Sciencemadness Discussion Board - Diethylamine Synthesis

Diethylamine Synthesis

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mbrown3391 - 8-9-2008 at 12:15

Yesterday, I mixed the stoichiometrically correct amounts of DEET and water (saturated with NaOH) and propylene glycol as a cosolvent. The mixture was placed in a stoppered flask and left at room temperature over night. When i checked it this afternoon, it had turned from white to yellow/orange colored. Clearly, some type of reaction is occurring. Are you sure this will not work at room temperature for extended time periods?

Klute - 8-9-2008 at 12:46

It's the base that needs to be in stoechiometric amount, not the water. This isn't a catalyzed reaction like acidic hydrolysis, but stoichiometric: if there isn' enough base around, you amide will not hydrolyze further....

mbrown3391 - 8-9-2008 at 12:50

oh i forgot about the base reacting with the methylbenzoic acid. I will add more tonight

But thats not the point. Is this reaction producing diethylamine at room temperature? or is there another possible reaction that would cause the coloration?

[Edited on 8-9-2008 by mbrown3391]

pantone159 - 8-9-2008 at 12:57

When I tried this reaction (DEET + NaOH + H2O + MeOH/EtOH), I got a pale yellow color as soon as I mixed all these up. Upon heating with a water bath, a pink/purple color formed, particularly on the surface of the liquid, and near the stopper on the test tube. I assume that there was some kind of reaction with air?

The pink/purple color seemed to be a reversible pH indicator, changing to yellow upon acidification, it also seemed to be a neutral organic compound (it stayed in a DCM layer vs. aq layer, both in acid and base conditions.)

However, I got these observations even when there seemed to be no sign of any free amine. (Meaning no ammonia-like smell. If you are making any significant amount of Et2NH in basic conditions, it should be obvious.)

[Edited on 8-9-2008 by pantone159]

Klute - 8-9-2008 at 21:26

There could be lots of polymerisation, condensation and other reactions going on at RT. Your DEET mixture is surely far from pur.

mbrown3391 - 15-9-2008 at 11:30

A transparent, red-brown third-layer has now formed in my solution and the mixture is in fact developing an ammonia-like smell. Apparently Diethylamine can have a brownish tint if it is impure. Even if i am producing Diethylamine, however, i'm sure at some point this reaction will reach an equilibrium. I could, however, distill out the diethylamine developed up to this point and let it keep going.

[Edited on 15-9-2008 by mbrown3391]

panziandi - 15-9-2008 at 11:40

are you using the glycol-hydroxide method? I suspect if you are you are getting condensation reactions perhaps. Collect you crude amine and redistil. You can dry the DEA with solid KOH and then distil it again if desired.

mbrown3391 - 15-9-2008 at 11:51

I am using a solution of 50% propylene glycol/distilled water saturated with NaOH. This is combined with 1 oz of 99% DEET. It has been sitting in a stoppered flask for 7 days now.

mbrown3391 - 15-9-2008 at 11:53

Actually, will an equilibrium be reached? If the DEA is in a separate layer then it is essentially removed from the reaction.

It Appears that the propylene glycol solution is on the bottom, followed by the DEET, followed by DEA on top. I guess the reaction is occurring very slowly where the bottom two layers meet, then the product rises to the top.

[Edited on 15-9-2008 by mbrown3391]

[Edited on 15-9-2008 by mbrown3391]

panziandi - 15-9-2008 at 12:11

I don't see why it would be in a separate layer, it is incredibly soluble in water. Can you not reflux the reaction mixture? It will almost certainly reduce the time required and should limit side reactions such as condensations which would develop over time in a stoppered flask.

mbrown3391 - 15-9-2008 at 12:14

I don't currently have a hotplate/stirrer and im not sure if it is a good idea to attempt to reflux it without one.

panziandi - 15-9-2008 at 12:22

If you clamp it well and have a descent reflux condenser you should be able to reflux it fine with a small burner. If your water isn't cold from the tap chill water with ice in a bucket and pump it through you condenser with a pond pump should do wonders. Boiling will also keep the layers moving so the DEET and hydroxide will be constantly mixed together. And little DEA should escape, even so do it outside if possible. Then swap the setup around and distil off the amine, dry it with KOH and redistil. You could probably set up something where the DEA distils off as it is formed. Chill the reciever with iced-water though!

S.C. Wack - 15-9-2008 at 16:43

I'd recommend a Friedrich condenser for the reflux, I should have put on a 24/40 adapter and used one instead of the 19/22 Liebig. The receiver contained fuming HBr. The hydrobromide is no less hygroscopic than the HCl salt.

mbrown3391 - 15-9-2008 at 17:51

All i have is an Allihn condenser and its quite oversized to say the least (around 30 inches a believe!)

panziandi - 16-9-2008 at 04:27

You could try it I suppose, Lead a vapour tube from the top through a wash bottle of HCl or water that way any escaping DEA fumes will be caught and you can maximise your yields by reducing losses.

S.C. Wack - 1-1-2009 at 17:24

Back in the day, some people were happy with preparation of ethylamines from ethyl bromide, with separation of the mixed amines utilizing ethyl oxalate. Authors preparing their own amine reagent tend not to detail this separation method in their journal references decades after this was introduced, and there seemed to be some conflicting vague details, so I searched for the best way of doing this in the original lit and here it is; I suppose Houben-Weyl has details as well. There are other methods in the older lab manuals.

The methylamines are also made here, in a way that I don't recall hearing of before, using methyl nitrate instead of a halide.

68 pages in French. An abstract in English starts on page 6 here.

Oh BTW after my experiment above, I ended up isolating a considerable amount of additional hydrobromide salt after workup, so my yields given above were quite low. Do not use HBr for neutralization of the amine.

[Edited on 1-1-2009 by S.C. Wack]

Attachment: ann_chim_phys5_23_289_1881.pdf (2.1MB)
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help hydrolyzing DEET

poisoninthestain - 7-3-2009 at 02:00

I've tried several times to hydrolyze DEET into its corresponding carboxylic acid and amine. I used 20%, 30%, and 98% DEET and still no success. I added various solutions of NaOH and H20(distilled) and the first thing that comes over during distillation is something around ~80C WTF!

There was a definite color change after adding the NaOH to a red, and once heat was added it changed yet again to a "bromine" brown.

...still confused. maybe it needs more time to react. diethylamine is the goal here.

[Edited on 7-3-2009 by poisoninthestain]

garage chemist - 7-3-2009 at 02:10

Try using HCl instead, and reflux for a long time.
If it worked, you will immediately see it upon cooling the solution- the m-toluic acid will precipitate. Filter, basify, distill diethylamine.
If there is no reaction with refluxing HCl, try adding a solvent that dissolves both the organic and the aqueous phase.

poisoninthestain - 7-3-2009 at 03:38

Quote:

Originally posted by garage chemist
Try using HCl instead, and reflux for a long time.
If it worked, you will immediately see it upon cooling the solution- the m-toluic acid will precipitate. Filter, basify, distill diethylamine.
If there is no reaction with refluxing HCl, try adding a solvent that dissolves both the organic and the aqueous phase.

I'll try refluxing for 1 hour with concentrated HCl and report back. The diethylamine should form the hydrochloride salt too so I'll most likely have to basify and distil again. Hopefully, acid catalyzed hydrolysis for amides is more effective than base. My organics text by "L.G. Wade" hints otherwise.

[Edited on 7-3-2009 by poisoninthestain]

garage chemist - 7-3-2009 at 05:10

I just remembered my experience with hydrolysis of benzyl cyanide to phenylacetic acid- with 70% H2SO4, 10 minutes reflux were enough for complete hydrolysis, while with 30% NaOH, there was still unconverted benzyl cyanide after 45 minutes reflux.
The H2SO4 has the big advantage of reaching higher temperatures.
If HCl doesn't do the job, try 70- 80% H2SO4 instead.
For workup, dilute with water and filter before basifying.

Paddywhacker - 7-3-2009 at 14:29

Original poster, with NaOH hydrolysis you do not need water.

Try a test-tube experiment.

Add 0.5 g NaOH to a clean dry test tube.
Add 5 ml of ethylene glycol, propylene glycol, or, maybe, glycerol.
Heat to dissolve the NaOH.
Cool.
Add 1 ml of DEET.
Add a boiling chip.
Carefully heat with agitation and report any observations.

Edit:
We all start out without much practical experience. Those of us that are canny enough to avoid killing or maiming ourselves, physically or mentally, are the old hands you see today.

So take my advice when I strongly advise you not to scale up this hydrolysis as much as you have done. An accident with NaOH dissolved in hot glycol will cut you to the bone. Keep it small.

Edit for pantone159 and DJF90

R.CO.N(Et)2 + NaOH -> R.CO.ONa + NH(Et)2

Note.... no free water involved, although you could argue that NaOH is Na2O bound to water.

[Edited on 8-3-2009 by Paddywhacker]

pantone159 - 7-3-2009 at 15:23

Quote:

Originally posted by Paddywhacker
Original poster, with NaOH hydrolysis you do not need water.

But H2O is added to the products (H to the NHEt2, OH to the m-toluic acid), so I don't see how this could work without water.

DJF90 - 7-3-2009 at 16:08

paddywacker: I think you will find that water is required for the reaction. The sodium hydroxide is employed as a catalyst (an acid could be alternatively used). A concentration of about 2M NaOH is generally used for esters (IIRC) but amides will need a little more "wack" seeing as they are less reactive carboxylic acid derivatives. A 5M NaOH solution ought to do it I would think? Using base has the advantage (over acid catalysis) that the reaction is non reversible and so it is possible to hydrolyse all of the ester/amide, but acid hydrolysis can be good yielding so long as there is a lot of water present (as this shifts the equilibrium).

poisoninthestain - 7-3-2009 at 19:52

after trial and error countless times i have arrived at a single conclusion...base catalyzed hydrolysis of DEET will work...the reaction just has to be refluxed for a VERY VERY long time...unfortunately i do not have to the time or convience for that.

Paddywhacker - 7-3-2009 at 20:58

Quote:

Originally posted by DJF90
paddywacker: I think you will find that water is required for the reaction. The sodium hydroxide is employed as a catalyst (an acid could be alternatively used). A concentration of about 2M NaOH is generally used for esters (IIRC) but amides will need a little more "wack" seeing as they are less reactive carboxylic acid derivatives. A 5M NaOH solution ought to do it I would think? Using base has the advantage (over acid catalysis) that the reaction is non reversible and so it is possible to hydrolyse all of the ester/amide, but acid hydrolysis can be good yielding so long as there is a lot of water present (as this shifts the equilibrium).

Water is not required in the case of alkaline hydrolysis.
If you don't believe me then look up the hydrolysis of PET with NaOH in glycol in one of the other forums.

The only problem is that you will get a slurry of the sodium salt that might cake at the bottom and lead to overheating if you scale it up.

Do as I suggested and perform the experiment on a test tube scale, then tell me which of us is mistaken.

Edit:
I am quite prepared to eat my words.... I have been wrong before and will be so again.... that is how we all learn. But first do the experiment.

[Edited on 8-3-2009 by Paddywhacker]

DJF90 - 7-3-2009 at 21:21

Ideally water is present, but you are correct in saying that it is not needed. Heating an ester or amide with solid NaOH is pretty extreme though, when a solution of NaOH will do just fine. The water will aid the reflux, as you indirectly suggest.

Fusing an ester/amide with NaOH cannot really be done in a flask (i.e. on a preparative scale) because the molten caustic soda will eat away at the glass. This generally leads to using a corrosion resistant material (stainless steel? or nickel?) which is usually of the open topped variety (e.g. a crucible) for the hydrolysis (as in the thread you point to). At the temperatures required for fusion of the NaOH, the Et2NH is readily vaporised (bp ~ 50C) and I can imagine rigging up some kind of condenser to such a setup kind of challenging.

Using a solution of sodium hydroxide for the hydrolysis means a quickfit apparatus can be used, with minimal/no corrosion so long as the concentration is low enough. Most Et2NH will reflux back into the flask and when the hydrolysis is deemed complete, it can be distilled from the mixture.

My point is that fusing with NaOH is fine for isolating the m-toluic acid, but in the case of the volatile amine, an aqeuous solution is likely to prove more appropriate.

[Edited on 8-3-2009 by DJF90]

haribo - 8-3-2009 at 04:46

Hydrolysis of diethyl formamide with NaOH.

panziandi - 8-3-2009 at 15:38

Formamides are generally deemed toxic. I doubt you'd find any formamides OTC. Dimethylformamide is quite common solvent but is expensive, diethylformamide is uncommon and would be even more expensive! Dimethylformamide is a convenient source of dimethylamine which people often overlook. I think the best route to diethylamine for the home chemist is aqueous hydrolysis of DEET. This is quite an old thread I haven't been in this one for a while!

nitric - 15-4-2009 at 04:56

The DEET procedure seems the most fesiable procedure of all, using HCL may be the most efective, diethylamine HCl dosent melt 'till 227*C and doesnt boil untill 320*C, so the execce water and hydrochloric acid can be evaporated or distilled off leaving most likely pure diethylamine HCl and 3-methyl benzoic acid in the vessel which could have a NaOH solution added to it and the triethylamine distilled of( bp 55.5*C) and purified with 1-3 distillation more if no azotropes are formed of less if a fractionating column is used, sorry if this was posted before but i didnt read the second page.

[Edited on 15-4-2009 by nitric]

Agent MadHatter - 26-8-2009 at 18:28

I'm so lost. I've read all 10 pages and not one of you guys have successfully Distilled the DEA.

What I've got, is adding NaOH/H2O, with DEET (100% from target), and Ethanol/Methanol/Other solvent into a flask and refluxing for two days would produce a mixture of chemicals.

I'm just confused about what chemicals would be produced and getting DEA from it.

Saber - 27-8-2009 at 00:13

In the DEET procedure you are hydrolysing the DEET in an alkaline enviroment (NAOH/H2O) to produce DEA and 3-methylbenzoic acid.
The DEA can then be distilled form the hydrolysis mix. That is a summary of the thread.
If you are so confused as to obtaining the DEA then maybe you should think twise about what you are planning to use it for! you are obviously new to org chem and it sounds like you are after the DEA for illegal purposes. Read the whole thread again, it contians plenty of information.

[Edited on 27-8-2009 by Saber]

Bolt - 28-8-2009 at 11:08

If you hydrolyze the benzamide in an alkaline environment, you'll be left with the conjugate base of the benzoic acid.

panziandi - 28-8-2009 at 11:48

This thread was lost ages ago! I gave up explaining the procedure to people.

DEET + alkali => DEA + salt of toluic acid

I personally would use 30% aq NaOH and have one very good reflux condenser, then distill out the diethylamine after the reaction is complete.

Or you can use 70% aq H2SO4 forming the DEA sulphate (hydrogensulphate), the toluic acid won't be very soluble. Can fractionally collect the DEA sulphate and then add excess base and distill to collect the DEA.

And to make a point, DEA is extremely volatile and extremely flammable, not to mention it is corrosive and smelly. So a very efficient condenser with pre-chilled water is essential (especially if you live in a warm country) and chill the receiver in ice-water. I would use an ether condenser.

entropy51 - 28-8-2009 at 13:15

Quote: Originally posted by Agent MadHatter

I'm so lost. I've read all 10 pages and not one of you guys have successfully Distilled the DEA.

The First Theorem of Science Madness: the longer the thread the less likely anybody saw any product

Quote: Originally posted by Saber

If you are so confused as to obtaining the DEA then maybe you should think twise about what you are planning to use it for! you are obviously new to org chem and it sounds like you are after the DEA for illegal purposes.

New to org chem says the guy asking about using jelly jars instead of glassware just one year ago. And the same guy who was bragging about "legally" being able to possess red P and HI just yesterday. Give us a break. I don't see one word in Agent MadHatter's post that implies illegal intent. Neither do you. Read it slowly and sound out the words.

crazyboy - 14-9-2009 at 15:55

Quote: Originally posted by entropy51

Give us a break. I don't see one word in Agent MadHatter's post that implies illegal intent. Neither do you. Read it slowly and sound out the words.

Stop kidding yourself. I don't see one word that implies illelagl intent I see a whole fucking thread that practicaly states it outright.

Quote:

Do certain amides change forms from pH?

For example. Lysergic acid amide. If that amide was exposed in low pH (say 2) would the molecule turn into a salt?

And would it become freebase if it was exposed to a base (10-13 pH)?

Where would someone find information on similar amides? And solubilities of Salts/Freebase forms?

Hmmmm now do you think he's making dyes with that DEA and just wanted to know about freebasing lysergic acid amide?

Don't get me wrong I have nothing against people synthesizing LSD but people like MadHatter who have little to no chemistry experience are more likely to be injured or arrested than make any LSD.

Picric-A - 15-9-2009 at 07:13

Quote: Originally posted by crazyboy

Quote: Originally posted by entropy51

Give us a break. I don't see one word in Agent MadHatter's post that implies illegal intent. Neither do you. Read it slowly and sound out the words.

Stop kidding yourself. I don't see one word that implies illelagl intent I see a whole fucking thread that practicaly states it outright.

Quote:

Try to rise above entropys stabbing... he seems to be doing it to everybody these days...

[Edited on 15-9-2009 by Picric-A]

entropy51 - 15-9-2009 at 07:36

Quote: Originally posted by Picric-A

Try to rise above entropys stabbing... he seems to be doing it to everybody these days...

Just to the three of you Picric, Saber, and Labxyz.

[Edited on 15-9-2009 by entropy51]

turd - 15-9-2009 at 23:09

Quote: Originally posted by crazyboy

Hmmmm now do you think he's making dyes with that DEA and just wanted to know about freebasing lysergic acid amide?

Freebasing an amide...with diethylamine...

Edit: sorry - misread your post...

There seems to be two kinds of posters: Those that do chemistry (however amateurish it might be) and those who like to tell others what to do.

Does this board have a killfile feature? Since I have only little time at the moment it's quite annoying to wade through tons of (imho useless) posts produced by the latter kind. Or could we have a subforum where only people who really do chemistry are allowed to post or something like that?

[Edited on 16-9-2009 by turd]

JohnWW - 16-9-2009 at 01:10

"DEA" also stands for the corrupt U$ "Drug Enforcement Agency". I wonder what would happen if you mixed the two DEAs together.

Ephoton - 22-9-2009 at 01:41

you would end up with sea bacon pigs that swim in the sea

The_Natural - 5-3-2010 at 16:10

To approximately 50 grams of deet in 50-60 grams of ethanol was added 50 grams of conc. H2SO4 in 100 mls of water, this formed a yellow solution. Upon cooling following a 5 hour reflux a viscous clear oil separated which stuck to the walls of the flask when swirled in a gel like fashion. The smell of the solution had changed to an appealing mint like aroma.

The solution was cooled in the freezer overnight a large amount of white wax and gel like substance separated, this would surely be impure m-toluic acid (?), suspect EtOH is solubilizing the toluic acid when at room temp. When some of this semi-solid was scraped from the flask and added to cold water it was insoluble, a sticky white solid with the minty aroma.

To the workup of this mixture to obtain the free amine.. current thinking goes along these lines.. remove EtOH by distillation >> filter solids >> basify to 10 >> gently distill amine (use column?) to ice/salt bath receiver. Need i remove the alcohol and filter at all?

[Edited on 6-3-2010 by The_Natural]

DJF90 - 6-3-2010 at 09:37

Hate to say it, but that faint mint smelling aroma... sounds to me like diethyl sulfate... and the conditions suggest it could have been made too.

The_Natural - 6-3-2010 at 17:03

ok so the ethanol should have been removed prior.. glad i didnt decide to boil away whats left of the ethanol and this brown oil in an open beaker or anything like that..

anyhow.. more water was added to the mix and separated were lots of white solid on the flasks walls and a brown minty oil (my bad) which was discarded. The white solid was insoluble in acid but easily soluble in NaOH.

Now left with a cloudy aqeous solution that does release a strong ammonical odor upon addition of base and heating of small samples.

I unsure, however, if i want to proceed any further with this mix knowing that diethyl sulfate may still be present..

that and the fact that i just discovered a cooling spray containg only Diethylamine Salicylate 10%w/w; Camphor 0.5% w/w; Menthol 0.75% w/w; Hydroxybenzoates 0.3% w/w

Rogeryermaw - 11-7-2011 at 13:46

experimental:

to 127 ml of 95% ethanol in a 500 ml flat bottom boiling flask on a stirplate was added 124 grams of ethyl bromide. the flask was fitted with a two hole stopper, through one of which was led a length of 8mm glass tubing. the other hole was vented outside using a length of hose.

the glass tubing was used to feed dried (by passing through a washing bottle filled with calcium chloride) NH3 gas into the reaction mixture. over the course of two days, several additions (with good stirring to maximize contact) of ammonia were made by using one mole of NH4NO3 to one mole of NaOH producing one mole each of NH3 + H2O + NaNO3. some of the ammonia gas is lost to the water formed in the reaction and will be recovered by evaporation of the dissolved ammonia into distilled water for later use as will the NaNO3 be recrystallized and used to produce HNO3 and whatever else my twisted heart desires.

after 12 additions had been completed and after standing, a very fine, almost imperceptible, suspension of micro-crystalline NH4Br was observed. after this point, five more additions were made, for a total of 17 moles of NH3 (minus the NH3 absorbed into the water so closer to 10-11 moles). the process was stopped at this point and the reaction mixture allowed to react in a refrigerator overnight. upon standing the next day, while allowing residual ammonia to evaporate, NH4Br began to crystallize out of the solution. after filtering, an addition of NaOH solution (40 grams to 40 ml H2O) was used to decompose the mixed amine hydrobromides to release the amine freebases.

the remaining mixture is now being fractionally distilled through a 300 mm vigreaux. i will report back with results and yields later today (or tonight).

fractionation is not yet complete but i have so far obtained approx. 20 ml of a clear, colorless liquid with a strong ammonical odor that came over at a range between 50 - 70 degrees celsius. will perform a boiling point test shortly.

[Edited on 11-7-2011 by Rogeryermaw]

checking the boiling point was done with a carefully monitored warm water bath held at 50 degrees and slowly raised until mild effervescence was noted in a test tube suspended in the bath. the crude product showed signs of boiling at about 53 degrees indicating a small amount of impurity, likely ethylamine or ethyl bromide. i am leaning toward ethyl bromide since any ethylamine produced would have been gaseous at 16 degrees and up. will re-distill from KOH to remove any water.

the triethylamine has not yet been accounted for since i have not had the distillation bath above 80 degrees. the boiling point of TEA is 88.5 degrees. that report comes later.

[Edited on 11-7-2011 by Rogeryermaw]

[Edited on 11-7-2011 by Rogeryermaw]

Rogeryermaw - 13-7-2011 at 12:06

after distilling the triethylamine i stopped after about 30 ml (it's more than i will likely ever use). after re-distilling the diethylamine from KOH i have 18 ml of a clear ammonia smelling liquid that boils at a steady 55 degrees. it is highly flammable and leaves no soot or smoke.

i would like to repeat this experiment while adjusting the ammonia content to see how it affects the division of the products.

overload - 14-7-2011 at 07:00

Does anyone know the difference between diethylamine and diethylamide?

fledarmus - 14-7-2011 at 09:07

Quote: Originally posted by overload

Does anyone know the difference between diethylamine and diethylamide?

One is an amine, the other is an amide (or part of one anyway)...

Nitrogen forms three bonds. In diethylamine, two of those bonds are to methyl groups and the third is to a hydrogen. In diethylamide, two of those bonds are to methyl groups, and the third is to a carbon double-bonded to an oxygen.

Rogeryermaw - 15-7-2011 at 19:34

i'm sorry if forgot to mention that the liquid boiling at 55 degrees (that i suspect is diethylamine) gives a pH reading of 14 or higher (i do not yet have the means to measure pH above 14 or below 0) and the liquid boiling in the 87-89 degree range (that i suspect is triethylamine) gives a pH of around 13.

does this sound consistent with these products? are there any tests (within the range of home chemistry) that i can perform to verify these products? i may wait till the school season begins and ask if it can be tested by the university chemistry department with their available apparatus (if they have such capabilities).

peach - 16-7-2011 at 18:26

Glad to see you're working away roger.

If you have some accurate volumetric glass, like a pipette or flask, and one of those 0.01g pocket balances, you could check it's density. Should be 7.074g for 10 mls. Class A volumetric flask have a 0.02 / 0.03ml error on the volume I think (0.2 / 0.3%). You could determine the mass with about 0.5% error using a 0.01g pocket balance, from my experience with them. The cheap .01g pocket balances are excellent value for money (remarkably accurate and resistant for £5)! Get one with a bigger than microscopic pan on it though, because those tiny ones are barely usable with larger masses, unless they're weighing lead. One that plugs into a wall adaptor would be good, so it's not chewing through the batteries.

You could also try freezing it with some dry ice, using a low temperature thermometer to check when it melts. And can produce a nice graph by recording the temperature every 30 seconds or minute or so. There'll be a horizontal line at the melting point.

[Edited on 17-7-2011 by peach]

Rogeryermaw - 16-7-2011 at 18:50

those are some excellent suggestions. i do happen to have a recently purchased .001 g scale for about 40 dollars on ebay with calibration weights and a lid to prevent inaccuracies from drafts. unfortunately it does have a dismally small dish but i can weigh accurately enough on it. i have several 3 ml syringes that i can use for accurate volume. i will weigh 1 then 2 then 3 ml and report back with the results. the melting point analysis will have to wait until i can afford to get the dry ice.

thank you peach for the suggestions...i feel a bit daft for not checking the density as soon as it was distilled

peach - 16-7-2011 at 19:03

Look at it this way, if you'd checked it immediately after distillation, it'd still be warm, so the density would be different.

The density of water changes by about 1 to 2% between 25 and 60 Celsius.

[Edited on 17-7-2011 by peach]

Nicodem - 18-7-2011 at 08:42

Good work!

You can derivatize your product in order to characterize them by a melting point measurement. The simplest derivatives are the hydrochlorides. The mp differences of the ethylamine hydrochlorides are large enough and you can evaluate the purity from the mp depression and interval.

Just because EtNH2 is a gas at room temperature, it does not mean that diethylamine can not dissolve large amounts of it. The purity depends on the fractionation efficiency of the distillation column used.

The use of ammonia gas appear terribly impractical. If you can obtain 25% aqueous ammonia, you could try using that instead as an alternative. I don't think you even need a cosolvent, if using good stirring and slowly adding ethyl bromide. The mixture should become monophasic at the end of the reaction. Concentration by evaporation of the water and excess ammonia should give a concentrated mixture of the amine hydrobromides to be worked up as you did. The diethylamine vs. triethylamine selectivity would be somewhat different though, possibly or not in favour of whatever product prefer.

If you ever optimize the process to produce and separate diethylamine and triethylamine, please post the whole report in the Prepublication.

Rogeryermaw - 18-7-2011 at 14:21

Quote: Originally posted by Nicodem

Good work!

You can derivatize your product in order to characterize them by a melting point measurement. The simplest derivatives are the hydrochlorides. The mp differences of the ethylamine hydrochlorides are large enough and you can evaluate the purity from the mp depression and interval.

it is funny you should mention this! last night i had the inspiration to do this very thing. i began on a test tube scale to see if it would work so i poured a few oz. of 31.45% muriatic into a flask fitted with a one hole stopper with a hose led to a bent piece of glass tubing in the bottom of a test tube with about 5 ml of the crude amine product. i lightly heated the acid to drive off HCl gas into the test tube and was rewarded with about a gram and a half of bright white precipitate after a couple of hours.

i am currently in the process of trying a similar procedure, but by adding the acid directly to the amine. the reaction is highly exothermic but forms no immediate precipitate (i believe due to the water content in the acid which i am boiling off right now.

i will report back with results and if i can streamline and optimize this process i will be happy to do a formal write-up for the prepublications section complete with pictures.

my only concern is that any excess dissolved ammonia may form ammonium chloride and that may be difficult to separate. i have been searching for differences in solubility between the amine hydrochlorides and ammonium chloride to assist in the separation but since the solution is not water based, it is harder to find information.

perhaps it is time to take a trip to the library.

as far as the use of ammonia solution, i have plenty of concentrated ammonia solution from the previous experiment and will definitely give this a try. thanks for the tip! i note that you advise stirring during the process. is this due to the fact that EtBr is not miscible with water?

on another note i recently obtained about 30 ml of deet from walmart (repel 100 claims to be 98% +) for less than 6 dollars. i plan to attempt a hydrolysis with KOH solution. i will give report on this as well when i have completed it.

[Edited on 18-7-2011 by Rogeryermaw]

[Edited on 18-7-2011 by Rogeryermaw]

jon - 19-7-2011 at 10:27

i got this from a chemist who made it from deet

i used all OTC products aside from some ebay items for labware. made my own mini coil condenser from a 2 foot section of 5mm boro glass tube. used a regular mapp gas torch to bend it around a aluminum cigar tube. for the glass i used a 2 neck distillation flask 24/40 on the top neck and the angle side neck had #7 thread and a plastic cap. i drilled the cap and affixed the condencer through there sealing with a little JB weld.

OTC Hydrolysis of N,N-diethyl-meta-toluamide (DEET) to Diethylamine and M-toluic acid

To a 250ml autoclavable media bottle is added in order, 175ml N,N-diethyl-meta-toluamide (98.11% comerc grade, $15) followed by 40ml 70% EtOH. the media bottle is capped and vigorusly shaken for one minute. the EtOH and DEET should now be a homogenous mixture. to this solution is added 40g NaOH and once again capped. the media bottle containing the mix is now sealed and heated in a hot water bath (crock pot set on low) added to the bath at 55*C (125*F) ending at 70*C (160*F) periodicly agitating for the legnth of time it takes to compleatly desolve the NaOH plus 1.5hr. the solution should now be a deep yellow color the crock pot is turned off and allowed to cool to RT. it is removed from the bath and allowed to stand at RT for one day minimum. the bottle will then be carefuly opened after cooling in the refridgerator for 1hr. obsedved was the strong smell of diethylamine, no longer did it smell of DEET and EtOH. the solution is fractionaly distilled (dont forget boiling chips, this stuff likes to bump) collecting the fraction along a 9 degree tempeture arc centered on 55*C (51-59*C). the solution may solidify twords the end of the distilation and a small ammount of DH2O can be added to liquify the waxy mass of M-toluic acid and NaOH. total yeild form aprx 225ml of solution was 57ml of crystal clear diethylamine in freebase form. 25.3%

MeOH can be used in a pinch but i like EtOH, it mixes better with the DEET and has just enough water for the hydrolysis but not enough to cause separation.

Diethylamine C4H11N 73.14g/mol boiling point 55.5*C (131.9*F)

N,N-Diethyl-M-Toluamide C12H17NO 191.27g/mol boiling point 288-292*C (550.4-557.6*F)

M-toluic acid C8H8O2 136.15g/mol boiling point 263*C (505.4*F) (melt at 111-113*F)
-------------------------------------------------------------------------------------------------------------------------------------
Ethanol C2H6O 46.07g/mol boiling point 78.4*C (173.12*F)

Methanol CH4O 32.04g/mol boiling point 64.7*C (148.4*F)

water H2O 18.015g/mol boiling point 100*C (212*F)

Rogeryermaw - 20-7-2011 at 12:55

that is very interesting. have you performed this synthesis? it is next on my list to try out so it would be fortunate to know if this is from anecdote or personal experience.

sorry it took me so long to post again but there is some work being done up the street from my home and the tore up the phone line yesterday so i was without contact to the outside world via conventional methods.

i have checked MSDS information on the DEA(HCl) and the NH4Cl and they are both soluble in water and insoluble in Et2O but this is as far as the solubility data goes pertaining to both chemicals. this may get interesting.

jon - 20-7-2011 at 19:58

no this is no anectodote this is from a colleague i have no use for diethylamine, and he is rarely available but the information is accurate.
also i think if you peruse kirk othomer's encyclopeadia of industrial chemicals you will find a way to make pocl3 from sodium metaphosphate and chlorine gas catalyzed by a little hyderogen chloride gas.
this has also been done too, but that is another topic altogether.

Rogeryermaw - 20-7-2011 at 22:54

a quick search of this title gives kirk othmer's encyclopedia of chemical technology. i could not find encyclopedia of industrial chemicals. there is a title like this but it is from ullmann. aparently one can get free 30 day access. however POCl3 is not to hard to make from PCl3 and O2 gas. garage chemist has a lovely guide to synthesizing PCl3 but it is in german i believe. i translated most of it and this cat is ingenious. i just searched for over 20 minutes to find a link to this and then it tells me access forbidden. poop! good thing i already translated most of it and saved the synthesis in my files. thank you garage chemist!

Chordate - 17-9-2011 at 01:27

According to this guy right here:

http://pubs.acs.org/doi/pdf/10.1021/ar00010a001

Diethylamine synthesis can be achieved by a modified gabriel synthesis with sodium saccharin. First step is monoalkylation of the saccharin followed by basic hydrolysis of the amide side of the molecule (the ing-manske procedure would probably be counterproductive here). The intermediate is a stable sulfonamide which can then be dialkylated. In the reference they give the dialkylation is done in a one pot fashion by adding a 1:2 ratio of saccharine to the alkylating agent and then basifying in the same pot, but it might be possible to do an asymmetric alkylation by adding different alkylating agents in two separate steps before and after hydrolysis of the amide side of saccharin.

Anyhoo, after hydrolysis, the mess is then acidified to cleave the sulfonamide, which according to the lit is much easier than with most sulfonamides.

Gabriel without hydrazinolysis requires some harsh conditions and some experimentation would be necessary to figure out what kind of conditions and times would give the best yields, since the source for this procedure as cited in the above article is 50 years old, in japanese, and seemingly only the index is available. Still, this may be a good route if you have some alkylating agents on hand.

al-k-mist - 2-9-2012 at 16:14

The tek above, posted by jon, was posted on zoklet in 09.
the same dude has a tek for lysergamides from A. nervosa seeds, a tek on making POCl3, and his equivilants were pretty much shulgin scaled down.
I havent heard much else about it

[Edited on 3-9-2012 by al-k-mist]

Rogeryermaw - 3-9-2012 at 05:38

you offer no useful information and discuss the extraction of illegal substances. this is not the forum for you.

The_Natural - 6-9-2012 at 01:41

For the small chance that anyone was interested in my experimentation with the ethanolic DEET and aqueous sulfuric acid.. previous page..

I did end up distilling about 20 mls at the correct still head temp, vapors were strongly alkaline with the typical diethylamine odor.. no formal confirmation though..

This even with the laziness and generation of the messy by-products..

It works but the NaOH sounds better..

Mush - 11-11-2014 at 13:29

Sorry , I had to restart it!
A Rapid Procedure for the Hydrolysis of Amides to Acids

H. L. Vaughn , M. D. Robbins
J. Org. Chem., 1975, 40 (8), pp 1187–1189
DOI: 10.1021/jo00896a050

"An aqueous suspension of the amide is treated with 1equiv of sodium peroxide at 50' (or more conveniently on asteam bath). The amide rapidly dissolves and ammonia(for primary amides) is evolved. After 60 min, the reactionis essentially complete and only marginal yield increasesare observed if heating is continued for another hour. Isolationof the acid is accomplished by careful neutralization of the reaction mixture and yields are usually greater than85% (Table I). Primary, secondary, and tertiary amides are all hydrolyzed and either the acid or the amine can be recovered."

Copper complex catalyzed hydrolysis of amides
Mrejen, Karen
McGill University, 1991
Copper complex catalyzed hydrolysis of amides

Catalytic Hydrolysis of Amides at Neutral pH
Jik Chin, Vrej Jubian and Karen Mrejen
J. Chem. Soc., Chem. Commun., 1990, 1326-1328

Attachment: jo00896a050.pdf (375kB)
This file has been downloaded 803 times

Attachment: Catalytic hydrolysis of amides at neutral pH.pdf (275kB)
This file has been downloaded 915 times

[Edited on 11-11-2014 by Mush]

clearly_not_atara - 2-8-2015 at 11:04

http://en.wikipedia.org/wiki/Acetaldehyde_ammonia_trimer
https://www.erowid.org/archive/rhodium/chemistry/acetaldehyd... (Rhodium's Archive, describes AAT synthesis)

If this is peralkylated with EtBr the product is 1,3,5-triethyl-1,3,5-triaza-2,4,6-trimethylcyclohexane, which i'll call TTTC for short. Reduction of TTTC with a typical imine-reducing agent should produce diethylamine with no side products. Alkylation of TTTC should be impossible due to steric hindrance, although I hope TTTC isn't so incredibly unstable that it immediately reverts to ethylamine and acetaldehyde.

So acetaldehyde + ammonia >> AAT, AAT + 3EtBr >> TTTC, TTTC + HCOOH + Pd/C >> Et2NH. Not as elegant as we'd like I guess but overalkylation is impossible and the intermediates are both solid at r.t. and the reactions should happen relatively easily. The hardest part is acetaldehyde. Alkylation might occur in ethanol with heterogeneous Na2CO3. Precipitating TTTC might be tricky. Bon chance!

[Edited on 2-8-2015 by clearly_not_atara]

careysub - 8-8-2015 at 10:30

Quote: Originally posted by S.C. Wack

Back in the day, some people were happy with preparation of ethylamines from ethyl bromide, with separation of the mixed amines utilizing ethyl oxalate. Authors preparing their own amine reagent tend not to detail this separation method in their journal references decades after this was introduced, and there seemed to be some conflicting vague details, so I searched for the best way of doing this in the original lit and here it is; I suppose Houben-Weyl has details as well. There are other methods in the older lab manuals.

Here is a description of this procedure for separating the ethylamines from Journal of the Chemical Society, Volume 69, 1896, p. 662-663.

"Although they differ considerably in boiling point it is impossible the separate the ethylamines by fractional distillation. The “simple and elegant process,” as he himself originally termed it, devised by Hofmann (Proc. Roy. Soc., Nov., 1860, xi, 66) is based on the observation that when submitted to the action of ethylic oxalate, ethylamine is converted into diethyloxamide, a crystalline substance, only sparingly soluble in water; whilst diethylamine yields ethylic ethyloxamate, a liquid boiling at a high temperature; triethylamine remaining unchanged. Hence, after subjecting the mixture to the action of the oxalate, it is possible to separate the terrtiary base by distillation, and to mechanically separate the crystalline amide from the oily oxamate; the amide may then be purified by recrystallization from boiling water, and distilled with alkali, the oxamate being similarly treated after separating the dissolved oxamide by cooling to 0C, and then fractionally distilling the liquid.

It was subsequently pointed out (ibid., p. 526) that a simpler and more perfect separation of the oxamide and oxamate might be effected by submitting the mixture at once to the action of boiling water, when diethyloxamide dissoves, the oxamate remaining as an insoluble layer floating upong the hot solution."

It would seem to me that the oxalic amine salts would be convenient forms in which to store the amines until needed.

With the above separation procedure in hand it looks to me that the Werner ethyl bromide, ammonia, ethanol reaction, and variants, should be the preferred method for obtaining all three ethylamines.

Although Werner's lengthy room temperature procedure produced very little triethylamine (about an equal split between ethylamine and diethylamine) Rajit's [1] use of a two hour steam oven heating produced almost all triethylamine. So you can get all three ethylamines in good quantity by varying temperature and duration.

Diethyl oxalate is made from oxalic acid (found in Bartender's Friend) and ethanol; ethyl bromide is made from sodium bromide (available as a spa treatment), sulfuric acid (drain cleaner), and ethanol; and the final procedure uses ammonia (can be ammonium hydroxide), ethanol and the ethyl bromide.

So all three ethylamines can be obtained with reasonable ease from entirely OTC cheap chemicals.

[1] http://chemistry.mdma.ch/hiveboard/chemistrydiscourse/000330...

Googling "Rajit triethylamine" brings up a paper on Sciencemadness you can download through the search link, I don't know where the paper is attched ona thread.

S.C. Wack - 8-8-2015 at 13:42

Houben-Weyl it turned out had nothing to say about ethyl oxalate. Werner's details were on page 35 of the relevant 1957 volume 11.

Hofmann:

The product of the reaction of oxalate of ethyl upon the mixture of the ethyl-bases, when distilled in the water-bath, yields triethylamine free from ethylamine and diethylamine.

The residue in the retort solidifies on cooling into a fibrous mass of crystals of diethyloxamide, which are soaked with an oily liquid. They are drained from the oil and recrystallized from boiling water. Distilled with potassa, these crystals furnish ethylamine free from diethylamine and triethylamine.

The oily liquid is cooled to 0°, when a few more of the crystals are deposited; it is then submitted to distillation. The boiling point rapidly rises to 260°. What distils at that temperature is pure diethyl-oxamate of ethyl, from which, by distillation with potassa, diethylamine free from ethylamine and triethylamine may be obtained.

* The separation of the ethyl-bases has been since repeatedly carried out. The process, as described in the 'Proceedings,' admits of a slight improvement. I proposed to separate the mixture of diethyloxamide and diethyloxamate of ethyl by filtration, and to purify the former by recrystallization from boiling water, the latter by exposure to a temperature of 0°. The separation is simpler and more perfect by submitting the mixture at once to the action of boiling water, when diethyloxamide dissolves, the diethyloxamate of ethyl remaining as an insoluble layer floating upon the hot solution, from which it may be separated by a tap-funnel.

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