Benzylamine may be alkylated as shown in the following equation?


Which of the following alkyl halides is best suited for this reaction through SN1 mechanism?

1. CH3Br2. C6H5Br3. C6H5CH2Br4. C2H5Br

Hint: Stability of carbocation

SN1 reaction proceeds through formation of carbocation. Hence, more stable be the carbocation, more reactive is the compound towards SN1 mechanism.

Alkyl halides

, Intermediate

a. CH3Brb. C6H5Brc. C6H5CH2Brd. C2H5Br  CH3 C6He C6H5CH2( more stable ) C2H5
Hence, the reaction will proceed through SN1 mechanism when C6H5CH2Br is the substrate because on ionisation it gives a resonance stabilised carbocation (C6H5CH2+).