|Preferred IUPAC name
3D model (Jmol)
|Molar mass||74.12 g·mol−1|
|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|
|Vapor pressure||4.1 kPa (at 20 °C)|
|Acidity (pKa)||16.54 |
Refractive index (nD)
|215.37 J K−1 mol−1|
|189.5 J K−1 mol−1|
Std enthalpy of
|−360.04–−358.36 kJ mol−1|
Std enthalpy of
|−2.64479–−2.64321 MJ mol−1|
|Safety data sheet||inchem.org|
|GHS signal word||DANGER|
|H225, H319, H332, H335|
|P210, P261, P305+351+338|
EU classification (DSD)
|R-phrases||R11, R20, R36/37|
|S-phrases||(S2), S9, S16, S46|
|Flash point||11 °C (52 °F; 284 K)|
|480 °C (896 °F; 753 K)|
|Lethal dose or concentration (LD, LC):|
LD50 (median dose)
|3559 mg/kg (rabbit, oral)
3500 mg/kg (rat, oral)
|US health exposure limits (NIOSH):|
|TWA 100 ppm (300 mg/m3)|
|TWA 100 ppm (300 mg/m3) ST 150 ppm (450 mg/m3)|
IDLH (Immediate danger)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
|what is ?)(|
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 miscible with water, ethanol and diethyl ether.
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.
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.
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.
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.
- K + tBuOH → tBuO−K+ + 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.
It also reacts with sodium in liquid ammonia.
- "NIOSH Pocket Guide to Chemical Hazards #0078". National Institute for Occupational Safety and Health (NIOSH).
- Reeve, W.; Erikson, C.M.; Aluotto, P.F. Can. J. Chem, 1979, 57, 2747.
- "Tert-Butyl alcohol". Immediately Dangerous to Life and Health. National Institute for Occupational Safety and Health (NIOSH).
- In tert-butyl alcohol, three methyl groups substitute for three hydrogen atoms in methanol, just as two methyl groups substitute for two hydrogen atoms in isopropyl alcohol, and one methyl group substitutes for one hydrogen atom in ethanol.
- D.D. Perrin, W.L.F. Armarego (1988). Purification of Laboratory Chemicals (3rd ed.). Pergamon Press Ltd.
- Johnson, W. S.; Schneider, W. P. (1950). "β-Carbethoxy-γ,γ-diphenylvinylacetic acid". Org. Synth. 30: 18.; Coll. Vol., 4, p. 132