Acetamide when heated with `PCl_5` gives

Options

A. `CH_3Cl`
B. `CH_3CN`
C. `CH_3"CCl"_2NH_2`
D. `CHCl_2CONH_2`

Answer

To solve the question, "Acetamide when heated with PCl5 gives," we will follow these steps:

### Step 1: Understand the structure of Acetamide
Acetamide has the chemical formula CH3CONH2. It consists of a methyl group (CH3) attached to a carbonyl group (C=O) and an amine group (NH2).

### Step 2: Identify the reaction with PCl5
When acetamide is heated with phosphorus pentachloride (PCl5), it undergoes a reaction where the amide group is converted into an amidochloride. PCl5 is a chlorinating agent that can replace the oxygen in the amide with chlorine.

### Step 3: Reaction mechanism
1. The oxygen atom in the carbonyl group of acetamide is replaced by a chlorine atom from PCl5.
2. The phosphorus oxychloride (POCl3) is formed as a byproduct.
3. The nitrogen remains attached to the carbon, and the chlorine atoms from PCl5 replace the oxygen.

### Step 4: Write the product
The product formed from the reaction is N-chloroacetamide, which can be represented as:
- The carbon atom now has two chlorine atoms attached (CCl2) and the nitrogen remains as NH2.
- Therefore, the structure can be represented as CH3CCl2NH2.

### Step 5: Finalize the answer
The final product of the reaction between acetamide and PCl5 upon heating is N-chloroacetamide, or more specifically, it can be written as CH3CCl2NH2.

### Conclusion
Thus, the answer to the question is that acetamide when heated with PCl5 gives N-chloroacetamide (CH3CCl2NH2) and POCl3 is released as a byproduct.

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