tert-Butyl chloride

From WikiChem
Jump to: navigation, search

tert-Butyl chloride
Tert-butyl-chloride-2D-skeletal.png
Tert-butyl-chloride-3D-balls.png
IUPAC name 2-chloro-2-methylpropane
Other names 1,1-dimethylethyl chloride
1-chloro-1,1-dimethylethane
chlorotrimethylmethane
trimethylchloromethane
t-butyl chloride
Identifiers
InChI InChI=1/C4H9Cl/c1-4(2,3)5/h1-3H3
InChIKey NBRKLOOSMBRFMH-UHFFFAOYAL
Standard InChI InChI=1S/C4H9Cl/c1-4(2,3)5/h1-3H3
Standard InChIKey NBRKLOOSMBRFMH-UHFFFAOYSA-N
CAS number [507-20-0]
EC number 208-066-4
UN number 1127
RTECS TX5040000
ChemSpider 10054
PubChem 10486
SMILES
Properties[1]
Chemical formula C4H9Cl
Molar mass 92.567 g/mol
Appearance Colorless liquid
Density 0.847 g/cm3 (15 ºC)
Melting point

−26.5 °C

Boiling point

51 °C

Solubility in water 0.29 g/100 ml (15 ºC)
Solubility in ethanol miscible
Solubility in diethyl ether miscible
log P 2.45 (est.)
Vapor pressure 34.9 kPa (20 °C)
kH 0.0128 atm m3/mol (est.)
Hazards[1][2]
Material safety data sheet (MSDS) External MSDS
EU index number not listed
GHS pictograms Flam. Liq. 2
GHS signal word DANGER
GHS hazard statements H225
GHS precautionary statements P210, P233, P240, P241, P242, P243, P280, P303+361+353, P370+378, P403+235, P501
Flash point 0 °C (32 ºF)
Autoignition temp. 540 °C (1004 ºF)
Explosive limits 1.8–10.1%
Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)

tert-Butyl chloride is a colorless, liquid organic compound at room temperature. It is sparingly soluble in water, with a tendency to undergo spontaneous solvolysis when dissolved into it. The compound is flammable and volatile, and its main use is as a starting molecule to carry out nucleophilic substitution reactions, to produce different substances, ranging from alcohols to alkoxide salts.

When tert-butyl chloride is dissolved in water, a polar and protic solvent, the bulky chloride substituent is carried away by it, and isolated from the aliphatic chain, causing an heterolytic rupture of the compound, giving rise to a carbocation which eventually becomes a tertiary alcohol after a water molecule reacts with it, releasing hydrochloric acid as the final product. If a different, stronger nucleophilic agent is present at the moment of reaction, reaction product may not be an alcohol, but a tertiary carbon with the nucleophile as a substituent.

Synthesis

tert-Butyl chloride can be synthesized in the laboratory by the SN1 reaction of tert-Butanol with concentrated hydrochloric acid, as shown below.

Step 1
Step 2
Step 3
1-HCl-protonates-tBuOH-2D-skeletal.png
2-water-leaves-protonated-tBuOH-2D-skeletal.png
3-chloride-attacks-tBu-cation-2D-skeletal.png
The acid protonates the alcohol, forming a good leaving group (water).
Water leaves the protonated t-BuOH, forming a relatively stable tertiary carbocation.
The chloride ion attacks the carbocation, forming t-BuCl.

The overall reaction, therefore, is:

0-SN1-tBuOH-to-tBuCl-2D-skeletal.png

Because tert-butanol is a tertiary alcohol, the relative stability of the tert-butyl carbocation in the step 2 allows the SN1 mechanism to be followed, whereas a primary alcohol would follow an SN2 mechanism.

See also

References

  1. 1.0 1.1 Chemical Risk Information Platform (CHRIP), <http://www.safe.nite.go.jp/english/db.html> (accessed 22 August 2009), National Institute of Technology and Evaluation (Japan).
  2. HSNO Chemical Classification Information Database, <http://www.ermanz.govt.nz/Chemicals/ChemicalDisplay.aspx?SubstanceID=15657> (accessed 22 August 2009), New Zealand Environmental Risk Management Authority.

External links

Error creating thumbnail: Unable to save thumbnail to destination
Wikipedia-logo.png This page was originally imported from Wikipedia, specifically this version of the article "Tert-Butyl chloride". Please see the history page on Wikipedia for the original authors. This WikiChem article may have been modified since it was imported. It is licensed under the Creative Commons Attribution–Share Alike 3.0 Unported license.