Sciencemadness Discussion Board

Simple Route to RDX free from HMX

Sauron - 15-1-2007 at 01:27

This route eschews the use of hexamine and acetic anhydride completely.

Trioxane + MeCN = TRAT

This is an Org.Syn. procedure. (See attachment) The rxn is catalyzed by conc H2SO4.

This is same TRAT formed along with TAT in the preparation of HMX starting with acetolysis of hemaxine then further acetolysis of DAPT.

However by this route no TAT is formed.

The TRAT is readily nitrated to RDX.

Because no TAT was present no HMX is present to compromise the shock sensitivity of the RDX.

I realize that HMX is more interesting, and thus an efficient prep of TAT is eagerly sought while TRAT is usually a nuisance to be removed.

However, since TRAT is available facilely from acetonitrile and trioxane (or I believe paraformaldehyde) why not use it as a feedstock for RDX?

Making hexamine is tedious. Buying hexamine may be increasingly problematic. And Ac2O is IMO a wee bit too precious to squander on this if not necessary.

I'd appreciate your thoughts.

The Org.Syn. prep is a general procedure, for TRAT see refs 3 and 4.

I make no pretense of originality, this is in the lit., the patent lit as well, and is anyway obvious. It does seem to have been overlooked by some of us who are still raking over the nitration of hexamine.


[Edited on 15-1-2007 by Sauron]

Attachment: CV4P0518[1].pdf (141kB)
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Sauron - 15-1-2007 at 03:37

NB to above

By readily nitrated I mean as readily nitrated as TAT.

TAT nitration usually gives rather poor to moderate yields of HMX accompanied by appreciable amounts of RDX. This implies fragmentation or ring opening and reorganization to the favored six membered ring.

I am assuming that a similar process is absent in nitration of TRAT.

Am I mistaken?

Rosco Bodine - 15-1-2007 at 06:53

Increasing the efficiency and economy for the nitrolysis of hexamine dinitrate to RDX is a matter which benefits from being " raked over " by experimenters who have sufficient insight gleaned from the literature and their own experimental results to tweak the process .

That tweaking has been done and reported here in this forum to a level of advancement beyond anything else reported in the literature .

It seems strange that you would favor a route that uses
acetonitrile as a precursor , while being dismissive of
hexamine / HDN as tedious .

PS : when you edit more than once , you can backspace
out your previous editing notices so they don't form a sloppy looking dangling string of multiple edit notices ,
and only one edit notice will be added to the end of your
amending .

quicksilver - 15-1-2007 at 06:56

In a long past post I mentioned that Trioxane was being sold off for pennys and in fact I could see a fantastic supply for 15 dollars. - I was wondering what could be done with it and you answered my question. I think the above is workable and as for propionitrile, it is very commonly available via photo chem suppliers. The concept seems workable enough. And I, for one, apprieciate you posting this!

Bert - 15-1-2007 at 07:34

Quote:
Originally posted by quicksilver
and as for propionitrile, it is very commonly available via photo chem suppliers.


A quick check of The Photographer's Formulary failed to disclose this.

quicksilver - 15-1-2007 at 07:56

This is the sound of me eating my words. Propionitrile, (cas) 107-12-0 is now on the EPA list HOWEVER I'll bet I can find it through Globelspec (www.globalspec.com/Industrial-Directory/urethane_dispersion_... - 81k -) as a urathane release agent and it's used by the gallon. Can't get a price just this moment but if you want to U2U me I could find I suppose. But your right, It's not in the usual photog-chem places any more (my bad).

Sauron - 15-1-2007 at 08:20

But propionitrile is not what you want, to get to TRAT, it's acetonitrile. Common MeCN solvent. Propionitrile was simply the example illustrated in the quite general Org.Syn. article as I pointed out. Acetonitrile is mentioned in the Notes, TRAT is produced in references 3 and 5. And paraformaldehyde also cheap is alternative to trioxane per reference 5.

@Roscoe, nitration of hexamine has been studied intensively for the last eighty years. Has it not? Same goes for the dinitrate. What I am talking about is almost as hoary as that but looks less problematic. That's all I am saying. Anyone wants to continue with hexamine is welcome to do so and hardly needs my blessing. Meanwhile what is wrong with TRAT?

[By tedious I was referring to preparation of hexamine from aqueous ammonia and formalin soln. The condensation is easy, the removal of all that water is tedious, isn't it?

AFAIK the industry still uses the Bachman process after lo all these many decades. Because they have not found a single process to be economically or technologically advantageous, or so they say. True or is this just the "Not Invented Here" syndrome at work?

My suggestion falls flat if (a) acetonitrile is harder to obtain than hexamine, or (b) TRAT does not nitrate at least as well as hexamine. However since the nitration of either hexamine or HDN passes through TRAT (and TAT byproduct) anyway in the Bachman process...does it not?

I am not an explosives chemist, never said I was. But I've been reading about RDX/HMX preparation for four decades. So I didn't just fall off the turnip truck.

I've seen friends mess themselves up nitrating hexamine at home and ending up in hspital from NOx inhalation. And I've seen colleagues burn down a lab at my department when an Ac2O nitration got out of control. A very bright doctoral candidate lost his position because of that (well, he was also making MDA and that didn't help.) So I am a wee bit skittish about hexamine nitrations at home, and about acetic anhydride mediated nitrations anywhere anytime. Coward that I am! Forgive my absent cojones.

[Edited on 15-1-2007 by Sauron]

Rosco Bodine - 15-1-2007 at 08:48

Quote:
Originally posted by Sauron

@Roscoe, nitration of hexamine has been studied intensively for the last eighty years. Has it not? Same goes for the dinitrate. What I am talking about is almost as hoary as that but looks less problematic. That's all I am saying. Anyone wants to continue with hexamine is welcome to do so and hardly needs my blessing. Meanwhile what is wrong with TRAT?


There's nothing wrong with your proposed route except there are at least three more economical and direct methods
for RDX which you seem to be saying are inferior when they aren't .

It just seems like you are treating the experiments done
in regards to RDX and reported here in this forum with the
same lack of depth as when you were commenting on the matter of hydrazine when you first started posting here in this forum , as if the literature was where we should all go to
learn what we needed to know .....which is an incorrect premise . While this and similar forums are absolutely rife
with " suggestions " from what I call " reader chemists " well
versed in useless and impractical or " textbook " or primer type of general references , many of those references are already well known as a *preliminary* for more advanced experiments that have been proposed and actually done by hands on chemists who inhabit this forum .

While it is appreciated any suggestions of new and interesting methods , and your knowledge and expertise
is appreciated .....you should have a bit more reserve about
the " superior nature " of some new idea until all the pros and cons about it are proved , reproduced , confirmed ....
and not be dismissive of efforts which have produced improvements and gone beyond already reported and valued
methods .

There's a lot of knowledge here on the pages of this forum
that is not the product of kiddies stumblings or simply copying the old work of others and the synthesis of RDX
via HDN is just one of those matters where you can learn things here from this forum that aren't in the literature .....
yet .

Diss what's been good work going beyond the literature reported here and you may be guaranteed of getting a response from a few of the members here ......
especially me . Don't let the rather poor quality or
elementary nature of many recent posts which seems to have been a trend for the newbies wanting to carve their niche reporting what is old news ....convey to you the wrong impression that this forum is fully populated by novices ,
when indeed there are more than a few phd's here ,
and a definite inclination towards post graduate level
work in areas that are novel .

Sauron - 15-1-2007 at 09:14

Not my intention to be dismissive of anything; nor to claim any superiority; and certainly not to pose as possessing any expertise. If that's the way anything I wrote sounded, I disavow that here and now loudly and clearly.

My intention was merely to suggest a route that I have not personally investigated but that appears to me to sidestep a number of problems and to avoid reagents that are or are becoming problematic.

Nothing more. If anyone bristled, mea maxima culpa. I was trying to be helpful not haughty.

Sauron - 15-1-2007 at 09:36

References 3 and 4 from the Org.Syn. article I cited above are now available from the Wanted References thread in References forum courtesy of @arkansas.

If anyone does not have a PW to there, and does not wish to wait while one has been requested, I till post the references here as attachments if asked to do so.

These references detail the preparation of TRAT from formaldehyde and acetonitrile in presence of acid catalyst.

TRAT Hexahydro-triacetyl-s-triazine

Rosco Bodine - 15-1-2007 at 09:52

I have no doubt that there are numerous aspects
of industrial scale chemical synthetic methods which
are " trade secrets " ....little details encompassed by
that catch all phrase in patents " known to those skilled in the art " ....little details which seem unknown to
some of us who would think how skilled we are but
too often find out there are a few things we don't know
that would exclude us from that particular references
assignation of the adjective " skilled " .

Experiments may provide us with the missing information that will then elevate us from the great unwashed hordes
of the unskilled , crowning us in glory as being skilled
for what we have learned .

Unfortunately there is a whole lot about the trade secret
details of patent processes which has escaped mention
in the academic literature , as well as in patents themselves ....and it presents a small victory when any of these details are discovered and then translated to
improvements of a laboratory scale synthesis which is exactly where the refinement was probably discovered
and too often not described for business reasons ....
in the first place .

Personally , I love to do experiments which look for
exactly those sorts of undisclosed details , and then
blab them all over the internet so they are not secrets anymore :D

Sauron - 15-1-2007 at 09:59

When they taught me synthetic chemistry they gave me three rules

1. Do not trust patent procedures
2. See rule #1
3. When in doubt see rule #2.

Patent law requires complete disclosure and if you can PROVE trade secrecy remaining you can in principle have the patent invalidated. However that is a tough burden and as usual it becomes a question of the deeper pocket prevailing. "The Golden Rule: Them what have the gelt, make the rules."

Having a few patents myself, albeit not chemical ones, I know what you mean.

Rosco Bodine - 15-1-2007 at 10:24

A patent is too often like a beautiful woman showing
a bit of cheek when bending over , or flashing one tit
as a wardrobe malfunction sort of tease ....your interest
is caught right away , and you know you have only that part of the larger picture , which you may wish to further
investigate to confirm your suspicions :P

Sauron - 15-1-2007 at 10:33

The other thing they hammered into me was not to put too much faith in 19th century chemical lit. That is not to say it never works. Just that sometimes it does and sometimes it doesn't and sometimes it fails you at a critical juncture. On balance 20th century chemical lit. is not quite so pocketed with quicksand.

Or so I was taught, by a student of a student of a student of Kekule himself. And I was his student, his RA in fact.

Rosco Bodine - 15-1-2007 at 10:46

There's a lot to be learned from those ancient chemists who are the namesakes for a lot of the equipment being
used by contemporary experimenters ....too distant
from knowledge that may have been common even to
the alchemists , which is where every basic course
in chemistry should start ...complete with the latin names :D Otherwise it is like a study of steel for
swordmaking without making mention of Damascus
or that the iron age was born of meteorites that
fell from the sky as a little gift from above .

Sauron - 15-1-2007 at 11:04

I'm not a swordsmith but if I were I'd put my trust in Japanese steel and learn to be a katanakaji. I used to collect Japanese art srt swords, oldest I had were c.1590 and remarkable. Specimens 800-1000 years old are national treasures.

I respect the heritage of chemistry and the old literature. I was just taught to temper that with some caution. Modern standards of reproducibility did not always apply. Details were often maddeningly ommited (little things like proportions and yields and conditions.) So yes I respect it and venerate it without a doubt.

But don't bet the farm on it.

Whereas for the last hundred years who wants to be ridiculed for lacking reproducibility?

Lest we forget those two unfortunates with the cold fusion?

I think they still have paper bags over their heads.

chromium - 15-1-2007 at 11:34

Modern chemistry too has its drawbacks. It does its research mostly to fill gaps in theory or to get better alternatives and new advancements to well estabilished commercial methods. Alternative ways of making particular compounds get almost no attention if they do not seem to give good competition to well estabilished industrial methods.

Most of preprative chemistry books still use 19th century (or in best case first half of 20-th century) advancements in chemsitry. One will not find preparations that use such methods as vapour phase catalysis, ion exchange or molecular sieves. Instead there are still old preps - only products are analysed with FTIR, NMR or chromatography.

[Edited on 15-1-2007 by chromium]

Sauron - 15-1-2007 at 18:17

I wouldn't quarrel with that as a sweeping generalization. But, researchers are in the main only going where "market forces" lead. If you want to get grants you pick your ground carefully, such academics are departmental fair haired boys. If you want to get published at least in the more elite journals, you don't choose subject matter that no one cares about and that the editors will snooze over. C'est dommage.

But we are only taking the advice of Willie Sutton. When asked why he robbed banks, old Willie said "That's where the money is."

Of somewhat larger concern is the ever escalating cost of synthesis which I for one attribute to an absurd regulatory burden resulting in burgeoning admin overhead.

This is driving the paradigm shift to screening and QSAR/QSPR, so evident in the pharm industry and emerging elsewhere.