[cathi_]

Hey there,
I cant figure out the mechanism of a reaction I need to explain in a homework for uni as nothing seems to make sense.

The reaction is an acid-katalysed reaction from a Fluor-substituted pyridine to a pyridone. The reaction is carried out at 100°C with 100%acetic acid as the acid component.

How is this reaction able to work with Flour being such a bad leaving group an acetic acid as a weak nucleophile? Is this even a nucleophilic substitution or something else (cant think of anything else actually)?
Help would be so appreciated!

[cathi_]

This is the reaction:

[Borek]

What is Ka of HF? At what pH does the reaction take place?

(I am not saying it explains anything, but it is an obvious thing to consider)

[cathi_]

The reaction takes place at pH 2,5 as 100% acetic acid is used an other solvents were removed before hand. the Ka oh HF is 3.15
Im not really sure what to do about this information

[Borek]

If it is in pure acetic acid speaking of pH doesn't make much sense, as pH is a property of a water solution.

Still, do you think you have F^- in the liquid phase, or is it mostly protonated?

[AWK]

The reaction takes place at pH 2,5 as 100% acetic acid is used an other solvents were removed before hand. the Ka oh HF is 3.15
Im not really sure what to do about this information

pH 2.5 shows ~4% or ~0.6 M acetic acid.