Question

Benzene diazonium chloride when warmed with water gives a compound, whose sodium salt when reacted with allyl bromide gives compound [X]. Identify [X].

• A. \(\mathrm{C_6H_5-CH-(CH_3)_2}\)
• B. \(\mathrm{C_6H_5-O-CH_2-CH=CH_2}\)
• C. \(\mathrm{C_6H_5-O-CH_2-CH_2-CH_3}\)
• D. \(\mathrm{C_6H_5-CH_2-CH_2-CH_3}\)

Hint:

Benzene diazonium chloride gives phenol on warming with water. Phenoxide ion reacts with alkyl or allyl halides to form ethers by Williamson ether synthesis.

Answer 1

The Correct Option is B

Step 1: Reaction of benzene diazonium chloride with water.
Benzene diazonium chloride gives phenol when warmed with water.
\[ \mathrm{C_6H_5N_2^+Cl^- + H_2O \xrightarrow{\Delta} C_6H_5OH + N_2 + HCl} \]

Step 2: Identifying the compound formed.
The compound formed is phenol.
\[ \mathrm{C_6H_5OH} \]

Step 3: Formation of sodium salt of phenol.
Phenol reacts with sodium hydroxide to form sodium phenoxide.
\[ \mathrm{C_6H_5OH + NaOH \rightarrow C_6H_5ONa + H_2O} \]

Step 4: Reaction of sodium phenoxide with allyl bromide.
Sodium phenoxide reacts with allyl bromide through Williamson ether synthesis.
\[ \mathrm{C_6H_5ONa + BrCH_2CH=CH_2 \rightarrow C_6H_5OCH_2CH=CH_2 + NaBr} \]

Step 5: Identifying the product [X].
The product formed is allyl phenyl ether.
\[ \mathrm{C_6H_5-O-CH_2-CH=CH_2} \]

Step 6: Matching with the options.
Option (B) represents:
\[ \mathrm{C_6H_5-O-CH_2-CH=CH_2} \] This is exactly allyl phenyl ether.

Step 7: Final conclusion.
Thus, compound [X] is allyl phenyl ether.
\[ \boxed{\mathrm{C_6H_5-O-CH_2-CH=CH_2}} \] Hence, the correct answer is option (B).