Which of the following conversion is incorrect :

Options

A. `CH_(3)CNunderset("or LAH")overset(Na//C_(2)H_(5)OH)(to)CH_(2)CH_(2)NH_(2)`
B. `CH_(3)CONH_(2)overset(Br_(2)//KOH)(to)CH_(3)CH_(2)NH_(2)`
C. `CH_(3)CONH_(2)overset(NaNO_(2)+HCl)(to)CH_(3)COOH`
D. `CH_(3)CONH_(2)overset(P_(2)O_(5))(to)CH_(3)CN`

Answer

To determine which conversion is incorrect among the options provided, we will analyze each reaction step by step.

### Step 1: Analyze Option A
- **Reaction**: CH3CN + Na + C2H5OH (or LAH) → CH3CH2NH2
- **Explanation**: This reaction is known as the Mendeus reaction. In this reaction, the organic nitrile (CH3CN) is reduced to a primary amine (CH3CH2NH2). The conversion is correct as it follows the expected outcome of the reaction.

### Step 2: Analyze Option B
- **Reaction**: CH3CONH2 + Br2 + KOH → ?
- **Explanation**: This reaction is known as the Hoffman Bromamide Degradation. The amide (CH3CONH2) is converted to a primary amine (CH3NH2) by losing one carbon atom. The expected product is CH3NH2, not CH3CH2NH2 as stated in the question. Therefore, this conversion is incorrect.

### Step 3: Analyze Option C
- **Reaction**: CH3CONH2 + NaNO2 + HCl → ?
- **Explanation**: For aliphatic amides, the reaction with NaNO2 and HCl results in the formation of a carboxylic acid. In this case, acetic acid (CH3COOH) is formed. This conversion is correct.

### Step 4: Analyze Option D
- **Reaction**: CH3CONH2 + P2O5 → ?
- **Explanation**: In this reaction, the amide (CH3CONH2) is converted to a nitrile (CH3C≡N) when treated with phosphorus pentoxide (P2O5). This conversion is also correct.

### Conclusion
After analyzing all the options:
- **Incorrect Conversion**: The incorrect conversion is in **Option B**, where CH3CONH2 is incorrectly stated to produce CH3CH2NH2 instead of the correct product, CH3NH2.

### Final Answer
The answer to the question is **Option B**.

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