During acetylation of amines, what is replaced by acetyl groups?

Options

A. Hydrogen atom attached to nitrogen atom
B. One or more hydrogen atoms attached to carbon atom
C. One or more hydrogen atoms attached to nitrogen atom
D. Hydrogen atoms attached to either carbon atom or nitrogen atome

Answer

To solve the question "During acetylation of amines, what is replaced by acetyl groups?", we can break down the process step by step.

### Step-by-Step Solution:

1. **Understanding Acetylation**:
- Acetylation is a chemical reaction where an acetyl group (CH3C(=O)-) is introduced into a molecule. In the case of amines, this process involves the reaction of amines with acetylating agents, such as acetyl chloride.

2. **Identifying the Amines**:
- Amines are compounds that contain a nitrogen atom bonded to hydrogen atoms and/or carbon-containing groups. In this question, we are specifically looking at methyl amine (CH3NH2), which is a primary amine.

3. **Reaction Mechanism**:
- When methyl amine reacts with acetyl chloride (CH3C(=O)Cl), the nitrogen atom in the amine has hydrogen atoms attached to it. The acetyl group replaces one or more of these hydrogen atoms.

4. **Formation of N-Methyl Acetyl Amide**:
- The reaction can be represented as follows:
\[ \text{CH}_3\text{NH}_2 + \text{CH}_3\text{C(=O)Cl} \xrightarrow{\text{pyridine}} \text{CH}_3\text{N(C(=O)CH}_3) + \text{HCl} \]
- In this reaction, one of the hydrogen atoms attached to the nitrogen in methyl amine is replaced by the acetyl group, resulting in the formation of N-methyl acetyl amide.

5. **Conclusion**:
- Therefore, during the acetylation of amines, one or more hydrogen atoms attached to the nitrogen atom are replaced by acetyl groups.

### Final Answer:
During acetylation of amines, one or more hydrogen atoms attached to the nitrogen atom are replaced by acetyl groups.

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