Question

Schotten-Baumann reaction is a reaction of phenols with

• A. benzoyl chloride and NaOH
• B. acetyl chloride and NaOH
• C. salicylic acid and cone. $H_2SO_4$
• D. acetyl chloride and cone. $H_2SO_4$

Answer 1

The Correct Option is A

 The Schotten-Baumann reaction is a well-known method in organic chemistry for forming amides from amines and acid chlorides, or esters from alcohols. Specifically, when applied to phenols, this reaction involves the use of benzoyl chloride and sodium hydroxide (NaOH). This combination is used to introduce the benzoyl group into the phenolic compound, resulting in the formation of a phenyl benzoate.

Let's understand why this is the correct answer:

1. In the Schotten-Baumann reaction, an acid chloride is reacted with a nucleophile, under alkaline conditions. Here, benzoyl chloride acts as the acid chloride and NaOH provides the basic environment necessary for the reaction to proceed. The role of NaOH is crucial because it neutralizes the hydrochloric acid (HCl) that is formed during the reaction, thereby driving the reaction to completion and preventing any side reactions with HCl.
2. Benzoylation of phenols involves the reaction between the hydroxyl group of phenols and benzoyl chloride. When NaOH is present, it deprotonates the phenol, enhancing its nucleophilicity and facilitating the attack on benzoyl chloride to form phenyl benzoate.
3. The other options listed do not align with the requirements of the Schotten-Baumann reaction:
   • \("acetyl chloride and NaOH"\) - Although similar, this reaction would produce an acetylated phenol (phenyl acetate) and is not the classical Schotten-Baumann reaction for benzoyl derivatives.
   • \("salicylic acid and cone. H_2SO_4"\) - This represents an esterification or sulfonation process, not a Schotten-Baumann reaction.
   • \("acetyl chloride and cone. H_2SO_4"\) - This could lead to acetylation under acidic conditions but doesn't represent the correct reaction type discussed.

Therefore, the correct answer is benzoyl chloride and NaOH. This aligns with the mechanism and requirements of the Schotten-Baumann reaction for phenols.