Tert-Butyl chloride

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tert-Butyl chloride
IUPAC name

2-chloro-2-methylpropane

Other names

1,1-dimethylethyl chloride
1-chloro-1,1-dimethylethane
chlorotrimethylmethane
trimethylchloromethane
t-butyl chloride

Identifiers
CAS number 507-20-0 YesY
PubChem 10486
ChemSpider 10054 YesY
EC-number 208-066-4
UN number 1127
ChEMBL CHEMBL346997 YesY
RTECS number TX5040000
Jmol-3D images Image 1
Properties
Molecular formula C4H9Cl
Molar mass 92.57 g/mol
Appearance Colorless liquid
Density 0.84 g cm−3
Melting point −26 °C; −15 °F; 247 K
Boiling point 51 °C; 124 °F; 324 K
Solubility in water Sparingly sol in water, miscible with alcohol and ether
Vapor pressure 34.9 kPa (20 °C)
Hazards
EU classification Flammable (F)
R-phrases R12, R36/37/38
S-phrases S7, S9, S16, S29, S33
NFPA 704
3
2
0
Flash point −9 °C (open cup)
−23 °C (closed cup)
Autoignition temperature 540 °C; 1,004 °F; 813 K
Related compounds
Related alkyl halides tert-Butyl bromide
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Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
Infobox references

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
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:

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

External links

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