Tert-Butyl alcohol

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tert-Butyl alcohol
Skeletal formula of tert-butyl alcohol Tert-butyl-alcohol-2D-skeletal.svg
Skeletal formula of tert-butyl alcohol
Ball and stick model of tert-butyl alcohol Tert-Butanol molecule ball from xtal.png
Ball and stick model of tert-butyl alcohol
TBuOH 1133.jpg
Names
Preferred IUPAC name
2-Methylpropan-2-ol
Other names
  • t-Butyl alcohol
  • tert-Butanol
  • t-Butanol
  • t-BuOH
  • Trimethyl carbinol [1]
  • Tertiary butanol
  • 2-Methyl-2-propanol
  • 2M2P
Identifiers
3D model (JSmol)
906698
ChEBI
ChEMBL
ChemSpider
DrugBank
ECHA InfoCard 100.000.809 OOjs UI icon edit-ltr-progressive.svg
EC Number
  • 200-889-7
1833
MeSH tert-Butyl+Alcohol
PubChem CID
RTECS number
  • EO1925000
UNII
UN number 1120
  • InChI=1S/C4H10O/c1-4(2,3)5/h5H,1-3H3 Yes check.svgY
    Key: DKGAVHZHDRPRBM-UHFFFAOYSA-N Yes check.svgY
  • CC(C)(C)O
Properties
C4H10O
Molar mass 74.123 g·mol−1
AppearanceColorless solid
Odor Camphorous
Density 0.775 g/mL
Melting point 25 to 26 °C; 77 to 79 °F; 298 to 299 K
Boiling point 82 to 83 °C; 179 to 181 °F; 355 to 356 K
miscible [2]
log P 0.584
Vapor pressure 4.1 kPa (at 20 °C)
Acidity (pKa)16.54 [3]
5.742×10−5 cm3/mol
1.387
1.31 D
Thermochemistry
215.37 J K−1 mol−1
Std molar
entropy
(S298)
189.5 J K−1 mol−1
−360.04 to −358.36 kJ mol−1
−2.64479 to −2.64321 MJ mol−1
Hazards
GHS labelling:
GHS-pictogram-flamme.svg GHS-pictogram-exclam.svg
Danger
H225, H319, H332, H335
P210, P261, P305+P351+P338
NFPA 704 (fire diamond)
NFPA 704.svgHealth 2: Intense or continued but not chronic exposure could cause temporary incapacitation or possible residual injury. E.g. chloroformFlammability 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
2
3
0
Flash point 11 °C (52 °F; 284 K)
480 °C (896 °F; 753 K)
Explosive limits 2.4–8.0%
Lethal dose or concentration (LD, LC):
3559 mg/kg (rabbit, oral)
3500 mg/kg (rat, oral) [4]
NIOSH (US health exposure limits):
PEL (Permissible)
TWA 100 ppm (300 mg/m3) [1]
REL (Recommended)
TWA 100 ppm (300 mg/m3) ST 150 ppm (450 mg/m3) [1]
IDLH (Immediate danger)
1600 ppm [1]
Safety data sheet (SDS) inchem.org
Related compounds
Related butanols
2-Butanol

n-Butanol
Isobutanol

Related compounds
2-Methyl-2-butanol
Trimethylsilanol

Nonafluoro-tert-butyl alcohol

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 ?)

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.

Contents

Natural occurrence

tert-Butyl alcohol has been identified in beer and chickpeas. [5] It is also found in cassava, [6] which is used as a fermentation ingredient in certain alcoholic beverages.

Preparation

tert-Butyl alcohol is derived commercially from isobutane as a coproduct of propylene oxide production. It can also be produced by the catalytic hydration of isobutylene, or by a Grignard reaction between acetone and methylmagnesium chloride.

Purification cannot be performed by simple distillation due to formation of an azeotrope with water, although initial drying of the solvent containing large amounts of water is performed by adding benzene to form a tertiary azeotrope and distilling off the water. Smaller amounts of water are removed by drying with calcium oxide (CaO), potassium carbonate (K2CO3), calcium sulfate (CaSO4), or magnesium sulfate (MgSO4), followed by fractional distillation. Anhydrous tert-butyl alcohol is obtained by further refluxing and distilling from magnesium activated with iodine, or alkali metals such as sodium or potassium. Other methods include the use of 4  Å molecular sieves, aluminium tert-butylate, calcium hydride (CaH2), or fractional crystallization under inert atmosphere. [7]

Applications

tert-Butyl alcohol is used as a solvent, ethanol denaturant, paint remover ingredient, and gasoline octane booster and oxygenate. It is a chemical intermediate used to produce methyl tert-butyl ether (MTBE) and ethyl tert-butyl ether (ETBE) by reaction with methanol and ethanol, respectively, and tert-butyl hydroperoxide (TBHP) by reaction with hydrogen peroxide.

Reactions

Unlike other isomers of butanol, tert-butyl alcohol, as a tertiary alcohol, has no hydrogen atom next to hydroxy-group, which makes it resistant to oxidation to carbonyl compounds.

tert-Butyl alcohol is deprotonated with a strong base to give the alkoxide. Particularly common is potassium tert-butoxide, which is prepared by treating tert-butanol with potassium metal. [8]

K + t-BuOH → t-BuOK+ + 1/2 H2

The tert-butoxide is a strong, non-nucleophilic base in organic chemistry. It readily abstracts acidic protons from substrates, but its steric bulk inhibits the group from participating in nucleophilic substitution, such as in a Williamson ether synthesis or an SN2 reaction.

tert-Butyl alcohol reacts with hydrogen chloride to form tert-butyl chloride.

O-Chlorination of tert-butyl alcohol with hypochlorous acid to give tert-butyl hypochlorite: [9]

(CH3)3COH + HOCl → (CH3)3COCl + H2O

Pharmacology and toxicology

There is limited data on the pharmacology and toxicology of tert-butanol in humans and other animals. [10] Human exposure may occur due to fuel oxygenate metabolism. Tert-butanol is poorly absorbed through skin but rapidly absorbed if inhaled or ingested. Tert-butanol is irritating to skin or eyes. Toxicity of single doses is usually low but high doses can produce a sedative or anesthetic effect.

Related Research Articles

<span class="mw-page-title-main">Alcohol (chemistry)</span> Organic compound with at least one hydroxyl (–OH) group

In chemistry, an alcohol is a type of organic compound that carries at least one hydroxyl functional group bound to carbon. Alcohols range from the simple, like methanol and ethanol, to complex, like sugars and cholesterol. The presence of an OH group strongly modifies the properties of hydrocarbons, conferring hydrophilic (water-loving) properties. The OH group provides a site at which many reactions can occur.

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, sec-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">Heptane</span> Chemical compound

Heptane or n-heptane is the straight-chain alkane with the chemical formula H3C(CH2)5CH3 or C7H16. When used as a test fuel component in anti-knock test engines, a 100% heptane fuel is the zero point of the octane rating scale (the 100 point is 100% iso-octane). Octane number equates to the anti-knock qualities of a comparison mixture of heptane and iso-octane which is expressed as the percentage of iso-octane in heptane, and is listed on pumps for gasoline (petrol) dispensed globally.

Isobutane, also known as i-butane, 2-methylpropane or methylpropane, is a chemical compound with molecular formula HC(CH3)3. It is an isomer of butane. Isobutane is a colorless, odorless gas. It is the simplest alkane with a tertiary carbon atom. Isobutane is used as a precursor molecule in the petrochemical industry, for example in the synthesis of isooctane.

Methyl <i>tert</i>-butyl ether Chemical compound

Methyl tert-butyl ether (MTBE), also known as tert-butyl methyl ether, is an organic compound with a structural formula (CH3)3COCH3. MTBE is a volatile, flammable, and colorless liquid that is sparingly soluble in water. Primarily used as a fuel additive, MTBE is blended into gasoline to increase its octane rating and knock resistance, and reduce unwanted emissions.

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

Ethanethiol, commonly known as ethyl mercaptan, is an organosulfur compound with the formula CH3CH2SH. is a colorless liquid with a distinct odor. Abbreviated EtSH, it consists of an ethyl group (Et), CH3CH2, attached to a thiol group, SH. Its structure parallels that of ethanol, but with sulfur in place of oxygen. The odor of EtSH is infamous. Ethanethiol is more volatile than ethanol due to a diminished ability to engage in hydrogen bonding. Ethanethiol is toxic in high concentrations. It occurs naturally as a minor component of petroleum, and may be added to otherwise odorless gaseous products such as liquefied petroleum gas (LPG) to help warn of gas leaks. At these concentrations, ethanethiol is not harmful.

In organic chemistry, butyl is a four-carbon alkyl radical or substituent group with general chemical formula −C4H9, derived from either of the two isomers (n-butane and isobutane) of butane.

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

Diisopropyl ether is a secondary ether that is used as a solvent. It is a colorless liquid that is slightly soluble in water, but miscible with organic solvents. It is used as an extractant and an oxygenate gasoline additive. It is obtained industrially as a byproduct in the production of isopropanol by hydration of propylene. Diisopropyl ether is sometimes represented by the abbreviation DIPE.

<span class="mw-page-title-main">Isobutylene</span> Unsaturated hydrocarbon compound (H2C=C(CH3)2)

Isobutylene is a hydrocarbon with the chemical formula (CH3)2C=CH2. It is a four-carbon branched alkene (olefin), one of the four isomers of butylene. It is a colorless flammable gas, and is of considerable industrial value.

<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">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. Me2SO4 is a colourless oily liquid with a slight onion-like odour. Like all strong alkylating agents, Me2SO4 is toxic. Its use as a laboratory reagent has been superseded to some extent by methyl triflate, CF3SO3CH3, the methyl ester of trifluoromethanesulfonic acid.

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

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.

<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">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.

Potassium <i>tert</i>-butoxide Chemical compound

Potassium tert-butoxide (or potassium t-butoxide) is a chemical compound with the formula [(CH3)3COK]n (abbr. KOtBu). This colourless solid is a strong base (pKa of conjugate acid around 17), which is useful in organic synthesis. The compound is often depicted as a salt, and it often behaves as such, but its ionization depends on the solvent.

<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.

tert-Butyl chloride is the organochloride with the formula (CH3)3CCl. It is a colorless, flammable liquid. It is sparingly soluble in water, with a tendency to undergo hydrolysis to the corresponding tert-butyl alcohol. It is produced industrially as a precursor to other organic compounds.

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

Di-<i>tert</i>-butyl chromate Chemical compound

Di-tert-butyl chromate is an alkoxide with the formula CrO2(OC(CH3)3)2. It is prepared by treatment of t-butanol with chromic anhydride. It forms red crystals at temperatures below –5 °C, above which it melts to give a red oil. The complex, which is diamagnetic, is of fundamental interest as a model for the intermediates in oxidations of alcohols by chromium(VI). This complex is stable because as a t-butyl groups lack beta-hydrogens. This complex and its analogues have tetrahedral geometry at chromium, as established by X-ray crystallography of its analogues.

<i>tert</i>-Butoxybis(dimethylamino)methane Chemical compound

tert-Butoxybis(dimethylamino)methane is an organic compound with the formula (CH3)3COCH(N(CH3)2)2. The compound is classified as an aminal ester, i.e. the tert-butyl alcohol derivative of the aminal bis(dimethylamino)methane. It is a colorless liquid with a amine odor.

References

  1. 1 2 3 4 NIOSH Pocket Guide to Chemical Hazards. "#0078". National Institute for Occupational Safety and Health (NIOSH).
  2. "ICSC 0114 – tert-Butanol". Inchem.org. Retrieved 29 March 2018.
  3. Reeve, W.; Erikson, C. M.; Aluotto, P. F. (1979). "tert-Butyl alcohol". Can. J. Chem. 57: 2747. doi: 10.1139/v79-444 .
  4. "tert-Butyl alcohol". Immediately Dangerous to Life or Health Concentrations (IDLH). National Institute for Occupational Safety and Health (NIOSH).
  5. "t-Butyl Alcohol". National Library of Medicine HSDB Database. National Institute for Health. Retrieved 29 March 2018.
  6. "Archived copy" (PDF). Archived from the original (PDF) on 2016-03-04. Retrieved 2013-03-05.{{cite web}}: CS1 maint: archived copy as title (link)
  7. Perrin, D. D.; Armarego, W. L. F. (1988). Purification of Laboratory Chemicals (3rd ed.). Pergamon Press. ISBN   9780080347141.
  8. Johnson, W. S.; Schneider, W. P. (1950). "β-Carbethoxy-γ,γ-diphenylvinylacetic acid". Organic Syntheses . 30: 18. doi:10.15227/orgsyn.030.0018 .
  9. Mintz, H. M.; Walling, C. (1969). "t-Butyl Hypochlorite". Org. Synth. 49: 9. doi:10.15227/orgsyn.049.0009.
  10. Douglas McGregor (2010). "Tertiary-Butanol: a toxicological review". Critical Reviews in Toxicology . 40 (8): 697–727. doi:10.3109/10408444.2010.494249. PMID   20722584. S2CID   26041562.