The reaction of ethyl p - amiobenzoate with `HNO_2` and then with `HBF_4` yields a compounds (X), a crystalline ionic compound. Compound (X) , when heated forms `C_9H_9O_2F`(Y). The compound (Y) is

Options

A. ethyl p - fluorobenzoate
B. ethyl o - fluorobenzoate
C. ethyl m - fluorobenzoate
D. mixture of all the above

Answer

To solve the problem, we need to understand the reactions involved and the compounds formed step by step.

### Step 1: Identify the starting compound
The starting compound is ethyl para-aminobenzoate. Its structure can be represented as follows:

- **Structure**:
- Ethyl group (C2H5) attached to the carboxylate (COO-) group of benzoic acid.
- An amino group (NH2) is located at the para position relative to the carboxylate group.

### Step 2: Reaction with HNO2
When ethyl para-aminobenzoate reacts with nitrous acid (HNO2), it forms a diazonium salt. The amino group (-NH2) is converted into a diazonium group (-N2+).

- **Reaction**:
- Ethyl para-aminobenzoate + HNO2 → Ethyl para-diazobenzenoate (Compound X)

### Step 3: Reaction with HBF4
The diazonium salt formed in the previous step is then treated with tetrafluoroboric acid (HBF4). This reaction leads to the formation of a crystalline ionic compound, which is the tetrafluoroborate salt of the diazonium compound.

- **Reaction**:
- Ethyl para-diazobenzenoate + HBF4 → Ethyl para-diazobenzenoate tetrafluoroborate (Compound X)

### Step 4: Heating Compound X
When Compound X is heated, it undergoes a decomposition reaction. During this process, nitrogen gas (N2) is released, and the diazonium group is replaced by a fluorine atom from the BF4- ion, resulting in the formation of ethyl para-fluorobenzoate.

- **Decomposition Reaction**:
- Ethyl para-diazobenzenoate tetrafluoroborate (X) → Ethyl para-fluorobenzoate (Y) + N2 + BF3

### Step 5: Identify Compound Y
The final compound formed after heating is ethyl para-fluorobenzoate. Its molecular formula is C9H9O2F, which matches the given formula for compound Y.

- **Compound Y**: Ethyl para-fluorobenzoate (C9H9O2F)

### Final Answer
The compound (Y) is **ethyl para-fluorobenzoate**.

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