Question

Alkylbenzyldimethyl ammonium chloride is a leave-on skin antiseptic used to treat such things as cuts and cold sores. It is also the antiseptic in many hand sanitizers. It is actually a mixture of compounds that differ in the number of carbons (any even number between 8 and 18) in the alkyl group. Show three different sets of reagents (each set composed of an alkyl chloride and an amine) that can be used to synthesize the alkylbenzyldimethyl ammonium chloride shown here.

Accepted Answer

Step 1: Identify the structure of the target compound, alkylbenzyldimethyl ammonium chloride. It consists of a benzyl group attached to a nitrogen atom, which is further bonded to two methyl groups and an alkyl chain (with an even number of carbons between 8 and 18). The nitrogen carries a positive charge, and the chloride ion is the counterion. Step 2: Understand the synthesis mechanism. The target compound can be synthesized via a nucleophilic substitution reaction (SN2) where an alkyl chloride reacts with a tertiary amine. The tertiary amine must contain a benzyl group and two methyl groups to form the desired quaternary ammonium salt. Step 3: Select the alkyl chloride. Choose three different alkyl chlorides with even numbers of carbons in the alkyl chain (e.g., octyl chloride, decyl chloride, and dodecyl chloride). These will provide the varying alkyl groups in the final product. Step 4: Select the amine. Use benzyl dimethyl amine as the amine reagent in all three cases. This amine contains the benzyl group and two methyl groups required for the quaternary ammonium structure. Step 5: Combine the reagents. For each set of reagents, react the chosen alkyl chloride with benzyl dimethyl amine under appropriate conditions (e.g., heating in a polar solvent) to form the desired alkylbenzyldimethyl ammonium chloride. Ensure the reaction proceeds via SN2 to achieve the quaternary ammonium salt.

비슷한 문제에 대한 검증된 영상 답변:

주요 개념

Quaternary Ammonium Compounds

Alkyl Halides

Nucleophilic Substitution Reactions