Preparation of t-butyl chloride
description
Transcript of Preparation of t-butyl chloride
(2-chloro-2-methylpropane)
C
CH3
CH3
CH3
OHHCl
C
CH3
CH3
CH3
Cl + H2O
t-butyl alcohol t-butyl chloride
Preparation of t-butyl chloride
(CH3)3COH + HCl
(CH3)3CCl + H2O
Reaction Mechanism?
(CH3)3COH + H-Cl
(CH3)3COH2 + Cl + -
Leaving Group
(CH3)3C-OH2 +
(CH3)3C + H2O
Cation
(CH3)3C +
+ Cl-
(CH3)3CCl
Cation Adds Chloride
+sp2 flat
p
tert-Butyl Cation
Reaction Coordinate
R .... OH2
+ +
Transition State
Animation
Substitution
Nucleophilic
1 bond at a time
SN1
Increasing Stability
Side Reaction
C
CH3
CH3
CH3
OHHCl
C
CH3
CH3
CH3
Cl + H2O
t-butyl alcohol t-butyl chloride
C
CH3
CH3
CH3
OHHCl
+ H2O
t-butyl alcohol
CH2C
CH3
CH3
isobutylene
Main Reaction
CH2C
CH3
CH3
C
CH3
CH3CH3
C
CH3
CH3
CH3
Cl
SN1E1
Shake t-BuOH with concentrated HCl
Separate layers
Wash saturated aqueous NaCl
Wash saturated aqueous NaHCO3
Dry
Distill
Procedure
t-BuCl
Shake t-BuOH with HCl
NaHCO3 + HCl
CO2 + H2O + NaCl
Wash to remove excess HCl
Cool receiver
Distill product
Clamp joints
A + B CMW 100 100 200
Use: 10 g A 20 g B
Limiting Reagent
Theoretical Yield
Experimental Yield
Yield Calculations
A + B CMW 100 100 200
Cpd Mass MW Moles
A 10 g 100 0.10
B 20 g 100 0.20
0.10 moles x 200 = 20 g
Experimental yield (%):100 x wt product / 20
LimitingReagent
Theoretical yield:
CH3CH2CH2CH2OH
n-butyl alcohol
HBr
CH3CH2CH2CH2Br
n-butyl bromide
n-Butyl Alcohol + HBr
RCH2OH + H+ RCH2OH2
+
C
R
HH
OH2Br
transition state
RCH2Br
Transition State
Mechanism
XCY
- -
CY X-XCY
-
Reaction Coordinate
Energy
TransitionState
Substitution
Nucleophilic
2 bonds at a time
SN2