Sciencemadness Discussion Board - Diethylamine Synthesis

Diethylamine Synthesis

Pages: 1 2 3

mbrown3391 - 26-8-2008 at 07:27

After a bit of research i have found 3 mentioned ways to synthesize diethylamine:

1. N,N-Diethyl-3-methylbenzamide + Ethylene Glycol + NaOH + Heat

2. Ethylchloride + Ammonia (forms diethylamine HCL)

3. Ethanol + Ammonia + Sulfuric Acid

Are reactions #2 and #3 spontaneous? If not, what is needed to cause the reaction to proceed?

Also, do these methods produce diethylamine alone, or do they produce ethylamine and triethylamine as well?

Which seems to be the best choice?

ScienceSquirrel - 26-8-2008 at 07:44

Making diethylamine is an awful fag.

Method 1 will produce small amounts of pure diethylamine at fairly high cost unless you can buy cheap DEET.

Methods 2 and 3 will produce mixtures that you will have to fractionate. Fine in industry, a right pig on a small scale in the lab.

mbrown3391 - 26-8-2008 at 07:46

So do you know of any other, possibly more efficient methods?

ScienceSquirrel - 26-8-2008 at 08:02

I believe that you can react the dianion of cyanamide with an alkyl bromide to prepare a dialkyl cyanamide.
Hydrolysis and purification would yield the diethylamine.
Simple amines are worth buying if you can as they are cheap and not that easy to make on a small scale with laboratory type chemistry.
I would guess that industrially it is made by passing ethylene and ammonia over a catalyst. The reaction products are fractionated and recirculated as required and all three amines are produced at the same time.

Arrhenius - 26-8-2008 at 08:12

Method #2 is spontaneous, definitely, but will yield varying amounts of ethylamine, diethylamine, triethylamine and tetraethylammonium cation. The extend of each product is dependent on the quantity of reactants, and probably temperature. One would need an excess of ammonia to avoid tri/tetra-alkylation. Keep in mind this won't work with aqueous ammonia, only pure liquid ammonia or perhaps dissolved in an unreactive solvent.

Method #3 is not spontaneous. I'm guessing this involves the dehydration of ethanol to ethylene in order to react with ammonia, which requires heat. I'll try searching some literature, but this one's not panning out well in my head, I agree it's probably gas phase. It is likely that this reaction would produce more ethylamine than your desired diethylamine.

If you go via acylation, you may be able to acylate a primary amine, if you can produce the primary amine of your desired product.

[Edited on 26-8-2008 by Arrhenius]

[Edited on 26-8-2008 by Arrhenius]

mbrown3391 - 26-8-2008 at 08:29

any idea what type of acylating agent / catylist would be used in this case?

ScienceSquirrel - 26-8-2008 at 08:43

Acylation and reduction would work but it is a big no no on the grounds of cost.

You would have to react acetic acid with urea to from acetamide, reduce that to ethylamine and then react it with acetyl chloride to produce the N ethyacetamide. A final reduction would produce the desired diethylamine.
Hydrolysing DEET would be miles cheaper and easier.

Sauron - 26-8-2008 at 08:57

Buy N,N,-diethylformamide and hydrolyze it to diethylamine and formic acid, using HCl.

This method works for DMF -> dimethylamine so why not?

[Edited on 27-8-2008 by Sauron]

Arrhenius - 26-8-2008 at 08:58

acetyl chloride with the primary amine would be your best bet. Acetic anhydride or ketene would likely also work. This would require reduction with LAH, optimally. H2 + catalyst would probably work if done carefully, or NaBH4 + I2 or H2SO4 (not positive on this one).

Arrhenius - 26-8-2008 at 09:02

I've never heard of hydrolizing DMF... if you can cite this it would be appreciated.

Sauron - 26-8-2008 at 09:02

N,N-DiETHYLformamide hydrolyzes to diethylamine and formic acid, its constituents. Do this with concentrated hydrochloric acid or with dry HCl gas. The procedure ought to be in the literature.

Doing same with DMF gets you diMETHYLamine.

Diethylformamide is $55/100 g from Acros. So a lot more expensive than DMF. But not so bad. This gets youpure diethylamine hydrochloride uncontaminated by ethylamine or TEA.

Maybe there's a cheaper source with larger packing than Acros, too.

[Edited on 27-8-2008 by Sauron]

Arrhenius - 26-8-2008 at 09:04

No.. producing an alkyl-diethylamine. Read carefully.

ScienceSquirrel - 26-8-2008 at 09:04

Quote:

Originally posted by Sauron
Buy N,N,-diethylforamide and hydrolyze it to diethylamine and formic acid, using HCl.

This method works for DMF -> dimethylamine so why not?

I think he wants a method that uses OTC materials.

He is not going to get diethylformamide down his local hardware store, phamacist or camping store.

He will probably get 100% DEET for £30 a litre if he shops around. Expensive, but cheaper on a mole for mole basis than diethylformamide.

Arrhenius - 26-8-2008 at 09:11

If you can do hydrogenation, it is possible to hydrogenate acetonitrile to get a mixture of products, though predominately mono & di alkyl.

I'm guessing you can't buy anything from Acros, Fisher, VWR, or any other commercial supplier (nor can I).... but feel free to peruse their prices.

[Edited on 26-8-2008 by Arrhenius]

Sauron - 26-8-2008 at 09:18

Well, that sort of lets out ketene and LAH or catalytic hydrogenation too doesn't it?

I'm fed up to here with all this bricks-without-straw OTC crap.

I routinely buy from Merck, Acros, Aldrich, Fluka, Panreac, Carlo Erba, Ajax Finechem, and others. But then I live in a free country and I have a registered corporation as well.

[Edited on 27-8-2008 by Sauron]

Arrhenius - 26-8-2008 at 09:23

I wouldn't say catalytic hydrogenation is out of reach of the hobbyist, nor ketene. LAH is nearly out of reach, but sodium borohydride is not quite. On the other hand, Acros is out of reach, unless you're playing middleman.

MrBrown wishes to make diethylamine, so I'll offer my small amount of knowledge to him. I can think of a few reactions that certainly don't need very much of it... so maybe 10% yield is okay.

Power to you... we would all love to own a commercial lab, and live in a "free" country, but you have to make money with it to pay the bills in the West.

[Edited on 26-8-2008 by Arrhenius]

ScienceSquirrel - 26-8-2008 at 09:24

Quote:

Originally posted by Sauron
Well, that sort of lets out ketene and LAH or catalytic hydrogenation too doesn't it?

I'm fed up to here with all this bricks-without-straw OTC crap.

The next thing he will be looking to make lysergic acid from icing sugar, brick dust and seagull poop fermented in the cellar for one month in a dried out catskin and then extracted with Everclear

Anyway there is no point in making it if you can deal with Sigma et al as the stuff is cheap as chips.

[Edited on 26-8-2008 by ScienceSquirrel]

Sauron - 26-8-2008 at 09:29

Yeah that's what questions about OTC diethamine from the clueless, dazed and confused set are usually all about, sad to say.

Not that I am pointing a finger at this particular newbie, I'm sure he's an eagle scout trying for his merit badge in chemistry.

Arrhenius - 26-8-2008 at 09:35

Hmm.. so this is a forum for professional chemists? Your postings are really helpful, thank you so very much.

ScienceSquirrel - 26-8-2008 at 09:49

If you have a look back through my postings I do make some helpful suggestions.

The best way to make diethylamine at home is the hydrolysis of DEET (Method 1 in the original post)
It can be carried out with a modicum of glassware in a simple lab setup.

However it is not cheap.

I occasionally mock some posters as they come on here looking to make something that is a known precursor of a drug and they do not say why they want it or cannot go through the usual suppliers.
Also it is often the only thing that they are interested in or they display very little chemical knowledge.

Sauron - 26-8-2008 at 09:50

Make money with my company? What a novel idea. The company is a black hole and my money disappears over the event horizon. The country is Thailand. The local agents for all those suppliers and more are happy to sell to a registered company. If what I want is not in local stock I must wait 30-60-90 days for delivery.

I keep my nose clean so the government is not a nuisance.

Some things are verboten. CHCl3, CCl4, ethylene chloride, ethylene bromide. SO2, Cl2, SOCl2, SO2Cl2, PCl3, POCl3, PCl5. But I2 is no problem. AcdCl is restricted so is Ac2O. But in general all these can be made if and when I need them.

Ketene? If you have a hood and a SCBA or supplied air maybe. Hydrogenation? Some people on this forum have medium pressure autoclaves rated 1900 psi. But not many. My point is, your advise to a guy who must go OTC to acquire a secondary aliphatic amine, seems a little esoteric, not to mention expensive. And in the case of ketene probably lethal.

Ritter - 26-8-2008 at 09:57

Quote:

Originally posted by ScienceSquirrel

Method 1 will produce small amounts of pure diethylamine at fairly high cost unless you can buy cheap DEET.

Commercial DEET (25% concentration) is available OTC in most 'big box' stores in the U.S.: http://www.deet.com/ It is said to be stable in the pH range of 5-9, so hydrolysis under highly acidic or highly basic conditions looks feasible but I could not locate a recipe in the first several pages of Google results I browsed through.

ScienceSquirrel - 26-8-2008 at 10:55

The camping stores are thinking about sales around here and we can buy 100% DEET in Western Europe.
If I can spot some going cheap I might have a go at hydrolysing it.

[Edited on 26-8-2008 by ScienceSquirrel]

Ritter - 26-8-2008 at 11:12

Quote:

Originally posted by ScienceSquirrel
The camping stores are thinking about sales around here and we can buy 100% DEET in Western Europe.
If I can spot some going cheap I might have a go at hydrolysing it.

[Edited on 26-8-2008 by ScienceSquirrel]

If you used aq HCl you would wind up with a preciptate of 3-methylbenzoic acid & the amine hydrochloride in solution. If you used aq NaOH you would wind up with the amine base (volatile, bp 55-56 deg C) & the Na salt of the acid in solution. I think that procedures are probably out there or could be developed by the amateur chemist for either approach.

http://chemicalland21.com/industrialchem/organic/DIETHYLAMIN...

[Edited on 26-8-2008 by Ritter]

mbrown3391 - 26-8-2008 at 13:06

Ok a few more questions.

First, does diethylamine form an azeotrope with either ethylamine or triethylamine?
Second, would reaction #2 work either with all gaseous reactants, or maybe with gaseous ammonia bubbled through liquid Ethyl chloride?

[Edited on 26-8-2008 by mbrown3391]

ScienceSquirrel - 26-8-2008 at 13:17

I have had a quick check on your profile.

I think it is time that you got out there and did some leg work of your own.

If you can come back and tell me why you want to make diethylamine and show that you have looked into methods on your own I will help you further.

mbrown3391 - 26-8-2008 at 13:20

What did you discern from my profile, exactly?

not_important - 26-8-2008 at 18:20

Reaction #3 sounds a bit questionable to be. In the cold NH3 will react with H2SO4 to make ammonium sulfate or bisulfate. If the ethanol is first reacted with H2SO4 to form ethyl sulfate or diethyl sulfate, that will react with ammonia to give ethylamines.

ScienceSquirrel mentioned an OTC method - passing a mixture of NH3 and EtOH vapour over a hot catalyst (a "hot tube" reaction) to form water and mixed ethylamines. The ration of ammonia to ethanol controls which amine is the predominate product, getting the mono- or tri- amines as the major product is easier than doing so for the diamine. The amines can be fractionated and the unwanted amines returned to the feed side to increase yieldds of the wanted amine.

The reactions taking place are generally a complex mess. One series is the dehydrogenation of the alcohol to the aldehyde, which then reacts with ammonia or amine, then reduction by the hydrogen from the alcohol dehydrogenation step. Alkenes and carbenium ions are important in other paths. Various other products are formed in small amounts, so the final product will require fractionation and possible other purification steps.

Sauron - 27-8-2008 at 01:27

mrbrown, you are repeatedly asking for spoonfeeding. If you want to know whether or not the ethylamines form azeotropes, LOOK IT UP. One of the main advantages of being on the forum is access to a vast collection of chemical literature you can browse, download, and use. So use it.

Demonstrate some scholarship and if you get stuck, people will help you.

It is to your advantage to avoid appearing to be a cook looking for a recipe to be spoonfed to him, because the forum has no use for such people.

stoichiometric_steve - 27-8-2008 at 06:31

mrbrown: what do you want, diethylamine for making acid? if you can't source or make diethylamine, how do you think you can make acid???

Arrhenius - 27-8-2008 at 09:08

MrBrown: Yes, rxn #2 will work with gaseous products as well as gaseous ammonia bubbled through a solution or liquid EtX. The halogenated carbon is easily attacked by the lone electron pair on nitrogen... always. Et2NH is separable by distillation, but you may find this difficult due to the high vapor pressure of all species present. No azeotrope that I can find.

It's great to do your own homework, but sometimes Google can only go so far. If you don't have access to published literature, you may have a difficult time. Erowid, Rhodium etc. can be sketchy sources for chemistry, albeit publicly available. Orgsyn and wikipedia are good resources, but not cookbook for making drugs. If you decide on a chemistry project that you for sure want to undertake, I would recommend visiting a local university to access published literature (you can usually get SciFinder or something similar on their computers). I can think of a few uses for diethylamine besides #25, and don't really care what you use it for. If you're merely curious, power to you.

mbrown3391 - 27-8-2008 at 12:35

Thanks to everyone who actually helped me, namely Arrhenius. i will now do some experiments and post my results. I will start with reaction #1 as it seems most promising.

diethylamine

tapira1 - 27-8-2008 at 15:22

Small quantities of diethylamine an be prepared by basic hydrolysis of OFF (m-diethyltoluamide) followed by careful distillation. OFF is an insect repellent.

ScienceSquirrel - 27-8-2008 at 16:24

Quote:

Originally posted by mbrown3391
Thanks to everyone who actually helped me, namely Arrhenius. i will now do some experiments and post my results. I will start with reaction #1 as it seems most promising.

I think I will leave the DEET on the shelf

pantone159 - 27-8-2008 at 19:52

Note that you need water present for the hydrolysis of DEET.

I did some small scale test tube trials hydrolyzing DEET with base and acid. I don't have any good heat sources at home, I am limited to baths of preheated water, which definitely limited my results. I used DEET (100%), water, and various alcohols (mostly EtOH I think) as co-solvents to try and make the mixture single phase. Then I added either aq NaOH, or conc HCl, and heated with water baths.

The desire for water for the hydrolysis reaction and the desire to keep the mix single phase are contradictory. Is ethylene glycol a better co-solvent? My first instinct was to have the bare minimum stoichiometric amount of water present, but I got best results with more, IIRC.

With base, on at least one trial, I got a strong smell of Et2NH, so that was working. I failed to work anything up due to mistakes. I think that, practically, to recover any that way, you would need to distill as you produce it.

With acid, I got nothing. With more heating, maybe it will work. I think the workup would be easier from the acid reaction, but it didn't go for me.

BTW - I don't entirely understand why Et2NH is so suspicious. I know that it is used in making LSD, but compared to the rest of what that synthesis involves, getting/making Et2NH is insignificant. I can't imagine that is the limiting factor for any aspiring LSD maker. I don't know any any other notorious (mis?) uses of it.

mbrown3391 - 27-8-2008 at 21:20

Good idea, pantone159, I will do reaction at around 55 degrees c in a distillation apparatus as soon as a get a chance to go searching for DEET.

[Edited on 28-8-2008 by mbrown3391]

Ritter - 28-8-2008 at 05:52

Quote:

Originally posted by pantone159
I don't know any any other notorious (mis?) uses of it.

Hmmm. N,N-Diethyltryptamine & related indolealkylamines?

ScienceSquirrel - 28-8-2008 at 06:26

The diethyl analogue of PCP?

Reportedly tastes and smells a bit nasty but is stronger than PCP.

[Edited on 28-8-2008 by ScienceSquirrel]

mbrown3391 - 28-8-2008 at 06:47

Quote:

Originally posted by pantone159
I did some small scale test tube trials hydrolyzing DEET with base and acid.

Im pretty sure an acid wont work at all. Seems to me that the hydrolysis reaction will produce diethylamine and m-Toluic acid. So a base would be needed to react with the acid product and prevent it from reacting with the deithylamine again. Im not sure what purpose the ethylene glycol plays, however.

Ritter - 28-8-2008 at 06:52

Quote:

Originally posted by ScienceSquirrel
The diethyl analogue of PCP?

Reportedly tastes and smells a bit nasty but is stronger than PCP.

[Edited on 28-8-2008 by ScienceSquirrel]

Yes & good thought.

Most garage chemists are unaware of the tremendous range of structural variation in the basic PCP molecule that will wind up producing the same or similar dissociative effects. And diethylamine is likely easier to source that piperidine.

The attached graphic from the Wikin article on PCP shows some of the analog structures of PCP that have known PCP-like effects. Notice that the N,N-diethyl analog appears in the lower right corner.

[Edited on 28-8-2008 by Ritter]

PCP analogs.jpg - 17kB

ScienceSquirrel - 28-8-2008 at 06:59

Amides can be hydrolysed in acidic and basic solution although generally the base catalysed reaction is faster.
Proteins are amides and they are hydrolysed in strong sulphuric acid solution. An excellent example of hydrolysis in sulphuric acid is to be found here

http://en.wikipedia.org/wiki/John_George_Haigh
The diethylamine won't react with the toluic acid as the acid formed is only weakly electrophilic and the amine will be protonated making it a very poor nucleophile.
The ethylene glycol cosolvent with water raises the boiling point of the reaction mixture over say water ethanol and keeps the amide in solution.

mbrown3391 - 28-8-2008 at 07:00

Maybe someone should make a thread, "Uses of Diethylamine in the Home Drug Lab," so that we can stop littering this one.

mbrown3391 - 28-8-2008 at 07:07

Quote:

Originally posted by ScienceSquirrel
The ethylene glycol cosolvent with water raises the boiling point of the reaction mixture over say water ethanol and keeps the amide in solution.

Does it also raise the boiling point of the amide? because if i am planning to do this in a distillation apparatus, i dont really want the amide to stay in solution.

Ritter - 28-8-2008 at 07:15

Quote:

Originally posted by mbrown3391
i dont really want the amide to stay in solution.

How do you expect it to react if it's not in solution? This is not solid-phase chemistry. It is solution-phase chemistry.

mbrown3391 - 28-8-2008 at 07:17

because it is soluble in water

ScienceSquirrel - 28-8-2008 at 07:17

I think you are mixing up the amide with the amine.

If I were you I would reflux the DEET in a solution of potassium hydroxide in ethanol and water and then distill off the ethanol and diethylamine collecting the product in a chilled receiver.
you can then standardise your product against hydrochloric acid and procede with your further chemistry from there.
The amine will be so much more nucleophilic than ethanol or water that it will not interfere with a lot of reactions.
Solutions of dimethylamine in water or water / ethanol are commonly used in the lab as they are easier to handle than the raw amine which is a gas at room temperature.

If you just tell us what you are planning on doing with the stuff you would kill the speculation stone dead.

Ritter - 28-8-2008 at 07:17

Quote:

Originally posted by mbrown3391
Maybe someone should make a thread, "Uses of Diethylamine in the Home Drug Lab," so that we can stop littering this one.

Maybe inquiring minds wonder why you are being so paranoid about our curiosity as to what you want to make diethylamine for.

Ritter - 28-8-2008 at 07:20

Quote:

Originally posted by mbrown3391
because it is soluble in water

From the DEET MSDS:

Quote:

Solubility in water: practically insoluble in water

Solubility in other solvents: Soluble in ethanol, ether, isopropanol, chloroform, carbon disulfide, alcohol, benzene, propylene glycol, cotonseed oil, ketones, petroleum distillates; sparingly soluble in petroleum ether and glycerin

You need to add an organic co-solvent to your acid or base in order to get it into solution so you can hydrolyze the amide group. Propylene glycol is available OTC on eBay item #220274087412.

[Edited on 28-8-2008 by Ritter]

ScienceSquirrel - 28-8-2008 at 07:26

If you want to make anhydrous diethylamine ( eg free from water or alcohol ) then you are getting into a whole new ballgame.
If I had several kilos of DEET, a properly equipped lab, a few weeks to play with and no other alternative I might attempt it.

mbrown3391 - 28-8-2008 at 07:32

Sorry, i was thinking of the amine. so does the ethylene glycol raise the boiling point of the diethylamine?

ScienceSquirrel - 28-8-2008 at 07:36

Quote:

Originally posted by mbrown3391
Sorry, i was thinking of the amine. so does the ethylene glycol raise the boiling point of the diethylamine?

No.

It is just a higher boiling solvent to carry out the hydrolysis in.
The higher the temperature the quicker the reaction.
Watch out for the hot potassium hydroxide in ethylene glycol and water though. It will strip skin like hot water will remove wallpaper.

Ritter - 28-8-2008 at 07:37

Quote:

Originally posted by ScienceSquirrel
If you want to make anhydrous diethylamine ( eg free from water or alcohol ) then you are getting into a whole new ballgame.

Yes. The alkaline hydrolysis would allow you to distill over the amine but it would be wet with water. $17 would get you 5 lbs of anhydrous sodium sulfate on eBay item # 270268727018 .

Ritter - 28-8-2008 at 07:39

Quote:

Originally posted by mbrown3391
Sorry, i was thinking of the amine. so does the ethylene glycol raise the boiling point of the diethylamine?

I think you should consider taking a couple of basic chemistry courses including organic before you injure yourself or others.

Basic rule of thumb for insuring personal safety: "If you don't know what you're doing, don't do it."

[Edited on 28-8-2008 by Ritter]

ScienceSquirrel - 28-8-2008 at 07:41

Quote:

Originally posted by Ritter

Quote:

Originally posted by ScienceSquirrel
If you want to make anhydrous diethylamine ( eg free from water or alcohol ) then you are getting into a whole new ballgame.

Yes. The alkaline hydrolysis would allow you to distill over the amine but it would be wet with water. $17 would get you 5 lbs of anhydrous sodium sulfate on eBay item # 270268727018 .

Sodium sulphate will not dry the amine to any appreciable degree.
The only practical home method is to prepare the hydrochloride and then dry distill from solid potassium hydroxide.
It f**ks up the flask but it works!
Alternatively you can reflux it with loads of calcium hydride but that is like rocking horse sh*t to the average home chemist.

And I would echo Ritter's remark above.
You need a lot of knowledge and experience before you attempt this!

[Edited on 28-8-2008 by ScienceSquirrel]

mbrown3391 - 28-8-2008 at 07:46

i read that the amine was water soluble and remembered it as the amide. That doesn't mean i cant carry out a simple distillation at 55 degrees c. The dangers of this distillation aren't more than many other distillations.

ScienceSquirrel - 28-8-2008 at 07:49

Quote:

Originally posted by mbrown3391
i read that the amine was water soluble and remembered it as the amide. That doesn't mean i cant carry out a simple distillation at 55 degrees c. The dangers of this distillation aren't more than many other distillations.

If you ignore the fact that you are distilling from a hot solution of potassium hydroxide in ethylene glycol.
It will remove your skin and give you a deep flesh burn in seconds if you spill it on yourself.

mbrown3391 - 28-8-2008 at 07:59

First of all, there is no reason to believe that experience in chemistry is proportional to ability not to spill something on yourself.

Second of all, if used in stoichiometrically correct proportions, will all the KOH not be neutralized by the m-Toluic acid?

[Edited on 28-8-2008 by mbrown3391]

ScienceSquirrel - 28-8-2008 at 08:05

Quote:

Originally posted by mbrown3391
First of all, there is no reason to believe that experience in chemistry is proportional to ability not to spill something on yourself.

Second of all, if used in stoichiometrically correct proportions, will all the KOH not be neutralized by the m-Toluic acid?

[Edited on 28-8-2008 by mbrown3391]

You are going to have to use say two moles of potassium hydroxide for each mole of DEET.
This will ensure complete hydrolysis of the DEET which is your most expensive reagent and it will suppress protonation of the amine making it easier to distill it from the reaction mixture.
The waste caustic component left in the flask should be allowed to cool, treated with acid until neutral and disposed of appropriately.

[Edited on 28-8-2008 by ScienceSquirrel]

mbrown3391 - 28-8-2008 at 08:18

Good point. So are there any known, interesting uses of Sodium Phenylacetate, which will be the waste salt i believe.

ScienceSquirrel - 28-8-2008 at 08:24

Quote:

Originally posted by mbrown3391
Good point. So are there any known, interesting uses of Sodium Phenylacetate, which will be the waste salt i believe.

Your waste salt will be potassium 3-methylbenzoate.
If you could get sodium phenylacetate out of potassium hydroxide and DEET you would be a miracle worker and a friend to every drug cook in the world.

This is the structure of DEET

http://en.wikipedia.org/wiki/DEET

This is 3-methylbenzoic acid

http://en.wikipedia.org/wiki/M-Toluic_acid

This is phenylacetic acid

http://en.wikipedia.org/wiki/Phenylacetic_acid

[Edited on 28-8-2008 by ScienceSquirrel]

mbrown3391 - 28-8-2008 at 08:28

1. Prepare a solution of 80g NaOH in 73ml H2O.
2. To this solution, add 192ml of DEET. Two layers will form.
3. While stirring, slowly add propylene glycol to the mixture until homogeneous.
4. Heat to 55 degrees C in a distillation apparatus and maintain this temperature until boiling ceases.
5. Theoretical Yield: 103.39ml Diethylamine

Any problems with this procedure?

stoichiometric_steve - 28-8-2008 at 08:28

Quote:

Originally posted by mbrown3391
First of all, there is no reason to believe that experience in chemistry is proportional to ability not to spill something on yourself.

You bet there is. Even more so for people who cannot discern phenylacetates from benzoates...

Ritter - 28-8-2008 at 08:29

Quote:

Originally posted by mbrown3391
i read that the amine was water soluble and remembered it as the amide.

An example of not knowing what you are doing. If you can't visualize the difference between an amide and an amine or between your target product and your starting material you should not be attempting this.

Quote:

That doesn't mean i cant carry out a simple distillation at 55 degrees c. The dangers of this distillation aren't more than many other distillations.

This, of course, depends on your apparatus setup, what kind of glassware you'll be using, what kind of heating you will be using, and most especially your technique. Assuming for the moment that you will not be using a magnetic stirrer, how will you be preventing 'bumping' that could propel hot caustic glycol all over you and your work area?

ScienceSquirrel - 28-8-2008 at 08:29

Quote:

Originally posted by mbrown3391
1. Prepare a solution of 80g NaOH in 73ml H2O.
2. To this solution, add 192ml of DEET. Two layers will form.
3. While stirring, slowly add propylene glycol to the mixture until homogeneous.
4. Heat to 55 degrees C in a distillation apparatus and maintain this temperature until boiling ceases.
5. Theoretical Yield: 103.39ml Diethylamine

Any problems with this procedure?

Where did you get it from?

mbrown3391 - 28-8-2008 at 08:32

C12H17NO + H2O --> C4H11N + C7H7COOH
C7H7COOH + NaOH --> NaC8H7O2 + H2O

NaC8H7O2 is Sodium Phenylacetate according to http://www.encyclo.co.uk/define/NaC8H7O2

Ritter - 28-8-2008 at 08:32

Quote:

Originally posted by ScienceSquirrel

Quote:

Sounds like an Internet recipe.

[Edited on 28-8-2008 by Ritter]

mbrown3391 - 28-8-2008 at 08:33

i just wrote it based on the discussion in this thread.
Im assuming that NaOH can be used in place of KOH since i already have plenty of NaOH

[Edited on 28-8-2008 by mbrown3391]

Ritter - 28-8-2008 at 08:34

Quote:

Originally posted by mbrown3391
C12H17NO + H2O --> C4H11N + C7H7COOH
C7H7COOH + NaOH --> NaC8H7O2 + H2O

NaC8H7O2 is Sodium Phenylacetate according to http://www.encyclo.co.uk/define/NaC8H7O2

What does this have to do with making diethylamine? I think you're lost.

ScienceSquirrel - 28-8-2008 at 08:35

Quote:

Originally posted by mbrown3391
C12H17NO + H2O --> C4H11N + C7H7COOH
C7H7COOH + NaOH --> NaC8H7O2 + H2O

NaC8H7O2 is Sodium Phenylacetate according to http://www.encyclo.co.uk/define/NaC8H7O2

Have a look at my post above!

3-Methylbenzoic acid and phenylacetic acid have the same molecular formulas but different structural formulas.

mbrown3391 - 28-8-2008 at 08:37

to be fair, you edited your post after i posted that reply

mbrown3391 - 28-8-2008 at 08:38

but thats irrelevant. Can anyone point out any mistakes with the procedure i posted?

ScienceSquirrel - 28-8-2008 at 08:39

Quote:

Originally posted by mbrown3391
to be fair, you edited your post after i posted that reply

I edited the post to include the structures so that it was clearer for you.
The proper chemical names were in there to start with.

mbrown3391 - 28-8-2008 at 08:42

Quote:

Originally posted by stoichiometric_steve

Quote:

Originally posted by mbrown3391
First of all, there is no reason to believe that experience in chemistry is proportional to ability not to spill something on yourself.

You bet there is. Even more so for people who cannot discern phenylacetates from benzoates...

Good one!

ScienceSquirrel - 28-8-2008 at 08:47

Quote:

Originally posted by mbrown3391
but thats irrelevant. Can anyone point out any mistakes with the procedure i posted?

Where do I start;

1) Too big a scale, a reaction like this should be executed on a scale of say 10 - 50 millimoles to start with. You do not know how hot it is going to get or how quickly it is going to react.

3) A mixture like that will have to heated above 55 C to get a hydrophilic substance like diethylamine to distill out. I would guess that 80 - 100 C would be reasonable.

2) You have substituted sodium hydroxide for potassium hydroxide. It is a lot less soluble in alcohols, it may not matter but it is still a stupid change.

3) You have switched ethylene glycol for propylene gycol

4) Your product will be a low boiling, corrosive and irritant liquid.The apparatus should have a cooled receiver and a gas take off connected to a pipe that goes outside your workplace.

[Edited on 28-8-2008 by ScienceSquirrel]

mbrown3391 - 28-8-2008 at 08:49

1. Prepare a solution of 80g NaOH in 73ml H2O.
2. To this solution, add 192ml of DEET. Two layers will form.
3. While stirring, slowly add ethylene glycol to the mixture until homogeneous.
4. Add a small amount to a distillation apparatus and heat to 55 degrees C. If all goes well, add the rest and maintain 55 degrees C until boiling ceases
5. Theoretical Yield: 103.39ml Diethylamine

[Edited on 28-8-2008 by mbrown3391]

ScienceSquirrel - 28-8-2008 at 08:53

Quote:

Originally posted by mbrown3391
1. Prepare a solution of 80g NaOH in 73ml H2O.
2. To this solution, add 192ml of DEET. Two layers will form.
3. While stirring, slowly add ethylene glycol to the mixture until homogeneous.
4. Add a small amount to a distillation apparatus and heat to 55 degrees C. If all goes well, add the rest and maintain 55 degrees C until boiling ceases
5. Theoretical Yield: 103.39ml Diethylamine

[Edited on 28-8-2008 by mbrown3391]

That is a recipe for a trip to A & E

Ritter - 28-8-2008 at 09:01

Quote:

Originally posted by ScienceSquirrel
3) You have switched ethylene glycol for propylene gycol

[Edited on 28-8-2008 by ScienceSquirrel]

PG is listed as a solvent for DEET on the MSDS. Pure PG is available on eBay. I think the inexperienced might be tempted to use antifreeze instead of going to the bother of sourcing pure EG. Antifreeze contains a lot of other stuff that might cause problems.

ScienceSquirrel - 28-8-2008 at 09:06

But heating a solution of potassium hydroxide in propylene glycol may result in side reactions producing brown goos.

If he uses antifreeze all bets are off.

Anyway look at the scale he is thinking of trying this on.

He will have about half a litre of hot, corrosive liquid.

If that stuff decided to misbehave it could go everywhere.

[Edited on 28-8-2008 by ScienceSquirrel]

Ritter - 28-8-2008 at 09:14

Quote:

Originally posted by ScienceSquirrel
But heating a solution of potassium hydroxide in propylene glycol may result in side reactions producing brown goos.

I doubt it but this is all about amateur experimentalism, right? My first trial would be to heat a little NaOH in PG & see if there is any color formed.

[Edited on 28-8-2008 by Ritter]

ScienceSquirrel - 28-8-2008 at 09:22

Quote:

Originally posted by Ritter

I doubt it but this is all about amateur experimentalism, right?
My first trial would be to heat a little NaOH in PG & see if there is any color formed.

[Edited on 28-8-2008 by Ritter]

I agree.

But his first attempt is on a semi bucket scale and he is not even thinking of investigating the solubility of sodium hydroxide in water / propylene glycol to start off with.
His starting solution of sodium hydroxide is ca 10M!
Then he is going to add 192ml of DEET, that is about £20 by my reckoning. I bought 50ml of neat DEET today for £5.
Then he is going to add propylene gylcol until it all forms a homogenous mix.
I reckon it will start to react before he gets it in the flask and his shed will fill with a cloud of diethylamine vapour.

[Edited on 28-8-2008 by ScienceSquirrel]

Nicodem - 28-8-2008 at 09:26

Quote:

Start reading books! That should be the point number one in your recipe.
There are several examples in this thread that show you are still too ignorant about organic chemistry too safely conduct the hydrolysis of this amide:
1.) That you use empirical formulas instead of rational means you are completely clueless about the theory behind this reaction (or any other organic reaction).
2.) That you want to attempt the first reaction on a 1 mol scale shows how irresponsible and uncareful you are.
3.) That you believe your reaction mixture will boil at 55°C shows you are completely clueless about basic physics and physical chemistry.
4.) That you can't tell the difference between an amide and amine and furthermore believe such an benzamide can be hydrolysed at such low temperature shows you have no lab experience and no knowledge of preparative chemistry.
I could continue, but it is pointless....

Now, do you think anybody here is going to lead you step by step and risk of causing you injury? This is not the Beginnings section, so find an example of benzamide hydrolysis yourself and put it forward for discussion to bring some sense into this thread, that is developing so pathetically. For some reason you are even too lazy to check out the procedures in Vogel, Organikum or other books, some of which you could have found in our library as well.

Besides, you still did not explain why you want to hydrolyze DEET. Obviously you are more interested in diethylamine rather than the more precious m-methylbenzoic acid, which makes all this highly unusual. Diethylamine is way cheaper than DEET, unregulated and can be ordered trough any chemical reseller without troubles. If you wanted to prepare it yourself as some sort of a chalange than why have you not searched the literature first?

Arrhenius - 28-8-2008 at 09:56

Howdy Mrbrown. A few things first:

1.) NaOH v. KOH, no difference in this reaction.. both are plenty basic
2.) Hot NaOH in water will not dissolve your flask.
3.) Ethylene glycol (EG) (same stuff that you put in your car radiator) or propylene glycol only sufices to raise the boiling point of water a few degrees. It will not effect the boiling point of the amine.
4.) Ritter's suggestion to use EG/PG is to improve the solubility of DEET in the water. This is important because the water is what's actually breaking the amide bond and forming the meta-methylbenzoic acid. A research laboratory would accomplish this by use of a phase transfer catalyst (PTC), so as to not indroduce EG as a contaminant.
5.) 80g of NaOH sounds quite near to a saturated solution of NaOH. Sure.. start with this. Perhaps a little more water is easier to work with, giving you a bit of room to work with the distillation, since water will distill also.
6.) The density of DEET is very similar to that of water... hence it may not float on top, it may create an emulsion, more on this later.
7.) Small molecular weight alkylamines are more easily(safely too) handled and stored as an ammonium salt, such as the hydrochloride (HCl), which is easily converted back into the free base by preparing a basic aqueous solution of the ammonium salt and extracting into organic solvent.
8.) here are the rough procedures I might try experimenting with.

Base Hydrolysis:

I.) Prepare a solution of ~20:30 NaOH:H20 (w:v) (careful, this gets quite hot while it dissolves.. prepare it in a glass container standing in some room temperature water)
II.) Add ~1 part (v) EG (I'm not certain about this step.. may cause rxn to fail).
III.) To the aqueous NaOH add ~30 parts (v) of 100% DEET (this is ~0.2mol% relative to the base. i.e. plenty of excess NaOH). This will probably create an emulsion, and the solution may look a little bit cloudy.
IV.) Gently reflux this mixture for ~30-60min with a cold condenser (preferably <0*C).
V.) Either steam distill your diethylamine. OR partition it into organic solvent such as dichloromethane or hexane.
VI.) Acidify the distillate with slight (~1.2) molar excess of HCl and boil off the water to yield Et2NH*HCl. OR Dry the organic layer with suitable anhydrous drying agent (I like MgSO4 or Na2SO4).

*Note: for those worried about safety, see the next method. This approach to base hydrolysis would prove more difficult for the novice than dangerous.

Acid Hydrolysis (already suggested by Ritter):

I.) Reflux a solution of ~ 3:1 (v:v) DEET:HCl (30% muriatic acid is probably okay) for ~1-2hr.
II.) Cool the solution to room temperature.
III.) Extract the resulting solution with toluene (easy to get) to remove the (similar to toluene) m-methylbenzoic acid.
IV.) Boil off the water/acid in a fume hood or outdoors to yield Et2NH*HCl.
IIV.) For fun, let the toluene evaporate and hopefully you'll find your m-methylbenzoic acid left behind.

*Note: I don't believe there's anything particularly dangerous with this procedure. As always, a hot plate is preferred over a bunsen burner, toluene is flammable (DEET too), and if you get acid on yourself wash it with water immediately. HCl vapor is not particularly dangerous as it is too irritating to stay near for more than a couple seconds. Oh.. and don't eat any of your products.

My personal suggestion... start small... it's cheaper, and when it doesn't work you'll have plenty of material to try a different approach. If it works, do it again.

The acid hydrolysis method seems tame to me. Tame enough that I might say try it, and if you get zero yield... you'll atleast get a motivation to further your understanding of chemistry by continuing reading. Seems like you're on the right track. Don't get too discouraged by people flaming you for confusing "amine" and "amide"... ask the average college science student, and they won't be able to draw either one. Ask as many questions as you'd like, those willing will help.

Others: Any thoughts?

[Edited on 28-8-2008 by Arrhenius]

Arrhenius - 28-8-2008 at 10:30

Haha, censorship.. grand...

mbrown3391 - 28-8-2008 at 10:47

I'm pretty sure that it is a watched substance. and I don't need the fbi at my door (i have been active in the energetic materials forum) so I don't think I will be buying diethylamine. besides, that eliminates all the fun. anyway, ill be trying this soon and ill post my results

mbrown3391 - 28-8-2008 at 10:57

and I don't see why this thread should be closed. I swear there is a unique psycology behind forums. one person posts something negative, and suddenly a bunh of elitist followers start swarming around, repeating insults over and over again until no further information can get through. its unbelievavly annoying

ScienceSquirrel - 28-8-2008 at 10:57

Quote:

Originally posted by stoichiometric_steve
close&delete this thread

There is some rubbish in this thread, but which thread does not contain some rubbish?
But there is also some good and thoughtful chemistry so I do not think closing and sending it to detritus or deletion is the right course of action.
Anyway we are promised an update when he tries an experiment....

ScienceSquirrel - 28-8-2008 at 11:04

Quote:

Originally posted by mbrown3391
and I don't see why this thread should be closed. I swear there is a unique psycology behind forums. one person posts something negative, and suddenly a bunh of elitist followers start swarming around, repeating insults over and over again until no further information can get through. its unbelievavly annoying

That is complete rubbish.
There are a few negative comments but what do you expect?
Your original post was poor and you have done very little since to improve and you have ignored most of the advice that you were given.
Ritter, Arrhenius and myself have been the major posters in the thread and we have disagreed with each other as much as with you.
Buying 100ml of diethylamine will not bring you to the attention of the FBI or anyone else in law enforcement. The whole system of trading in chemicals would seize up completely if that sort of thing happened.
Diethylamine probabaly has dozens of uses in all sorts of products, it is a multiton bulk chemical!

[Edited on 28-8-2008 by ScienceSquirrel]

Ritter - 28-8-2008 at 11:19

Quote:

Originally posted by mbrown3391
I'm pretty sure that it is a watched substance. and I don't need the fbi at my door so I don't think I will be buying diethylamine.

Just because you're not paranoid doesn't mean they're not out to get you.

Sauron - 28-8-2008 at 11:22

stoichiometric_steve

If you are not a moderator, and you aren't, then the proper course of action if you think a thread ought to be closed or trashed is to use the REPORT function. Posting as you did is, I have been advised, improper.

Arrhenius

You are new around here. You do not have a clue as to the sort of people who are regulars on this forum. There are many here who are either professional chemists, meaning they work at chemistry for a living, or else professionally qualified chemists, meaning formally trained graduate chemists, including current MS and PhD candidates and postdocs, or retired chemists. In my case I was formally trained, worked as a RA, have been published in JOC, own patents, and am now retired. So kindly do not get on some hobbyhorse about professionals vs amateurs.

Furthermore the forum membership is highly international, and not restricted to north America and Europe. Restrictions common in USA do not necessarily apply to all other places.

Finally, you have not the slightest sense of what resources some members may have and some members may lack. There are people on this forum who are extremely well equipped and deep pocketed. There are others not so well off.

So quit making assumptions and presumptions as to what members can or can't so, can or can't buy, etc. Those are uncalled for and most of all inaccurate.

All here share a love of chemistry as a science and as a hobby. That is sufficient.

mbrown3391 - 28-8-2008 at 11:22

I would not all my orriginal post poor. learly I did in fact do some of my own "legwork" as I offered 3 possible reactions and asked specific questions about them. however almost immediately people start questioning my motives(whih are irrelevant) and it eventually leads to ridiculous claims that someone who mistakes the solubility of an amide for that of an amine must be unable to hold somethbing without spilling it all over himself

Nicodem - 28-8-2008 at 11:44

Do not search for excuses for your laziness. You did not provide a single reference and your lazy spelling is pure annoyance to the reader. All you do is taking wild guesses hoping this would incite others to do a literature search for you. This kind of behavior is only acceptable in Beginnings section where you can post questions even without checking the literature to have some basic understanding of the problem. But as you can see from what happened to this thread, such a behavior is highly destructive for those who want a serious discussion about chemistry.
You are not a new member, so no excuses. Go find a book about preparative chemistry or some paper about amide hydrolysis and find some experimental to repair this thread or else it will inevitably end up closed due to lack of progress and members flaming each other.

mbrown3391 - 28-8-2008 at 12:01

first of all do not cite spelling as a represenatation of anything. it is the most tired, cliché insult around, used only when the flamer has run out of fuel. my posts have been entirely legible and I am not the only one who has made spelling mistakes.

Arrhenius - 28-8-2008 at 12:15

Sauron: I don't wish to share who I am, nor what my background or merit is. It is not your business. You wouldn't get off your pedastel if I told you anyway. I have suggested one method which anyone should be able to perform, maybe even in a test tube, or even in a 27L flask. You're making a very large stretch with what you just said. Smear away though.

And yes, I do love chemistry.

Mrbrown:
Yes, diethylamine will likely prove difficult to purchase in the West. There is constant talk, sadly, of how to obtain 'watched' or 'restricted' chemicals, but whether you'll get in trouble with the law is entirely circumstantial. For instance, the recent threat on Mr. Deebs in the Legal Matters subforum. If you had genuine interests and legal persuits in chemistry, diethylamine would still prompt prosecutors to slap some drug manufacture charges on your case. From outside the box, it looks like people are concerned about you making one certain semi-synthetic alkaloid which I've already referred too. I personally don't care what you use diethylamine for. If you can make it, and that spurs your continued interest in chemistry, then I'd say it's worth making. No one is saying you have to post your results, but I would read them.

Also, if I've made an incorrect presumption about anything pertaining to you, please PM me and let me know. I apologize in advance.

Check out this thread if you're willing to purchase some reading material. Most of the books listed will discuss alkylamines as well, but probably not a recipe.
Decent Chemistry books

To all:
I don't mind a few spelling errors so long as it's comprehensible. If a PhD chemist was posting here who didn't write perfect english, would this discredit their merit? I hope not. I don't think anyone should help Mrbrown who doesn't wish to. There is no obligation.

[Edited on 28-8-2008 by Arrhenius]

[Edited on 28-8-2008 by Arrhenius]

ScienceSquirrel - 28-8-2008 at 12:22

I bought some DEET today and everything else is to hand so I am going to have a go at hydrolysing it this weekend.

I am not making diethylamine or its hydrochloride but I bet that I will have a few grams of shiny needles of m toluic acid by close of play on Sunday

panziandi - 28-8-2008 at 12:28

If you really want to get a source of DEA (hahaha so aptly abbreviated) then DEET is probably the best bet. Although it may be worth asking a local chemical company if they have it in stock and if they could sell it to you. I don't see why they shouldn't it's not particularly hazardous and it is fairly legitimate I can certainly think of a good number of uses for it in the hands of a private chemist!

Nicodem - 28-8-2008 at 12:52

The posts unrelated to the topic and those inciting flame wars were removed. Use the U2U function for personal messages!
From now on only post chemistry related posts.

Quote:

Originally posted by ScienceSquirrel
I bought some DEET today and everything else is to hand so I am going to have a go at hydrolysing it this weekend.

I am not making diethylamine or its hydrochloride but I bet that I will have a few grams of shiny needles of m toluic acid by close of play on Sunday

You can reflux it with HCl for several hours. That should work and you don't have to use a cosolvent. I have not read the paper as I have other work now, but there is supposed to be an experimental procedure using HCl(aq) for the hydrolysis of N,N-diethyl-ortho-methylbenzamide in DOI: 10.1016/S0040-4039(00)94113-3 (you can find the Tetrahedron Letters volume 24 in References if you don't have access to the journal).
N,N-Dialkylbenzamides can also be hydrolysed with NaOH(aq) reflux - also no need for a cosolvent - but using the acid saves you from the nasty smell of diethylamine so you can do this without even using a fume hood.

mbrown3391 - 28-8-2008 at 13:07

ScienceSquirrel, what kind of store did you get your DEET from?

ScienceSquirrel - 28-8-2008 at 13:17

Quote:

Originally posted by mbrown3391
ScienceSquirrel, what kind of store did you get your DEET from?

Most pharmacists aka chemists sell 50% DEET. The rest of it is denatured alcohol and fragrance. Often the fragrance is based around citrus oils that do have a discouraging effect on insects.
Hard core travelling / camping stores that deal with people off to places with serious bug problems sell 90 - 100% DEET.
Mine is 95% DEET, the rest is denatured alcohol and a spot of citronella.

panziandi - 28-8-2008 at 13:19

In the UK some camping stores sell solutions of DEET as an insect repellant in spray bottles of 100mL. Now I have not seen it at 100% concentration but you may be able to find a high strength even 100% if you go to a camping store. Chances are if you search for some walking camping backpacking store online you could find high strength DEET. To be honest I haven't looked at the labels of stuff like that for a good number of years! Good hunting and keep us posted on the experiments.

ScienceSquirrel - 28-8-2008 at 14:01

I have to admit to a compulsive label reading tendency.
I can buy most things but there is that tiny edge of subverting the system, finding something dead cheap in a shop that a chemical supplier would have done you £30 for.
Anyway 100% DEET is available quite cheap if you look around.

http://cgi.ebay.co.uk/REPEL-120ml-100-DEET-MOSQUITO-INSECT-R...

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