Furoxanyltriazole oxide

note that the two oxygen atoms are on the same side of the molecule, in this way the NH group can more easily be elctron donating to the positively charged nitrogen atom in the furoxan ring. Furoxans behave as vicinal (adjacent) nitroso (--N=O) groups in that tautomers exist, yet the furoxan ring is highly resistant to any attempts at oxidation.
FTO has a formula of C2N5HO3.
FTO will also have several stabilizing resonances, being aromatic. The NH group in the ring will serve as an electron donor. In other words, FTO should be both around as powerful as HMX, while being more resistant to impact.
Begin with 4-amino,5-nitro triazole (ANTZ). Bubble in Cl2. This will form furoxanyl triazole in good yield. Then add peroxy trifluoric acid (or use one of the many other easier methods that can oxidize a heterocyclic nitrogen atom). This should furoxanyl trizole oxide (which will now be abbreviated as FTO). I think plain H2O2 in the presence of some FeCl3 (fenton reactions)could also be used as the oxidizer in the last step, without causing much destructive damage to product).

There are several routes to ANTZ on the other site ("energeticchemical"). For some reason the professional energetic chemists seem to want to make everything far more complex than needed. ANTZ is a fairly simple molecule, and its synthesis should not be difficult using some clever reactions. For example, excess N(CH2CH3) should react with NaBr and acidified H2O2 to form (via well known radical mechanism) (CH3CH2)2NCH(Br)CH3. (the bromine can be in any position, it matters not, but the reactant ratios should prefer non- and mono-bromo substitution, and avoid di-bromo substitution) Then add conc. NaOH to form
(CH3CH2)2NCH=CH2. Bubble in NO2, then react with conc NaOH and NaN3. This should form
(CH3CH2)2N{C2N3H}NO2. Add some dilute acidified permanganate, then hydrolyze off the acetyl groups with 20% solution NH4OH, and finally ANTZ will result (triazole with one amino and one nitro group).
Preparation of ANTZ precursor
4-amino, 5-nitro, 1,2,3-triazole was synthesized by condensing acetaldehyse with ethyl 2,2-dinitro-acetate in the presence of sodium azide, to form 3-methyl, 5-nitro, 1,2,3-triazole.
The cyclization reaction with the azide ion is very comlex. To get some idea of the intermediate steps, see the attachment at the bottom of the page. For step #3, a nitrous acid is pulled out under the alkaline conditions, leaving a double bond between carbons. (cyclize is the American spelling)
CH3CH=O  (NO2)2CHC(=O)OCH2CH3. I think that (NO2)2CHC(=O)O(-) converts to (-)NO2=C(NO2)H and CO2.
The (-)NO2=C(NO2)H would then condense with CH3CH=O, in a Michael-type addition, and the aldehyde would disproportionate, being reduced while oxidizing another free CH3CH=O under the alakine conditions. Then an azide ion would displace one of the nitro groups. So now the intermediate is CH3CH*C(=NO2(-))(--N=N=N). Where the * signifies a radical. This then spontaneously cyclizes, the electron moves toward a nitrogen in the ring, and then a hydrogen ion stick on. This is all just my own conjecture. So the methyl group on the resulting ring almost certainly comes from the methyl on the acetaldehyde. The carboxyl groups comes off as CO2. The original ester gets hydrolyzed by the NaN3, and in so doing acts as a dehydrating agent.
A simpler reaction might be able to utilize 1-nitro-acetone reacting with NaN3. This could potentially directly cyclize into
4- methyl, 5-nitro, 1,2,3-triazole. To help understand the cyclization, Nitroacetone can be thought of as having a
CH3C(OH)=C=NO2H tautomer. See  the section "nitroalkanes" for an easy synthesis for nitroacetone.
Now with the 3-methyl, 5-nitro, 1,2,3-triazole, the methyl group is oxidized to a carboxyl group (with permanganate, and using sodium carbonate). The triazol, because of the electron withdrawing nitro group) is actually fairly resistant to any oxidation, that NH group in the ring is not going to be oxidized by conc HNO3 during a short nitration. An ester of the carboxyl group is formed, addition of NH4OH gives a carboxy amide --C(=O)NH2 , and then bromine and NaOH oxidize this into an amine, which surprisingly does not get further oxidized, presumably because of the electron withdrawing nitro.  
A carboxy-amine can get oxidized into an a plain amine, through a a Hofmann reaction with ordinary hypochlorite solution.
It is known that acetamide CH3C(=O)NH2 reacts with hypochlorite to give off methylamine CH3NH2 gas.
Obviously the methylamine escapes as soon as it is formed before it can be further oxidized (since it would be more vulnerable to oxidation than the initial acetamide. In the reaction the CH3C(=O)N** initially gets formed. This rearranges into an isocyanate CH3N=C=O, which hydrolyzes with H2O, giving off CO2, and leaving CH3NH2. 
Final Oxidation Step
There are several other routes that could substitute for the final oxidation, so trifluoroacetic acid is NOT necessarily required.
A catalyst can be used to allow the H2O2 to oxidize the hetrocyclic nitrogen.
Selective mono N-oxidation of substituted pyrazines in good yields using 30% dilute H2O2 as an oxidant with a specially prepared titanium silicate catalyst is possible. Or methyl cyanide can activate the H2O2 so that it can oxidize the cyclic nitrogen atom.

Preparation of the Catalyst
Add a solution of titanium peroxide to ethyl silicate (with or without an organic solvent) to obtain a gel. Hydrolyze the homogeneous gel previously obtained, by adding an organic base to the gel. The ammount of organic base should be only 6-15% of the ammount of silica gel. Next, add deionised water after the yellowish-white color of the gel begins to turn into a greenish-white color. Stir the greenish-white gel for about 1 hour, then heat the gel in a pressure cooker at 100 -110 C. The gel must be constantly heated in this way for at least 20 hours. Further heating, up to 2 days, is preferable. This will result in a solid composite product. Separate out the resultant solid composite material, dry, and bake at a 350-500C temperature to obtain the final product. This is a catalyst and so only a small quantity need be prepared. The organic base should be an organic amine with lots of bulky organic groups on it, either a tri- or tetra-alkyl amine, such as tetrapropyl ammonium hydroxide. Alternatively positively charged coated silica particles can be used instead of the ethyl silicate. These can be prepared by mixing an aqueous colloidal silica with stabilized basic aluminum acetate. The aluminum composition is stabilized with a small quantity of boric acid, which controls the hydrolysis of the aqueous solution of basic aluminum acetate.

The catalyst produced above is known as TS-1 and is basically a porous titanium silicate crystal with a structure analogous to zeolite. TS-1 is not yet commercially available. It can also catalyze the oxidation by H2O2 of imines R2C=NH into
oximes R2C=NOH.

Methyl Cyanide Activation
At a pH of 8 , H2O2 reacts with CH3CN to form a peroxycarboximidic acid intermediate CH3C(=NH)O--OH. This is unstable and immediately oxidizes whatever reducing agent is in solution. If no reducing agent is present, acetamide will result and oxygen gas will escape from solution. Other nitriles beside methylcyanide also will work, possibly even addition of threads of acrylic fabric (synthetic wool) will work. An alkaline solution of a nitrile and H2O2 can also oxidize an alkene to an epoxide. I am not entirely sure that the amine will not be vulnerable however. The trifluoroacetic acid and H2O2 route are known to create an N-oxide while leaving the amine on the electron deficient (because of two nitro groups) ring unoxidized, but the strong acidity might be important in protecting the amine group. The fact that the ring is electron deficient makes the amine less vulnerable to oxidation, but I am unsure if this is enough without strongly acidic conditions. The methyl cyanide activation necessitates alkaline conditions.
Using H2O2 and Acetic Acid

"Oxidation of  2,6-diamino-3,5-dinitropyridine by refluxing with a 30% solution of H2O2 in acetic acid produced 2,6-diamino,3,5-dinitropyridine-N-oxide in 80% yield."

R. Hollins, L. Merwin, R Nissan, Journal of Heterocyclic Chemistry 33, p895 (1996)

H. Ritter, H. Licht. Journal of Heterocyclic Chemistry, 32, p585 (1995)


Using "Peroxone"

This procedure works for oxidizing nitrotetrazole, so it could likely work for furoxanyl triazole.

12.5g of the sodium salt of 5-nitrotetrazole is dissolved in 50mL water, then reacted with 45g of potassium peroxy-monosulfate ("Oxone") and 20g of potassium acetate, which acts as a buffer. The solution is stirred for 24 hours at 50 degC.
A solution containing 0.09 moles of tertiary amine sulfate, such as Et3NH(+), Na(+), SO4(-2), dissolved in 200mL of water, is added. Then the 5-nitro tetrazole-2N-oxide is extracted using 300mL of ethyl acetate. The yellow product moves into the ethyl acetate layer. The 5-nitro tetrazole-2N-oxide product may be purified by crystallization from EtOAc or toluene, resulting in thin yellow crystals. The yield is 70%.
Oxidation with Fluorine
Fluorine can be bubbled in using an H2O and CH3CN solvent, to add the second oxygen atom to the ring. For the specifics of the procedure, see "The Tetrazole 3-N-Oxide Synthesis" Tal Harel, Shlomo Rozen, School of Chemistry, Tel-Aviv University, Tel-Aviv, Israel. J. Org. Chem., 2010, 75 (9), p3141–3143
Alternate Formation of triazole N-oxide

4,5-dimethyl-2-phenyl-1,2,3-triazole-1-oxide was synthesized in 75% yield by oxidizing “diacetyl phenylhydrazonoxime” CH3C(=NNC6H5)C(=NOH)CH3 with mercuric oxide HgO.