Halogenation (benzene)

Br₂  / Cl₂

------------------->

FeBr₂ / FeCl₂

bromobenzene + HBr

or

chlorobenzene + HCl

Nitration

HNO₃

------------->

H₂SO₄

nitrobenzene + H₂O

H from sulfuric bonds to OH on HNO₃; H₂NO₃ forms H₂O and NO₂. Benzene attacks NO₂. H₂O steals H from Benzene; returns to H₂SO₄

Iodination (benzene)

NaI

---------------->

NaOCl

Friedel-Crafts Alkylation

Alkyl with Chlorine

-------------------------->

AlCl₃

Chlorine is removed by AlCl₃, leaving carbocation, benzene bonds to carbocation

Limitations: Rearrangement, polyalkylation, only works with E^- donating benzene derivatives, alkenes do not react

Friedel-Crafts Acylation

Acid Chloride

--------------------->

AlCl₃

Limitations: Alkenes do not react, only works with E^- donating benzene derivatives, polyalkylation, rearrangement

Reduction of Nitro (benzene)

Sn

-------------->

HCl

Reduces all NO₂ groups directly connected to benzene to NH₂ groups

Oxidation of Alkyl Side Chains (benzene)

KMnO₄ or Na₂Cr₂O₇

--------------------------->

Reduces carbons in the benzilic position to carboxylic acid with a phenyl substituent.

Limits: Only works if there is a proton available to react on the benzilic carbon

Bromination of Alkyl Side Chains (benzene)

NBS

------------>

ROOR

Adds a bromine to all carbons in the benzilic position with accessible protons. 

Reduction of Ketones

H₂

-------------->

Pd / C

Reduces a ketone in benzilic position into an alkyl chain. Reduces nitro substituents into amine. 

Limits: Only reduces ketones and aldehydes (not acids)