Tert-Butanol 2006095 216107923 2008-05-31T02:52:41Z Cacycle 83784 + [[Category:Alcohols]] {{lowercase|title=tert-Butanol}} {{Chembox new | Name = ''tert''-Butanol | Reference =<ref>''Merck Index'', 11th Edition, '''1542'''</ref> | ImageFileL1 = Tert-butanol-2D-skeletal.png | ImageSizeL1 = 120px | ImageNameL1 = ''tert''-Butanol | ImageFileR1 = Tert-butanol-3D-balls.png | ImageSizeR1 = 120px | ImageNameR1 = ''t''-BuOH | IUPACName = 2-Methyl-2-propanol | OtherNames = ''t''-Butanol<br />''tert''-Butanol<br />''t''-Butyl alcohol<br />''tert''-Butyl alcohol<br />''tertiary''-Butyl alcohol | Section1 = {{Chembox Identifiers | CASNo = 75-65-0 | SMILES = C(C)(C)(C)O }} | Section2 = {{Chembox Properties | Formula = C<sub>4</sub>H<sub>10</sub>O | MolarMass = 74.1216(42) g/mol | Density = 0.78086 g/cm³ | MeltingPt = 25.69 °C - 298.84 K | BoilingPt = 82.4 °C - 355.55 K }} | Section7 = {{Chembox Hazards | NFPA-H = 1 | NFPA-F = 3 | NFPA-R = }} }} '''''tert''-Butanol''', or 2-methyl-2-propanol, is the simplest [[tertiary alcohol]]. It is one of the four isomers of [[butanol]]. ''tert''-Butanol is a clear liquid with a [[camphor]]-like odor. It is well soluble in water and miscible with [[ethanol]] and [[diethyl ether]]. It is unique among the isomers of butanol because it tends to be a solid at room temperature, with a melting point slightly above 25 degrees Celsius. ==Applications== ''tert''-Butyl alcohol is used as a solvent, as a [[denatured alcohol|denaturant]] for ethanol, as an ingredient in [[paint remover]]s, as an [[octane rating|octane]] booster for [[gasoline]], as an [[oxygenate]] [[gasoline additive]], and as an intermediate in the synthesis of other chemical commodities such as flavors and perfumes. ==Preparation== ''tert''-Butyl alcohol can be manufactured industrially by the catalytic [[hydration reaction|hydration]] of [[isobutylene]]. ==Chemistry== As a tertiary alcohol, ''tert''-butanol is more stable to oxidation and less reactive than the other isomers of butanol. When ''tert''-butanol is deprotonated with a strong [[base (chemistry)|base]], the product is an [[alkoxide]] anion. In this case, it is ''tert''-butoxide. For example, when ''tert''-butanol is deprotonated with [[sodium hydride]], the resultant is sodium ''tert''-butoxide. :NaH + ''t''BuOH → ''t''BuO<sup>−</sup>Na<sup>+</sup> + H<sub>2</sub> The ''tert''-butoxide species is itself useful as a strong, non-nucleophilic base in organic chemistry. It is able to abstract acidic protons from the substrate molecule readily, but its steric bulk inhibits the group from participating in nucleophilic addition, such as in a [[Williamson ether synthesis]] or an [[SN2|S<sub>N</sub>2]] reaction. ==Conversion to alkyl halide== ''tert''-Butanol (also ''tert''-butyl alcohol) reacts with [[hydrogen chloride]] to form ''tert''-butyl chloride and water via an S<sub>N</sub>1 mechanism. {{clear}} {|align="center" class="wikitable" |<center>'''Step 1'''</center>||<center>'''Step 2'''</center>||<center>'''Step 3'''</center> |- |<center>[[Image:1-HCl-protonates-tBuOH-2D-skeletal.png|250px]]</center>||<center>[[Image:2-water-leaves-protonated-tBuOH-2D-skeletal.png|250px]]</center>||<center>[[Image:3-chloride-attacks-tBu-cation-2D-skeletal.png|250px]]</center> |} The overall reaction, therefore, is: [[Image:0-SN1-tBuOH-to-tBuCl-2D-skeletal.png|250px]] Because ''tert''-butanol is a tertiary alcohol, the relative stability of the ''tert''-butyl carbocation in the Step 2 allows the S<sub>N</sub>1 mechanism to be followed. Primary alcohols generally require an S<sub>N</sub>2 mechanism because the energy barrier to produce a primary carbocation is so high that it will not reasonably happen. The S<sub>N</sub>2 mechanism allows the carbocation intermediate to be avoided. ==References== {{reflist}} ==External links== *[http://www.atmos.umd.edu/~russ/MSDS/tertbutanol.html MSDS for tert-butanol] *[http://physchem.ox.ac.uk/msds/BU/tert-butyl_alcohol.html Physchem MSDS for tert-butanol] {{alcohols}} {{DEFAULTSORT:Butanol, tert}} [[Category:Alcohols]] [[Category:Alcohol solvents]] [[Category:Oxygenates]] [[de:Tert-Butylalkohol]] [[es:Terbutanol]] [[fr:Méthylpropan-2-ol]] [[it:2-metil-2-propanolo]] [[ja:tert-ブタノール]] [[nl:2-methyl-2-propanol]] [[fi:Tert-butanoli]] [[zh:叔丁醇]]