[408]

Hi,

I have a heterocyclic amine which I need to protect towards oxidizing conditions.  Any recommended protecting groups?  It needs to survive aqueous acidic peroxide based oxidation reagents.

Thanks,
408

[Honclbrif]

You can probably get away with Fmoc

[OC pro]

If it is only slightly acidic: Boc boc boc boc boc boc...one of my favorites.
Survives generally even acetic acid at room temperature.

[Oxime]

Cbz (Benzyloxy carbamate) protecting group is stable to even highly acidic conditions (TFA at room temp, 2-4 hours) but I'm not sure about its stability under oxidative conditions.

[Honclbrif]

Depending on what's being oxidized, it may all be undone when removing the Cbz.

[fledarmus]

Echo what Honclbrif said - you may need to select your deprotection conditions carefully. Cbz is frequently removed by reduction, which may also reduce the group you just oxidized.

[408]

I will give the above a shot!  Thanks!

[Åke]

You can probably get away with Fmoc

Is using Fmoc really getting away with it? 408, have you considered good old acetyl? Trifluoroacetyl is another, very useful protecting group for amines, it's really easy to attach and to hydrolyze - I'd give it a shot. Next on the list would be tosyl and analogs. I'd consider fancy protecting groups only if the simpler ones would prove unsuitable. What ya reckon, bad boys? 

[408]

I protected with pthalic anhydride   cheap and easy. 
And far more stable than the others, its gotta survive hypofluorous acid ( Did I mention I love my chemistry?)

[Åke]

I protected with pthalic anhydride   cheap and easy. 
And far more stable than the others, its gotta survive hypofluorous acid ( Did I mention I love my chemistry?)

That's interesting, I didn't suggest phtalimide earlier since I assumed that your amine wasn't a primary one - based on your earlier post:

Hi,

I have a heterocyclic amine which I need to protect towards oxidizing conditions.  Any recommended protecting groups?  It needs to survive aqueous acidic peroxide based oxidation reagents.

Thanks,
408

Now, either your "heterocyclic amine" substrate contains a mysterious primary amino group, which you happily protected with phtalic anhydride, or you made a really bad choice when selecting a protecting group for the endocyclic amino group. 

[Honclbrif]

Also, when did we go from peroxide to hypofluorous acid?

[408]

It was a heterocyclic N-NH2 group.  Sorry for confusion.

HOF stinks. Fluorine smells like clean chlorine, but this stuff smells like F2 farted in an elevator.

[veselin]

Is Phthalimide as protective group for amines stabile in alkylation with NaH/propargyl bromide? Thanks