Sciencemadness Discussion Board

Question about Ullmann type coupling

tyro - 31-8-2023 at 13:44

I'm looking into the feasibility of synthesizing N-(2-carboxyphenyl)glycine from glycine and 2-bromobenzoic acid using an Ullmann coupling.

I found one vague example of such a reaction, but it has no information about reaction conditions, reactant amounts, yield, and provides no references1.

One paper indicates that glycine doesn't perform at all in an optimized Ullmann reaction where coupling of alpha-amino acids is able to occur at lower temperatures2. It's not clear to me if glycine's lack of reactivity in this case is due to more mild reaction conditions in the paper and/or differences in reactivity between bromobenzene/2-bromobenzoic acid, or is generalizable to more traditional reaction conditions as well. I'm struggling to find much other literature on such coupling reactions with glycine, or alpha-amino acids more broadly.

Is anyone able to provide insight or point me towards literature which might help me towards a better understanding here?

[1] - https://labphoto.tumblr.com/post/161476475556/the-ullmann-ty...
[2] - https://doi.org/10.1021/ja981662f

dettoo456 - 31-8-2023 at 14:58

What’s the end molecule you’re looking to make? If it’s just the 2-carboxyphenylglycine, then you could try the rxn in a standard molar scale with a Cu(I) catalyst and phenanthroline - the only expensive reagent would be the 2-bromobenzoic acid and even if you didn’t get any product you wouldn’t really lose any $.

Or just react anthranillic acid with ClAcOH, they’re both dirt cheap and that would yield the product you’re after, right? Or do you want the bi-aryl product?