Benzotrifuroxane (BTF) Synthesis

[Diabolique]

The source report for this info is MHSMP-71-880, from LLNL.

Benzotrifuroxane (BTF)

Formula: C6N6O6
Melting point: 195° C
Boiling point: decomposes at 265° C
Solubility;
water: insoluble
95+% ethanol: soluble

Benzotrifuroxane (BTF) is a stable explosive investigated by the US explosives labs. It has a base structure of a hexane ring, the pi bonds of the TNTAB's benzene ring being broken in forming the trioxane rings.


1,3,5-Trinitro-2,4,6-triazidobenzene (TNTAB)

Formula: C6(N3)3(NO2)3
Melting point: unknown
Boiling point: unknown
Solubility;
water: insoluble to slightly soluble
95+% ethanol: soluble

TNTAB is an intermediate in the production of Benzotrifuroxane (BTF). It is likely a shock sensitive explosive, but no information in unclassified literature is available about this.

Synthesis (TNTAB):

1) A 500 ml 3-neck flask is fitted with a mechanical stirrer, a thermometer, and a graduated addition funnel. A circulating water bath is used to maintain the reaction at a constant temperature.

2) 5.3 g of 1,3,5-Trinitro-2,4,6-trichlorobenzene (TNTClB, also designated in other reports as TCTNB) is added to 150 ml of ethanol in the flask.

3) Prepare, in a beaker, add 20 ml of water to 60 ml of 95+% ethanol. To this, add 3.2 g of sodium azide and stir until disolved. Pour this solution into the addition flask.

Note: The report mentions elsewhere that not all of the sodium azide or TNTClB will go into solution.

4) While stirring, slowly add, over 30 minutes, the sodium azide solution to the TNTClB solution. Continue the stirring for the next 6 hours. Adjust the water bath flow to maintain a 20° C temperature for the solution.

5) When complete, add 150 ml of water to the solution with stirring. The TNTAB intermediate will precipitate out of solution.

6) Filter out the TNTAB and wash with 100 ml of water (the last is their recommendation).

Note: It is recommended that the purification process mentioned in the LLNL report not be followed. The people who were performing the experiment used 10 washings of the product with 95% ethanol, and discovered that they were washing away the product (even the pros screw up). They used a final wash consisting of 75 ml of ethanol and 75 ml of water, which did not appear to disolve much of the product. This was followed by a wash of 100 ml of water. I suspect that washing out the unreacted sodium azide and resultant sodium chloride can be done with water only. The implications of the report are that TNTAB is only slightly soluble, or insoluble, in water.


Synthesis (BTF):

1) Dissolve 10 g of TNTAB (above) in 45 ml propanoic acid, and place the solution in a reflux apparatus on an oil bath at 135° - 140° C for 30 minutes. As the solution is warmed, all solids will go into solution at approximately 80° C. Considerable N2 gas is evolved as the azo groups break down and form the furoxane rings.

2) The solution is allowed to cool, and is poured into 400 ml of water. The BTF precipitates out of solution

3) Filter off and dry the BTF.

Note: The report recommends refluxing in xylene, but also mentions that they do not have a viable method to recover the BTF from the xylene. The refluxing in propanoic acid has the advantage of recovery of the product by precipitating the BTF by adding water.

[Diabolique]

I just found out that the refluxing may need improvement. Propanoic acid is what gives rancid butter its 'distintive' odor. This may be why they recommended switching to xylene for the refluxing step.

Anyone have any ideas, other than giving a whole new dimention to the term "stink bomb"?

[Chris The Great]

TATNB has some detailed information in Urbanski, COPAE and Federoff. It is an explosive more powerful than RDX, and initiates as well as lead azide. It decomposes along the above reaction very slowly at RT but is complete in 14 hours at 100*C. So on a small scale there is no need for a reflux at all, just a hot water bath and test tube.
Some more infor missed in the above post about TATNB:
mp: 131*C (decomposes)
d: 1.81
VoD: 7500m/s at 1.51
Pb block: 500
0.01g initiaties tetryl when pressed at 300kg/cm2, or 0.02g initiates TNT under the same conditions.

There is no information on solubility of use for this reaction (easily soluble in acetone, slightly in alcohol, insoluble in water). Perhaps something like ethylene glycol or glycerin could be used? Or perhaps just heat it in boiling water, so that the explosive is not dry while being heated. Then it is just filtered out...

Explosive info on Benzotrifuroxane was found to be vague in Urbanski, merely that it is more sensitive than tetryl and also more powerful than tetryl.

[cutefix]

If TNTAB is to be manufactured its likely...to used only as an intermediate in the manufacture of other explosives

[megalomania]

I happen to have the original article, MHSMP-71-88G. It is 88G not 880, Diabolique. This is one of the compunds on my list of things to add...

Since the original is a bit too large to attach, even compressed, you can get the original from the DOE itself at http://www.osti.gov/bridge/product.biblio.jsp?osti_id=532475
It is available as a pdf download.

Since the work done on benzotrifuroxane is decades old, I have scheduled it for further review. Hopefully I will find something more modern before I add it to my website. The synthesis is valid, but the yield leaves much to be desired.

[Diabolique]

Megalomania: You caught my typo. That is also where I obtained it.

I felt that they may have had a much better yield, but washed it down the drain. Obviously, more work is needed. Unfortunately, I have nerve damage from when I was in the military, and my hands shake enough to set off TATB.

Some explosive labs' manuals mention it, but not in detail. They seem interested in BTF, but not to any great extent.

I have many reports, books, etc., in PDF that I am willing to share. Could you recommend the best way to do this?

[Bugger]

Probably the simplext way would be to upload them to www.rapidshare.de .They now accept uploaded files of up to 300 Mb each, but there may be some sort of condition that each file has to be uploaded in less than 1 hour. Collections of several small files should be combined into a compressed ZIP or RAR archive.

[nbk2000]

A free account for creating a folder is best. Then you can collect all files in one online folder for easy downloading. Something like 500 files are permitted on rapidshare per folder. :)

[Diabolique]

Thanks, Bugger, NBK. Will do when I get the time (so many files to catalog). I'll post the links in the references section.

I'm uncertain what is considered good manners, so instead of starting a new thread, I'll post this propellant/explosive here. I've been scouring my files for obscure energetic compounds as I catalog.
_________
This information from LA-UR-95-2637 (LANL)

5,5'-Dinitro-3,3'-azo-1,2,4-Triazole (DNAT)
1,1'-Dinitro-3,3'-azo-1,2,4-Triazole (N-DNAT)

(isomorphs)

Formula: C4 H2 N10 O4
Molecular weight: 254.2
%N: 55%

Two 5 atom rings joined by an azo-chain (?) similar to that in Guanidine. Each ring has a nitro group. The two carbons in each ring are seperated by 1 and 2 nitrogens.

Heat of formation: 94.4 kcal/mol

Density; N-DNATOR: 1.831
N-DNATYE: 1.701

DTA exotherm; N-DNATOR: 157° C
N-DNATYE: 147° C

Crystal form: Monoclinic, planar
N-DNATOR: ribbons in a herringbone pattern
N-DNATYE: ribbons in alternate orientation

Impact sensitivity: ~11 cm, both similar (ERL test, type 12 head)

Note: Not considered to be usable as an explosive due to its sensitivity. Recommended for use as a replacement for NaN3 in airbags as there is no Na2O -> 2NaOH, which causes burns if the bag bursts.

BKW (C-J) Detonation velocity: 8.191 km/sec (calculated)
Pcj: 299.7 kbar (calculated)
Gas Produced: 7.502 moles/mole (calculated)
H2O: 1
O2: 0.0
CO2: 1.498
CO: 0.004
N2: 5.0

Specific Impulse; Isp: 225.3 seconds (calculated)
D-Isp: 412.2 seconds-gram/ml (calculated)


Synthesized from 3,3'-azo-1,2,4-Triazole (ATA) using Acetyl nitrate at 0-6° C, followed by precipitation from ice water. (sorry, that's all they gave)

Preparation of orange N-DNAT (N-DNATOR):
Recrystalize N-DNAT from acetone with a small amount of ethanol. Filter, an allow to remain at ambient temperature for several hours.

Preparation of yellow N-DNAT (N-DNATYE):
Disolve N-DNAT in a small amount of acetone, then add ethanol until the N-DNATYE precipitates out. Allow the suspension to remain at ambient temperature for 24 hours. Filter.

Note: X-ray diffraction indicated the products were pure, and free from each other.

[Diabolique]

Chris the Great: The LLNL people use TNTAB for trinitotriazidobenzene as TATNB is their old designation for TATB. This is why I give the chemical name at least once, to eliminate any ambiguity.

Every time I see AP, my first thought is ammonium perchlorate, not acetone peroxide, which the labs call triacetone triperoxide (TATP). Too many abbreviations, which is why I am creating a list of designators and chemicals used in explosives, incendiaries and propellants. I cannot remmenber them all.

[nbk2000]

the use of TATP is misleading, implying a state of purity that is rarely achieved, as it usually exists as a mix of dimeric/trimeric forms, depending on exact reaction conditions.

Context is everything, anyways. If you're discussing vest-buster bullets, AP is very unlikely to mean either peroxide or perchlorate, and more likely Armor Piercing, eh? ;)

Best way to avoid ambiguity over chemical names is to use CAS registry numbers, when known/possible.

[Diabolique]

The explosives manuals from the big labs reference each explosive by code designator, chemical name, CAS number (and sometimes the European eqv.) at the least. My problem is too much exposure to the pros, so please pardon my being pedantic at times. I fear someone mistaking one thing for another, or confusion over what compound is being refered to.

Imagine some amature rocket scientist reading that AP is used in high impulse rocket fuel, and reads here how to make AP from acetone and hydrogen peroxide. That would make for some very high 'impulse' rocket fuel. unless there is some objection, I will refer to this material as "TATP (AP)" just so there is no mistaking it for ammonium perchlorate.

I've been catching up on my reading on propellants and found an interesting fact. NASA measured the burining rate of flake aluminum in rocket fuel - about 10 to 15 milliseconds. It is this slow burn rate that keeps flake aluminum from contributing to brisance, but adding to blast.

[nbk2000]

We would prefer to continue using AP (in context) as the designator for Acetone Peroxide.

You're not the first to try arguing this point here over the years, and we're not going to go through it again.

If the hypothetical rocket experimenter had UTFSE, he'd know that Acetone Peroxide is NOT the thing to be using. :)

So another k3wL bites the dust, leaving the cautious and thorough researcher in peace to continue on unimpeded by the idiots. :D

That's why we don't make things TOO clear for the low-hanging fruit pickers.

[megalomania]

It is certainly true that AP has several designations including ammonium picrate, ammonium perchlorate, advanced placement, associated press, and acetone peroxide. We have adopted our own conventions to suite the context most often encountered at The Forum, and that is to use the acronym for acetone peroxide. Acronyms have no governing body, they are literary tools adopted by whatever group uses it in their discourse.

[cutefix]

The term AP is rather to common to use as the name for a particular explosive; just like what mega has mentioned it can mean many things that is why TATP is the term used by professionals in the field.
If used in tank ordnance AP can mean armor piercing...

Besides there is an acetone peroxides that is used for industrial purpose such was what is called as Keetox ( ketone peroxide?)in the flour milling business, where it is used to bleach and improve the baking qualities of flour.

[FUTI]

This is the first time I have heard of Keetox...I think that makes milling dust explosions much more understandable :p :D ;) It's just me having a dark day.

[Diabolique]

I bow to the masses, AP it is. I'll use the explosive labs designations in my other works.

I have been scouring the explosives labs' reports, internet, rs.org, etc. for the various designators used for energetic, and related, materials. Too big to post, and a work in progress. Would this be of use to anyone other than me? It includes formulations of many interesting explosives.

[cutefix]

Fuji the name keetox has nothing to do with flour explosions as that particular chemical is used in already diluted form.
Its a known fact that flour dust form an explosive mixture with air, and can be initiated by machine spark and even static electricity.

IIRC in the CIA improvised Explosive manuals there is even a technique to create explosives using such dust mixtures.
BTW there are also other oxidizing agents added in flour during the milling process such as benzoyl peroxide ( Chefarox) and Chlorine dioxide (Dyox...)

"Too big to post, and a work in progress. Would this be of use to anyone other than me? It includes formulations of many interesting explosives"

Diabolique what ever new information related to energetic materials will always be useful to the members of this forum.