Question

When phenol is treated with chloroform and aqueous sodium hydroxide, the major product formed is:

• A. Salicylic acid
• B. Salicylaldehyde
• C. Benzoic acid
• D. Benzyl chloride

Hint:

Remember the reagent distinction: Phenol + \(\text{CHCl}_3\) / NaOH yields Salicylaldehyde (Reimer-Tiemann formylation), whereas Phenol + \(\text{CO}_2\) / NaOH yields Salicylic acid (Kolbe's reaction).

Answer 1

The Correct Option is B

Step 1: Understanding the Question:
The question asks to identify the major organic product formed when phenol undergoes a reaction with chloroform (\(\text{CHCl}_3\)) and an aqueous base (NaOH).

Step 3: Detailed Explanation:
The reaction of phenol with chloroform in the presence of sodium hydroxide is a classic named reaction known as the

Reimer-Tiemann reaction.
In this reaction, the base (NaOH) deprotonates chloroform to generate a highly reactive electrophilic intermediate called dichlorocarbene (\(:\text{CCl}_2\)).
The dichlorocarbene attacks the electron-rich phenoxide ring, predominantly at the ortho position due to the stabilizing proximity effect.
Subsequent hydrolysis of the intermediate leads to the introduction of an aldehyde group (\(-\text{CHO}\)) at the ortho position of the phenol ring.
The resulting major product is \(o\)-hydroxybenzaldehyde, which is commonly known as

salicylaldehyde.
If carbon tetrachloride (\(\text{CCl}_4\)) were used instead of chloroform (\(\text{CHCl}_3\)) under similar conditions, the product would have been salicylic acid.

Step 4: Final Answer:
The correct choice is (B).