Why would the following reaction not proceed through SN2 reaction?
The substrate in this reaction is an Acyl Chloride, which is highly susceptible to nucleophilic acyl substitution, more so than other carboxylic acid derivatives, so SN2 attack (as mentioned in the comments) is highly improbable. The mechanism for this nucleophilic acyl substitution is as follows:

With equilibrium constant $K_c &gt;&gt; 1$ favouring the products on the right.