Question

Benzyl amine may be alkylated as shown in the following equation $ {{C}_{6}}{{H}_{6}}C{{H}_{2}}N{{H}_{2}}+R-X\xrightarrow{{}}{{C}_{6}}{{H}_{5}}C{{H}_{2}}NHR. $ Which of the following alkyl halides is best suited for this reaction through $ {{S}_{N}}1 $ mechanism?

• A. $ C{{H}_{3}}Br $
• B. $ {{C}_{2}}{{H}_{5}}Br $
• C. $ {{C}_{6}}{{H}_{5}}C{{H}_{2}}Br $
• D. $ {{C}_{2}}{{H}_{5}}Br $

Answer 1

Answer: (C)

Since, $ {{C}_{6}}{{H}_{5}}C{{H}_{2}}Br $ on ionsation gives a resonance stabilised benzyl carbocation $ ({{C}_{6}}{{H}_{5}}\overset{+}{\mathop{C{{H}_{2}}}}\,) $ therefore $ {{C}_{6}}{{H}_{5}}C{{H}_{2}}Br $ is best for $ {{S}_{N}}1 $ reaction.