Question

Methyl fluoride is prepared by heating methyl bromide in the presence of AgF. This reaction is known as

• A. Swarts reaction
• B. Finkelstein reaction
• C. Sandmeyer’s reaction
• D. Wurtz reaction
• E. Kolbe’s reaction

Hint:

The Finkelstein reaction is commonly used to substitute one halogen for another, especially for preparing alkyl fluorides like methyl fluoride.

Answer 1

The Correct Option is B

The Finkelstein reaction is a nucleophilic substitution reaction in which an alkyl halide reacts with a sodium halide in a polar solvent (usually acetone). In this specific case, methyl bromide (CH₃Br) reacts with silver fluoride (AgF) to produce methyl fluoride (CH₃F). - Option (A): The Swarts reaction is used to prepare alkyl fluorides from alkyl chlorides or bromides, but it requires the use of metal fluorides like AgF under high temperatures. Although related, this is not the correct answer for the given reaction. - Option (B): The Finkelstein reaction is the correct answer. In this reaction, methyl bromide (CH₃Br) is treated with silver fluoride (AgF) to form methyl fluoride (CH₃F). It is a classic nucleophilic substitution process. - Option (C): The Sandmeyer’s reaction is a method for the synthesis of aryl halides from aryl amines using copper(I) halides, and it is not applicable to the preparation of methyl fluoride. - Option (D): The Wurtz reaction is used to couple alkyl halides in the presence of sodium metal to form alkanes, but it is not used for the preparation of fluorides. - Option (E): Kolbe’s reaction is used for the formation of carboxylic acids and is unrelated to the preparation of methyl fluoride. Thus, the correct answer is (B) Finkelstein reaction, as it describes the process of preparing methyl fluoride from methyl bromide in the presence of AgF.