Sciencemadness Discussion Board

RDX from CH2Cl2 + NH4NO3 ?

AndersHoveland - 4-3-2012 at 15:59

Is it potentially possible that methylene chloride and ammonium nitrate could be made to react to form RDX ?

Now first let me make it clear that if you just try mixing these two chemicals nothing is going to happen. There would need to be an appropriate solvent and catalysts.

Methylene chloride, CH2Cl2, is commonly found as an automotive solvent. CH2Cl2 is like an ester, and as such, energy will actually be released when it hydrolyses with water to form CH2O and HCl. It is well known that passing anhydrous HCl gas into chemical solutions can have a powerful dehydrating effect, very similar to the effect of concentrated sulfuric acid. However, the hydrolysis rate of CH2Cl2 is extremely low, almost negligible under normal conditions. Indeed, CH2Cl2 is even soluble in water, without any noticible reaction. (methylene bromide or methylene iodide are very much more reactive in nucleophilic reactions)

So although CH2Cl2 has the potential to be a powerful acidic dehydrating agent, it is essentially inert under normal conditions. But the presence of a copper ion catalyst can make it much more reactive, so that the reaction only takes 24 hours rather than many months.

see in the SM library:
"Copper-Catalyzed Halogen Exchange in Aryl Halides: An Aromatic. Finkelstein Reaction." Artis Klapars and Stephen L. Buchwald
www.sciencemadness.org/talk/files.php?pid=7109&aid=96Sim...

It is also well known that ammonium nitrate can be made to condense with formaldehyde, and dehydrated to the nitramine, using a strong dehydrating agent such as acetic anhydride.
Quote:

The so called "E" method of nitration, initially developed by Ebele, does not require any nitric acid, but does require a large excess of acetic anhydride. Later, in 1940, independant from the research of the german Ebele, Ross and Schiessler, at McGill University, obtained RDX from formaldehyde, ammonium nitrate and acetic anhydride in the absence of nitric acid.


Usually a small quantity of a Lewis acid catalyst is also added. In the E-method of making RDX, typically BF3 is used.
Quote:

"Addition of boron fluoride to the mixture promotes the initiation of the reaction and increases its safety"
"The conduct of the reaction in the presence of boron fluoride reduces the number of by-products formed"
[Chemistry and Technology of Explosives Vol. III, T. Urbański, 1967 - Pg.109]

But it would seem probable that ZnCl2 could be used instead as the Lewis acid catalyst.
Quote:

"Dimethylnitramine has been prepared in 65% yield by the dehydration of dimethylamine nitrate in acetic anhydride to which 4% mole percentage anhydrous zinc chloride had been added. The same reaction in the absence of the [zinc chloride] generates only a 5% yield of dimethyl nitramine."


NH4NO3 and CH2Cl2 might be able to react using DMSO as the solvent, with some CuCl2 and ZnO as the catalysts. The reaction would probably take about 24 hours.

Under these conditions, the ammonium ions should be able to act as a nucleophile toward the CH2Cl2, and the resulting HCl should be able to act as the dehydrating agent.


DMSO is actually sold at many health food stores, surprisingly.


[Edited on 5-3-2012 by AndersHoveland]

Adas - 5-3-2012 at 09:02

Very interesting. These chemicals seem to be easily-get.

What do you think would be the reaction between chloroform and nitramine? Would it form HANA?

AndersHoveland - 5-3-2012 at 13:26

this might have some related chemistry:
"A New Method of Preparing the High Explosive RDX" , W. Bachmann, John Sheehan
http://pubs.acs.org/doi/abs/10.1021/ja01173a092
Quote: Originally posted by Adas  

What do you think would be the reaction between chloroform and nitramine? Would it form HANA?

I do not think so. But I am not sure what exactly would form.
see the "Nitramide reactions" thread http://www.sciencemadness.org/talk/viewthread.php?tid=4861


[Edited on 5-3-2012 by AndersHoveland]

Motherload - 9-9-2012 at 17:25

What I was curious about was dry formaldehyde gas dissolved in dichloromethane and ammonium nitrate.
I can't find much on solubility of CH2O in CH2Cl2.
NH4NO3 + CH2O does generate HNO3 along with Hexamine.
Since there is no water present .... The dry HNO3 should be able to nitrate the Hexamine in CH2Cl2 solution.
Any thoughts ?
Also if paraformaldehyde/trioxane could be substituted for CH2O ?

AJKOER - 21-9-2012 at 19:00

Quote: Originally posted by AndersHoveland  

NH4NO3 and CH2Cl2 might be able to react using DMSO as the solvent, with some CuCl2 and ZnO as the catalysts. The reaction would probably take about 24 hours.


Here is a reference using DMSO as the solvent for CH2Cl2 (link: http://www.ab.ust.hk/hseo/chem_info/Shock%20and%20Explosive%... ). To quote:

"Metal azide is reported to react with dichloromethane (CH2Cl2) in the presence of DMSO to form explosive products."

Per this reference, Poly (Ethylene glycol) (PEG) 1,500 serves as a phase catalyst and CH2Cl2 as a solvent and reagent (see http://www.tandfonline.com/doi/abs/10.1080/10426509408016397... ).