Describe with anisole as an example what are the major products obtained as a result of nitration of with HNO3+H2SO4. Also indicate the resonace structures for each mechanism involved inculding the formation of nitronium ion.
By using sulfuric acid with nitric acid to form the nitronium ion electrophile
NO2+ then forms a sigma complex with benzene or substituted benzene (here anisole), and loses H+ to form nitrocompound
--Remember that alkyl groups stabilize the sigma complex by induction, donating electron density through the sigma bond.
--Substituents with a lone pair of electrons like -OCH3 stabilize the sigma complex by resonance.
Attachment of an electrophile ortho or para to them leads to a more stable complex because of ...
Attachment of an electrophile ortho or para to them leads to a more stable complex because of resonance involving the electrondonating substituent. On the other hand, meta attack does not permit any resonance stabilization or interaction and order of the distribution of final products in the reaction is Para>ortho>>meta (kp>ko>>km).