Sciencemadness Discussion Board

ETN synthesis problem

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EWillies - 22-12-2017 at 08:16

Bert - Thanks for the feedback and for moving my post. There will be no doings of illegal activities or subsequent postings there of.

Everyone else - Thanks for the feedback as well. After reading more into it is seems that as previously mentioned, the NH4NO3 method of synthesis results in much lower yields. I've seen better results when people use 70% or greater Nitric Acid and Sulfuric Acid for the nitrating mixture. This is interesting since I've seen nitroglycerine synthesis with AN and other nitrate salts get much closer to theoretical yield.

It seems best to stick to Nitric Acid for nitration of alcohols. Not sure what the mechanism there is but I'll do some research and figure it out for myself.

Thanks again gentlemen.

Rocinante - 22-12-2017 at 08:28

I!ve used 68% nitric with conc. sulphuric and got 20 % yields, with finely crushed erythritol and controlled temperature.. dunno what went wrong.

Has anyone tried 68%HNO3/KNO3/conc. sulphuric combo?

[Edited on 22-12-2017 by Rocinante]

sipuli - 29-12-2017 at 06:14

Hi all!

I have been working with some ETN synth with new to me process and i seem to have very poor yields. Last run with 28gr of E gave me 24gr of ETN!

Process in question in nitration with ammonium nitrate and sulfuric acid.

I have sneaking suspicion that the ammonium nitrate I have is not pure enough, originally it is cold bag AN that has gone through the usual "dissolve to water-filter-boil off water-dry" process.

Could cold pack AN have some sort of water soluble additive which could ruin the nitration process? The AN does work very well in ANNM and others.

Reason why i suspect something is not right with the AN is the way it dissolves to the sulfuric acid: there seems to be quite a bit of outgassing of what i think is NOx along with maybe something else. There is so much outgassing that the solution likes to foam up when the AN powder (very fine!) is added.

Is this normal?

XeonTheMGPony - 29-12-2017 at 08:48

should be no out gassing, just a steady rise of temp at each addition. Allot of cold packs are doped now days with poisoning agents to nitrating, urea, calcium in some cation and such.

Cold packs best to recrystallize, I been doing it by dissolving in ammonia, then filtering out solids then drying.

sipuli - 29-12-2017 at 14:42

That was my initial impression as well.

I did some reading and I think what i have here is calcium contamination.

It will pass through when AN is dissolved in water.

I think it goes partially like this

Ca + H2SO4 -> CaSO4 + H2

And then CaSO4 is somewhat soluble in nitric acid so it does not form precipitate. This will be easy to prove with small test reaction and flame test.

[Edited on 29-12-2017 by sipuli]

XeonTheMGPony - 2-1-2018 at 17:56

here they are a mixture of ammonium nitrate and calcium nitrate, so I dissolve in ammonia then filter off the calcium then recrystallize the AN

Melgar - 21-5-2018 at 15:37

Quote: Originally posted by sipuli  
That was my initial impression as well.

I did some reading and I think what i have here is calcium contamination.

It will pass through when AN is dissolved in water.

I think it goes partially like this

Ca + H2SO4 -> CaSO4 + H2

And then CaSO4 is somewhat soluble in nitric acid so it does not form precipitate. This will be easy to prove with small test reaction and flame test.

[Edited on 29-12-2017 by sipuli]

I guarantee you do not have calcium metal in your cold packs.

What's probably happening is that you're using wet ammonium nitrate. Ammonium nitrate is very hygroscopic, and will have a considerable amount of water in it. When you add this to sulfuric acid, this addition of water can make it very hot, and other nitrogen oxide compounds can form due to the heat. This is one of the reasons that it's so important to keep the whole mixture at a low temperature, to avoid having this happen.

Laboratory of Liptakov - 14-6-2018 at 07:56

Recrystallisation and maximum dry NH4NO3 is basic condition for successful yields. Same as maximal fine and maximal dry Erythritol. Otherwise, it is a waste of valuable acids. ...:cool:...Dr.

Rocinante - 14-6-2018 at 12:47

it's time to stock up on sulfuric acid anyway, since the EU is moving on to ban the sell of conc. sulphuric acid.
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