Question

Identify the final product [D] formed when Benzyl alcohol undergoes the following series of reactions: $ C_6H_5CH_2OH + SOC_2 \rightarrow [A] \quad + \quad KCN \rightarrow [B] \quad + \quad H_2O^+ (\text{partial hydrolysis}) \rightarrow [C] \quad + \quad [D] $

• A. 4-Chlorobenzoic acid
• B. Benzoic acid
• C. 2-Chlorobenzoic acid
• D. 2-Phenylethanolic acid

Hint:

When reacting with SOC2, benzyl alcohol is converted to benzyl chloride. A subsequent reaction with KCN gives a cyanide, which upon hydrolysis yields 2-phenylethanolic acid.

Answer 1

The Correct Option is D

Let's analyze the reactions one by one: - First, benzyl alcohol \((C_6H_5CH_2OH)\) reacts with \(\text{SOC}_2\), a chlorinating agent. This forms benzyl chloride (\(C_6H_5CH_2Cl\)). \[ C_6H_5CH_2OH + SOC_2 \rightarrow C_6H_5CH_2Cl + SOCl_2 \] - The second
step involves benzyl chloride \((C_6H_5CH_2Cl)\) reacting with potassium cyanide (\(KCN\)), which undergoes nucleophilic substitution, replacing the chlorine atom with a cyanide group, forming benzyl cyanide \((C_6H_5CH_2CN)\).
\[ C_6H_5CH_2Cl + KCN \rightarrow C_6H_5CH_2CN + KCl \] - In the final step, hydrolysis of benzyl cyanide takes place, where water breaks the nitrile group \((CN)\), resulting in 2-Phenylethanolic acid \((C_6H_5CH_2COOH)\). \[ C_6H_5CH_2CN + H_2O^+ \rightarrow C_6H_5CH_2COOH \]
Thus, the final product [D] is 2-Phenylethanolic acid.