Aldehyde with `NH_(2)NH_(2)` forms

Options

A. Hydrazone
B. Aniline
C. Nitrobenzene
D. none of these

Answer

To solve the question regarding the reaction of an aldehyde with hydrazine (NH2NH2), we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Reactants**:
The reactants in this reaction are an aldehyde (general formula RCHO) and hydrazine (NH2NH2).

2. **Understand the Reaction**:
When an aldehyde reacts with hydrazine, it undergoes a condensation reaction. In this reaction, the carbonyl group (C=O) of the aldehyde reacts with the hydrazine.

3. **Mechanism of Reaction**:
- The nitrogen atom in hydrazine has a lone pair of electrons, which can attack the electrophilic carbon atom of the carbonyl group in the aldehyde.
- This results in the formation of a tetrahedral intermediate where the oxygen atom of the carbonyl group becomes negatively charged.

4. **Formation of Hydrazone**:
- The negatively charged oxygen can then protonate (lose a hydrogen ion) and water (H2O) is eliminated from the intermediate.
- The remaining structure forms a double bond between the carbon and the nitrogen, resulting in the formation of a hydrazone (RCH=N-NH2).

5. **Final Product**:
The final product of the reaction is a hydrazone, which is characterized by the presence of a C=N bond.

### Conclusion:
The reaction of an aldehyde with hydrazine results in the formation of a hydrazone.