I want to know the role of N-Nitrosobis(2-oxopropyl)amine reagent in the following amide formation from compound 11 to 12. Is there any specific reason for its use here?
If possible, please explain with mechanism as well.
I see your point and it might be a mistake. Benzotriazole-1-yloxy- tris-(dimethylamino)-phosphonium hexafluorophosphate (BOP; Castro’s reagent) is well known for the coupling of amines with carboxylates and has the same abbreviation BOP !