Reactants:

* Benzene (C6H6): An aromatic hydrocarbon with a stable ring structure.

* Acetyl chloride (CH3COCl): The acylating agent, providing the acetyl group (CH3CO-).

* Anhydrous Aluminum chloride (AlCl3): A Lewis acid catalyst that activates the acyl chloride.

Mechanism:

1. Formation of the Electrophile: Anhydrous AlCl3 acts as a Lewis acid and accepts a lone pair of electrons from the oxygen atom of acetyl chloride. This forms a complex where the carbon atom of the carbonyl group becomes highly electrophilic.

2. Electrophilic Attack: The highly electrophilic carbon atom of the acetyl group attacks the electron-rich benzene ring, breaking the aromaticity.

3. Rearrangement: The intermediate formed rearranges to regenerate the aromatic system by losing a proton.

4. Deprotonation: The proton is removed by AlCl4- (formed from AlCl3 and Cl- from acetyl chloride), regenerating the catalyst.

Product:

The product of the reaction is acetophenone (C6H5COCH3).

Overall Reaction:

```

C6H6 + CH3COCl --AlCl3--> C6H5COCH3 + HCl

```

Key Points:

* This reaction is a substitution reaction where an acetyl group replaces a hydrogen atom on the benzene ring.

* The reaction requires an anhydrous environment because water will react with AlCl3, rendering it ineffective.

* Friedel-Crafts acylations are important in organic chemistry for introducing acyl groups into aromatic compounds, leading to the synthesis of various important products.