Which of the following cannot be acylated ?

Options

A. `C_2 H_5 NH_2`
B. `C_6H_5NH_2`
C. `(CH_3)_2 NH`
D. `(CH_3)_(3)N`

Answer

To solve the question "Which of the following cannot be acylated?", let's break down the process step by step.

### Step 1: Understand Acylation
Acylation is a chemical reaction where an acyl group (RCO−) is introduced into a compound. In the case of amines, this typically involves the reaction of an amine with an acyl chloride (RCOCl) to form an amide.

### Step 2: Identify the Types of Amines
Amines can be classified into three categories based on the number of carbon groups attached to the nitrogen:
- Primary amines (RNH2): One carbon group attached to nitrogen.
- Secondary amines (R2NH): Two carbon groups attached to nitrogen.
- Tertiary amines (R3N): Three carbon groups attached to nitrogen.

### Step 3: Determine the Reactivity of Amines
For acylation to occur, the amine must have at least one hydrogen atom that can be replaced by the acyl group. This is crucial because the base used in the reaction abstracts a proton from the amine to generate a nucleophile.

- **Primary amines** can be acylated because they have two hydrogens attached to nitrogen.
- **Secondary amines** can also be acylated because they have one hydrogen attached to nitrogen.
- **Tertiary amines** cannot be acylated because they do not have any hydrogen atoms directly attached to the nitrogen.

### Step 4: Conclusion
Based on the above reasoning, the type of amine that cannot be acylated is the **tertiary amine**.

### Final Answer
The amine that cannot be acylated is the **tertiary amine**.

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