| Pages:
1
..
11
12
13
14
15
..
28 |
Panache
International Hazard
Posts: 1290
Registered: 18-10-2007
Member Is Offline
Mood: Instead of being my deliverance, she had a resemblance to a Kat named Frankenstein
|
|
what is the most likely culprit for tubidity in my sodium methoxide solution. I am making the methoxide by adding sodium metal to methanol, the
methanol was dried over potassium carbonate, its density coming in at 0.78g/l, the sodium was patted to absorb excesss mineral oil then rinsed in
methanol then added to fresh methanol. My only guess is that some paraffin was not effectively removed and this is forming a verry finely divided
suspension, to test this i allowed a hunk of sodium to half dissolve before adding it to fresh methanol. All glassware was dry however what would the
visual result be of using less than optiomally dry glassware i imagine one could not distinguish between a methoxide/hydroxide solution in methanol
and a methoxide solution in methanol.
|
|
|
Fleaker
International Hazard
Posts: 1252
Registered: 19-6-2005
Member Is Offline
Mood: nucleophilic
|
|
A shot from the ship here, but I think it is probably carbonate from minuscule amounts of CO2 reacting with the alkoxide.
Whenever I make methoxide solutions (especially the more concentrated it gets) I always notice this turbidity too whenever it is exposed to air. On
one occasion, I made up a methoxide solution in MeOH and did it under argon and it was clear. Convinced me!
Neither flask nor beaker.
"Kid, you don't even know just what you don't know. "
--The Dark Lord Sauron
|
|
|
Panache
International Hazard
Posts: 1290
Registered: 18-10-2007
Member Is Offline
Mood: Instead of being my deliverance, she had a resemblance to a Kat named Frankenstein
|
|
| Quote: | Originally posted by Fleaker
A shot from the ship here, but I think it is probably carbonate from minuscule amounts of CO2 reacting with the alkoxide.
Whenever I make methoxide solutions (especially the more concentrated it gets) I always notice this turbidity too whenever it is exposed to air. On
one occasion, I made up a methoxide solution in MeOH and did it under argon and it was clear. Convinced me! |
Voila!, under argon tis also clear for me, thanking you!
|
|
|
raiden
Harmless
Posts: 38
Registered: 4-2-2008
Member Is Offline
Mood: Curious
|
|
Further to my vacuum questions, are there any good ways to improvise a cold trap? Just gave my medical pump a run and was boiling water at room temp
with a change of oil 
|
|
|
Panache
International Hazard
Posts: 1290
Registered: 18-10-2007
Member Is Offline
Mood: Instead of being my deliverance, she had a resemblance to a Kat named Frankenstein
|
|
| Quote: | Originally posted by raiden
Further to my vacuum questions, are there any good ways to improvise a cold trap? Just gave my medical pump a run and was boiling water at room temp
with a change of oil |
Man i have ben hanging out to give this tip. I use an ice-cream maker for my benchtop vac-pump cold trap. its probably the best thing i've ever
improvised. It sits at -45. I turn it on at the start of the week and off at the end of the week, it has a basin of 1.5l in size which perfectly fits
a 1L schott bottle and about 10mm of space around it to fill with methylated spirits as the cold bit. I simply have a bubbler head on the bottle. It's
important to have any bleed valve (that bleeds to atmosphere) you might have between the cold trap and the pump, otherwise you consume all your
cooling capacity cooling down the bleed air.
Of course it has it limitations being only at -45 but it beats the hell out of dry-ice or liq N2 for convenience. Its an italian thing but sold
throughtout australia, i got mine second hand for like $30 because the stiring mechanism was broken, but given i wasn't making ice cream iit really
didn't matter. Apparently this model always breaks stirrers so you should find one easily. The brand name is Nimox.
|
|
|
Aubrey
Harmless
Posts: 37
Registered: 16-11-2008
Member Is Offline
Mood: No Mood
|
|
Ethylamine Synthesis?
I've searched fo a synth for this, wikipedia is a little lacking, would be interested to know how people here make it
thanks in advance
|
|
|
Klute
International Hazard
Posts: 1378
Registered: 18-10-2006
Location: France
Member Is Offline
Mood: No Mood
|
|
I don't thin k many people make it themselves, this is the kind of chemical that is much easier to purchase than to make...
Best options seems to me as been ethylation of protected ammonia, forming either the benzaldimine, or the phtalimide.. Ethylating acetamide or
formamide with EtX, KOH and a PTC might be another good option, hydrolyzing the amide and distilling the ethylamine solution out.. There was a thread
on diethylamine synthesis where I gave a few references on the subject, check it out: diethylamine synthesis.
I think there are some vapor methods using ethanol, ammonia and some catalyst, although you would surely obtain a mixture or mono-di and perhaps
triethylamines.
\"You can battle with a demon, you can embrace a demon; what the hell can you do with a fucking spiritual computer?\"
-Alice Parr
|
|
|
DJF90
International Hazard
Posts: 2266
Registered: 15-12-2007
Location: At the bench
Member Is Offline
Mood: No Mood
|
|
How about an Sn2 reaction between ammonia in an appropriate solvent and an ethyl halide. A large excess of NH3 should be used to prevent multiple
N-subtitutions (forming di and tri ethyamines, and quaternary ammonium salt).
|
|
|
Klute
International Hazard
Posts: 1378
Registered: 18-10-2006
Location: France
Member Is Offline
Mood: No Mood
|
|
No, unfortunaly this reaction cannot be used in a preparative way, there will always be various poly-alkylation products... Well, as far as I know.
I would rather concentrate on reactions producing only the primary amine, as seperating them will not be easy.
\"You can battle with a demon, you can embrace a demon; what the hell can you do with a fucking spiritual computer?\"
-Alice Parr
|
|
|
12AX7
Post Harlot
Posts: 4803
Registered: 8-3-2005
Location: oscillating
Member Is Offline
Mood: informative
|
|
Phthalimide process.
Phthalic acid or anhydride + ammonia --> phthalimide (or buy phthalimide itself)
Phthalimide + base (pKa ~ 9) + electrophile (e.g. bromoethane) --> N-ethyl phthalimide
Hydrolyze alkyl phthalimide with dilute H2SO4. Freebase monoalkyl amine, purify etc.
Tim
|
|
|
Formula409
Hazard to Others
Posts: 129
Registered: 13-12-2008
Member Is Offline
Mood: No Mood
|
|
Does anyone have any information regarding extracting PTCs from shampoos etc?
Formula409.
|
|
|
kclo4
National Hazard
Posts: 916
Registered: 11-12-2004
Location:
Member Is Offline
Mood: No Mood
|
|
What PTCs are even in Shampoos?
|
|
|
Formula409
Hazard to Others
Posts: 129
Registered: 13-12-2008
Member Is Offline
Mood: No Mood
|
|
| Quote: | Originally posted by kclo4
What PTCs are even in Shampoos? |
I do not know. I have read several forum posts which mention extracting them from shampoos and conditioners with no citations  Hmm. Will try and post links, however, with most things when you're looking for it you
can never find it.
Formula409.
[Edited on 15-12-2008 by Formula409]
|
|
|
12AX7
Post Harlot
Posts: 4803
Registered: 8-3-2005
Location: oscillating
Member Is Offline
Mood: informative
|
|
My shampoo lists ammonium laureth/lauryl sulfate, polymethacrylamidopropyltrimonium chloride and other chemicals that sound rich with alkyl chains.
Detergents, especially antibacterials, often contain quaternary amines, though usually much larger than your average PTC, things like (12 to 18)-alkyl
phenylethylmethylammonium.
Tim
|
|
|
not_important
International Hazard
Posts: 3873
Registered: 21-7-2006
Member Is Offline
Mood: No Mood
|
|
| Quote: | Originally posted by Aubrey
Ethylamine Synthesis?
|
Might consider the Hofmann rearrangement of propionamide.
Having said that, I've used the reaction of ethanol with ammonia over hot Ni-Cu to get a mix of all three ethyl amines and fractionated them.
Wintertime in an unheated area and it's just separating three compounds that have boiling points about 40 C apart.
|
|
|
kclo4
National Hazard
Posts: 916
Registered: 11-12-2004
Location:
Member Is Offline
Mood: No Mood
|
|
| Quote: | Originally posted by Aubrey
Ethylamine Synthesis?
I've searched for a synth for this, wikipedia is a little lacking, would be interested to know how people here make it
thanks in advance |
I'm not sure, This is how I would attempt to make it. I beleive Acetaldehyde + Ammonia might form a complex similiar to that of hexamine, which is
formed from Formaldehyde and Ammonia.
You could then react that compound with some hydrochloric acid as they do hexamine in the methylamine synthesis. Look around on the Rhodium Archive,
It has some information on making Methylamine.
If this reaction worked, it would allow using aqueous reagents, making it easier to produce mostly Ethlyamine, instead of the other amines that can
form as well.
Ammonia and Ethanol seem like it would be nice, if you could regulate it to form mostly Ethylamine however.
Hoffman degradation would probably be the best if you could find the appropriate amide, which might be tricky, however acetaldehyde might be a bit
tricky to get also.
|
|
|
Axt
National Hazard
Posts: 814
Registered: 28-1-2003
Member Is Offline
Mood: No Mood
|
|
| Quote: | Originally posted by Aubrey
Ethylamine Synthesis?
|
Theres over 800 articles on scifnder reporting its preparation or at least as a product of a reaction. 145 reactions are given of which 100 are
attached, they seem mainly by way of hydrogenation of acetonitrile.
There was only one reporting an ethyl analogue of hexamine and then no preparation, and was only a Jap patent.
Attachment: ethylamine product reactions.pdf (250kB)
This file has been downloaded 2007 times
|
|
|
Rosco Bodine
Banned
Posts: 6370
Registered: 29-9-2004
Member Is Offline
Mood: analytical
|
|
Nitroethane could possibly be reduced to ethylamine.
Al amalgam or Al isopropoxide would probably do it.
Metaldehyde and ammonium nitrate would possibly react
giving a nitrate salt which could then be basified to
free the volatile amine. This is not something I have ever seen described
but there is an analogous reaction for methylamine.
These reactions could be hazardous, but manageable.
You would have to distill out the free amine and
absorb it in water.
[Edited on 17-12-2008 by Rosco Bodine]
|
|
|
Klute
International Hazard
Posts: 1378
Registered: 18-10-2006
Location: France
Member Is Offline
Mood: No Mood
|
|
I'm sure to many nitroethane is more preciosu than ethylamine  I think the idea
of oxidizing ethylamine to nitroethane popped up a few times!
I'm very impressed by the fact that Not_important succeded with vapor phase method, it would seem it is a very usefull procedure as diethylamine and
triethylamine are also valuable reagents. I had just assumed seperating ethylamine and diethylamine would be very tricky..
How did you prepare your catalyst Not_important?
\"You can battle with a demon, you can embrace a demon; what the hell can you do with a fucking spiritual computer?\"
-Alice Parr
|
|
|
brew
Hazard to Self
Posts: 96
Registered: 25-4-2008
Member Is Offline
Mood: enthralled
|
|
question regarding spongy copper being used as electrodes, well this is what an article has implied. I have somewhat sorted this out.
[Edited on 19-12-2008 by brew]
[Edited on 19-12-2008 by brew]
|
|
|
solo
International Hazard
Posts: 3975
Registered: 9-12-2002
Location: Estados Unidos de La Republica Mexicana
Member Is Offline
Mood: ....getting old and drowning in a sea of knowledge
|
|
What would o-Phenylenediamine be called if it had a methylamine attached at both sites instead of the amine......solo
[Edited on 20-12-2008 by solo]
It's better to die on your feet, than live on your knees....Emiliano Zapata.
|
|
|
sparkgap
International Hazard
Posts: 1234
Registered: 16-1-2005
Location: not where you think
Member Is Offline
Mood: chaotropic
|
|
That would conceivably be N,N'-dimethyl-o-phenylenediamine, or better yet, 1,2-bis(methylamino)benzene.
sparky (^_^)
"What's UTFSE? I keep hearing about it, but I can't be arsed to search for the answer..."
|
|
|
solo
International Hazard
Posts: 3975
Registered: 9-12-2002
Location: Estados Unidos de La Republica Mexicana
Member Is Offline
Mood: ....getting old and drowning in a sea of knowledge
|
|
......follow up question regarding amines
if this is true,
o-Phenylenediamine condenses with ketones and aldehydes to give rise to Schiff bases.
.......source,
http://en.wikipedia.org/wiki/O-Phenylenediamine
....then can this also be true?
N,N'-dimethyl-o-phenylenediamine condenses with ketones and aldehydes to give rise to Schiff bases.
It's better to die on your feet, than live on your knees....Emiliano Zapata.
|
|
|
kalacrow
Harmless
Posts: 38
Registered: 23-5-2008
Member Is Offline
Mood: No Mood
|
|
Industrial Chemistry Question
Re: The Sodium-mercury amalgam created by electrolysis of a saturated NaCl solution - applicable to Li ?
Very facile process, and although you do need to distill off the mercury at the end to get the pure sodium out, it does work. It was originally used
to make NaOH, but instead of adding water at the end, you can just remove the mercury.
I was wondering, I was looking at the LiCl/KOH electro process and I wondered if anything analogous to the sodium process could be done here? I am
guessing I would have found something already if so... but I do know that Li/Hg forms an amalgam when mixed, and so the stopping block would be the
solvent, electrochemical problems.
That is to say, is there a solvent that would free the Li ions, allow for electro amalgamation at a mercury cathode, and release Cl gas as a
byproduct, meanwhile amalgamating the Li ions into the mercury, or is that just wishful thinking?
For that matter, what about KCl?
Pointing me at an Electro chem reference that resolves this would be a fine answer, as well!
Thanks
|
|
|
not_important
International Hazard
Posts: 3873
Registered: 21-7-2006
Member Is Offline
Mood: No Mood
|
|
Lithium amalgam is less reactive towards water than sodium amalgam, you should be able produce low concentrations of Li without much trouble. Or at
least much trouble from a technical standpoint, as Li-6 concentrates in the mercury the process is used to produce lithium enriched in Li-6 for
tritium production, and thus falls into the arena of nuclear weapons technology.
here's a little on making Li-Hg amalgam and extracting Li metal from it.
Attachment: 80971.pdf (551kB)
This file has been downloaded 1238 times
|
|
|
| Pages:
1
..
11
12
13
14
15
..
28 |
![[*]](images/xpblue/default_icon.gif){kind=icon}
