A convenient synthesis of bisamides with BF3 etherate as catalyst

A convenient synthesis of bisamide from aldehyde and amide with BF3 etherate as catalyst was reported. Both aryl and aliphatic bisamides could be prepared with this procedure in high yield at room temperature and the catalyst loading as low as 0.5 mol % was achieved. Fine-tuned solvent was utilized for both rapid conversion and simple isolation. Two CB2 receptor inverse agonists were synthesized with this protocol in high yield.