2-Butanol, or ''sec''-butanol, is an

organic compound In chemistry, organic compounds are generally any chemical compounds that contain carbon-hydrogen or carbon-carbon bonds. Due to carbon's ability to catenate (form chains with other carbon atoms), millions of organic compounds are known. T ...

with formula C H₃CH( OH)CH₂CH₃. Its structural isomers 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 dire ...

, and ''tert''-butanol. 2-Butanol is

chiral Chirality is a property of asymmetry important in several branches of science. The word ''chirality'' is derived from the Greek (''kheir''), "hand", a familiar chiral object. An object or a system is ''chiral'' if it is distinguishable from i ...

and thus can be obtained as either of two

stereoisomers In stereochemistry, stereoisomerism, or spatial isomerism, is a form of isomerism in which molecules have the same molecular formula and sequence of bonded atoms (constitution), but differ in the three-dimensional orientations of their atoms ...

designated as (''R'')-(−)-2-butanol and (''S'')-(+)-2-butanol. It is normally encountered as a 1:1 mixture of the two stereoisomers — a

racemic In chemistry, a racemic mixture, or racemate (), is one that has equal amounts of left- and right-handed enantiomers of a chiral molecule or salt. Racemic mixtures are rare in nature, but many compounds are produced industrially as racemates. ...

mixture. This

secondary alcohol In chemistry, an alcohol is a type of organic compound that carries at least one hydroxyl () functional group bound to a saturated carbon atom. The term ''alcohol'' originally referred to the primary alcohol ethanol (ethyl alcohol), which is ...

is a flammable, colorless liquid that is soluble in three parts water and completely miscible with organic solvents. It is produced on a large scale, primarily as a precursor to the industrial solvent methyl ethyl ketone.

Manufacture and applications

2-Butanol is manufactured industrially by the hydration of 1-butene or

2-butene But-2-ene is an acyclic alkene with four carbon atoms. It is the simplest alkene exhibiting ''cis''/''trans''-isomerism (also known as (''E''/''Z'')-isomerism); that is, it exists as two geometric isomers ''cis''-but-2-ene ((''Z'')-but-2-ene) and ...

: : Sulfuric acid is used as a

catalyst Catalysis () is the process of increasing the rate of a chemical reaction by adding a substance known as a catalyst (). Catalysts are not consumed in the reaction and remain unchanged after it. If the reaction is rapid and the catalyst recyc ...

for this conversion.. In the laboratory it can be prepared via

Grignard reaction The Grignard reaction () is an organometallic chemical reaction in which alkyl, allyl, vinyl, or aryl-magnesium halides (Grignard reagent) is added to a carbonyl group in an aldehyde or ketone. This reaction is important for the formation of ...

by reacting

ethylmagnesium bromide Ethylmagnesium bromide is a Grignard reagent with formula C2H5MgBr. It is widely used in the laboratory synthesis of organic compounds. Reactions Apart from acting as the synthetic equivalent of an ethyl anion synthon for nucleophilic addition, ...

with acetaldehyde in dried

diethyl ether Diethyl ether, or simply ether, is an organic compound in the ether class with the formula , sometimes abbreviated as (see Pseudoelement symbols). It is a colourless, highly volatile, sweet-smelling ("ethereal odour"), extremely flammable li ...

tetrahydrofuran Tetrahydrofuran (THF), or oxolane, is an organic compound with the formula (CH2)4O. The compound is classified as heterocyclic compound, specifically a cyclic ether. It is a colorless, water- miscible organic liquid with low viscosity. It is ...

. Although some 2-butanol is used as a solvent, it is mainly converted to

butanone Butanone, also known as methyl ethyl ketone (MEK), is an organic compound with the formula CH3C(O)CH2CH3. This colourless liquid ketone has a sharp, sweet odor reminiscent of acetone. It is produced industrially on a large scale, but occurs in ...

(methyl ethyl ketone, MEK), an important industrial solvent and found in many domestic cleaning agents and paint removers. Though most paint removers have ceased using MEK in their products due to health concerns and new laws. Volatile

ester In chemistry, an ester is a compound derived from an oxoacid (organic or inorganic) in which at least one hydroxyl group () is replaced by an alkoxy group (), as in the substitution reaction of a carboxylic acid and an alcohol. Glycerides a ...

s of 2-butanol have pleasant aromas and are used in small amounts as perfumes or in artificial flavors.

Solubility

The listed solubility of 2-butanol is often incorrect, including some of the most well-known references such as the ''

Merck Index ''The Merck Index'' is an encyclopedia of chemicals, drugs and biologicals with over 10,000 monograph on single substances or groups of related compounds published online by the Royal Society of Chemistry. History The first edition of the Mer ...

'', the '' CRC Handbook of Chemistry and Physics'', and ''Lange's Handbook of Chemistry''. Even the

International Programme on Chemical Safety The International Programme on Chemical Safety (IPCS) was formed in 1980 and is a collaboration between three United Nations bodies, the World Health Organization, the International Labour Organization and the United Nations Environment Programme, t ...

lists the wrong solubility. This widespread error originated because of Beilstein's ''Handbuch der Organischen Chemie'' (''Handbook of Organic Chemistry''). This work cites a false solubility of 12.5 g/100 g water. Many other sources used this solubility, which has snowballed into a widespread error in the industrial world. The correct data (35.0 g/100 g at 20 °C, 29 g/100 g at 25 °C, and 22 g/100 g at 30 °C) were first published in 1886 by Alexejew and then similar data was reported by other scientists including Dolgolenko and Dryer in 1907 and 1913, respectively.

Precautions

Like other butanols, 2-butanol has low acute toxicity. The is 4400 mg/kg (rat, oral). Several explosions have been reported during the conventional

distillation Distillation, or classical distillation, is the process of separating the components or substances from a liquid mixture by using selective boiling and condensation, usually inside an apparatus known as a still. Dry distillation is the heat ...

of 2-butanol, apparently due to the buildup of peroxides with the boiling point higher than that of pure alcohol (and therefore concentrating in the still pot during distillation). As alcohols, unlike ethers, are not widely known to be capable of forming peroxide impurities, the danger is likely to be overlooked. 2-Butanol is in Class B Peroxide Forming Chemicals

References

External links

* * * * {{DEFAULTSORT:Butanol, 2- Alkanols Alcohol solvents Secondary alcohols