12. Aromatic Substitution Reactions Flashcards
will benzene undergo addition reactions with bromine
no its inert
what is required for an electrophilic aromatic substitution reaction to take place
iron
what happens in an electrophilic aromatic substitution reaction
one proton from benzene ring is replaced by an electrophile
what is a sulfonation reaction
benzene is treated with fuming sulfuric acid (H2SO4 & SO3 gas)
what is a nitration reaction
benzene treated with mix of sulfuric acid and nitric acid
how does nitration reactions occur
via electrophilic aromatic substitution reaction
NO2+ nitronium ion is electrophile
what is formed from nitration reaction
nitrobenzene
what will a methyl group connected to benzene ring do to an aromatic ring
activates it
why does the methyl group connected to a benzene ring activate the aromatic ring
methyl group donates e- density to the ring which lowers the energy of activation for its formation
which of the following predominates in a nitration reaction of toluene
ortho
meta
para
ortho and para
very small amounts of meta are produced
why is a nitro group e- withdrawing
positively charged nitrogen atom is highly electronegative
when an activating group is present which ortho/meta/para-regiochemical outcome predominates
ortho and para
when a deactivating group is present which ortho/meta/para-regiochemical outcome predominates
meta
what is the exception to the rule that activating groups are ortho-para directors and deactivating groups are meta directors.
There is one exception to this rule. Halogens (Cl, I, and Br) are ortho-para directors and deactivators.
