Hello!

There are a lot of options and coupling agents to form an amide bond.

1) you can prepare the acid chloride using, e.g., thionyl chloride and subsequently perform the coupling with the amine;

2) you can prepare the acid anhydride followed by coupling reaction;

3) you can use coupling agents (widely used in peptide chemistry): DCC (dicyclohexycarbodiimide), HOBt (1-hydroxy-benzotriazole), HOAt (1-hydroxy-7-aza-benzotriazole), or even newer ones such as HBTU, HATU, TBTU, BOP, pyBOP, ...

We have used pyBOP several times - and it worked fine and in high yields.

Regards.

Thank you

As I remember there is a way using Me3Al as catalyst

With dicyclohexylcarbodiimide as activator of carboxylic group (in dichloromethane, THF or dioxane as solvent).

You can carry out the reaction by heating in  dehydrating acid & amine solven .Dicyclohexylcarbodiimide(DCC) Or by heating  in SOCl2