Benzaldehyde can be prepared from

Options

A.
B.
C.
D.

Answer

To determine how benzaldehyde can be prepared, we will analyze each of the given options step by step.

### Step 1: Analyze Option A - Benzoyl Chloride Reduction
- **Reaction**: Benzoyl chloride (C6H5COCl) is reduced in the presence of palladium (Pd) and barium sulfate (BaSO4) as a catalyst.
- **Products**: The reduction of benzoyl chloride results in the formation of benzaldehyde (C6H5CHO) and hydrochloric acid (HCl).
- **Conclusion**: This reaction successfully produces benzaldehyde, making option A a valid choice.

### Step 2: Analyze Option B - Aromatic Cyanide Reduction
- **Reaction**: An aromatic cyanide is reduced using tin (Sn) and hydrochloric acid (HCl).
- **Products**: This reaction typically yields an aromatic amine instead of benzaldehyde.
- **Conclusion**: Since the desired product is benzaldehyde and this reaction does not yield it, option B is incorrect.

### Step 3: Analyze Option C - Aromatic Amide Reaction
- **Reaction**: An aromatic amide is treated with bromine (Br2) and potassium hydroxide (KOH).
- **Products**: This reaction is known as the Hofmann bromamide reaction, which converts the amide into an aromatic amine along with the formation of K2CO3, KBr, and water.
- **Conclusion**: This reaction does not produce benzaldehyde, so option C is also incorrect.

### Step 4: Analyze Option D - Benzene Diazonium Chloride Hydrolysis
- **Reaction**: Benzene diazonium chloride is hydrolyzed in water.
- **Products**: The hydrolysis yields phenol (C6H5OH) along with the liberation of nitrogen (N2) and hydrochloric acid (HCl).
- **Conclusion**: Since this reaction does not produce benzaldehyde, option D is incorrect.

### Final Conclusion:
After analyzing all options, we find that only **Option A** (the reduction of benzoyl chloride) leads to the formation of benzaldehyde. Therefore, the correct answer is:

**Benzaldehyde can be prepared from Benzoyl Chloride.**

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