The functional group which is formed when Phenol is made to react with Chloroform in the presence of dilute sodium hydroxide

Options

A. `-CH_(2)Cl`
B. `-COOH`
C. `-CHCl_(2)`
D. `-CHO`

Answer

To solve the question regarding the functional group formed when phenol reacts with chloroform in the presence of dilute sodium hydroxide, we can follow these steps:

### Step 1: Identify the Reactants
We start with two reactants:
- Phenol (C₆H₅OH)
- Chloroform (CHCl₃)

### Step 2: Understand the Reaction Conditions
The reaction occurs in the presence of dilute sodium hydroxide (NaOH). This indicates that we are likely dealing with a nucleophilic substitution reaction, specifically a Reimer-Tiemann reaction.

### Step 3: Formation of the Electrophile
In the presence of NaOH, chloroform reacts to form dichlorocarbene (CCl₂). This occurs through the deprotonation of chloroform, leading to the formation of a carbanion:
\[ \text{CHCl}_3 + \text{NaOH} \rightarrow \text{CCl}_2^- + \text{Cl}^- + \text{H}_2\text{O} \]

### Step 4: Formation of Phenoxide Ion
Phenol reacts with NaOH to form the phenoxide ion (C₆H₅O⁻):
\[ \text{C₆H₅OH} + \text{NaOH} \rightarrow \text{C₆H₅O}^- + \text{Na}^+ + \text{H}_2\text{O} \]

### Step 5: Electrophilic Attack
The dichlorocarbene (CCl₂) acts as an electrophile and attacks the phenoxide ion. This results in the formation of a new carbon-carbon bond, leading to the formation of ortho- and para-hydroxybenzaldehyde.

### Step 6: Hydrolysis and Final Product
The resulting compound undergoes hydrolysis and rearrangement to yield ortho-hydroxybenzaldehyde (salicylaldehyde) and para-hydroxybenzaldehyde. The functional group that is formed in this reaction is the aldehyde group (CHO).

### Conclusion
Thus, the functional group formed when phenol reacts with chloroform in the presence of dilute sodium hydroxide is the aldehyde group (CHO).

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