For each pair, predict the stronger nucleophile in the reaction (using an alcohol as the solvent). Explain your prediction.
The reaction relies on the rear-side attack of a strong nucleophile on a sterically unhindered electrophile containing a good leaving group.
The pair of compounds are and.
Note that is a secondary amine, and is less hindered than the other compound (which is a tertiary amine). There is less steric hindrance around the secondary amine, and so it will be the stronger nucleophile; it can more easily attack the electrophile.
Therefore, will be the stronger nucleophile.