njl - 4-7-2020 at 17:40
I first mentioned this in a short thread titled "Definitive POCl3 Prep" but got no response. Anyway: P2O5 can dehydrate primary amines to nitriles,
and I assume that if an ammonia carboxylate salt is used in place of a primary amide then the dehydration will roughly end up in the same place, with
the primary amide formed as a dehydrated intermediate. Since the nitrogen in a nitrile is fully bonded to a carbon, it follows that a substituent on
that original amine might prevent nitrile formation and stop at the substituted amide. When doing a bit of searching for amide synthesis by
dehydration all I can find are procedures for simple and robust lower amides that simply use heat to drive of the water. Would a dehydrating agent
like P2O5 work for amide synthesis? If anyone knows then I won't waste anyone's time on it but if nobody can find any glaring holes in this logic then
I would like to do some experimenting.
Sigmatropic - 5-7-2020 at 08:05
https://www.sciencedirect.com/science/article/pii/S004040391...
njl - 7-7-2020 at 13:58
I didn't see any mention of secondary amines, is there a obvious reason why that is?