The reaction in question involves treating acetamide \((\text{CH}_3\text{CONH}_2)\) with bromine \((\text{Br}_2)\) in an aqueous potassium hydroxide \((\text{KOH})\) medium. This is a classic example of the Hofmann Bromamide Reaction, also known as the Hofmann Degradation of Amides.
Concept: The Hofmann Bromamide Reaction is used to degrade amides to primary amines with one less carbon atom (loss of one carbon). Here, a carboxamide group is converted into an amine with the help of bromine and a strong base.
Reaction Mechanism: The general reaction mechanism involves the formation of an N-bromoamide intermediate which then undergoes rearrangement through the deprotonation and opening of the carbon-nitrogen bond.
Application to Given Reaction: Here, \(\text{CH}_3\text{CONH}_2\) is treated with bromine in an aqueous potassium hydroxide medium. The reaction proceeds as follows:
Product Analysis: The final product of this reaction is \(\text{CH}_3\text{NH}_2\) (methylamine), as the amide is degraded to the primary amine form.
Conclusion: The main product of the reaction of acetamide \((\text{CH}_3\text{CONH}_2)\) with bromine in aqueous potassium hydroxide medium is indeed methylamine \((\text{CH}_3\text{NH}_2)\). Hence, the correct option is \(\text{CH}_3\text{NH}_2\).