Friedel–Crafts reaction
What is the reaction?
Formation of C–C bond to aromatic ring
C
C
Two types
•
C–C bond forms
Alkylation
substitution with R
e.g. CH3Cl
R
•
Acylation
substitution with R–CO
e.g. CH3COCl
O
C
R
Alkylation
Reagents and conditions
•
Alkyl chloride, RCl
•
Halogen carrier catalyst, e.g. AlCl3
•
Anhydrous conditions
+ RCl
R
AlCl3 catalyst
+ HCl
Examples of alkylation
CH3
Substitution with CH3Cl
+ CH3Cl
C–C bond forms
AlCl3 catalyst
+ HCl
C2H5
Substitution with C2H5Cl
+ C2H5Cl
AlCl3 catalyst
+ HCl
Acylation
Reagents and conditions
•
Alkyl chloride, RCOCl
•
Halogen carrier catalyst, e.g. AlCl3
•
Anhydrous conditions
O
C
+ RCOCl
AlCl3 catalyst
R
+ HCl
Examples of acylation
Substitution with CH3COCl
O
C
+ CH3COCl
CH3
AlCl3 catalyst
+ HCl
C–C bond forms
Substitution with C2H5COCI
O
C
+ C2H5COCl
AlCl3 catalyst
C2H5
+ HCl