Ever hear of PL-1? New Explosive?

[megalomania]

I happen to have a nice journal article concerning the synthesis of an explosive compound called PL-1. For the technical it is 2,4,6-tris (3’,5’-diamino-2’,4’,6’-trinitrophenylamino)-1,3,5-triazine. Hence the name PL-1… This baby is a ‘benzene’ ring with 3 more benzene rings attached to that one and each of those 3 rings have alternating nitro and amine groups. The middle ‘benzene’ ring is actually alternating carbon and nitrogen molecules (its too damn late for me to look up what that is, triazine maybe).

I wonder if anybody knows anything about this compound. They say it is new in the article (as of 2000), and is a class of thermally insensitive high explosives.

The beauty of this stuff is it appears to be rather simple to synthesize (relatively speaking for me). I will do a full write up for my website, but here is an abstract. None of these chemicals are too exotic (as far as I know) or impossible to make (I would gather). I would like some feedback from people as to whether or not these chemicals are impossible to get or make.

Mix dichloroaniline with cyanuric chloride in DMF, heat for 5 hours, add fuming nitric acid, heat, add some acetone, bubble in some ammonia, heat for 12 hours, done.

It’s the cyanuric chloride I am worried about. It seems a peculiar molecule being basically triazine with some chlorine stuck on. I should have paid more attention to those synthesies with nitrogen additions to rings. All the rest of the chemicals are easy enough, and no exotic conditions or equipment. The yield is good, the explosive powerful and dense (7861 m/s at 2.02 g/cm3) which is defeated only by the likes of RDX, HMX, and HNIW, and it is quite resistant to heat, shock, and friction.

[nbk2000]

Acetone, ammonia, fuming nitric...no problem

DMF is used in meth cooking, so that be more difficult to buy, but it's makeable by any decent home lab.

The cyanuric...don't know. I know there's a cyanuric (something) used as a pool chemical, so that may be useable either straight, or as a precursor for the cyanuric chloride.

Dichloroaniline...make that from commerical aniline. Aniline is somewhat expensive to buy but, depending on yeilds, may be worthe the expense.

[CodeMason]

Sounds promising. Cyanuric chloride is trichlorocyanuric acid, which could forseeably be substituted with trichloroisocyanuric acid, a common and cheap pool chlorinator.

[vulture]

Cyanuric chloride is the benzene ring with the 3 N's and 3 Cl's bonded with the 3 carbons.

Trichloroisocyanuric acid is somewhat different. This has the same ring structure as RDX (3 carbons, 3 nitrogens all SINGLE bonded) with 3 oxygens double bonded to the carbon atoms and 3 chlorines bonded to the 3 nitrogen atoms.

So they are quite different and I don't think it's going to be easy to produce the one out of the other.

[Mr Cool]

Cyanuric acid forms a cyclic trimer (-C(OH)=N-)3, isocyanuric acid is similar but (-(C=O)-NH-)3. I'm not sure if you could substitute isocyanuric trichloride for cyanuric trichloride. You couldn't do it directly, but you may be able to convert it somehow. Otherwise, I think cyanuric acid is formed when nitrourea decomposes, but that might've been iso-.
Then you have to chlorinate it, that shouldn't be hard but it adds another step... I'm thinking this might be a lot more trouble than it's worth unless you can buy the cyanuric trichloride (I assume it does want the trimer).
For the dichloroaniline, maybe benzene -> nitrobenzene -> 3,5-dichloronitrobenzene (is that what forms? I think it is, but maybe it's ortho/para) -> dichloroaniline, should be easy if you have benzene. I'm not sure, but I think if you tried to chlorinate aniline you might get N- or N,N-chloroanilines, maybe not but you wouldn't do with NB..

DMF - dimethylfurazan?? I don't see why this would be necessary, assuming it's a solvent you could probably use THF or dioxane (made from ethylene glycol and H2SO4).

But overall, I think for us there are much easier to make alternatives, often with more power. Unless of course you can buy the precursors, in which case go for it.

[vulture]

DMF = Dimethylformamide, a universal solvent which can also dissolve ionic molecules. Formula: CH=O -N(CH3)2 It's highly toxic btw.
Synthesis by reacting methylformate (Formic acid methyl ester) and dimethylamine or carbonylization of dimethylamine in methanol. Another dangerous option is Dimethylamine and HCN.

[megalomania]

Well perhaps the synthesis of cyanuric chloride is not so difficult after all. After a brief search I have found a few choice bits. One could either halogenate cyanuric acid (as theoriticially alcohols are readily replaced by bubbling in some HX gas, in our case HCl) or one could make the stuff directly from cyanide compounds.

From Organic Synthesis, Collective Volume 1, pg 140 (see <a href="http://www.orgsyn.org/orgsyn/prep.asp?prep=cv1p0140" target="_blank">http://www.orgsyn.org/orgsyn/prep.asp?prep=cv1p0140</a> ), the preparation of cyanuric acid (seemingly by accident in this prep) is accomplished by nothing more exotic than n-butyl alcohol (butanol), urea, and ammonia:

In a 2-l. round-bottomed flask fitted with a reflux condenser is placed 970 g. (1200 cc., 13.1 moles) of n-butyl alcohol. This is warmed, and 180 g. (3 moles) of urea is added to the warm liquid in small portions, with shaking. While the temperature rises, care must be taken that the urea goes into solution without melting and does not form a layer of molten urea beneath the solution (Note 1). The last portions of the urea are finally dissolved by boiling the liquid. The solution is then refluxed for thirty hours (Note 2), during which time ammonia escapes from the top of the condenser (Note 3). The reflux condenser is then removed and the liquid is distilled through an efficient column until the temperature of the liquid reaches 150°. The distillate consists of butyl alcohol containing ammonia and may be used directly in another run. The material which remains in the flask solidifies on cooling. It is boiled with 1 l. of ligroin (b.p. 60–90°) (Note 4), filtered, and the undissolved solid again boiled with two 100-cc. portions of ligroin, filtered, and finally washed on the filter with 100 cc. more of warm ligroin. The white gritty material which remains undissolved is practically pure cyanuric acid (Note 5). The yield of cyanuric acid is 12–18 g. (9–14 per cent of the theoretical amount).
Notes
1. If molten urea settles to the bottom near the source of heat, it will cause the liquid to bump and will decompose to produce cyanuric acid to the detriment of the yield of butyl carbamate.
2. If thirty hours of continuous heating is impracticable, care must be taken, on resuming the heating, that the urea goes into solution without melting.
3. A small amount of ammonium carbamate collects in the condenser during the reaction and may cause clogging. This should be removed from time to time by pushing it down by means of a glass tube which fits snugly into the condenser. The gases evolved when the solid falls into the hot liquid are carried off through the tube.
4. "Aviation" gasoline (86° Baumé) may also be employed if it is first distilled and the fraction boiling above 120° rejected.
5. The extraction with ligroin may be completed satisfactorily by means of the apparatus described on p. 375. Butyl allophanate is not soluble in ligroin and, if present, would remain with the cyanuric acid. However, when the material which is insoluble in ligroin is washed with hot acetone the washings yield no appreciable residue on evaporation. This is evidence that butyl allophanate and urea are not present in the cyanuric acid.

Now this particular preparation is intended for the production of n-butyl carbamate, and so note 1 should be not only ignored by purposely disobeyed. Subsequent bubbling of HCl gas into a solution of cyanuric acid should result in cyanuric chloride. It is also worth noting that this compound has been employed as an antibacterial agent in swimming pools, so it may be available in the stores.

See also United States Patent 3,947,419 Preparation of cyanuric chloride and United States Patent 3,949,060 Process for the production of cyanogen chloride. Both of these patents make use of cyanogens chloride to make cyanuric chloride. That first patent uses an electrochemical means of producing cyanogens chloride from a cyanide salt, like NaCN, and some table salt and chlorine is thrown in there somewhere. The trimerization is accomplished by passing the gas over heated activated carbon. The other patent uses hydrogen cyanide and chlorine to make cyanogens chloride and passes it over alumina. I am sure there are many other patent references and such out there.

For additional reading I suggest the two Organic Synthesis references for the preparation of cyanogen bromide and cyanogen iodide at <a href="http://www.orgsyn.org/orgsyn/prep.asp?prep=cv2p0150" target="_blank">http://www.orgsyn.org/orgsyn/prep.asp?prep=cv2p0150</a> and <a href="http://www.orgsyn.org/orgsyn/prep.asp?prep=cv4p0207" target="_blank">http://www.orgsyn.org/orgsyn/prep.asp?prep=cv4p0207</a> respectively. There is nothing on cyanogens chloride unfortunately, but one can easily see how both those reactions involve adding bromine or iodine gas to NaCN in solution. It is not a great leap of faith to assume adding chlorine gas under the same conditions should make cyanogens chloride.

[nbk2000]

There's an easy lab-scale CNCl synth in "The War Gases by Sartori" PDF on the FTP.

[Keref]

How about you learn not to talk back to staff.

You're out of here.

NBK

<small>[ September 07, 2002, 07:55 AM: Message edited by: nbk2000 ]</small>

[Mr Cool]

I wonder if cyanuric acid could be prepared simply by holding urea at slightly above its melting point for X hours, with the release of ammonia? That'd be nice and easy (hehe, trinitrocyanuric acid / triazocyanuric acid here we come... :D (N.S. with NaNO2/NaN3 on the trichloro-, respectively)).

Unfortunately, I've only ever seen the iso- being sold OTC in any form.

<small>[ September 06, 2002, 12:57 PM: Message edited by: Mr Cool ]</small>

[megalomania]

I have found numerous journal references that use cyanuric chloride to make a varity of other high explosive compounds. It seems to be a valuable source of research nowadays. For example I have a journal article here that describes the synthesis of ANTA (5-amino-3-nitro-1H-1,2,4-triazole) which may in turn be used to prepare other explosives. ANTA is apparently explosive itself.

[nbk2000]

If there's a solvent of suitably high boiling point that is inert to hot urea and ammonia, than you'd simply fill up a flask, pour in your urea, heat till the reaction is done and Voila', cyanuric acid aplenty. :)

How do you convert the acid form to the chloride though? HCL, or Cl gas?

[Alchemist]

Hello all,

In California at least I have seen in several pool stores Cyanuric Acid!

For example; Stabilizer Conditioner by Kem-Tek is 99% Cyanuric Acid with only 1% inert.

About $10-12, for 4 pounds.

<small>[ September 07, 2002, 02:30 PM: Message edited by: Alchemist ]</small>

[nbk2000]

I downloaded the MSDS file <a href="http://www.kem-tek.com/msds/KemTekMSDS.zip" target="_blank">(MSDS .zip file)</a> from Kem-Teks website...it's the Iso form of cyanuric acid...not the needed non-iso form. <img border="0" title="" alt="[Frown]" src="frown.gif" />

[Alchemist]

Hello all,

found this in a old chem book.

Cyanuric acid, H3C3N3O1, was obtained by Wohler and Liebig by heating urea (small yeilds though),
and by A. Wurtz by passing chlorine into melting urea. It forms white efflorescent crystals.
Treatment with phosphorus pentachloride gives cyanuric chloride, CIN3CI3, which is
also formed by the combination of anhydrous chlorine and prussic acid (Hydrocyanic Acid)
in the presence of sunlight. These substances contain a ring of three carbon and three
nitrogen atoms, i.e they are symmetrical triazines.

P.S., found another one;

Urea + Zinc Chloride at 220 deg C equals Cyanuric Acid and Ammonia.

3 H2N-CO-NH2 + (ZnCl2) @ 220 deg C &gt; 3 HO-CN &gt; (HOCN)3 Cyanuric Acid + 3 NH3.

<small>[ September 07, 2002, 06:53 PM: Message edited by: Alchemist ]</small>

[Polverone]

What's the difference between cyanuric acid and isocyanuric acid? I'm just curious, as chemfinder.com says they are synonyms and returns identical structural diagrams for them.

[megalomania]

Indeed my search today shows isocyanuric acid and cyanuric acid are the same. A few days ago when I looked these up because of the reference in the patent literature I saw a completly different compound. I want to say it was a double bonded oxygen coming from the carbon with chlorines from the nitrogen, but that is something completly different (that requiring there be no aromaticity). Ah ha, that was for trichloroisocyanuric acid as opposed to trichlorocyanuric acid.

Alchemist, is that info from Wohler and Liebig correct? I would think that first of all adding chlorine would make the trichloride, and second of all the chemical formula would have 3 oxygens instead of just the 1. Of course their formulas were bass ackwards in the long long ago.

[nbk2000]

So the iso is the same as the "normal" form? Then why the difference? I've always that that "iso" meant a mirror image (similar to the d- and l- forms of organics) of a chemical molecule.

If the iso is the same as the "normal" (tomato, tomatoe :p ), then this means pool chemicals to PL-1. :)

That is, if you can convert the acid to the chloride. Any info on how to do this?

[megalomania]

Bullshit! I have reviewed the chemistry of aromatic phenols to disturbing results. Apparantly nothing short of an act of god can make the damn alcohol functional group react! I looked over as many reactions as I could and 9 times out of ten any chemical reaction just adds something to the aromatic ring. The only reaction the damn things do undergo is the formation of ethers, esters and the like. But even those only react to reform an OH group again. Grr. The only potentially useful reaction I found is the Bucherer Reaction. This reaction specifically uses naphthols with ammonium sulfite in solution to replace the OH with NH3. The only other reaction breaks the aromaticity by reducing the compound to a quinine compound (=O).

Now, assuming we can actually get cyanuric acid to react like a naphthol (a mothball alcohol) we will need to make use of the resulting amine. For that we react it with a bit of sodium nitrite to form a diazonium salt. We could let this decompose to give benzene, but since we want to make a halogenated version we can do it all in one step via a Sandmeyer reaction. Bam, a one step reaction that mixes sodium nitrite and HCl in a cold solution, and then we add copper chloride and cook. Of course this is theory only. Who knows what single ring phenolic triazines will do! On page 568 of Vogel’s Practical Organic Chemistry (supplied by Polverone on the FTP site) you will find an example of a Bucherer reaction.

It would appear that cyanuric chloride is prepared from cyanuric with great difficulity, if it’s even possible at all.

I forgot to mention the effects of keto-enol tautomerism. Therin lies the difference between cyanuric and isocyanuric acid. The enol form is what one would call cyanuric acid. The isocyanuric acid is not aromatic, it is the double bonded C to O (N-C=O)3 form. According to the Merck Index it is typicially the keto form when solid, or solution. When in a basic solution we get the enol cyanuric acid. This of course changes everything as we now have to deal with a ketone C=O instead of an aromatic alcohol C-OH.

Unfortunatly there does not seem to be much one could do with a ketone. It may form some kind of enamine or imine with the Bucherer Reaction. I have no idea how they could be reacted. On the flip side of the coin we may just as easily end up with a geminal diol which we could react with HCl like an ordiniary alcohol to give us a halogenated product. The worry here is that if we do still have a lot of the keto form we will just a-halogenate to give a useless trichloroisocyanuric acid. There are a lot of what if's with this stuff.

<small>[ September 08, 2002, 11:22 AM: Message edited by: megalomania ]</small>

[nbk2000]

There's always chlorine and HCN...though I suppose the urea and zinc chloride would be more acceptable to those of lesser courage. <img border="0" title="" alt="[Wink]" src="wink.gif" />

[megalomania]

Here may be a use for isocyanuric acid... Heat the stuff to decompose it to cyanic acid, NCOH. Distill the cyanic acid into a solution of sodium hydroxide so it neutralizes to sodium cyanate. One could then distribute the solution to your local sickle cell stricken negro, or wait for it to decompose into sodium carbonate and urea. With the urea you can... AH CRAP. Disregard this, with urea you can just make cyanuric acid again :mad: Well, it looks like it's the cyanogen chloride route or bust. It seems I have scheduled the synth of cyanogen chloride to be put on my website in the chemical weapons section.

[Hystrix]

I think that raw material for PL-1 may be melamine, or 2,4,6-triamino-1,3,5-triazine. It can be prepared by heating of urea (preferably in closed vessel and in NH3 atmosphere). The other raw material must be 1-chloro-3,5-diamino-2,4,6-trinitrobenzene.

[Richy]

whats the detonation velocity for this explosive?

[megalomania]

From the journal article:

</font><blockquote><font size="1" face="Verdana, Arial, Helvetica">quote:</font><hr /><font size="2" face="Verdana, Arial, Helvetica"> The compound has a density 2.02 g/cm3 (determined by the method of the density bottle), detonation velocity 7861 m/s and has the oxygen balance -59.36%. PL-1 has promising blend of insensitivity to friction (~36 kg) and impact (height for 50% explosion) 170 cm. </font><hr /></blockquote><font size="2" face="Verdana, Arial, Helvetica">

[megalomania]

Better late than never I always say. Anyway, here we have the completed procedure for PL-1 as it will appear on my website. I thought I would share it here first before I go through the trouble of making the graphics, filling out the tables, and whatnot on my website. I have included a bonus at the end, the lab prep of cyanuric chloride.

</font><blockquote><font size="1" face="Verdana, Arial, Helvetica">quote:</font><hr /><font size="2" face="Verdana, Arial, Helvetica">The scientific name for PL-1 is 2,4,6-tris(3’,5’-diamino-2’,4’,6’-trinitrophenylamino)-1,3,5-triazine. Researchers looking for new thermally stable and insensitive high explosives developed PL-1. Explosives of this type are being developed for military applications around the world because they are very safe to store and use, as well as being powerful high explosives. Current research believes that introduction of nitro and amine groups give explosives of greater density and a decrease of impact sensitivity, all of which PL-1 has. In the year 2000, research into producing this compound in higher yields was released; today I bring you the fruit of that research. The explosive velocity of PL-1 puts it on par with the current top high explosives of today, and the chemicals used to synthesize it are not too exotic by far.

The synthesis of PL-1 is presented in three steps. The first step uses fairly simple chemicals to synthesize the compound 2,4,6-tris(3’,5’-dichlorophenylamino)-1,3,5-triazine. The second step uses the product of step one to make 2,4,6-tris(3’,5’-dichloro-2’,4’,6’-trinitrophenylamino)-1,3,5-triazine. The third step uses the product of step two to synthesize PL-1. The main reactants are listed in moles to allow for an easier scale up of the reaction. The procedure itself only produces a small quantity of PL-1.

Step 1: Into a 250-mL flask or beaker prepare a mixture of 1.84 g (0.01 mol) of cyanuric chloride, 4.86 g (0.03 mol) of 3,5-dichloroaniline, and 30 mL of dimethylformamide. Heat this mixture to 85-90 with constant stirring for 5 hours. The mixture is then allowed to cool by adding a small amount of crushed ice to the flask. While cooling a precipitate should form. Pour the mixture over a filter to collect these crystals, wash them thoroughly with water, and allow to dry. Yield should be about 5 g or 90% of the theoretical. The procedure in step 2 is calculated to use 5.61 g (0.01 mol) of the product from step 1, which may actually be less than the obtained yield. Therefore step 1 may need to be performed more than once, or increased.
Step 2: Prepare nitrating acid by carefully and slowly adding 11.4 mL (0.266 mol) of fuming nitric acid to 55 mL (0.603 mol) of fuming sulfuric acid in a 250-mL round-bottomed flask immersed in ice. It is best to pre-cool the sulfuric before adding the nitric acid and stir continuously during the addition. Try to maintain a temperature under 15 degrees C. Once the acid mix is finished, add 5.61 g (0.01 mol) of the product from step one to the acid in several portions with stirring. The mixture is stirred for an extra 30 minutes after the addition is complete. The flask is now set up for reflux and refluxed for one hour at 85-90 degrees C. After refluxing, the mixture is allowed to cool by pouring over crushed ice in a small beaker. A precipitate should form, it should be diluted with water, and then poured over a filter to collect it. The crystals are then thoroughly washed with water to remove all traces of acid and allowed to dry. Yield should be about 3.3 g.
Step 3: To prepare PL-1, place 100 mL of acetone in a small Erlenmeyer flask. Slowly add about 2 g (0.002 mol) of the product from step 2 to the flask in small portions with constant stirring. Maintain a constant room temperature and keep stirring until the mixture becomes homogeneous. The temperature of the solution is now raised to between 45-55 degrees C while ammonia gas is bubbled into the flask for 12-13 hours. The use of a bubbler is recommended to get the most efficient reaction. The reaction is completed when the precipitate that should form is done forming. The reaction mixture is now allowed to cool, it is poured over a filter to collect the precipitate which is thoroughly washed with acetone, and finally the crystals are allowed to dry. The final yield should be about 0.8 g of a yellow solid or a 50% yield.</font><hr /></blockquote><font size="2" face="Verdana, Arial, Helvetica">I did find a brief reference to the preparation of cyanuric chloride (not for the weak of heart). Does everybody have a bottle of household hydrogen cyanide lying around? Prepare a solution of 1 part hydrogen cyanide and 4 parts ether in a small flask. Keep this solution well cooled in an ice bath. Bubble chlorine gas into the solution for some time, the use of a bubbler is recommended to improve the reaction. A precipitate will begin to form after some time over the course of the reaction, presumably as long as there is hydrogen cyanide left. These crystals can be washed with ether and allowed to dry, these should be crystals of cyanuric chloride.

[Mr Cool]

"The explosive velocity of PL-1 puts it on par with the current top high explosives of today"
Hmmm... while it is on a par with the mixtures that are in common use, such as the A, B and earlier C compositions, it is far from equal to many pure HE's or modern PBX's (etc) that are already used, and nowhere near as fast as some of the things that are being developed! Especially when you compare it to other HE's of similar density, it's behind by up to about 2km/sec!

The (potential) trouble with many of these polyamino/polynitro aromatics is the fact that the hydrogen bonds resulting in increased density (between -NO2's and -NH2's) also mean that they can't be cast at safe temperatures, which gives them a disadvantage over things like TNAZ.

[megalomania]

Well good news because I am writing a review of TNAZ prep right now. The down side of something like TNAZ, it can't be manufactured yet. There is no economical process in the 16 published reports of its preperation. It comes to $5 a gram! But I will leave discussion of this for my TNAZ thread. The main benefits of something like PL-1 is its resistence to heat and low impact sensitivity. No, it is not as powerful as RDX or HMX, but for certain applications it is quite valuable (according to the literatre). I present it merly because I am interested in new explosive molecules, not blowing stuff up :p

I found a few more tidbids about making cyanuric chloride. One way to make the stuff is to expose a mixture of hydrogen cyanide and chlorine to sunlight. Another method is to react cyanuric acid with phosphorus pentachloride: C₃N₃O₃H₃ + 3PCl₅ = C₃N₃Cl₃ + 3POCl₃ + 3HCl
It is this latter reaction that seems interesting because it can be made from the commercially available cyanuric acid.

I would also like to know if anyone has any ideas about using cyanic acid to make possibly hydrogen cyanide. Cyanuric acid can be distilled dry to yield cyanic acid. Does anybody have a means of converting this to a better cyanide? I only ask as a possible alternative to using phosphorus pentachloride. As cyanuric acid is OTC, and heating to cyanic acid is quite simple, another simple reaction to make HCN would make this a simple OTC route.

<small>[ December 17, 2002, 12:06 AM: Message edited by: megalomania ]</small>

[Mr Cool]

Well, the only thing I can think of would be to make sodium cyanate and reduce it with hot charcoal, as described in the cyanide prep. thread.

Edit: D'ya reckon molten sulphur + Cl2 gas could be used instead of PCl5? That'd make it a little more OTC.

<small>[ December 17, 2002, 12:55 PM: Message edited by: Mr Cool ]</small>

[nbk2000]

Sulfur chlorides have much in common with phosphorus chlorides. But there's obviously differences as well since you can't make a sulfur based nerve agent by replacing the PCl3 with a Sulfur halide.

I have a book in storage that explains all the different reactions sulfur halides can be used for. Got it from Occidental Petroleum (MAJOR supplier) tech support. You might want to give them a call, eh? <img border="0" title="" alt="[Wink]" src="wink.gif" />

Fortunately PCl5 is much more common (and cheap) than the common "precursors of WMD" like PCl3 or POCl2 which are watched and regulated up the ying-yang.

[Mr Cool]

"But there's obviously differences as well since you can't make a sulfur based nerve agent by replacing the PCl3 with a Sulfur halide."
But when making nerve agents, the final product contains the P, right? So here you can't interchange P and S because that'd make a totally different chemical, which probably wouldn't be (as) biologically active.
But if the P/S is just being used as a carrier for the chlorine, then perhaps it could work? I'll do some info searching...