friedel crafts of benzene Flashcards
define friedel crafts
a substitution reaction where an acyl or alkyl chain replaces a hydrogen on an aromatic compound
e.g: benzene
what is an alkylation reaction
a hydrogen is replaced with a hydrocarbon group (e.g: methyl, ethyl)
what reaction conditions are needed for alkylation
- room temperature
- presence of a chloroalkane
(aluminium chloride AlCl3)
when you substitute a methyl group onto a benzene ring what is the name of the compound formed
methyl benzene
how do you separate the products of multiple substitutions of benzene at once
fractional distillation
if you have an excess of benzene what does this mean in terms of products formed
increase yield of single subsitituiton
define acylation
hydrogen is replaced with a carbonyl from an acyl chloride
what reaction conditions are needed for acylation
anhydrous conditions
reflux at 60 degrees for 3o mins
with AlCl3 catalyst
why can RCOCl be used along with a halogen carrier to react with benzene
substitute one hydrogen atom as the carbonyl group ( C = O) withdraws electrons so a less reactive ketone is formed
the reaction occurs under anhydrous conditions (no water) and reflux at 60 degrees for 3o minutes
write the equation for the preparation of the electrophile for acylation of benzene
AlCl3 + CH3COCl → AlCl4- + CH3CO+
write the equation for the regeneration of AlCl3 and what is the role of AlCl3 in this reaction
H+ + AlCl4 - → AlCl3 + HCl
