DTXSID3025469

Isoamyl alcohol, >=98%, FG

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

Magnesium bis(3-methylbutan-1-olate)

NATURAL ISOAMYL ALCOHOL P & F

DB02296

MCULE-7411270401

3-Methyl-1-butanol, mixture of isomers

3-Methyl-1-butanol, p.a., 99.8%

Isoamyl alcohol, natural, >=98%, FG

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

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)

3-Methyl-1-butanol, United States Pharmacopeia (USP) Reference Standard

3-Methylbutanol, p.a., ACS reagent, reag. ISO, reag. Ph. Eur., 98.5%

Isoamyl alcohol must be stored to avoid contact with strong oxidizers, such as chlorine, and bromine, since violent reactions occur.

Isoamyl alcohol is a colorless liquid. It has a disagreeable odor which causes coughing. Molecular weight=88.15 (primary-and sec-); specific gravity (H2O:1)=0.81 @ 20°C; boiling point=131 °C (primary); 116.3°C (secondary); freezing/melting point=−117.2°C (primary-); −69°C (sec-); vapor pressure=28 mmHg (primary-); 7.5 mmHg @24°C (sec-); vapor pressure=0.75 mmHg @ 13°C (primary-); flash point=43°C (cc); 55°C (oc) (primary-); 35°C (sec-); autoignition temperature=350°C. Explosive limits: LEL (primary-)=1.2% @ 100°C; UEL (primary-)=9.0% @100°C. Hazard identification (based on NFPA-704 M Rating System): Health 2, flammability 3, reactivity 0. Slightly soluble in water; solubility=2% @ 13.9°C.

Reactivity Alerts

Highly Flammable

Air & Water Reactions

Highly flammable. Water soluble.

Fire Hazard

Excerpt from ERG Guide 129 [Flammable Liquids (Water-Miscible / Noxious)]:

HIGHLY FLAMMABLE: Will be easily ignited by heat, sparks or flames. Vapors may form explosive mixtures with air. Vapors may travel to source of ignition and flash back. Most vapors are heavier than air. They will spread along ground and collect in low or confined areas (sewers, basements, tanks). Vapor explosion hazard indoors, outdoors or in sewers. Those substances designated with a (P) may polymerize explosively when heated or involved in a fire. Runoff to sewer may create fire or explosion hazard. Containers may explode when heated. Many liquids are lighter than water. (ERG, 2016)

Health Hazard

Very high vapor concentrations irritate eyes and upper respiratory tract. Continued contact with skin may cause irritation. (USCG, 1999)

Reactivity Profile

ISOAMYL ALCOHOL attacks plastics [Handling Chemicals Safely, 1980. p. 236]. Mixtures with concentrated sulfuric acid and strong hydrogen peroxide may cause explosions. Mixing with hypochlorous acid in water or water/carbon tetrachloride solution can generate isoamyl hypochlorites, which may explode, particularly on exposure to sunlight or heat. Mixing with chlorine would also yield isoamyl hypochlorites [NFPA 491 M, 1991]. Base-catalysed reactions with isocyanates can occur with explosive violence [Wischmeyer,1969].

Belongs to the Following Reactive Group(s)

Alcohols and Polyols

Potentially Incompatible Absorbents

Use caution: Liquids with this reactive group classification have been known to react with the absorbent listed below. More info about absorbents, including situations to watch out for…

Cellulose-Based Absorbents

Alternate Chemical Names

FERMENTATION AMYL ALCOHOL

FUSEL OIL

ISOAMYL ALCOHOL

ISOAMYL ALCOHOL (PRIMARY)

ISOBUTYL CARBINOL

ISOBUTYLCARBINOL

ISOPENTYL ALCOHOL

ISOPENTYL ALCOHOL {ISOAMYL ALCOHOL}

3-METHYL-1-BUTANOL

POTATO SPIRIT OIL

PRIMARY ISOAMYL ALCOHOL

Other names: Isopentyl alcohol; Fermentation amyl alcohol; Fusel Oil; Isoamyl alcohol; Isoamylol; Isobutyl carbinol; Isopentanol; 2-Methyl-4-butanol; 3-Methyl-1-butanol; 3-Methylbutanol; Alcool amilico; Alcool isoamylique; Amylowy alkohol; iso-amylalkohol; 3-Methylbutan-1-ol; 3-Metil-butanolo; Isoamyl alcohol, primary; Butanol, 3-methyl-; Butan-1-ol, 3-methyl; i-Amyl alcohol; Isopentan-1-ol; Methyl-3-butan-1-ol; NSC 1029; UN 1105; 3-methylbutanoI; Isoamyl alcohol (3-methyl butanol)

Isoamyl alcohol (isopentanol or 3-methylbutan-1-ol) that can be biologically produced is among the possible alcohols usable as an alternative fuel in internal combustion engines. 

Isoamyl alcohol has a higher energy density than smaller alcohols (ca. 28.5 MJ/L, as compared to ca. 21 MJ/L for ethanol and 27 MJ/L for 1-butanol). It is less hydroscopic than ethanol and mixes better with hydrocarbons.

Synonyms

1-Butanol, 3-methyl-; 2-Methyl-4-butanol; 3-Methylbutan-1-ol; 3-Methylbutanol; 3-Metil-butanolo [Italian]; Alcool amilico [Italian]; Alcool isoamylique [French]; Amylowy alkohol [Polish]; Fermentation amyl alcohol; Fusel Oil; ISOAMYLALCOHOL; Iso-amylalkohol [German]; Isoamyl alcohol (natural); Isoamyl alkohol [Czech]; Isoamylol; Isobutyl carbinol; Isobutylcarbinol; Isopentanol; Isopentyl alcohol; Primary isoamyl alcohol; [ChemIDplus]l

Apart from the primary metabolite ethanol, several higher alcohols are formed at different levels, of which isoamyl alcohol (Fig. 1B, descriptors: ‘alcoholic’, ‘vinous’, ‘sweet’) is the most abundant secondary metabolite and typically found well above its flavor threshold in beer. Isoamyl alcohol has also some banana flavor character and has been identified above its threshold in banana, orange, mango, pineapple and passion fruit 

Isoamyl Alcohol is a banana oil or hot alcohol like flavour. It is very light but has a lingering taste and mouthfeel. It commonly occurs due to poor fermentation conditions – when the temperature is not correct or dissolved gases are not optimal.

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, Isoamyl alcohol 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.

Isoamyl alcohol is a diluent in some printing inks, lacquers and gums.

In pharmaceuticals, it is the initial raw material for a number of drug preparations such as Barbamil, Validol, Corvalol and Isoamyl nitrite.

A derivative of Isoamyl alcohol, the p-methoxycinnamate is used as a UV absorber in some cosmetic formulations, and the product itself finds application as a cosmetic flavouring and in perfume.

Explore: