Question

Can anyone explain the electrophilic aromatic substitution experiment: the diacetylation ferrocen? Two seperate steps: synthesis of diacetylferrocen and purification by column chromatography. Please explain the experiment background, purpose and hypothesis. Structures will help a lot.

Answer 1

Electrophilic aromatic substitution (S_EAr) is an organic reaction in which an atom that is attached to an aromatic system (usually hydrogen) is replaced by an electrophile.

The reaction acetylation of ferrocene is a classic example of this reaction. The di or multiple acetylation follows the same mechanism and as acetylation progresses attack of another acetyl group becomes more and more difficult.

The reaction is carried out in the presence of phosphoric acid and acetic anhydride is the aource of acetyl unit.

The overall mechanism is

Not sure what you mean by purpose. But the experiment is straight forward.