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| 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 |
| EC Number |
|
| 49282 | |
| KEGG |
|
| RTECS number |
|
| UNII | |
| UN number | 1212 |
| |
| |
| Properties[3] | |
| C4H10O | |
| Molar mass | 74.122 g/mol |
| Appearance | Colorless liquid |
| Odor | sweet, musty[1] |
| 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[2] | |
| logP | 0.8 |
| Vapor pressure | 9 mmHg (20°C)[1] |
Refractive index (nD) | 1.3959 |
| Viscosity | 3.95 cP at 20 °C |
| Hazards[3] | |
| GHS labelling: | |
  | |
| 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) | |
| 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): | |
LDLo (lowest published) | 3750 mg/kg (rabbit, oral) 2460 mg/kg (rat, oral)[4] |
| NIOSH (US health exposure limits): | |
PEL (Permissible) | TWA 100 ppm (300 mg/m3)[1] |
REL (Recommended) | TWA 50 ppm (150 mg/m3)[1] |
IDLH (Immediate danger) | 1600 ppm[1] |
| Safety data sheet (SDS) | ICSC 0113 |
| Related compounds | |
Relatedbutanols | 1-Butanol sec-Butanol tert-Butanol |
Related compounds | Isobutyraldehyde Isobutyric acid |
Except where otherwise noted, data are given for materials in theirstandard state (at 25 °C [77 °F], 100 kPa). | |
Isobutanol (IUPAC nomenclature:2-methylpropan-1-ol) is anorganic compound with theformula (CH3)2CHCH2OH (sometimesrepresented asi-BuOH). This colorless, flammable liquid with a characteristic smell is mainly used as a solvent either directly or as its esters. Itsisomers are1-butanol,2-butanol, andtert-butanol, all of which are important industrially.[5]
Fusel alcohols including isobutanol are grain fermentation byproducts. Therefore, trace amounts of isobutanol may be present inmany alcoholic beverages.
In 1852Charles Adolphe Wurtz subjected such alcohols tofractional distillation and identified in some of them a butylic alcohol boiling at around 108°C.[6] Its structure was initially unclear, with some chemists believing it corresponded tobutyric acid, but theoretical considerations indicated that normal butanol should have a higher boiling point, and in 1867Emil Erlenmeyer and independentlyVladimir Markovnikov determined its actual structure by proving its oxidation product to beisobutyric acid.[7][8]
Isobutanol is produced by thecarbonylation ofpropylene. Two methods are practiced industrially,hydroformylation is more common and generates a mixture ofisobutyraldehyde andbutyraldehyde:
The reaction is catalyzed by cobalt or rhodium complexes. The resulting aldehydes arehydrogenated to the alcohols, which are then separated. In Reppecarbonylation, the same products are obtained, but the hydrogenation is effected by thewater-gas shift reaction.[5]
Propanol andmethanol can be reacted to produce isobutyl alcohol viaGuerbet condensation.[9]
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 fromvaline, is prone to decarboxylation to giveisobutyraldehyde, which is susceptible to reduction to the alcohol:[10]
The uses of isobutanol and1-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 commonplasticizers.[5] Isobutanol is also a component of somebiofuels.[11]
Isobutanol is one of the leasttoxic of the butanols with anLD50 of 2460 mg/kg (rat, oral).[5]
In March 2009, theGovernment of Canada announced a ban on isobutanol use incosmetics.[12]
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.
| Authority control databases: National |
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