''tert''-Butyl alcohol is the simplest

tertiary alcohol In chemistry, an alcohol (), is a type of organic compound that carries at least one hydroxyl () functional group bound to a Saturated and unsaturated compounds, saturated carbon atom. Alcohols range from the simple, like methanol and ethanol ...

, with a

formula In science, a formula is a concise way of expressing information symbolically, as in a mathematical formula or a ''chemical formula''. The informal use of the term ''formula'' in science refers to the general construct of a relationship betwe ...

of (CH₃)₃COH (sometimes represented as ''t''-BuOH). Its

isomer In chemistry, isomers are molecules or polyatomic ions with identical molecular formula – that is, the same number of atoms of each element (chemistry), element – but distinct arrangements of atoms in space. ''Isomerism'' refers to the exi ...

s are

1-butanol 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 ...

isobutanol 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 dir ...

, and butan-2-ol. ''tert''-Butyl alcohol is a colorless solid, which melts near room temperature and has a

camphor Camphor () is a waxy, colorless solid with a strong aroma. It is classified as a terpenoid and a cyclic ketone. It is found in the wood of the camphor laurel (''Cinnamomum camphora''), a large evergreen tree found in East Asia; and in the kapu ...

-like odor. It is miscible with

water Water is an inorganic compound with the chemical formula . It is a transparent, tasteless, odorless, and Color of water, nearly colorless chemical substance. It is the main constituent of Earth's hydrosphere and the fluids of all known liv ...

ethanol Ethanol (also called ethyl alcohol, grain alcohol, drinking alcohol, or simply alcohol) is an organic compound with the chemical formula . It is an Alcohol (chemistry), alcohol, with its formula also written as , or EtOH, where Et is the ps ...

and

diethyl ether Diethyl ether, or simply ether, is an organic compound with the chemical formula , sometimes abbreviated as . It is a colourless, highly Volatility (chemistry), volatile, sweet-smelling ("ethereal odour"), extremely flammable liquid. It belongs ...

Natural occurrence

''tert''-Butyl alcohol has been identified in

beer Beer is an alcoholic beverage produced by the brewing and fermentation of starches from cereal grain—most commonly malted barley, although wheat, maize (corn), rice, and oats are also used. The grain is mashed to convert starch in the ...

and

chickpea The chickpea or chick pea (''Cicer arietinum'') is an annual plant, annual legume of the family (biology), family Fabaceae, subfamily Faboideae, cultivated for its edible seeds. Its different types are variously known as gram," Bengal gram, ga ...

s. It is also found in

cassava ''Manihot esculenta'', common name, commonly called cassava, manioc, or yuca (among numerous regional names), is a woody shrub of the spurge family, Euphorbiaceae, native to South America, from Brazil, Paraguay and parts of the Andes. Although ...

, which is used as a fermentation ingredient in certain

alcoholic beverages Drinks containing alcohol are typically divided into three classes—beers, wines, and spirits—with alcohol content typically between 3% and 50%. Drinks with less than 0.5% are sometimes considered non-alcoholic. Many societies have a di ...

Preparation

''tert''-Butyl alcohol is derived commercially from

isobutane 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 a ...

as a coproduct of

propylene oxide Propylene oxide is an epoxide with the molecular formula C3H6O. This colourless volatile liquid with an odour similar to ether, is produced on a large scale industrially. Its major application is its use for the production of polyether polyols f ...

production. It can also be produced by the catalytic hydration of

isobutylene Isobutylene (or 2-methylpropene) is a hydrocarbon with the chemical formula . 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. Product ...

, or by a

Grignard reaction The Grignard reaction () is an organometallic chemical reaction in which, according to the classical definition, carbon alkyl, allyl, vinyl, or aryl magnesium halides (Grignard reagent) are added to the carbonyl groups of either an aldehyde or ...

between

acetone Acetone (2-propanone or dimethyl ketone) is an organic compound with the chemical formula, formula . It is the simplest and smallest ketone (). It is a colorless, highly Volatile organic compound, volatile, and flammable liquid with a charact ...

and

methylmagnesium chloride Methylmagnesium chloride is an organometallic compound with the general formula . This highly flammable, colorless, and moisture sensitive compound is the simplest Grignard reagent and is commercially available, usually as a solution in tetrahydro ...

. Purification cannot be performed by simple distillation due to formation of an

azeotrope An azeotrope () or a constant heating point mixture is a mixture of two or more liquids whose proportions cannot be changed by simple distillation.Moore, Walter J. ''Physical Chemistry'', 3rd e Prentice-Hall 1962, pp. 140–142 This happens beca ...

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 Calcium oxide (formula: Ca O), commonly known as quicklime or burnt lime, is a widely used chemical compound. It is a white, caustic, alkaline, crystalline solid at room temperature. The broadly used term '' lime'' connotes calcium-containing ...

(CaO),

potassium carbonate Potassium carbonate is the inorganic compound with the formula . It is a white salt, which is soluble in water and forms a strongly alkaline solution. It is deliquescent, often appearing as a damp or wet solid. Potassium carbonate is mainly used ...

(K₂CO₃),

calcium sulfate Calcium sulfate (or calcium sulphate) is an inorganic salt with the chemical formula . It occurs in several hydrated forms; the anhydrous state (known as anhydrite) is a white crystalline solid often found in evaporite deposits. Its dihydrate ...

(CaSO₄), or

magnesium sulfate Magnesium sulfate or magnesium sulphate is a chemical compound, a salt with the formula , consisting of magnesium cations (20.19% by mass) and sulfate anions . It is a white crystalline solid, soluble in water but not in ethanol. Magnesi ...

(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 sieve A molecular sieve is a material with pores of uniform size comparable to that of individual molecules, linking the interior of the solid to its exterior. These materials embody the molecular sieve effect, in which molecules larger than the pore ...

s, aluminium ''tert''-butylate,

calcium hydride Calcium hydride is the chemical compound with the formula , an alkaline earth hydride. This grey powder (white if pure, which is rare) reacts vigorously with water, liberating hydrogen gas. is thus used as a drying agent, i.e. a desiccant. is ...

(CaH₂), or fractional crystallization under inert atmosphere.

Applications

''tert''-Butyl alcohol is used as a solvent, ethanol denaturant, paint remover ingredient, and

gasoline Gasoline ( North American English) or petrol ( Commonwealth English) is a petrochemical product characterized as a transparent, yellowish, and flammable liquid normally used as a fuel for spark-ignited internal combustion engines. When for ...

octane Octane is a hydrocarbon and also an alkane with the chemical formula C8H18, and the condensed structural formula CH3(CH2)6CH3. Octane has many structural isomers that differ by the location of branching in the carbon chain. One of these isomers ...

booster and

oxygenate In the liquid fuel industry, oxygenates are hydrocarbon-derived fuel additives containing at least one oxygen atom to promote complete combustion. Absent oxygenates, fuel combustion is usually incomplete, and the exhaust stream pollutes the air ...

. It is a chemical intermediate used to produce methyl ''tert''-butyl ether (MTBE) and ethyl ''tert''-butyl ether (ETBE) by reaction with

methanol Methanol (also called methyl alcohol and wood spirit, amongst other names) is an organic chemical compound and the simplest aliphatic Alcohol (chemistry), alcohol, with the chemical formula (a methyl group linked to a hydroxyl group, often ab ...

and

, respectively, and ''tert''-butyl hydroperoxide (TBHP) by reaction with

hydrogen peroxide Hydrogen peroxide is a chemical compound with the formula . In its pure form, it is a very pale blue liquid that is slightly more viscosity, viscous than Properties of water, water. It is used as an oxidizer, bleaching agent, and antiseptic, usua ...

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 In chemistry, an alkoxide is the conjugate base of an alcohol and therefore consists of an organic group bonded to a negatively charged oxygen atom. They are written as , where R is the organyl substituent. Alkoxides are strong bases and, whe ...

. Particularly common is potassium ''tert''-butoxide, which is prepared by treating ''tert''-butanol with

potassium Potassium is a chemical element; it has Symbol (chemistry), symbol K (from Neo-Latin ) and atomic number19. It is a silvery white metal that is soft enough to easily cut with a knife. Potassium metal reacts rapidly with atmospheric oxygen to ...

metal. :K + ''t''-BuOH → ''t''-BuO⁻K⁺ + H₂ The ''tert''-butoxide is a strong, non-

nucleophilic In chemistry, a nucleophile is a chemical species that forms bonds by donating an electron pair. All molecules and ions with a free pair of electrons or at least one pi bond can act as nucleophiles. Because nucleophiles donate electrons, they a ...

base in organic chemistry. It readily abstracts acidic protons from substrates, but its steric bulk inhibits the group from participating in

nucleophilic substitution In chemistry, a nucleophilic substitution (SN) is a class of chemical reactions in which an electron-rich chemical species (known as a nucleophile) replaces a functional group within another electron-deficient molecule (known as the electrophile) ...

, such as in a

Williamson ether synthesis The Williamson ether synthesis is an organic reaction, forming an ether from an organohalide and a deprotonated alcohol (alkoxide). This reaction was developed by Alexander Williamson in 1850. Typically it involves the reaction of an alkoxide ...

or an S_N2 reaction. ''tert''-Butyl alcohol reacts with

hydrogen chloride The Chemical compound, compound hydrogen chloride has the chemical formula and as such is a hydrogen halide. At room temperature, it is a colorless gas, which forms white fumes of hydrochloric acid upon contact with atmospheric water vapor. Hyd ...

to form ''tert''-butyl chloride. O-Chlorination of tert-butyl alcohol with hypochlorous acid to give

tert-butyl hypochlorite ''tert''-Butyl hypochlorite is the organic compound with the formula (CH3)3COCl. A yellow liquid, it is a rare example of an organic hypochlorite, i.e. a compound with an O-Cl bond. It is a reactive material that is useful for chlorinations. It ...

: :(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. 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 of tert-Butyl alcohol can produce a sedative or anesthetic effect.

References

External links

* * * * {{DEFAULTSORT:Butyl alcohol, tert Alcohol solvents Tertiary alcohols Oxygenates GABAA receptor positive allosteric modulators Glycine receptor agonists Sedatives Hypnotics Alkanols Tert-butyl compounds