Name the end product in the following series of reactions
`C_(6)H_(5)COOH overset(NH_(3))rarr P overset(Delta)rarr Q overset(P_(2)O_(5))rarr R overset(LiAlH_(4))rarr S`

Options

A. Aniline
B. Benzylamine
C. Acetonitrile
D. Acetamide

Answer

To determine the end product in the series of reactions starting from benzoic acid (C₆H₅COOH), we will analyze each step of the reaction sequence.

### Step-by-Step Solution:

1. **Starting Material: Benzoic Acid (C₆H₅COOH)**
- The structure of benzoic acid consists of a benzene ring (C₆H₅) attached to a carboxylic acid group (-COOH).

2. **Reaction with Ammonia (NH₃) to form Product P:**
- When benzoic acid reacts with ammonia, it forms ammonium benzoate. The nitrogen in ammonia acts as a nucleophile and attacks the proton (H⁺) of the carboxylic acid group, resulting in the formation of an ammonium salt.
- **Product P:** Ammonium benzoate (C₆H₅COONH₄).

3. **Heating Product P to form Product Q:**
- Upon heating, the ammonium benzoate undergoes dehydration, losing a molecule of water (H₂O). The reaction involves the loss of the -NH₄⁺ ion and the -OH from the carboxylate ion.
- **Product Q:** Benzamide (C₆H₅CONH₂).

4. **Reaction of Product Q with Diphosphorus Pentoxide (P₂O₅) to form Product R:**
- Diphosphorus pentoxide is a strong dehydrating agent. When benzamide is treated with P₂O₅, it loses another molecule of water, resulting in the formation of benzonitrile.
- **Product R:** Benzonitrile (C₆H₅CN).

5. **Reduction of Product R with Lithium Aluminum Hydride (LiAlH₄) to form Product S:**
- Lithium aluminum hydride is a powerful reducing agent. It reduces benzonitrile to benzylamine by adding hydrogen across the carbon-nitrogen triple bond, converting the nitrile group (-CN) to an amine group (-NH₂).
- **Product S:** Benzylamine (C₆H₅CH₂NH₂).

### Final Answer:
The end product (S) of the reaction sequence is **Benzylamine (C₆H₅CH₂NH₂)**.

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