text: Amides are usually prepared by coupling a carboxylic acid with an amine. The direct reaction generally requires high temperatures to drive off the water:
  Esters are far superior substrates relative to carboxylic acids.
  Further "activating" both acid chlorides (Schotten-Baumann reaction) and anhydrides (Lumière–Barbier method) react with amines to give amides:
  Peptide synthesis use coupling agents such as HATU, HOBt, or PyBOP.