which of the following does not react with `HNO_2`

Options

A. `CH_3 CONH_2`
B. `(CH_3)_3 C(NO_2)`
C. `(C_2H_5)_2 NH`
D. `CH_(3)CH_(2)NH_(2)`

Answer

To determine which of the following does not react with HNO2 (nitrous acid), we need to analyze the types of compounds typically involved in reactions with nitrous acid.

### Step 1: Understand the Reactivity of Compounds with HNO2
Nitrous acid primarily reacts with primary and secondary amines to form diazonium salts. Tertiary amines, on the other hand, do not react with HNO2 because they lack an alpha hydrogen atom.

### Step 2: Identify the Types of Amines
- **Primary Amines**: These have one alkyl group attached to the nitrogen and have two hydrogen atoms available for reaction.
- **Secondary Amines**: These have two alkyl groups attached to the nitrogen and have one hydrogen atom available for reaction.
- **Tertiary Amines**: These have three alkyl groups attached to the nitrogen and do not have any hydrogen atoms available for reaction.

### Step 3: Analyze the Options
If the options provided include a tertiary amine, that would be the compound that does not react with HNO2.

### Conclusion
Based on the information provided, the correct answer is that tertiary nitroalkanes (or tertiary amines) do not react with HNO2.

### Final Answer
The compound that does not react with HNO2 is the tertiary nitroalkane.

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