Which of the following is not a nitro derivatives?

Options

A. `C_6H_5-NO_2`
B.
C. `CH_3-underset(O)underset(darr)N=O`
D. `CH_3CH_2-O-N=O`

Answer

To determine which of the following is not a nitro derivative, we need to understand what constitutes a nitro derivative. A nitro derivative typically involves a nitro group (-NO2) attached to a carbon atom, whereas a compound that has a nitrogen atom bonded to an oxygen atom (like in alkyl nitrites) is not classified as a nitro derivative.

### Step-by-Step Solution:

1. **Understanding Nitro Derivatives**:
- Nitro derivatives contain a nitro group (-NO2) attached to a carbon atom.
- Examples include nitroalkanes (where the nitro group is attached to an alkane) and nitroarenes (where the nitro group is attached to an aromatic ring).

2. **Identifying the Options**:
- We need to analyze each option provided in the question to see which one does not fit the definition of a nitro derivative.

3. **Analyzing Each Option**:
- **Option 1**: If this option has a nitro group attached to a carbon, it is a nitro derivative.
- **Option 2**: Similar to option 1, if it contains a nitro group attached to a carbon, it is also a nitro derivative.
- **Option 3**: Again, if this option has a nitro group attached to a carbon, it qualifies as a nitro derivative.
- **Option 4**: If this option shows a nitrogen atom directly bonded to an oxygen atom (as in alkyl nitrites), it does not contain a nitro group attached to a carbon. Instead, it represents a different class of compounds.

4. **Conclusion**:
- After analyzing the options, we find that **Option 4**, which is an alkyl nitrite (e.g., ethyl nitrite), is not a nitro derivative because it has a nitrogen-oxygen bond instead of a nitrogen-carbon bond with a nitro group.

### Final Answer:
- **Option 4 is not a nitro derivative.**