tert-Butyl alcohol

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tert-Butyl alcohol
Skeletal formula of tert-butanol
Ball and stick model of tert-butanol
Sample of partially crystalised tert-butanol
Names
IUPAC name
2-Methylpropan-2-ol[1]
Other names
tert-Butanol,[1]
Trimethyl carbinol,[2]
2-Methyl-2-propanol,[1] 2-methylpropan-2-ol, 2M2P
Identifiers
75-65-0 YesY
906698
ChEBI CHEBI:45895 YesY
ChEMBL ChEMBL16502 YesY
ChemSpider 6146 YesY
DrugBank DB03900 YesY
EC Number 200-889-7
1833
Jmol 3D model Interactive image
MeSH tert-Butyl+Alcohol
PubChem 6386
RTECS number EO1925000
UNII MD83SFE959 YesY
UN number 1120
Properties
C4H10O
Molar mass 74.12 g·mol−1
Appearance Colorless liquid
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[3]
log P 0.584
Vapor pressure 4.1 kPa (at 20 °C)
Acidity (pKa) 16.54 [4]
1.387
Thermochemistry
215.37 J K−1 mol−1
189.5 J K−1 mol−1
−360.04–−358.36 kJ mol−1
−2.64479–−2.64321 MJ mol−1
Hazards
Safety data sheet inchem.org
GHS pictograms The flame pictogram in the Globally Harmonized System of Classification and Labelling of Chemicals (GHS) The exclamation-mark pictogram in the Globally Harmonized System of Classification and Labelling of Chemicals (GHS)
GHS signal word DANGER
H225, H319, H332, H335
P210, P261, P305+351+338
Highly Flammable F Harmful Xn
R-phrases R11, R20, R36/37
S-phrases (S2), S9, S16, S46
NFPA 704
Flammability code 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., gasoline) Health code 1: Exposure would cause irritation but only minor residual injury. E.g., turpentine Reactivity code 0: Normally stable, even under fire exposure conditions, and is not reactive with water. E.g., liquid nitrogen Special hazards (white): no codeNFPA 704 four-colored diamond
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)[5]
US health exposure limits (NIOSH):
PEL (Permissible)
TWA 100 ppm (300 mg/m3)[2]
REL (Recommended)
TWA 100 ppm (300 mg/m3) ST 150 ppm (450 mg/m3)[2]
IDLH (Immediate danger)
1600 ppm[2]
Related compounds
Related butanols
2-Butanol

n-Butanol
Isobutanol

Related compounds
2-Methyl-2-butanol
Trimethylsilanol
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Infobox references

tert-Butyl alcohol (TBA), also called tert-butanol, is the simplest tertiary alcohol, with a formula of (CH3)3COH (sometimes represented as t-BuOH). It is one of the four isomers of butanol. tert-Butyl alcohol is a colorless solid, which melts near room temperature and has a camphor-like odor. It is very soluble in water and miscible with ethanol and diethyl ether.

Natural occurrence[edit]

t-Butyl alcohol has been identified in beer and chickpeas.[6] It is also found in cassava[7] which is used as fermentation ingredient in certain alcoholic beverages.

Preparation[edit]

tert-Butyl alcohol is derived commercially from isobutane as a co-product 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.

When produced from aqueous media, samples consist of 88.24 per cent alcohol, with the remainder as water that cannot be removed by distillation.[8] Instead, the anhydrous alcohol requires drying agent such as calcium oxide.

Applications[edit]

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 MTBE and ETBE by reaction with methanol and ethanol, and TBHP by reaction with hydrogen peroxide.

Reactions[edit]

As a tertiary alcohol, tert-butyl alcohol is more resistant to oxidation and less reactive than the other isomers of butanol.

When tert-butyl alcohol is deprotonated with a strong base, the product is an alkoxide anion. In this case, it is tert-butoxide. For example, the commonly used organic reagent potassium tert-butoxide is prepared by refluxing dry tert-butanol with potassium metal.[9]

K + tBuOH → tBuOK+ + 0.5 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.

References[edit]

  1. ^ a b c "tert-Butyl Alcohol - Compound Summary". PubChem Compound. National Center for Biotechnology Information. 2005-03-26. Retrieved 2012-05-19. 
  2. ^ a b c d "NIOSH Pocket Guide to Chemical Hazards #0078". National Institute for Occupational Safety and Health (NIOSH). 
  3. ^ http://www.inchem.org/documents/icsc/icsc/eics0114.htm
  4. ^ Reeve, W.; Erikson, C.M.; Aluotto, P.F. Can. J. Chem, 1979, 57, 2747.
  5. ^ "Tert-Butyl alcohol". Immediately Dangerous to Life and Health. National Institute for Occupational Safety and Health (NIOSH). 
  6. ^ http://toxnet.nlm.nih.gov/cgi-bin/sis/search/a?dbs+hsdb:@term+@DOCNO+50
  7. ^ http://www.sc.mahidol.ac.th/scbc/bc_internet/publication/696.pdf
  8. ^ James F. Norris and Alanson W. Olmsted "tert-Butyl Chloride" Org. Synth. 1928, volume 8, pp. 50. doi:10.15227/orgsyn.008.0050
  9. ^ Johnson, W. S.; Schneider, W. P. (1950). "β-Carbethoxy-γ,γ-diphenylvinylacetic acid". Org. Synth. 30: 18. ; Coll. Vol. 4, p. 132 

External links[edit]