Recently, I learnt about the Schotten-Baumann synthesis method. I know that this synthesis method was invented to overcome the problem of neutralising the acidic by-products of the amide synthesis reaction without introducing strong basic nucleophiles to compete with the amines. The alternative to this synthesis method would be to use two equivalences of the amine, allowing the 2nd equivalence of the amine to act as a base to neutralise the acidic by-product. I would like to enquire more about the differences between these two synthesis methods. In particular, I would like to know the advantages and disadvantages of each of these synthesis methods.