Isobutanol

Last updated
Isobutanol (2-Methyl-propan-1-ol)
Isobutanol-2D-skeletal.png
Isobutanol-3D-balls.png
Isobutanol.jpg
Names
Preferred IUPAC name
2-Methylpropan-1-ol
Other names
Isobutyl alcohol
IBA
2-Methyl-1-propanol
2-Methylpropyl alcohol
Isopropylcarbinol
Identifiers
3D model (JSmol)
1730878
ChEBI
ChEMBL
ChemSpider
ECHA InfoCard 100.001.044 OOjs UI icon edit-ltr-progressive.svg
EC Number
  • 201-148-0
49282
KEGG
PubChem CID
RTECS number
  • NP9625000
UNII
UN number 1212
  • InChI=1S/C4H10O/c1-4(2)3-5/h4-5H,3H2,1-2H3 Yes check.svgY
    Key: ZXEKIIBDNHEJCQ-UHFFFAOYSA-N Yes check.svgY
  • InChI=1/C4H10O/c1-4(2)3-5/h4-5H,3H2,1-2H3
  • CC(C)CO
Properties [1]
C4H10O
Molar mass 74.122 g/mol
AppearanceColorless liquid
Odor sweet, musty [2]
Density 0.802 g/cm3, liquid
Melting point −108 °C (−162 °F; 165 K)
Boiling point 107.89 °C (226.20 °F; 381.04 K)
8.7 mL/100 mL [3]
log P 0.8
Vapor pressure 9 mmHg (20°C) [2]
1.3959
Viscosity 3.95 cP at 20 °C
Hazards [1]
GHS labelling:
GHS-pictogram-flamme.svg GHS-pictogram-exclam.svg
Danger
H226, H315, H318, H335, H336
P210, P233, P240, P241, P242, P243, P261, P264, P271, P280, P302+P352, P303+P361+P353, P304+P340, P305+P351+P338, P310, P312, P321, P332+P313, P362, P370+P378, P403+P233, P403+P235, P405, P501
NFPA 704 (fire diamond)
NFPA 704.svgHealth 1: Exposure would cause irritation but only minor residual injury. E.g. turpentineFlammability 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. gasolineInstability 0: Normally stable, even under fire exposure conditions, and is not reactive with water. E.g. liquid nitrogenSpecial hazards (white): no code
1
3
0
Flash point 28 °C (82 °F; 301 K)
415 °C (779 °F; 688 K)
Explosive limits 1.7–10.9%
Lethal dose or concentration (LD, LC):
3750 mg/kg (rabbit, oral)
2460 mg/kg (rat, oral) [4]
NIOSH (US health exposure limits):
PEL (Permissible)
TWA 100 ppm (300 mg/m3) [2]
REL (Recommended)
TWA 50 ppm (150 mg/m3) [2]
IDLH (Immediate danger)
1600 ppm [2]
Safety data sheet (SDS) ICSC 0113
Related compounds
Related butanols
1-Butanol
sec-Butanol
tert-Butanol
Related compounds
 Isobutyraldehyde
Isobutyric acid
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Yes check.svgY  verify  (what is  Yes check.svgYX mark.svgN ?)

Isobutanol (IUPAC nomenclature: 2-methylpropan-1-ol) is an organic compound with the formula (CH3)2CHCH2OH (sometimes represented as i-BuOH). This colorless, flammable liquid with a characteristic smell is mainly used as a solvent either directly or as its esters. Its isomers are 1-butanol, 2-butanol, and tert-butanol, all of which are important industrially. [5]

Contents

Occurence

Fusel alcohols including isobutanol are grain fermentation byproducts. Therefore, trace amounts of isobutanol may be present in many alcoholic beverages.

Production

Isobutanol is produced by the carbonylation of propylene. Two methods are practiced industrially, hydroformylation is more common and generates a mixture of isobutyraldehyde and butyraldehyde:

CH3CH=CH2 + CO + H2 → CH3CH2CH2CHO

The reaction is catalyzed by cobalt or rhodium complexes. The resulting aldehydes are hydrogenated to the alcohols, which are then separated. In Reppe carbonylation, the same products are obtained, but the hydrogenation is effected by the water-gas shift reaction. [5]

Laboratory synthesis

Propanol and methanol can be reacted to produce isobutyl alcohol via Guerbet condensation. [6]

Biosynthesis of isobutanol

E. coli as well as several other organisms has been genetically modified to produce C4 alcohols from glucose, including isobutanol, 1-butanol, 2-methyl-1-butanol, 3-methyl-1-butanol, and 2-phenylethanol. The host's highly active amino acid biosynthetic pathway is shifted to alcohol production. α-Ketoisovalerate, derived from valine, is prone to decarboxylation to give isobutyraldehyde, which is susceptible to reduction to the alcohol: [7]

(CH3)2CHC(O)CO2H → (CH3)2CHCHO + CO2
(CH3)2CHCHO + NADH + H+ → (CH3)2CHCH2OH + NAD+

Applications

The uses of isobutanol and 1-Butanol are similar. They are often used interchangeably. The main applications are as varnishes and precursors to esters, which are useful solvents, e.g. isobutyl acetate. Isobutyl esters of phthalic, adipic, and related dicarboxylic acids are common plasticizers. [5] Isobutanol is also a component of some biofuels. [8]

Safety and regulation

Isobutanol is one of the least toxic of the butanols with an LD50 of 2460 mg/kg (rat, oral). [5]

In March 2009, the Government of Canada announced a ban on isobutanol use in cosmetics. [9]

Related Research Articles

Butanol (also called butyl alcohol) is a four-carbon alcohol with a formula of C4H9OH, which occurs in five isomeric structures (four structural isomers), from a straight-chain primary alcohol to a branched-chain tertiary alcohol; all are a butyl or isobutyl group linked to a hydroxyl group (sometimes represented as BuOH, 1-BuOH, i-BuOH, and t-BuOH). These are 1-butanol, two stereoisomers of sec-butyl alcohol, isobutanol and tert-butyl alcohol. Butanol is primarily used as a solvent and as an intermediate in chemical synthesis, and may be used as a fuel. Biologically produced butanol is called biobutanol, which may be n-butanol or isobutanol.

<span class="mw-page-title-main">Methyl acetate</span> Chemical compound

Methyl acetate, also known as MeOAc, acetic acid methyl ester or methyl ethanoate, is a carboxylate ester with the formula CH3COOCH3. It is a flammable liquid with a characteristically pleasant smell reminiscent of some glues and nail polish removers. Methyl acetate is occasionally used as a solvent, being weakly polar and lipophilic, but its close relative ethyl acetate is a more common solvent being less toxic and less soluble in water. Methyl acetate has a solubility of 25% in water at room temperature. At elevated temperature its solubility in water is much higher. Methyl acetate is not stable in the presence of strong aqueous bases or aqueous acids. Methyl acetate is not considered a VOC in the USA.

<span class="mw-page-title-main">2-Butanol</span> Secondary alcohol

Butan-2-ol, or sec-butanol, is an organic compound with formula CH3CH(OH)CH2CH3. Its structural isomers are 1-butanol, isobutanol, and tert-butanol. 2-Butanol is chiral and thus can be obtained as either of two stereoisomers designated as (R)-(−)-butan-2-ol and (S)-(+)-butan-2-ol. It is normally encountered as a 1:1 mixture of the two stereoisomers — a racemic mixture.

<span class="mw-page-title-main">Acetone</span> Organic compound ((CH3)2CO); simplest ketone

Acetone is an organic compound with the formula (CH3)2CO. It is the simplest and smallest ketone. It is a colorless, highly volatile and flammable liquid with a characteristic pungent odor.

<span class="mw-page-title-main">Methyl methacrylate</span> Chemical compound

Methyl methacrylate (MMA) is an organic compound with the formula CH2=C(CH3)COOCH3. This colorless liquid, the methyl ester of methacrylic acid (MAA), is a monomer produced on a large scale for the production of poly(methyl methacrylate) (PMMA).

<i>tert</i>-Butyl alcohol Chemical compound

tert-Butyl alcohol is the simplest tertiary alcohol, with a formula of (CH3)3COH (sometimes represented as t-BuOH). Its isomers are 1-butanol, isobutanol, and butan-2-ol. tert-Butyl alcohol is a colorless solid, which melts near room temperature and has a camphor-like odor. It is miscible with water, ethanol and diethyl ether.

<span class="mw-page-title-main">Dimethyl sulfate</span> Chemical compound

Dimethyl sulfate (DMS) is a chemical compound with formula (CH3O)2SO2. As the diester of methanol and sulfuric acid, its formula is often written as (CH3)2SO4 or Me2SO4, where CH3 or Me is methyl. Me2SO4 is mainly used as a methylating agent in organic synthesis.

<span class="mw-page-title-main">Methyl isobutyl ketone</span> Chemical compound

Methyl isobutyl ketone (MIBK, 4-methylpentan-2-one) is an organic compound with the condensed chemical formula (CH3)2CHCH2C(O)CH3. This ketone is a colourless liquid that is used as a solvent for gums, resins, paints, varnishes, lacquers, and nitrocellulose.

<span class="mw-page-title-main">Mesityl oxide</span> Chemical compound

Mesityl oxide is a α,β-unsaturated ketone with the formula CH3C(O)CH=C(CH3)2. This compound is a colorless, volatile liquid with a honey-like odor.

<span class="mw-page-title-main">Dimethylamine</span> Chemical compound

Dimethylamine is an organic compound with the formula (CH3)2NH. This secondary amine is a colorless, flammable gas with an ammonia-like odor. Dimethylamine is commonly encountered commercially as a solution in water at concentrations up to around 40%. An estimated 270,000 tons were produced in 2005.

<span class="mw-page-title-main">Butyl acetate</span> Chemical compound

n-Butyl acetate is an organic compound with the formula CH3CO2(CH2)3CH3. A colorless, flammable liquid, it is the ester derived from n-butanol and acetic acid. It is found in many types of fruit, where it imparts characteristic flavors and has a sweet smell of banana or apple. It is used as an industrial solvent.

<span class="mw-page-title-main">Isobutyl acetate</span> Chemical compound

The chemical compound isobutyl acetate, also known as 2-methylpropyl ethanoate or β-methylpropyl acetate, is a common solvent. It is produced from the esterification of isobutanol with acetic acid. It is used as a solvent for lacquer and nitrocellulose. Like many esters it has a fruity or floral smell at low concentrations and occurs naturally in raspberries, pears and other plants. At higher concentrations the odor can be unpleasant and may cause symptoms of central nervous system depression such as nausea, dizziness and headache.

<span class="mw-page-title-main">1-Propanol</span> Primary alcohol compound

1-Propanol is a primary alcohol with the formula CH3CH2CH2OH and sometimes represented as PrOH or n-PrOH. It is a colourless liquid and an isomer of 2-propanol. 1-Propanol is used as a solvent in the pharmaceutical industry, mainly for resins and cellulose esters, and, sometimes, as a disinfecting agent.

<i>m</i>-Xylene Chemical compound

m-Xylene (meta-xylene) is an aromatic hydrocarbon. It is one of the three isomers of dimethylbenzene known collectively as xylenes. The m- stands for meta-, indicating that the two methyl groups in m-xylene occupy positions 1 and 3 on a benzene ring. It is in the positions of the two methyl groups, their arene substitution pattern, that it differs from the other isomers, o-xylene and p-xylene. All have the same chemical formula C6H4(CH3)2. All xylene isomers are colorless and highly flammable.

<span class="mw-page-title-main">Isoamyl alcohol</span> Chemical compound

Isoamyl alcohol is a colorless liquid with the formula C
5H
12O, 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.

<span class="mw-page-title-main">2-Ethylhexanol</span> Chemical compound

2-Ethylhexanol (abbreviated 2-EH) is an organic compound with formula C8H18O. It is a branched, eight-carbon chiral alcohol. It is a colorless liquid that is poorly soluble in water but soluble in most organic solvents. It is produced on a large scale (>2,000,000,000 kg/y) for use in numerous applications such as solvents, flavors, and fragrances and especially as a precursor for production of other chemicals such as emollients and plasticizers. It is encountered in plants, fruits, and wines. The odor has been reported as "heavy, earthy, and slightly floral" for the R enantiomer and "a light, sweet floral fragrance" for the S enantiomer.

<span class="mw-page-title-main">1-Butanol</span> Chemical compound

1-Butanol, also known as butan-1-ol or n-butanol, is a primary alcohol with the chemical formula C4H9OH and a linear structure. Isomers of 1-butanol are isobutanol, butan-2-ol and tert-butanol. The unmodified term butanol usually refers to the straight chain isomer.

<span class="mw-page-title-main">Crotonaldehyde</span> Chemical compound

Crotonaldehyde is a chemical compound with the formula CH3CH=CHCHO. The compound is usually sold as a mixture of the E- and Z-isomers, which differ with respect to the relative position of the methyl and formyl groups. The E-isomer is more common (data given in Table is for the E-isomer). This lachrymatory liquid is moderately soluble in water and miscible in organic solvents. As an unsaturated aldehyde, crotonaldehyde is a versatile intermediate in organic synthesis. It occurs in a variety of foodstuffs, e.g. soybean oils.

<span class="mw-page-title-main">Isobutyraldehyde</span> Chemical compound

Isobutyraldehyde is the chemical compound with the formula (CH3)2CHCHO. It is an aldehyde, isomeric with n-butyraldehyde (butanal). Isobutyraldehyde is made, often as a side-product, by the hydroformylation of propene. Its odour is described as that of wet cereal or straw. It undergoes the Cannizaro reaction even though it has alpha hydrogen atom. It is a colorless volatile liquid.

Isopropyl alcohol is a colorless, flammable organic compound with a pungent alcoholic odor.

References

  1. 1 2 Isobutanol, International Chemical Safety Card 0113, Geneva: International Programme on Chemical Safety, April 2005.
  2. 1 2 3 4 5 NIOSH Pocket Guide to Chemical Hazards. "#0352". National Institute for Occupational Safety and Health (NIOSH).
  3. ↑ "Iso-butanol". ChemicalLand21.
  4. ↑ "Isobutyl alcohol". Immediately Dangerous to Life or Health Concentrations (IDLH). National Institute for Occupational Safety and Health (NIOSH).
  5. 1 2 3 4 Hahn, Heinz-Dieter; Dämbkes, Georg; Rupprich, Norbert (2005). "Butanols". Ullmann's Encyclopedia of Industrial Chemistry . Weinheim: Wiley-VCH. doi:10.1002/14356007.a04_463. ISBN   978-3527306732..
  6. ↑ Carlini, Carlo; Flego, Cristina; Marchionna, Mario (2004-09-01). "Guerbet condensation of methanol with n-propanol to isobutyl alcohol over heterogeneous copper chromite/Mg–Al mixed oxides catalysts". Molecular Catalysis. 220 (2): 215–220. doi:10.1016/j.molcata.2004.05.034. The synthesis of isobutyl alcohol from methanol (MeOH) and n-propanol (PrOH) through the Guerbet condensation has been studied [. . .] using catalytic system of copper chromite and Mg-Al mixed oxides.
  7. ↑ Atsumi, Shota; Hanai, Taizo; Liao, James C. (January 2008). "Non-fermentative pathways for synthesis of branched-chain higher alcohols as biofuels". Nature. 451 (7174): 86–89. Bibcode:2008Natur.451...86A. doi:10.1038/nature06450. PMID   18172501. S2CID   4413113.
  8. ↑ Peralta-Yahya, Pamela P.; Zhang, Fuzhong; del Cardayre, Stephen B.; Keasling, Jay D. (15 August 2012). "Microbial engineering for the production of advanced biofuels". Nature. 488 (7411): 320–328. Bibcode:2012Natur.488..320P. doi:10.1038/nature11478. PMID   22895337. S2CID   4423203.
  9. ↑ "Cosmetic Chemicals Banned in Canada", Chem. Eng. News, 87 (11): 38, 2009-03-16.
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