4. Halogenation and Friedel-crafts

Question 1

what is a friedel-crafts reaction

Answer 1

electrophilic substitution reaction where H is substituted for an alkyl or alkyl chain

Question 2

what is the reagent used (friedel-crafts)

Answer 2

haloalkane e.g. CH3Cl

Question 3

what is the catalyst used (friedel-crafts)

Answer 3

halogencarrier e.g. FeCl3

Question 4

how the catalyst generates electrophile (friedel-crafts)

Answer 4

R-Cl + FeCl3 -> R+ + FeCl4-

Question 5

how the catalyst is regenerated (friedel-crafts)

Answer 5

FeCl4- + H+ -> HCl + FeCl3

Question 6

why are multiple substitutions likely (friedel-crafts)

Answer 6

alkyl chain donates electrons to ring. more electron dense/ susceptible to electrophillic attack

Question 7

structural formula of acyl chloride

Answer 7

……O
……||
R- C -Cl

RCOCl

Question 8

reagent (Acylation of benzene)

Answer 8

acyl chloride RCOCL

Question 9

catalyst (Acylation of benzene)

Answer 9

halogen carrier AlCl3

Question 10

why can only one substitution occur (Acylation of benzene)

Answer 10

carbonyl withdraws electrons from aromatic ring. less reactive

Question 11

e.g. Equation (Acylation of benzene)

Answer 11

C6H6 + CH3COCl -> C6H5COCH3 + HCl