Sciencemadness Discussion Board

OTC synthesis of precious catalytic amines?!

mfilip62 - 14-12-2017 at 06:33

I am interested if anyone knows how to make things like TMEDA and DIPEA/DIEA OTC!?

Hünig's base (N,N-Diisopropylethylamine aka. DIPEA/DIEA) is extremely valuable catalytic substance that gives quantitative yields of secondary and tertialy amines from Halogenated Organic substances (even Chlorides),some common solvents and primary/secondary amines without the need for complex,expensive and dangerous reactants reserved for proffesional labs like liquid NH3+Alkaly Metals/Alkaly metal Amides and Hydrides.
See for yourself! http://www.arkat-usa.org/get-file/19416/

Easiest published synthesis suggest the use of diisopropylamine with dangerous diethyl sulfate.
But if you have even the smallest sample of Hünig's base,which is apparently autocatalyc
(promotes it's own synthesis) one could make it using things like IsopropylHalide+Bromoethane
+ammonia or acetone+hydoxylamine+Bromoethane or Ethylamine+IsopropylHalide or any such derivation of those easy to find/synthesize chemicals!
Does anyone has more concrete idea/process on their minds!?

Other such catalyst is TMEDA,which has numerous aplications could be made by halogenating 1,2-ethandiol on both ends and reacting it with
N,N-Dimethylamine (with presence of Hünig's base for example!)
And N,N-Dimethylamine is readily available trough number of processes (destructive distillation of N,N-DMF+NaOH for example)

Or even better,from completely unregulated and unwatched chemical sold at every pharmacy:
chelating agent EDTA! One could use number of Decarboxylation techhiques,one of them should work and viola:
This https://en.wikipedia.org/wiki/Ethylenediaminetetraacetic_aci...
becomes
this https://en.wikipedia.org/wiki/Tetramethylethylenediamine#/me...


What do you think!?

clearly_not_atara - 14-12-2017 at 11:57

Hunig's base is correctly made by alkylation of diisopropylamine with ethyl something. Diethyl sulfate is not too hard to make OTC but I bet if you mix diisopropylamine and ethyl bromide and let it sit for a week you'll get a decent yield of DiPEA. Once upon a time someone tried to do this by adding two isopropyl groups to ethylamine. That does not work, don't bother with it.

But people exaggerate the importance of DiPEA. While it does improve yields, you get decent yields of most tertiary amines using sodium carbonate as the base.

Dimethylethylenediamine can bee had by Eschweiler-Clarke permethylation of ethylenediamine. As for ethylenediamine itself it's hard to make so I suggest buying it. Dimethylamine is very hard to handle due to its low bp and strong odor. I don't recommend this route. It's a pretty niche ligand, anyway; I can't think of anything off the top of my head that requires it.

Corrosive Joeseph - 14-12-2017 at 12:21

Quote: Originally posted by clearly_not_atara  

While it does improve yields, you get decent yields of most tertiary amines using sodium carbonate as the base.


That is a quality piece of information for anyone interested in this.

And......

"Preparation of Hünig's base (diisopropylethylamine)"
https://www.sciencemadness.org/whisper/viewthread.php?tid=28...


/CJ

[EDIT] - Caffiene Deficiency


[Edited on 15-12-2017 by Corrosive Joeseph]

sykronizer - 18-12-2017 at 12:05

If you are really in need, you can also do an organic solvent extraction of Glyphosate based weed killers...yes I know how that sounds but it works..you will find that nearly all common cheapo weedkillers have the active ingredient, at up to 36 percent, made into a salt using simple amines, usually methyl amine, or di-isopropyl amine, or diethyl amine etc and free basing that out with Sodium Hydroxide is very easy, it is a ready source of these amines for whatever application you might have in mind.

Melgar - 2-2-2018 at 01:19

Quote: Originally posted by sykronizer  
If you are really in need, you can also do an organic solvent extraction of Glyphosate based weed killers...yes I know how that sounds but it works..you will find that nearly all common cheapo weedkillers have the active ingredient, at up to 36 percent, made into a salt using simple amines, usually methyl amine, or di-isopropyl amine, or diethyl amine etc and free basing that out with Sodium Hydroxide is very easy, it is a ready source of these amines for whatever application you might have in mind.

Pretty sure the amine that's used 99% of the time is isopropylamine. Just regular monoisopropylamine at that.

Cryolite. - 2-2-2018 at 02:15

Monoisopropylamine is still useful for conversion to diisopropylamine: see Scr0t's preparation of DiPA and subsequently DiPEA at http://www.sciencemadness.org/talk/viewthread.php?tid=28429

Melgar - 2-2-2018 at 05:11

Anyone feel like ordering diisopropylamine in a group buy? This seems to have come up a few times recently. 99% is maybe $40/liter. The monoisopropylamine is about the same.