[rolnor]

Thats true, para will not be a problem if not the phenylring itself is charged in some way.

[Babcock_Hall]

Just a quick update, our first attempt had some glitches which reduced yield, and we repeated the deacetylation.  This week we will purify the combined products and see what we have.

[rolnor]

How does it look on TLC?

[Babcock_Hall]

The product ran more slowly than the starting material on TLC, with the solvent being 3% acetone in DCM.  For a column 3% acetone is not polar enough to move the product much, but 6% is looking roughly right (the R_f was about 0.32).
EDT
Removal using hydrazine is probably a fine method, but if I had to start from scratch, I might use ammonia in methanol.

[rolnor]

That sound good. If you dipp the plate in 0.5%KMnO4 it should give strong staining compared to the diacetylcompound.

[Babcock_Hall]

Do I understand correctly that the phenol-type groups gives more reaction with KMnO₄ than the acetylated phenols?  I was unaware of that.

[kriggy]

Possibly due to oxidation to quinone(s) which is blocked when acetylated? Also, FeCl3 is selective stain for phenols giving gray ish spots on yellow/orange background IIRC.

Do you need to run the collumn? Dont know the structure but phenoxide could be water soluble so you can get rid of the remaining organics just by dissolving it in basic water and extract with organics, then acidify and maybe it precipitates or get extracted again.

[rolnor]

Yes, phenols stain KMnO4 very much, esters does not.

[Babcock_Hall]

We used d₆-acetone as our NMR solvent for the silica-purified material.  In retrospect my choice of solvent was not ideal; residual water is in the vicinity of the acetyl methyl groups, and the phenolic-OH signals were not strong.  There was a huge roll with an integral of less than one that may or may not have been a phenolic -OH.  The carbon NMR was a cleaner experiment; I have only glanced at it, but there is no sign of either carbon of an acetyl group.  Tentatively, I would say that the method was successful.  We may make up a sample in a different NMR solvent, such as DMSO.  Chloroform would be a challenge, but we might be able to get enough material into solution for ¹H NMR only.  Obtaining MS data is not trivial for us right now, but it may become much more routine in a few months.
EDT
Thanks to all.  Chemical Forums is a great resource for us!

[rolnor]

Great!

[Babcock_Hall]

One more follow-up:  I was able to get enough material into CDCl₃ for ¹H NMR, but the signal-to-noise ratio was low.  I see two candidates for the two Ar-OH hydrogens, and there is little to nothing where the acetyl methyl groups would be.  Again, thanks to everyone here.

[Babcock_Hall]

A very preliminary result suggests that our product has the desired biological effect (we have a long way to go).  I am very grateful for the advice received in these threads.

[rolnor]

Great!