MKSStal
Harmless
Posts: 21
Registered: 4-5-2015
Member Is Offline
Mood: No Mood
|
|
Quaternary ammonium salt from triethanolamine
For me typically used triethylamine is barely accesible. So I thought about reacting triethanolamine (HOC2H4)3N with
some alkyl halide to make quaternary ammonium salt. Do you think it will work or halide will rather attack oxygen atoms forming ethers?
|
|
|
Nicodem
|
Thread Moved
22-10-2015 at 10:02 |
MKSStal
Harmless
Posts: 21
Registered: 4-5-2015
Member Is Offline
Mood: No Mood
|
|
So in my opinion it depends on which alkyl halide would be used. For 1' reaction with alcohol shouldn't take place, for 2' might and for 3' would be
probably great problem
|
|
|
deltaH
Dangerous source of unreferenced speculation
Posts: 1663
Registered: 30-9-2013
Location: South Africa
Member Is Offline
Mood: Heavily protonated
|
|
You might also consider oxidising the triethanolamine with Caro's acid to form salts based on the protonated amine oxide or hydroxylammonium cation,
i.e. (HOCH2CH2)3N[+]-OH.
[Edited on 25-10-2015 by deltaH]
|
|
|
MKSStal
Harmless
Posts: 21
Registered: 4-5-2015
Member Is Offline
Mood: No Mood
|
|
Caro acid won't also oxidise hydroxyl groups to aldehydes or rather carboxilic acids?
|
|
|
deltaH
Dangerous source of unreferenced speculation
Posts: 1663
Registered: 30-9-2013
Location: South Africa
Member Is Offline
Mood: Heavily protonated
|
|
I'm not sure which would occur faster.
|
|
|
Pumukli
National Hazard
Posts: 708
Registered: 2-3-2014
Location: EU
Member Is Offline
Mood: No Mood
|
|
My two cents:
I would try something between methyl- to butyl-iodide. I mean the first four primary iodides may have chance to alkylate the N.
(N being more nucleophylic than O usually and primary alkyls having the least steric hindrance, though beyond 4 carbon in the chain the steric effect
probably would be too strong and prevent alkylation.)
If it worked you may still ran into problems because of the OH-s in the molecule though. These OH-s would surely affect the phys-chem properties of
the molecule and may react in the reaction where you used this salt. (Roughly: tetraethyl-ammonium-X and tetraethyl-beta-OH-ammonium-X are not the
same.)
|
|
|
byko3y
National Hazard
Posts: 721
Registered: 16-3-2015
Member Is Offline
Mood: dooM
|
|
MKSStal, look for neutral desinfection liquids, they contain quaternary ammonium chlorides.
Triethanolammonium is a no way to quaternary ammonium. Also, even if you have managed to prepare quaternary ammonium from triethanol amine, it would
not have the necessary PTC properties of quaternary ammonium salts.
|
|
|
MKSStal
Harmless
Posts: 21
Registered: 4-5-2015
Member Is Offline
Mood: No Mood
|
|
So, I tried to test it. On Tuesday I mixed about 13,2 ml (0,1 mol) of triethanolamine with 11,5 ml (0,1 mol) of benzyl chloride. BnCl I made myself by
reacting benzyl alcohol with hydrochloric acid. It was quite old sample, so it might contain some water in it. More probably because I haven't
purified it by destilation. And it has yellow colour (just after being created it was violet). I mixed it in 50ml Erlenmayer flask, capped and left to
react. After about 3 hours large mass of crystals have participated out. I left it to let the reaction come to the end (I thought that after the
reaction all liquid should convert into crystalline mass). And until today (Friday afternoon) nothing much changed. Crystalline mass and yellow liquid
above it. I decanted that liquid into test tube and heated for a while. Nothing happened even after cooling. However, by this operation I was able to
observ that crystals are colourless. Mass left in flask still is very wet so I'm thinking about adding some hexanes to it.
So I think that due to my experiment this reaction works but yield should be improved.
|
|
|
![[*]](images/xpblue/default_icon.gif){kind=icon}
