In a set of the given reactions, acetic acid yielded a product C:
$$CH_3COOH + PCl_5 \rightarrow A \xrightarro

Question

In a set of the given reactions, acetic acid yielded a product C:
$$CH_3COOH + PCl_5 \rightarrow A \xrightarrow[Anh. AlCl_3]{C_6H_6} B \xrightarrow[ether]{C_2H_5MgBr} C$$
Product C would be:

Accepted Answer

The reaction sequence proceeds as follows:
1.  **Formation of A:** Acetic acid ($CH_3COOH$) reacts with phosphorus pentachloride ($PCl_5$) to form acetyl chloride ($CH_3COCl$). This is a standard method for preparing acyl chlorides.
    $$CH_3COOH + PCl_5 \rightarrow CH_3COCl + POCl_3 + HCl$$
2.  **Formation of B:** Acetyl chloride (A) reacts with benzene ($C_6H_6$) in the presence of anhydrous aluminium chloride ($AlCl_3$) to form acetophenone ($C_6H_5COCH_3$). This is the **Friedel-Crafts Acylation** reaction.
    $$CH_3COCl + C_6H_6 \xrightarrow{AlCl_3} C_6H_5COCH_3$$
3.  **Formation of C:** Acetophenone (B), a ketone, reacts with ethyl magnesium bromide ($C_2H_5MgBr$, a Grignard reagent) followed by hydrolysis to form a tertiary alcohol. The alkyl group from the Grignard reagent adds to the carbonyl carbon.
    $$C_6H_5COCH_3 + C_2H_5MgBr \xrightarrow{ether} C_6H_5-C(OMgBr)(CH_3)-C_2H_5 \xrightarrow{H_3O^+} C_6H_5-C(OH)(CH_3)-C_2H_5$$

The final product C is 2-phenylbutan-2-ol.

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