mhalizade - 27-2-2009 at 22:35
Hi
I want react oxalic acid with a secondary amine to make a heavier secondary amine.
Please help me about reaction condition & ... .
Do you have a suggestion for replace oxalic acid with another acid?
[Edited on 28-2-2009 by mhalizade]
Sauron - 27-2-2009 at 22:57
There may be a difference between what you want and what is possible.
What makes you believe that oxalic acid and a secondary amine will react at all?
And if they did, they would not form a heavier amine but an amide.
To make that reaction happen you would need oxalyl chloride not oxalic acid.
Or you might prepare an oxamide from an oxalate ester and an amine although I am not sure a secondary amine will do this.
Then, you would have to reduce your intermediate to obtain a tertirary amine, with the oxalyl group reducing to ethyl. LAH most likely reagent.
As always please be specific about what substrate you are wanting to react and what is your target compound.
And kindly give us some sense that you have consulted the literature. Provide citations and references and do so coherently.
Otherwise no one can help you.
chemrox - 28-2-2009 at 11:53
A sec amine and oxalic acid should make the oxalate salt of the amine. These are used a lot, along with picates, for melting points. I am going to
look up the general method unless someone wants to post it (hopeful).
Sauron - 28-2-2009 at 12:02
The fellow is not trying to take a mp, he said he wants to make a heavier amine.
Only way he will do that from a secondary amine and anything like oxalic acid (or ano ther carboxylic acid) is by preparing an amide and reducing it.
Reacting the acid per se with the amine is hard, but reacting the acyl halide with amine is easy.
Or am I missing something? The fellow's post is very vague.
Klute - 28-2-2009 at 12:29
Very vague, indeed. I guess he is talking about forming the oxalate rather than a tertiary amine though. In that case, forming a solution of anhydrous
oxalic acid in methanol (by azeotropic drying with pet ether, followed by decantation and addition of dry MeOh), and dripping in stoechiometric amount
of the amine freebase is the way to go. The oxalate precipitates nicely, sometimes forming a gel-like slusge (addition of pet ether or toluene helps
getting a granular solid).
I have used this method successfully on several amines, so it should be pretty universal.
Sauron - 28-2-2009 at 12:52
I say let the fellow identify his amine and say what he wants clearly, otherwise we might as well be replying to globey.
chemrox - 1-3-2009 at 01:29
Yeah but hey Klute, thanks for the tip. I haven't done it before and was thinking of doing it for a melting point .
Nicodem - 2-3-2009 at 00:35
I don't have a clue what "a heavier secondary amine" is supposed to mean, but I guess this should go to Beginnings section.