Ethylenedinitramine

Ethylenedinitramine (EDNA) is a practical and powerful military explosive. Problem is, the routes to EDNA, as published always use either exotic chems or very high or very low pressures to form the precursor - ethyleneurea.

I found the following article that seems to open itself up to OTC synthesis. In this case made by the condensation of urea (fertiliser) with ethylene glycol (antifreeze) at 1atm, though the distillation/extraction of ethyleneurea as described requires very low pressures and high heat.

http://www.sciencemadness.org/scipics/axt/ethyleneurea-from-...

I have attempted this, with mixed results. Firstly this reaction scheme was assumed:

<img src="http://www.sciencemadness.org/scipics/axt/ednascheme-2.jpg">

Thus, if the intermediate "resin" as described in the article was assumed to be polyethyleneurea it should be possible to directly nitrate it, then cleave it though hydrolysis to ethylenedinitramine, thus removing the need to isolate the monomer though high temps & low pressures.

In the following urea, was as fertiliser and ethylene glycol was as 95% antifreeze.


Experimental 1:

3mol urea was refluxed with 1mol ethylene glycol in this <a href="http://www.sciencemadness.org/scipics/axt/ethyleneurea-condensor.jpg">setup</a>, the wine bottle was filled with hot water to condense the reaction products, but be hot enough to prevent the formation of ammonium carbonate (decomp. ~58°C). The hotplate on "high" initially stabalised at ~140°C which gradually increased throughout the reaction to 210°C where gassing nearly stopped and the <a href="http://www.sciencemadness.org/scipics/axt/ethyleneurea-foam.jpg">product</a> foamed up. This took about 3.5 hours and weight was reduced to 96% of theory of the scheme above. Much ammonia was released and some ammonium carbonate did form on the "condensor" which had to be removed throughout the course of the reaction.

The product set to a brittle solid that was easily powdered in a mortar & pestle, making the assumption that this could be polyethyleneurea, 20g was nitrated in KNO3/H2SO4 @ 5°C for two hours, when dunked into water a large quantity of <a href="http://www.sciencemadness.org/scipics/axt/edna-precip.jpg">precipitate</a> formed, and was filtered. Since EDNA is decomposed by dilute, boiling H2SO4 the recrystalisation was attempted in 5% sodium acetate formed by neutralising white vinegar with NaOH. This should buffer the solution and prevent decomposition by H2SO4 which is converted to sodium sulphate. The product dissolved easily in boiling solution but on cooling no product was formed.

A couple possibilities for the failure: The acid solution still decomposed the EDNA, or more likely it wasn't EDNA but a primary nitramide which was hydrolised in boiling water to nitramine, with subsequent decomposition.


Experimental 2:

4mol urea was heated with 1mol ethylene glycol without reflux for 6 hours @ 140-180°C. This was then placed into a toaster oven @ a setting of 280°C for two hours, during this time a lot of white smoke was released and a <a href="http://www.sciencemadness.org/scipics/axt/door-condensate.jpg">condensate</a> formed on the glass of the oven which showed no reaction to HCl (thus not (NH4)2CO3), but there wasn't enough to do other tests on it. If this white substance was indeed ethyleneurea it shows that it will volitalise at ~280°C and the low pressures in the article are only needed to keep it gasseous or liquid for long enough to make it to a recieving flask.

Sooo, thus far failure, but its an interesting route to an interesting explosive and being a primary nitramine is capable of undergoing further interesting reactions, futher investigation is in order. Since I as yet have no way of achieving the temperatures needed while effectively condensing any product formed I'm thinking of replacing the door of a toaster oven with a steel plate with a hole in it, to allow the "wine bottle condensor" to protrude from it, so the ethyleneurea can condense onto the bottom. Alternatively a microwave could also work and the turntable could be used to stir the solution . The hard brittle resin from experimental 1 melts and smokes (stinky) within 3 min in my kitchen microwave on "high" so its definately acted on.

EDNA from ethylenediamine

Following the article above, a 98% yield of ethyleneurea can be done at 1atm by condensing urea with ethylenediamine with loss of ammonia.

The most important aspect of their method is the moderation of the reaction by water which must be boiled off throughout the reaction. By refluxing the ethylenediamine/water azeotrope (bp ~110°C) but allowing the water once free to be extracted from the reaction. If no water is added, or it not extracted throughout the reaction it notes that the yeilds are very poor.

The "<a href="http://www.sciencemadness.org/scipics/axt/ethyleneurea-condensor.jpg">wine bottle condensor</a>" suited this well by allowing the temperature of the bottle to be varied with the quantity of water it holds. Due to the somewhat low surface area of the condensor I filled the bottle ~1/3 full, this stabalised at a temperature of about 75°C throughout the reflux.

<i>Experimental</i>: Into 50g urea and 25ml water was added 50g ethylenediamine in a 600ml beaker. Into the beaker was placed the winebottle proped up with a glass rod to act as the condensor.

With the hotplate on full the temperature of the reactants stabalised at ~110°C rising to 140°C in 1.5 hours, this was then left to reflux for a total of two hours.

After two hours the clear melt become turbid, and then very thick and pasty. This thick solution popped and spluttered as no stiring was (or could be) used. This thick solution lasted about 30 minutes upon which it turned into a clear amber melt. After three hours of reflux no more gassing was seen, and <a href="http://www.sciencemadness.org/scipics/axt/ethyleneurea1.jpg">crystals were condensing onto the bottom of the bottle</a>. The molten liquid now over >220°C was poured onto a <a href="http://www.sciencemadness.org/scipics/axt/ethyleneurea2.jpg">tray to set</a>, which was then broken up and powdered.

These observations were in agreement with the journal article, although the pasty mass formed about 1 hour quicker, thus the reaction was run 1 hour shorter.

Nitration of the supposed ethyleneurea was carried out by adding 20g ethylene urea to 148g 98% sulphuric acid & 52g 70% nitric acid whilst keeping the temperature around 10°C and leaving the mixture for 30 minutes. After this time the nitration mixture was thick with a white precipitate.

The mixture was poured into 1.5 litres of cold water then filtered, washed with a further 1 litre and filtered again to recieve a <a href="http://www.sciencemadness.org/scipics/axt/edna1.jpg">decent yeild</a>.

Recrystalisation was done in by dissolving the precipitate into 200ml of dilute sodium acetate solution. Upon boiling much foam was created gas given off as expected from hydrolysis of dinitroethyleneurea to ethylenedinitramine with release of carbon dioxide. Eventually the precipitate went into solution as temperature reached 90°C.

The solution was filtered and placed into a freezer to cool to 5°C. A large <a href="http://www.sciencemadness.org/scipics/axt/edna-recrystalised.jpg">crystaline precipitate</a> formed (yay ) which was filtered and dried.

The crystals flare off on ignition. No detonation thus far has been attempted. I did attempt to replace the active hydrogens with chlorine by way of NaOCl but thus far nope a "chloronitramine", (-NCl-NO2) would have been quite neatly dangerous

Anyway, this seems like a very simple way to EDNA if ethylenediamine can be had. Pitty it isn't so easy with ethyleneglycol, but the condensor did work as originally planned, with the ethyleneurea condensing onto the bottom surface. So I'm not sure what going wrong with the "antifreeze method".

[Edited on 5-10-2005 by Axt]

The ethylenebis(chloronitramine) (<-- yes, I'm making up names) was again attempted, this time by the action of chlorine gas on the sodium salt:

NaO2N=N-CH2-CH2-N=NO2Na + 2 Cl2 --> O2N-NCl-CH2-CH2-NCl-NO2 + 2 NaCl

Chlorine by way of MnO2 + HCl was bubbled into a solution of sodium-EDNA in a 100ml measuring cylinder. After a few minutes a dangerously large quantity of milky pale yellow oil fell out of the solution. I took a photo then knocked the chlorine generator over filling the cylinder with manganese oxides and HCl, no product could be saved The liquid product as shown below resembled the <a href="http://www.sciencemadness.org/scipics/axt/NTCED.jpg">tetrachloride</a> but a much paler yellow colour, though it did look like it was in an emulsion with water.

<center><img src="http://www.sciencemadness.org/scipics/axt/chloronitramine.jpg"></center>

The lead salt was also made by precipitating a solution of Na-EDNA (5g EDNA, 2.6g NaOH) with 10.8g lead acetate. The fine white amorphous precipitate was filtered and dried. On ignition it is quite feeble and certainly no initiating explosive.

<center><img src="http://www.sciencemadness.org/scipics/axt/pb-edna.jpg">
<a href="http://ww1.webtop100.net/~62552/xmovies.webtop100.net/banners/xmovies.html">movie</a></center>

The remainder of the EDNA (4.5g) was detonated with 0.5g PETN, it went ... bang.

Yes. I think it definately worth trying. I dont have DMF, whats the reason for choosing that solvent?

The documented synth of N,N-dinitramines being by reacting a primary nitramine in acetonitrile with a nitronium salt [patent attached]. If an analogous reaction was possible with nitrosyl salts it would produce a N-nitro-N-nitroso of O% OB. As far as I know there is no solvent for the easily made nitrosyl perchlorate/sulphate. I believe direct nitrosation of EDNA only results in ethyleneglycol.

Pitty no properties are reported for anything containing the -N(NO2)2 structure, its very interesting.

Another hare brained idea, cyclisation of EBCN with sodium peroxide, by using my nomenclature skillz that would give "cycloethyleneperoxydinitramine" OB also O%

BTW, "EBCN" MP is <60°C, melts into a clear oil when dropped into hot water out of the tap.

[Edited on 16-10-2005 by Axt]

Attachment: nn-dinitramines.pdf (455kB)
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Thanks, I was a bit worried that I was talking to myself

I found the reason we don't hear much of the -N(NO2) group in explosive literature.

"<i>All covalently bound alkyldinitramines suffer instability problems that presumably originate from a combination of the steric hindrance between the two nitro groups and the high electonegativity of the N,N-dinitro group. A N,N-dinitro group leaves the alkyldinitramine electron deficient, especially at the central nitrogen. These effects destabilize alkyldinitramines and the instability can be observed in their thermal properties; all known alkyldinitramines thermally decompose at temperatures less than 70 °C and are highly shock and impact sensitive.</i>" JACS, 1997, 119, 9405-9410

The rest of the article relates to the dinitramide anion, which is significantly more stable.

^ N(NO2) should of course be N(NO2)2.

Anyway....bingo!

"<i>Little work has been reported on the synthesis and reactions of N-halo-N-nitro amine derivatives. N,N'-Dichloro-N,N'-dinitro-l,2-ethylenediamine, isolated by Smart and Wright in 1948, remained the sole example of this class of compounds until the <b>recently reported synthesis of simple N-chloro-N-nitroalkylamines by the chlorination of aqueous salts of alkylnitramine</b>. The synthesis of N-chloro-N-nitrocarbamates by this method was reported by Thomas in 1955. N-Bromo-N-nitro amine derivatives have not been reported. N-Chloro-N-nitramines and N-chloro-N-nitrocarbamates are explosive compounds and decompose rapidly on storage.</i>" Vytautas Grakauskas, Kurt Baum; J. Org. Chem.; 1972; 37(2); 334-335.

Confirms the synthesis but also mentions its instability. I've stored some 8g cast for ~2 weeks now with seemingly no change, better get rid of it soon.

The article itself focuses on N-fluoronitramines, I'll attach the full article when I get it. It mentions N-fluoro-N-nitrobutylamine that it was stored @ room temp for months without apparent decomposition.

hmmm.. fluorine gas The ethylenediamine derivative would HAVE to be powerful.

[Edited on 6-11-2005 by Axt]

Maybe electrolysis with an excess of hydrofluroic acid (sodium hydroxide created from NaF electrolysis might decompose the wanted products) would serve to produce the -NFNO2 derivative without having to handle fluorine gas.

It would no doubt be powerful, not only would it have a very good O balance, it would produce HF for added energy, and compounds that have had F substituted onto them tend to have increased density over the parent compound

C2H4N4O4F2 --> 2HF + 2N2 + CO2 + CO + H2O

This is all fascinating stuff.
I am most impressed that the chlorination works so quantitatively, and that you actually got this to work!

I was wondering whether one could expand that to other nitramines. Nitrourea is one that springs to mind, plus it's probably easier to make than EDNA.

On the note of fluoronitramines - I also doubt it would work, at least with H2O as a solvent. The H2O is at a huge molar excess, and, and reactivity of hydrogen bound to the N would have to be significantly higher to outcompete H2O.

Also, if you make the iodonitramine, you could potentially chlorinate that... similar to what you did in the iodoso/iodoxy thread! If that'd work, you should get a medal

N-I bonds aren't known for their niceties . I guess one could try precipitating a solution of KI/I2 with Na-EDNA.

I did just happen along the reaction of alkyl chloramine with AgNO2 to form nitramine, so at least it can be done where:

R-NH-Cl + AgNO2 --> R-NH-NO2 + AgCl

It was in vol 8 PATR 2700, N68, under section on nitration though it doesnt provide any further information, nor references. EDIT: its in urbanski as well, vol 3 pg. 11, though they both say AgNO3 not AgNO2, that has to be wrong. It does reference to A. BERG, Ann. Chim. [7] 3, 358 (1894). Makes you wonder what could be produced from TCCA for example, maybe quick and dirty nitramide H2N-NO2 or triketo-RDX! C3N6O9.. hahahah, super dense, thats one thats too easy to be true.

Anyway, I still had a small sample of EDNA that was produced back whenever, put it under microscope, picture on left is from literature, on right was mine precipitated from water:

<center><img src="http://www.sciencemadness.org/scipics/axt/EDNA-crystals.jpg"></center>

Stick some VOD tables in too, 'cause I keep losing them. VOD is actually quite high but requires high pressure to achieve those densities. For example PETN requires only 40000psi to obtain 1.740.

<center><table cellpadding="5" border="1" style="font-size:12px"><tr><td colspan="9"><b><center>EDNA - Measured Velocity of Detonation</center></b></td><tr><td>Density (g/cm³</td><td>1.00</td><td>1.25</td><td>1.49</td><td>1.50</td><td>1.532</td><td>1 .562</td><td>1.663</td><td>1.71</td></tr><tr><td>VOD (m/s)</td><td>5650</td><td>6600</td><td>7570</td><td>7580</td><td>7639</td><td> ;7750</td><td>8237</td><td>TMD</td></tr></table></center>
<center><table cellpadding="5" border="1" style="font-size:12px"><tr><td colspan="9"><b><center>EDNA - Loading densities</center></b></td><tr><td>Pressure (psi)</td><td>5000</td><td>10000</td><td>12000</td><td>15000</td><td>20000</td><t d>40000</td></tr><tr><td>Density (g/cm³</td><td>1.28</td><td>1.39</td><td>1.41</td><td>1.44</td><td>1.49</td><td>1. 56</td></tr></table></center>

[Edited on 1-5-2006 by Axt]

Nitramine from TCCA

I just recently had this same idea occur to me , to react TCCA with Sodium nitrite
in dichloromethane. This merits investigation.
(CO)3(NCl)3 + 3 NaNO2 -> 3 NaCl + (CO)3(NNO2)3

Alternatively TCCA solid can be gassed with ammonia , then later ozonated.
(CO)3(NCl)3 + 6NH3 -> 3NH4Cl + (CO)3(NNH2)3 , ( cycloTricarbonylTihydrazinium ,
if it is more basic than ammonia , the only product then is the hydrochloride alone )

Ozone does not react with inorganic ammonium salts so only (CO)3(NNH2)3 can be
ozonolyzed , into the cyclo-TricarbonylTrinitramine.

Keeping with the idea of metasthesis , the sodium salt of nitromethane is itself
a priimary , reacted with TCCA instead of the nitrite could yield a useful compound.
(CO)3(NCl)3 + 3 NaCH2:NO2 -> 3 NaCl + ? ? ( cycloTricarbonylTriaminonitomethane )

This may possibly isomerize into the form on the right

Quote:

Quote: Originally posted by franklyn   I just recently had this same idea occur to me , to react TCCA with Sodium nitrite in dichloromethane. This merits investigation. (CO)3(NCl)3 + 3 NaNO2 -> 3 NaCl + (CO)3(NNO2)3 Alternatively TCCA solid can be gassed with ammonia , then later ozonated. (CO)3(NCl)3 + 6NH3 -> 3NH4Cl + (CO)3(NNH2)3 , ( cycloTricarbonylTihydrazinium , if it is more basic than ammonia , the only product then is the hydrochloride alone ) I really do not think any of these ideas would work, as there would be several insurmountable difficulties. Firstly, substitution of the chlorine atom in chloroalkanes with other anions is very problemetic (read about the Finkelstein reaction). Secondly, even if there existed the proper conditions, there would be side reactions (dinitromethane, and methylene groups bridging together several cyanuric acid rings). Reacting TCCA with NH3 would also be nearly fruitless. The TCCA would far more readily attack the hydrazone compounds that formed than it would react with the NH3. Even using large excesses of pressurized liquid NH3 would give low yields, because there are three, rather than one, groups on each molecule in which optimal outcomes are sought. For example, if yields of converting "N-chloro- tetramethyl biuret", with the structure (CH3)2NC(=O)NCl(C=O)N(CH3)2, to the hydrazine derivitive by "gassing with ammonia" were 50%, then trying to convert TCCA to a trihydrazine derivitive would give yields of only 12.5%. Although I have wondered about reacting dimethylamine with TCCA, since the hydrazine derivitive formed may likely be protected from further unwanted oxidation. Originally posted by Axt Makes you wonder what could be produced from TCCA for example, maybe quick and dirty nitramide H2N-NO2 or triketo-RDX! C3N6O9.. hahahah, super dense, thats one thats too easy to be true.