preparation of t-butyl chloride archives/1505050/chem234old... · preparation of t-butyl chloride...

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Preparation of t-butyl chloride (2-chloro-2-methylpropane) C CH 3 CH 3 CH 3 OH HCl C CH 3 CH 3 CH 3 Cl + H 2 O t-butyl alcohol t-butyl chloride

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Page 1: Preparation of t-butyl chloride Archives/1505050/Chem234old... · Preparation of t-butyl chloride (2-chloro-2-methylpropane) C CH3 CH3 CH3 OH HCl C CH3 CH3 CH3 Cl + H2O t-butyl alcohol

Preparation of t-butyl chloride(2-chloro-2-methylpropane)

CCH3

CH3CH3

OHHCl

CCH3

CH3CH3

Cl + H2O

t-butyl alcohol t-butyl chloride

Page 2: Preparation of t-butyl chloride Archives/1505050/Chem234old... · Preparation of t-butyl chloride (2-chloro-2-methylpropane) C CH3 CH3 CH3 OH HCl C CH3 CH3 CH3 Cl + H2O t-butyl alcohol

(CH3)3COH + HCl

(CH3)3CCl + H2O

Reaction Mechanism?

Page 3: Preparation of t-butyl chloride Archives/1505050/Chem234old... · Preparation of t-butyl chloride (2-chloro-2-methylpropane) C CH3 CH3 CH3 OH HCl C CH3 CH3 CH3 Cl + H2O t-butyl alcohol

(CH3)3COH + H-Cl

(CH3)3COH2 + Cl + -

Leaving Group

Page 4: Preparation of t-butyl chloride Archives/1505050/Chem234old... · Preparation of t-butyl chloride (2-chloro-2-methylpropane) C CH3 CH3 CH3 OH HCl C CH3 CH3 CH3 Cl + H2O t-butyl alcohol

(CH3)3C-OH2 +

(CH3)3C + H2O

Cation

Page 5: Preparation of t-butyl chloride Archives/1505050/Chem234old... · Preparation of t-butyl chloride (2-chloro-2-methylpropane) C CH3 CH3 CH3 OH HCl C CH3 CH3 CH3 Cl + H2O t-butyl alcohol

(CH3)3C + + Cl-

(CH3)3CCl

Page 6: Preparation of t-butyl chloride Archives/1505050/Chem234old... · Preparation of t-butyl chloride (2-chloro-2-methylpropane) C CH3 CH3 CH3 OH HCl C CH3 CH3 CH3 Cl + H2O t-butyl alcohol

C CH3

CH3

CH3

tert-Butyl Cation

+sp2 flat

p

Page 7: Preparation of t-butyl chloride Archives/1505050/Chem234old... · Preparation of t-butyl chloride (2-chloro-2-methylpropane) C CH3 CH3 CH3 OH HCl C CH3 CH3 CH3 Cl + H2O t-butyl alcohol
Page 8: Preparation of t-butyl chloride Archives/1505050/Chem234old... · Preparation of t-butyl chloride (2-chloro-2-methylpropane) C CH3 CH3 CH3 OH HCl C CH3 CH3 CH3 Cl + H2O t-butyl alcohol

2

Transition State

δ δ

Page 9: Preparation of t-butyl chloride Archives/1505050/Chem234old... · Preparation of t-butyl chloride (2-chloro-2-methylpropane) C CH3 CH3 CH3 OH HCl C CH3 CH3 CH3 Cl + H2O t-butyl alcohol
Page 10: Preparation of t-butyl chloride Archives/1505050/Chem234old... · Preparation of t-butyl chloride (2-chloro-2-methylpropane) C CH3 CH3 CH3 OH HCl C CH3 CH3 CH3 Cl + H2O t-butyl alcohol

Substitution

Nucleophilic

1 bondat a time

Page 11: Preparation of t-butyl chloride Archives/1505050/Chem234old... · Preparation of t-butyl chloride (2-chloro-2-methylpropane) C CH3 CH3 CH3 OH HCl C CH3 CH3 CH3 Cl + H2O t-butyl alcohol

Increasing Stability

Page 12: Preparation of t-butyl chloride Archives/1505050/Chem234old... · Preparation of t-butyl chloride (2-chloro-2-methylpropane) C CH3 CH3 CH3 OH HCl C CH3 CH3 CH3 Cl + H2O t-butyl alcohol

Main Reaction

Side Reaction

CCH3

CH3CH3

OHHCl

CCH3

CH3CH3

Cl + H2O

t-butyl alcohol t-butyl chloride

CCH3

CH3CH3

OHHCl

+ H2O

t-butyl alcohol

CH2CCH3

CH3

isobutylene

Page 13: Preparation of t-butyl chloride Archives/1505050/Chem234old... · Preparation of t-butyl chloride (2-chloro-2-methylpropane) C CH3 CH3 CH3 OH HCl C CH3 CH3 CH3 Cl + H2O t-butyl alcohol

CH2CCH3

CH3

C

CH3

CH3CH3

CCH3

CH3CH3

Cl

E1 N

Page 14: Preparation of t-butyl chloride Archives/1505050/Chem234old... · Preparation of t-butyl chloride (2-chloro-2-methylpropane) C CH3 CH3 CH3 OH HCl C CH3 CH3 CH3 Cl + H2O t-butyl alcohol

ProcedureShake t-BuOH with concentrated HCl

Separate layers

Wash saturated aqueous NaCl

Wash saturated aqueous NaHCO3

Dry

Distill

Page 15: Preparation of t-butyl chloride Archives/1505050/Chem234old... · Preparation of t-butyl chloride (2-chloro-2-methylpropane) C CH3 CH3 CH3 OH HCl C CH3 CH3 CH3 Cl + H2O t-butyl alcohol

t-BuCl

Shake t-BuOH with HCl

Page 16: Preparation of t-butyl chloride Archives/1505050/Chem234old... · Preparation of t-butyl chloride (2-chloro-2-methylpropane) C CH3 CH3 CH3 OH HCl C CH3 CH3 CH3 Cl + H2O t-butyl alcohol

NaHCO3 + HCl

CO2 + H2O + NaCl

Wash to remove excess HCl

Page 17: Preparation of t-butyl chloride Archives/1505050/Chem234old... · Preparation of t-butyl chloride (2-chloro-2-methylpropane) C CH3 CH3 CH3 OH HCl C CH3 CH3 CH3 Cl + H2O t-butyl alcohol

Distill product

Cool receiver

Page 18: Preparation of t-butyl chloride Archives/1505050/Chem234old... · Preparation of t-butyl chloride (2-chloro-2-methylpropane) C CH3 CH3 CH3 OH HCl C CH3 CH3 CH3 Cl + H2O t-butyl alcohol

Clamp joints

Page 19: Preparation of t-butyl chloride Archives/1505050/Chem234old... · Preparation of t-butyl chloride (2-chloro-2-methylpropane) C CH3 CH3 CH3 OH HCl C CH3 CH3 CH3 Cl + H2O t-butyl alcohol

Yield Calculations

A + B CMW 100 100 200

Use: 10 g A 20 g B

Limiting Reagent

Theoretical Yield

Experimental Yield

Page 20: Preparation of t-butyl chloride Archives/1505050/Chem234old... · Preparation of t-butyl chloride (2-chloro-2-methylpropane) C CH3 CH3 CH3 OH HCl C CH3 CH3 CH3 Cl + H2O t-butyl alcohol

A + B CMW 100 100 200

Cpd Mass MW Moles

A 10 g 100 0.10

B 20 g 100 0.20

Theoretical yield:0.10 moles x 200 = 20 g

Experimental yield (%):100 x wt product / 20

LimitingReagent

Page 21: Preparation of t-butyl chloride Archives/1505050/Chem234old... · Preparation of t-butyl chloride (2-chloro-2-methylpropane) C CH3 CH3 CH3 OH HCl C CH3 CH3 CH3 Cl + H2O t-butyl alcohol

CH3CH2CH2CH2OH n-butyl alcohol

HBr

CH3CH2CH2CH2Brn-butyl bromide

Page 22: Preparation of t-butyl chloride Archives/1505050/Chem234old... · Preparation of t-butyl chloride (2-chloro-2-methylpropane) C CH3 CH3 CH3 OH HCl C CH3 CH3 CH3 Cl + H2O t-butyl alcohol

RCH2OH + H+ RCH2OH2+

C

R

HHOH2Br

δ− δ+

transition state

RCH2Br

Page 23: Preparation of t-butyl chloride Archives/1505050/Chem234old... · Preparation of t-butyl chloride (2-chloro-2-methylpropane) C CH3 CH3 CH3 OH HCl C CH3 CH3 CH3 Cl + H2O t-butyl alcohol
Page 24: Preparation of t-butyl chloride Archives/1505050/Chem234old... · Preparation of t-butyl chloride (2-chloro-2-methylpropane) C CH3 CH3 CH3 OH HCl C CH3 CH3 CH3 Cl + H2O t-butyl alcohol

Substitution

Nucleophilic

2 bonds ata time