Sciencemadness Discussion Board

ethanolamine

acx01b - 13-11-2005 at 09:44

hi, how is there many reactions to make CH2OH-CH2-NH2 ?

Axt - 13-11-2005 at 11:18

I guess diazotisation of excess ethylenediamine will get you it, but ethanolamine is common OTC.

<center><img src="http://scimadpic.webtop100.net/images/ethanolamine-can.jpg"></center>

Search for oven cleaners and such.

unionised - 13-11-2005 at 12:15

Ethylene oxide and excess ammonia is a bit more traditional but just buying it seems a lot easier.

Marvin - 13-11-2005 at 12:32

Its popular as an alternative to sodium hydroxide for developing PCBs. 25% with something like 2-butoxy ethanol as the main solvent. Probably a lot purer source than cleaners.

Axt - 13-11-2005 at 16:29

Anyone have info on the azeotrope's boiling point and %'s of ethanolamine/water ? (whats the max concentration that can be made by boiling).

garage chemist - 25-3-2007 at 14:27

Ethanolamine does not form an azeotrope with water. It can be produced in over 99% purity by fractional distillation from an aqueous solution.

Let me use this thread for a discussion about the possible uses of mono- and diethanolamine for the hobby chemist, since I have recently acquired some of both.
With the monoethanolamine, I want to try to make:

-aziridine (esterification with H2SO4 or HBr, followed by treatment with strong NaOH solution to effect intramolecular alkylation)

- diphenhydramine (Benadryl), by first subjecting it to an Eschweiler-Clarke methylation to form N,N-dimethylethanolamine and then etherifying it with benzhydrol (diphenylmethanol). The benzhydrol will be prepared from phenylmagnesium bromide and benzaldehyde, the bromobenzene for this will also be prepared by myself.

With the diethanolamine, I had the preparation of piperazine in mind (esterification with HCl to dichlorodiethylamine (this is not a nitrogen mustard!), followed by reaction with an amine or ammonia), but now realized that this would be not so easy.

Do you know any other interesting syntheses with ethanolamines?
I can think of:
- acetylcholine
- detergents (ethanolamine soaps)
- maybe lidocaine (ethylation, followed by oxidation and reaction with m-xylidine, but it would probably be better to start with chloroacetic acid and diethylamine)

[Edited on 25-3-2007 by garage chemist]

Eclectic - 26-3-2007 at 04:42

Ethanolamine is apparently a good thing to have handy in a wash bottle to save your bacon:

http://orgprepdaily.wordpress.com/?s=ethanolamine

garage chemist - 26-3-2007 at 08:08

Yes, I've seen that link before.
My ethanoamine was expensive though (its biochemical grade, very pure), and I have only a small bottle (500ml), and I can't buy it again easily.
And I dont use large amounts of thionyl chloride.