aromatic compounds Flashcards
main type of reaction benzene undergoes
electrophilic substitution
why is benzene less reactive then a phenol
- in phenol, lone pair of electrons from O of -OH are donated to the π system of the ring
- increasing electron density
- meaning electrophiles are attracted more easily
evidence for delocalised model of benzene (3)
- does not react like an alkene - much less reactive - doesn’t decolourise bromine water (alkene does)
- the c-c bond length is between double and single
- the hydration enthalpy is not as expected (less energy produced when hydrated)
are phenols acidic?
yes
explain solubility of phenols
less soluble in water than an alcohol because of non-polar benzene ring - does partially dissolve
reactions of phenol and:
- strong base
- weak base
- yes - (alcohol wouldn’t)
- no
observations of reaction of bromine water by phenol (name products formed)
- decolourises bromine water
- white ppt. - 2,4,6-tribromophenol
where does -NH2 direct to
2,4
where does -OH direct to
2,4
where does -NO2 direct to
3
conditions required for nitration of phenol
- no conc. H2SO4 needed
- only dilute HNO3
alkylation
adding a haloalkane to benzene, lengthening carbon chain by adding alkyl group - by reacting w. a chloroalkane
special thing about alkylation
lengthens carbon chain
acylation
adding an acyl group to benzene, forming a ketone
-NO2 is: deactivating/activating?
deactivating
