DDNP & related compounds: The über thread!

@nitro-genes

That is your work nitro-genes so no need to credit me as a co-author of your work, when all I did was help with some references and added some untested ideas of my own. So you rightly own the copper[+1] cuprous / ascorbic acid reduction scheme. Let me own the magnesium idea... glycine ...ect. especially if all that turns out to be a "seemed like a good idea" that doesn't work at all. I'm good at thinking ideas that work great on paper and in theory but don't always work so great in the flask put at risk, when the laboratory and lab personnel are still around to report the interesting results

Yeah I think because of the complex parallel reaction pathways that are possible that is a similar story with the Zinin reduction scheme, it is definitely possible to tweak the reaction to obtain higher yields. Hennig was doing some sorting out of the variables for the Zinin reduction and got the yields to go up from around 80% in the beginning to later in the 95% to 100% by what are really trivial changes to the basic process. Very probably it is possible to refine the process if it follows the same for alternative schemes to the Zinin. These reduction schemes are somewhat general and what works out good for one reduction may also work well for other reductions as is or with slight adjustments.

This is probably novel what you have reported for the ascorbic acid and copper sulfate used to produce picramic acid. So all the Google searches on this topic will and already do lead here to SM. There is quite an extensive little compendium of obscure articles and experiments here at SM that is nowhere else to be found.

I am thinking about the diazotization and the scheme you described using copper wire.
If the picramic acid is dissolved in nitric acid strong enough to form the picramic acid nitrate via the amphoteric property similarly as was observed for the isopicramic acid, and copper wires are added, then the byproduct NO2 should work similarly as occurred when you were preparing the iso-DDNP or p-DDNP by diazotizing isopicramic acid nitrate. By using a 50/50 mixture of the picramic acid and isopicramic acid it may be possible to produce a racemic co-crystallized mixed isomer DDNP having unique properties and crystalline form if such a mixed isomer does exist and can be formed.

With regards to an alternative candidate transition metal salt that could function in small quantity as a regenerable catalyst not being sequestered as picramate during the reduction any of the ones described by Girard in 1853 may work as well as does the copper for the actual reduction, but by remaining in solution can be regenerated. For example, nickel sulfate, or possibly better nickel acetate or other organic acid nickel salt, is a candidate.

And these reduction schemes may likewise be applicable to styphnic acid for reduction to styphnamic acid for diazotization to DDNR.





https://www.youtube.com/watch?v=R_ApBrVJD48 A Space Journey

jai guru deva om (Sanskrit mantra)
I give thanks to the heavenly teacher.

[Edited on 3/7/2018 by Rosco Bodine]

That article posted by Axt was published as a contribution from an American laboratory at the University of Chicago in what was the premier chemistry professional journal of the era. It was in that same Chicago laboratory was built the world's first nuclear reactor.
The level of peer review for that article published 90+ years ago would very likely have been extreme and exhaustively thorough.

Berichte der deutschen chemischen Gesellschaft

http://onlinelibrary.wiley.com/wol1/doi/10.1002/cber.1927060...

Robert Edward Lyons, Ph.D. had been a Ph.D. and head of the university chemistry department for more than 30 years when that article was published.

http://webapp1.dlib.indiana.edu/archivesphotos/results/item....

In this post nearly four years ago I had done more study about the ferrous sulfate reduction

http://www.sciencemadness.org/talk/viewthread.php?tid=433&am...

You are encountering conflict with lowering the pH for using ascorbic acid instead of an ascorbate salt and I think also the order or manner of addition or both could be a factor.

I'll think more about the process and what may help.

"dark red solutions" standing in the cold sometimes produce some crystals of a picramate salt in good time

Your "dark brown amorphous stuff" is likely picramic acid but the color is off due to the state of subdivision and probable impurity of iron.

If you check the amorphous stuff will probably redissolve in HCl to form the picramic acid hydrochloride and on dilution will likely precipitate something looking more familiar.

I think you are making some overly broad general conclusions that aren't necessarily governing because of a very specific scenario where you see the unexpected occur. Hang in there and sort it out.

Process chemistry is highly nuanced and what may seem to be insignificant small changes can produce a drastic change in the course of a reaction and the resultant yield. There are an assortment of reactions where a small change in temperature or pH or the sequence and rate of addition or the form in which the reactants are brought into contact and intermixed, solubilities and concentrations also can all have enormous bearing ....and this reduction is definitely one of those more "fickle" reactions, evident from reading the earliest articles and later articles too. So, what on first glance appears at first may not work, may later work even splendidly well when the precise conditions needed are determined and provided. Calibrating the process conditions involves applied algebra that can't really be derived from one experiment. When you describe a dark red to almost black solution along with the exotherm, that is a good indicator of reduction to sodium picramate which is a very strong dye and would remain dissolved in super saturated solution in the hot alkaline liquid, but should crystallize out in the cold and on standing.

Something that could be occurring that makes the copper attractive and useful relates more to the insolubility of the copper picramate than to any catalytic activity with ascorbic acid. The reduction may be enhanced by being solubility driven due to the product precipitating as fast as it forms. That theory would be proven by use of other reducing agents than ascorbic acid in the presence of copper as a "solubility reagent" where basically the product is appearing like a low solubility "spot test" result. The "complex" with copper may have nothing to do with ascorbic acid, but could be a mixed valence copper salt, a double salt of cuprous picramate / cupric picramate. Only analysis of the intermediate precipitate would tell more or tell conclusively what is occurring. With simultaneous multiple different reaction paths possible, there could be an indefinite mixture of products of sodium picramate, cupric picramate, and cuprous picramate ....all present as possible mixed "picramate values" and likewise for other reductions using other metal salts as reagents or catalysts.

[Edited on 3/8/2018 by Rosco Bodine]

On heating picric to its ignition point, there is a definite sign of reduction going on, maybe picramic can be isolated from the condensed vapours.

Granted, you have a point about my conclusion about the iron reduction never to reach high yield being premature. Noticed in the article they used iron from which all organic contaminants were removed by glowing out (85% iron) maybe the oxydes introduced could be a factor. Still, I have a really hard time believing the 100% yield mentioned, hardly any information on isolation and compound identification is present, except mention of sodium carbonate extraction. As an amateur this may be acceptable to a certain extent, especially when on closer look, no definite conclusions are generally made at all.

The mixed valence picramate theory is interesting, but with such an excess of ascorbic acid and the very fast conversion of Cu(II) to Cu(I) (Even in the cold) I find it very hard to believe as well. A sodium double salt might also be possible, that is why I wrote "perhaps" in the report IIRC. Looking at the properties of Cu(I) salts and there ease of hydrolysis in general, it seems strange so little copper(I)oxide is isolated under these weakly acid conditions. Maybe most of the copper(I) remains as a Cu(I)ascorbyl radical complex during the reaction?

You mentioned at least 4 reactions to be possible during the copper/ascorbic reduction of picric, could you shed some more light on your thinking on this matter?

[Edited on 9-3-2018 by nitro-genes]

Quote: Originally posted by nitro-genes

On heating picric to its ignition point, there is a definite sign of reduction going on, maybe picramic can be isolated from the condensed vapours.

One ferrous picrate reduces another ferrous picrate to ferrous picramate just like one hand washing another. Didn't you get the memo that went out about 90 years ago? Sheesh...My dear missus, do hand me a new spoon feeding spoon since this one I have been using is worn down to the nub. And fetch for me my German - English dictionary and reading glasses. Seriously the end product is probably ferric picramate since likely the ferrous picramate is active as a reducing salt also, and there is a 6H+ represented by the 3:1 molar ratio of elemental Fe(++) to picric acid described by Lyons and Smith.

Quote:

Granted, you have a point about my conclusion about the iron reduction never to reach high yield being premature. Noticed in the article they used iron from which all organic contaminants were removed by glowing out (85% iron) maybe the oxydes introduced could be a factor. Still, I have a really hard time believing the 100% yield mentioned, hardly any information on isolation and compound identification is present, except mention of sodium carbonate extraction. As an amateur this may be acceptable to a certain extent, especially when on closer look, no definite conclusions are generally made at all.

The ascorbyl or dehydroascorbyl could have a chelating effect but I doubt it is the predominating influence on the copper.

When future experiments are done if you are sticking with sodium as the alkali maybe half-neutralize the ascorbic acid solution to a 50/50 molar ascorbic / sodium ascorbate. But magnesium would work better Reference the Clayton article and discussion about pH control that Hennig and I were sorting out with regards to the different reduction yields being pH sensitive, (in the other thread).

Picramate is a devil about pH sensitivity affecting yields, also temperature and reaction mixture concentration are other tricksters.

Regarding the possible formation of a mixed valence copper picramate double salt:

There is cupric picrate present in solution before the ascorbic acid is added and it is possible for that to be reduced to cupric picramate ...if there is not a specifically selective reduction of the cupric to cuprous in preference to reduction of the picrate to picramate.

Of course if the reduction went to completion all that would be present in the end would be entirely cuprous picramate. However, if there was formed a mixture of partly reduced and fully reduced copper picramates that tended to form an insoluble double salt there could be a mixed valence double copper picramate that accounts for the insoluble product chemical composition showing a discrepancy on analysis from what should be the mole weight and analysis for cuprous picramate.

It is uncertain what is the selectivity for the species being preferentially or first acted upon by the ascorbic acid .......is it the copper being first reduced, or is it the picrate, or is it a mixture of both reactions? You see the uncertainty present in a chaotic system allows for several different reductions and subsequent reactions for the reduced copper in particular, since its oxidation state can change. Reduced copper associated with either picrate or picramate can operate as a reducing agent itself towards unreduced picrate.

There is possibly a couple more that are pH and hydrolysis dependent

Reduction by ascorbic H++ (free ascorbic at < 4 pH)

Reduction by mono-dehydroascorbic H+
(cuprous ascorbate or sodium ascorbate)

Reduction by cuprous picrate (reduction by the Cu+1)

Reduction by cuprous picramate (reduction by the Cu +1)

Ascorbate will by itself reduce Picrate to Picramate

https://www.jstage.jst.go.jp/article/bcsj/65/4/65_4_1101/_ar...

Put on your thinking cap, and think about the concept of a regenerable catalyst needing to remain in solution, because copper won't do it. Obviously copper is useful for isolation because of the insoluble precipitate it does form. But that same usefulness works counter to the concept of a regenerable catalyst, because once the copper combines with the product it is sequestered by precipitation and leaves the reduction reaction, like a player in a sports game that has scored and as a reward has been benched....that copper is no longer participating in the reduction reaction and has been consumed and locked away in the insoluble precipitate. So then for a regenerable catalyst, a better candidate would be a metal that easily changes oxidation states either direction, but behaves differently and does not form an insoluble precipitate with either the picric or picramic value, but remains in solution to be recycled and regenerated as an intermediate reducing agent so that more usefulness as a catalyst is realized. Of course there would need also to be no precipitation of the catalyst due to reaction with the Ascorbic Acid or Ascorbate Salt, and no other reduction reaction parameter such as pH that would provoke precipitation of the soluble catalyst.

So what transition metal salts would be likely catalyst candidates?

Manganese, iron, cobalt, and nickel are likely and each would probably be optimal at a particular pH, temperature, and concentration which would need to be "process engineered" by the chemist / technician /operator keeping that pH and other parameters in mind with regards to order and time of addition and the reagents used.

My intuition about these was first on Manganese due to good solubility of the picrate and picramate, but what is the sensitivity with Ascorbic or Ascorbate is unknown. Nickel was another thought because of similar chemistry with copper but no report of an insoluble picramate to complicate things.

My collateral thoughts about buffering using Magnesium as the base was likewise good solubility for the picrate and picramate and having a limited swing for pH inherent by use of Magnesium for the base. Likewise using organic acid salts instead of mineral acid salts would dampen pH swings. And my thoughts regarding glycine as potentially useful related to a twofold potential usefulness as an organic acid buffer and solubility enhancer via chelation as well as a solubility enhancer for picric acid in a low pH reduction system which would enhance the activity of Ascorbic acid at a lower and optimum pH of about 2-3 pH where free Ascorbic acid is at peak activity as a 2H (++) value reducing agent.



As a further thought, some reactions absolutely do run differently on infusion of reactant streams by a Sigma pump flow through a capillary into a rapidly stirred reaction mixture as a finessed very gradual addition, rather than addition by "bucketful" splashes of drips for addition, or where the reactants are simply dumped together "in a lump" and a mass reaction follows where the process on a molecular level is like a bar room brawl

It depends on the target material being made what addition scheme may work better and there can be quite a difference in yield for some of the reactions, and even some reactions that can only be done by infusion to produce good results. I don't think this reduction is all that sensitive, but some of the diazotizations for example like for nitrotetrazole are indeed that sensitive.

When you devised that diazotization scheme using copper wire as a source for NO2 gas evolution that essentially emulated a Sigma pumped infusion diazotization scheme in situ, and is a lot simpler and more economical than using a Sigma infusion pump to very slowly inject a micro stream of nitrite solution into the reaction mixture. That thinking cap is the one I was referencing.


[Edited on 3/10/2018 by Rosco Bodine]

Quote: Originally posted by Rosco Bodine

Diazodinitrophenol - as a free running crystalline powder from a nitric acid diazotisation Abstract: Diazoltisation of picramic acid to produce the explosive is effected in nitric acid in the absence of hydrochloric or sulphuric acids or their salts and pref with as low a sodium content as possible. Conventional products tend to adhere to surfaces. A translation of the attached patent FR2106904 may be useful

Colloidal copper might be active as a reducer ....I'm not sure. Glycine would probably be helpful there as a sort of "emulsifier" or stabilizer that would operate as a solubilizer / chelating agent ....which essentially "associates" metal and organic acid as a sort of loose covalent / quasi ionic "salt" but not exactly a stable "electrical" salt like a usual mineral salt would be. The charge there for the compound association is minimal to almost non-existent. A chelate is almost like a soap or detergent "wetting agent" like a very minimal "glue" on a "sticky note" attachment of two things.

The "male" metal and "female" organic acid of a chelate are not joined in a tightly bonded "super glued" attachment, but are associated like "friends with benefits" not involved in some deeply committed soul mate sort of bonded relationship.

The organic acid offers mister macho metal a little joyous cathode stimulation / R&R / rejuvenation for the afternoon or as long as it can last ...until assertive competition arrives and it is time for girlfriend to go

My idea for using the glycine is raising the upper limit pH and soluble metal concentration where a metal hydroxide would precipitate, making the reaction less sensitive to alkalinity. It was also a means of working with an organic acid salt of the metal in a system that would have inherent buffering not present to as great an extent with mineral acid salts. Glycine would help tame the pH swings and the pH gradient in the reaction mixture where additions are being made dropwise also, because each added drop has a local reaction condition that fades across a gradient until the added drop of reactant becomes mixed thoroughly well with the bulk of the material being stirred in a beaker.

Adding a reactant solution dropwise is like dripping a red paint into a stirred bucket of white paint, and across the swirl of mixing different materials is a million different shades of pink before long stirring makes the entire bucketful an even color pink. In a chemical reaction a buffer helps narrow the range of extremes of pH that can occur only across a smaller limited gradient of pH for the mixing solutions.

The use of glycine in another scheme was as a solubility enhancer for picric acid that might be reducible to picramic acid or a picramate, particularly the magnesium salt. I tried to give a detailed and coherent description earlier what were my thoughts on that. My focus and note on magnesium having potential usefulness is explained more in this linked post in another thread.

http://www.sciencemadness.org/talk/viewthread.php?tid=433&am...

Note to moderator:

There needs to be an editing / export / merge done for the DDNP and picramic acid topic specific posts that have mislocated the discussion in another thread making it impossible to keep track of the discussion.

See the enumerated 23 posts below need to be merged following this linked post in this thread

(1-12-2018) Rosco Bodine

http://www.sciencemadness.org/talk/viewthread.php?tid=439&am...

That merge should fill the chronological gap in this thread where the off topic posts are located in a different general topic.

Nitro-genes started this detour off topic by not recognizing the subject matter for the unknown compound he had made. So this (linked below) first post "detour" off topic should be merged into this thread and all the posts listed should be exported to this topic thread, DDNP & related compounds: The uber thread!

[1] (1-14-2018) nitro-genes

http://www.sciencemadness.org/talk/viewthread.php?tid=26572&...

[2] (1-15-2018) Rosco Bodine

http://www.sciencemadness.org/talk/viewthread.php?tid=26572&...

[3] (1-15-2018) nitro-genes

http://www.sciencemadness.org/talk/viewthread.php?tid=26572&...

[4] (1-15-2018) Rosco Bodine

http://www.sciencemadness.org/talk/viewthread.php?tid=26572&...

[5] (1-16-2018) nitro-genes

http://www.sciencemadness.org/talk/viewthread.php?tid=26572&...

[6] (1-16-2018) nitro-genes

http://www.sciencemadness.org/talk/viewthread.php?tid=26572&...

[7] (1-16-2018) Rosco Bodine

http://www.sciencemadness.org/talk/viewthread.php?tid=26572&...

[8] (1-17-2018) nitro-genes

http://www.sciencemadness.org/talk/viewthread.php?tid=26572&...

[9] (1-17-2018) Rosco Bodine

http://www.sciencemadness.org/talk/viewthread.php?tid=26572&...

[10] (1-17-2018) nitro-genes

http://www.sciencemadness.org/talk/viewthread.php?tid=26572&...

[11] (1-17-2018) Rosco Bodine

http://www.sciencemadness.org/talk/viewthread.php?tid=26572&...

[12] (1-17-2018) nitro-genes

http://www.sciencemadness.org/talk/viewthread.php?tid=26572&...

[13] (1-17-2018) Rosco Bodine

http://www.sciencemadness.org/talk/viewthread.php?tid=26572&...

[14] (1-23-2018) nitro-genes)

http://www.sciencemadness.org/talk/viewthread.php?tid=26572&...

[15] (1-23-2018) Rosco Bodine

http://www.sciencemadness.org/talk/viewthread.php?tid=26572&...

[16] (1-23-2018) nitro-genes

http://www.sciencemadness.org/talk/viewthread.php?tid=26572&...

[17] (1-24-2018) Rosco Bodine

http://www.sciencemadness.org/talk/viewthread.php?tid=26572&...

[18] (1-24-2018) nitro-genes

http://www.sciencemadness.org/talk/viewthread.php?tid=26572&...

[19] (1-24-2018) Rosco Bodine

http://www.sciencemadness.org/talk/viewthread.php?tid=26572&...

[20] (1-26-2018) nitro-genes

http://www.sciencemadness.org/talk/viewthread.php?tid=26572&...

[21] (1-26-2018) Rosco Bodine

http://www.sciencemadness.org/talk/viewthread.php?tid=26572&...

[22] (1-27-2018) Rosco Bodine

http://www.sciencemadness.org/talk/viewthread.php?tid=26572&...

[23] (1-30-2018) Rosco Bodine

http://www.sciencemadness.org/talk/viewthread.php?tid=26572&...

Additional note to moderator:
There may need to later created a 3 branched bracketed grouping of this topic thread with the picramic acid from picric topic thread and the Picric acid: different instructions topic thread since the three topics are an inherently related "trifecta" sort of overlapping discussion. That would help organize the three related topics.

[Edited on 3/22/2018 by Rosco Bodine]

Would be interesting to know how exactly the reduction is occuring. Would something like this (Copper phthalocyanine-3,4′,4″,4″′-tetrasulfonic acid) be "glueye" enough to allow for catalysis? Or would the ascorbic still reduce the copper right back to the metal? It would be somewhat sterically hindered though.

https://www.chemicalbook.com/ProductChemicalPropertiesCB6113...

[Edited on 26-3-2018 by nitro-genes]

Styphnamic acid!!! :

The copper/ascorbic method of reducing picric acid to picramic acid seemed surprisingly specific in reducing one ortho nitro group (the method was posted on page 28 of this thread), even approaching the efficiency of the well known (hydro)sulfide reduction. I was curious whether the copper/ascorbic reduction would produce similar results for styphnic as for picric, as also mentioned by Rosco Bodine a while back. The product upon reduction of styphnic would be styphnamic acid, a pretty elusive compound, which is, (similar to it's diazo derivatives) only few times mentioned in literature. The diazo derivatives itself are of little interest as energetic materials in practice due to incompatibility/stability issues and the reported extreme friction sensitivities of their salts. The chemistry of both these selective reductions and diazo derivatives is still very interesting IMO.

Basically the same approach for the reduction of styphnic was used as that for picric posted earlier. The styphnic was produced by hydrolysis of 3-aminopicric using 3 molar eqvts of NaOH and boiling the solution until no more smell of ammonia could be noticed (~30 min) followed by acidification using HCl. Overall, the reduction of styphnic seems to behave very similar as that of picric. Curiously, whereas the reduction of picric produced very dark brown solutions and produced a lot of gas during the reaction, the reduction of styphnic was without any noticable gas formation and no dark brown solution was observed near the end of the reduction. Yield needs to be measured, though might be at least as good or even better as that for picric.

Experimental:

Reduction of styphnic to styphnamic acid:

0.5 g of styphnic was added to a 100 ml beaker and water was added to 75 ml in total. Then, 0.27 g basic copper carbonate was added and the solution heated until all styphnic had dissolved into a dark yellow solution and no more CO2 was produced. A bit of undissolved copper carbonate remained because of the slight excess used. The copper styphnate solution was cooled to about 10 deg C. Next, 1.5 g ascorbic acid was weighed out and added at once. After the ascorbic had dissolved, I let the reaction stirr in the cold for another 10 minutes, though no clouding or precipitation was observed. The hotplate was turned on and the solution was heated slowly. When at 25 deg C. Slight clouding could be seen forming first, followed quickly by a light green precipitate (very similar to that observed for the picrate reduction). Heating was continued and slowly brought up to about 65 deg. C. The light green precipitate started to colour increasingly more yellow-greenish-brownish (also similar to the picrate reaction). After 30 minutes at 60 deg. C., the mixture was cooled down to room temperature and the precipitate left to settle. Most of the supernatant was decanted, then another 75 ml of cold water was added and most decanted/siphoned off again. The beaker was added to the hotplate again, 10 ml water was added and warmed slightly while dropwise additions of concentrated HCl were started. The greenish-yellow precipitate slowly turned a more orange colour and dark copper-reddish crystals of styphnamic acid started forming. The solution was cooled down in the fridge, filtered and washed with water to remove all of the copper and finally dried. The crystals of styphnamic acid look very similar to picramic, though with a more golden-brown note to it (See attached photo, some cuprous styphnate seems to still be present). A rough melting point was taken on the hotplate and had a much higher melting point as picramic acid at around 210-220 deg. C. (with extensive bubbling and decomposition).


Diazotization to dinitro diazoresorcinol or DDNR:

About 100-200 mg of the stypnamic acid was added to a 10 ml beaker together with 5 ml of 10% HCl. Some of the styphnamic acid dissolved, most remained as suspension. This was cooled to 0 deg C. in an icebath and 2 ml's of water with a spatule of sodium nitrite dissolved was added dropwise. Here is where it gets weird... Each drop of the nitrite solution produced a pretty dark colour (maybe due to residual copper?, or an N-nitroso intermediate?). After only a few drops of the nitrite solution were added, all of the styphnamic acid dissolved into a clear dark yellow-brownish solution. After stirring for another couple of minutes, a very light yellow precipitate started to from (chloride salt of DDNR?). Thinking it was the DDNR itself, I reasoned adding another 5 ml of cold water would probably precipitate more of the DDNR. To my surprise however all product dissolved again. Since there hadn't been any gas production during the diazotization itself, it seemed unlikely the compound had decomposed somehow, as could have been the case for styphnamic containing an amino group in 2-position. To precipitate any possible DDNR as the salt, solid sodium bicarbonate was added in small increments. When most of the HCl was neutralized, large amounts of fine dark yellow needles started to precipitate, presumably the sodium salt of some DDNR isomer.

Since these salts are extremely dangerous (and I had made quite too much ) I saved a few mg's and dissolved the rest in warm water again. When dry it behaves very energetic though, detonating in tiny amounts, much resembling SADS.



What really puzzles me is how the presumed internal diazonium salt of styphnamic acid (DDNR) can actually seem more soluble in cold HCl as the styphnamic acid itself...Also curious which isomer is formed during the reduction, maybe that could explain things....hmmm....It also doesn't seem like the same compound as was obtained from the nitration of iso-picramic acid....pfff, I was expecting to close the loop and connect all dots here, and then this?!?!?! ...if anyone has some thoughts on this, please share them!!!

[Edited on 25-11-2018 by nitro-genes]

Redoing the copper/ascorbic reduction of styphnic to styphnamic, this time using 1.5 g of styphnic, I was able to measure yield.

Running the reduction again....1.5 g of styphnic resulted in 1.20 g of styphnamic acid. Assuming styphnamic does not form any hydrates (which didn't seem so when taking the melting point on the hotplate) this would translate to a 91% yield. Considering the scale of the reaction, any possible remaining styphnamic in the dilute HCl filtrate, and the fact I was too lazy to really scrape all styphnamic acid of the filter paper, I think the reduction might be almost quantitative... amazing!!!

Patent US4246052 deals with the styphnic reduction indeed, unfortunately yields of styphnamic acid are not mentioned, only that a 63% yield of an unspecified diazo derivative after diazotization is realized. How to interpret this depends on whether both the 2 and 4-amino isomers (see attachment) of styphnamic are able to form diazo compounds and whether SnCl2 acts as a specific reducing agent (don't think so). What isomers are formed during the copper/ascorbic reduction I'm not sure. Assuming the copper/ascorbic reduction is facilitated by forming some transient complex associated with any of the 2 hydroxylgroups of stypnamic, one would expect a 50:50 ration of 2 and 4-amino derivatives of styphnamic maybe?

Anyway, can't wait to experiment a bit with different diazotization schemes! The strontium salt might be interesting, though I don't have any strontium salts available.



[Edited on 26-11-2018 by nitro-genes]

Ok, I've run the diazotization of 200 mg styphnamic acid again, this time using concentrated (30%) hydrochloric acid and more according to the conditions outlined in US4246052 (SnCl2 reduction of styphnic). The stypnamic acid was all dissolved in about 2 ml of warm hydrochloric and the nitrite slowly added as concentrated solution at 0 deg. C. This time, small light yellow cubic crystals (chloride salt or free diazoquinone?) separated after 15 minutes. After filtering off these crystals, adding the least amount of water to wet them, and letting this react with bicarbonate until a pH of 6 was reached, a precipitate of light yellow needles of a very explosive compound occured, probably a sodium salt. Reacidifying the precipitated putative sodium salt brings everything back into solution and the sodium salt can be reprecipitated by adding bicarbonate again. This seems to exclude some obscure rearrangement taking place upon basifying.
Based on this, and after rereading patent US4246052, I'm reasonably sure the compound described in US4246052 and that obtained from the copper/ascorbic reduction of styphnic are one and the same. Diazotisation in concentrated hydrochloric probably precipitates the chloride salt of the diazoquinone due to the common ion effect. What remains strange is I have been unable to isolate the free diazoquinone itself, either it is extremely soluble in water, or the pH range needs to be very strict. Maybe a different pka/b of the diazo group (relative to that of the two hydroxyl groups) for 2-diazo 4,6-dinitro resorcinol compared to the 4-diazo derivative explains this, not sure.

Another observation was that the light yellow needles of the sodium salt, when acidified using acetic acid, did dissolve temporarily again, precipitating small golden cubic crystals again that might be the free diazoquinone, not sure yet. It also detonates in reasonably small quantities, so if it is the free diazoquinone, it behaves much different from 4-diazo 2,6-dinitro resorcinol, which only flashes upon ignition, like NC. It might be made easily by adding the diazo chloride salt to acetic acid and slowly adding a sodium acetate solution. If this is all true, it might also be interesting to see what the impact and friction sensitivity are compared to the salts, and 4-diazo 2,6-dinitroresorcinol.

4-diazo 2,6-dinitro resorcinol has been described by klapotke et al from a trinitro 4-aminophenol derivative. Describedly, it crystallizes from reasonably concentrated nitric, as was also observed for the compound obtained by me from further nitration of 4-amino 2,6-dinitrophenol, which therefore most likely also resulted in 4-diazo 4,6-dinitro resorcinol, as it was readily attacked by azides.

So it seems most likely that reduction of styphnic produces 2-amino-4,6-dinitro resorcinol and 4-diazo 2,6-dinitro resorcinol can only be obtained from protected 4-aminophenol derivatives, similar to the routes to obtain 2-DDNP and 4-DDNP. Mystery solved I think! Traces of 4-diazo 2,6-dinitro resorcinol would show up after reduction/diazotization, so why can ONLY the 2-nitrogroup of styphnic and picric be reduced, even by something as reasonably aspecific as SnCl2?


One other explanation could be the neat nitric or nitric/SA treatment results in some conversion back to stypnic (as has been show for picramic under some conditions), resulting in some strange pi stacking adduct with styphnic, that did crystallize more easily from dilute nitric, but this is not very likely IMO.


[Edited on 27-11-2018 by nitro-genes]

Surprisingly, 2,4,6-tridiazocyclohexane-1,3,5-trione (Trisdiazo phloroglucinate) exists and can be made directly from phloroglucinol using diazo transfer reagents (See 1st attachment), or trinitroso-phloroglucinol and hydrazine hydrate. (Attached article) Describedly, it detonates from heating only at 220 deg C, so this could mean it is even more temperature stable as the DDNP's.

So, I don't see any direct reasons why a diazo dinitro phloroglucinate, or maybe a mononitro-bisdiazo phloroglucinate wouldn't be possible. Wondering what could be the possible products for trinitrophloroglucinol, if the copper/ascorbic reduction is applied followed by HCl treatment. Guessing it might be possible to produce 2-amino-4,6-dinitrophloroglucinol this way. Maybe providing competing ligands for the Cu(I) (To keep the reduction products more solubilized) during the reduction and mild conditions, the mono-nitro diamino phloroglucinol can be possibly made as well. Not sure how suscpible those amino groups would be to hydrolysis. Curious if these would be able to produce diazo derivatives as well (2nd attachment). I'm guessing if they do, they would be completely undescribed diazo compounds!

The nitration of phloroglucinol kan be done under very mild conditions using KNO3/sulfuric acid IIRC, though where to get phloroglucinol, or 1,3,5-trihydroxybenzene?








Attachment: Samsonov, V.A., Gatilov, Y.V. & Volodarskii, L.B. Russ Chem Bull (2012) 61 ; 1776.pdf (304kB)
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[Edited on 28-11-2018 by nitro-genes]

Been doing some additional experiments involving styphnamic acid and it's diazotization, all is done on an extremely small scale (50-100 mg) due to the hazards of these compounds, so not very precise. The solubility of the styphnamic acid in hydrochloric is very particular. Adding very concentrated (30%) hydrochloric to the deep orange-red stypnamic, a light yellow precipitate is formed, probably of the chloride salt, that is nearly insoluble in the concentrated HCl. When the mix was carefully diluted stepwise and weighted, the maximum solubility of styphnamic acid in HCl seems to be at around 13-17% HCl. Further dilution results in a pretty sharp dissociation boundary, where the light yellow chloride salt transforms instantly back to the orange-red free styphnamic acid. Since the solubility of styphnamic also depends on temperature and total volume of acid added, this would be a lot of work to all sort out. It would also not be very meaningfull since the solubility of the diazoquinone in HCl seems to behave very different as that of styphnamic itself.

Diazotization using 20% HCl at 0 deg C. produces scales or cubes of a very light yellow compound, probably the chloride salt as guessed earlier, strange thing is that it seems to need 2 mole eqvts of nitrite in order the precipitate the light yellow chloride salt of the diazoquinone, but maybe I'm just impatient...hmmm...weirdness... The putative chloride salt in itself seems pretty explosive and large losses can occur due to the relatively high solubility of the diazoquinone in HCl. A better option seems diazotization in 30-60% sulfuric. The sulfate salt seems less explosive as the chloride salt, presumably due to the bulkyness of the sulfate group and recovery of the acid salt seems higher.

The potassium salt seems most interesting (if these are really salts and not the free diazoquinone), it is relatively insoluble in cold water and shows higher brisancy compared to the sodium salt. It is easily made by neutralizing the chloride/sulfate salt using bicarbonate to almost neutral and precipitation using saturated KCl. Upon recrystallization from hot water, the potassium salt precipitates as very fine light yellow needles clumping togther. It behaves INCREDIBLY brisant, the tiniest specks blow holes in aluminium foil, like an azide or tetrazole derivative would. Also did a rough explosion temperature measurement on my hotplate, surprisingly the explosion temperature seemed at least equal or even higher than that of the 2,6-dinitro 4-diazo resorcinol derivative, immidiate explosion temp. estimated around 250-260 deg C. Maybe due to higher purity.


Also tried the basic copper carbonate/ascorbic reduction for 3-aminopicric (3-amino 2,4,6-trinitrophenol) produced from the amination of picric acid using hydroxylamine. The reduction resulted in an only 40% yield of some reduction product (after HCL treatment), noticably more brown in colour than styphnamic. Melting point was similar to styphnamic though, as seemed the product upon diazotization. Wondering if this rather represents remaining stypnic acid from the amination reaction, since it is done under very caustic conditions. Any thoughts on whether reduction of 3-amino 2,4,6-trinitrophenol is possible at all and if so...what would be the probable isomer(s) formed?

[Edited on 14-12-2018 by nitro-genes]

Quote: Originally posted by nitro-genes

The potassium salt seems most interesting (if these are really salts and not the free diazoquinone), it is relatively insoluble in cold water [Edited on 14-12-2018 by nitro-genes]

That would indeed be a good idea, though I don't have any perchlorates available anymore. Experimenting with this putative diazoquinone on a very small scale is really difficult, no idea actually what is the acid salt (if exist at all) the free diazoquinone and metal salts. If the diazoquione is very acidic, the acid would just precipitate more due to less deprotonation, similar to picric being less soluble in dilute HCl. Been thinking that the putative sulfate salt could be analyzed using calcium salts. At these scales though, adding 1 drop of something can mean the difference between obtaining a precipitate or dissolving everything. For these kind of experiments you would also really need to wash things properly or perform at large scale, both are rather difficult and/or dangerous.

Talking about perchlorates and dangerous....if the precipitate obtained after diazotization of styphnamic truly is an acid salt of the diazoquinone, I wonder if a diazonium perchlorate would also exist and would precipitate, it would be like the ultimate primary from hell probably. It is good that I don't have any perchloric acid, or would likely loose an eye or some fingers....

[Edited on 14-12-2018 by nitro-genes]

A test was done to determine if the compound isolated after diazotization of styphnamic is an acid salt or free diazoquinone:

Experimental:

0.5 g styphnamic was dissolved in 6 g of 50% sulfuric with slight warming, forming a very light yellow solution. Upon cooling to <0 deg C, there was no precipitation of the sulfate salt (as can occur with concentrated HCl). Then, 0.17 g of sodium nitrite was added to 1.5 ml water and added dropwise while in an icebath, some foaming was observed near the end of the reaction. Halfway the addition (about 15 minutes in), light yellow crystals started forming. After stirring for another 60 minutes after the last addition, the light yellow crystals were filtered off, blotted dry as best as possible using paper towels and dried for 8 hours at room temperature. Yield after drying was 0.49 grams. The dried precipitate is somewhat flame sensitive, burning with an orange flame and sustains deflageration (although burnrate is very slow). Heated slowly to ignition point in 2-5 mg amounts on a spatule, it never produces a detonation though.

The dried compound was cautiously transfered to a 20 ml beaker and destilled water was added dropwise at room temperature untill all dissolved. In total, 0.82 grams of water (at room temperature) was needed. Then, 3 ml of a pH 7 buffered ~10% calcium acetate /acetic solution was added, total volume adjusted to 10 ml, and kept at 4 deg. C. overnight. Only ~15 mg of calcium sulfate could be recovered after overnight at 4 deg C. Then, 1 ml of the filtrate was transfered to a 5 ml beaker and a few drops of a near saturated KCl solution added while swirling. The solution immediately became almost solid in apparance from abudant precipitation of light yellow needles of the potassium salt.

To the rest of the filtrate containing the very soluble calcium salt of 2-diazo 4,6-dinitroresorcinol was added a slight excess of ammonia. N2 gas was evolved (quite slowly though) and long, light brown needles formed after 24 hours in the cold, presumably of 4,6-dinitropyrogallol or it's ammonium salt. It burns only weakly energetic after drying.



The nitration of styphnamic was also attempted:

Experimental:

0.5 grams of styphnamic was added to 7.5 g 97% sulfuric acid. The styphnamic formed sticky lumps when contacting the sulfuric and was very hessitant to dissolve, though eventually (and with a bit of persuasion) a light yellow solution was obtained. This was cooled to 0 deg C. in an ice bath and slowly 0.6 g KNO3 was addded over the course of an hour or so. The light yellow solution became an incredibly dark red (like red wine). After stirring for about 3 hours in total, the reaction was left on ice without stirring for another 12 hours. At this point the solution had become a light yellow-orange. While still in the icebath, about 15 ml's of ice cold water was added dropwise. A lof of NOx was released. After another 8 hours or so at -20C, yellow-orange and 3-5 mm long needles were present in the solution (judging by the colour, there might have been a lot more product left in the filtrate, perhaps less water would need to be added to precipitate more). The needles were filtered off, blotted dry with paper towels and after drying weighed about 100 mg. A few mg's on a spatule when heated slowly results in detonation. It also sustains deflageration from flame, flashing off reasonably quickly, leaving a large black stain. All in all, it seems more energetic as the product obtained from diazotization of styphnamic using nitrite/50% sulfuric above.

The rest of the product (~100 mg) was added to a 5 ml beaker, and distilled water again added until all dissolved. It needed 4.68 g of water to all dissolve, so also it's solubility seems very different from that of the product obtained from direct diazotization. A bit of calcium carbonate was added until the pH was neutral and a few drops of a saturated KCl solution again added. Upon cooling for several hours at 4 deg C., there was no precipitation of a putative potassium salt. Solid KCl was added untill nearly saturated and cooled again. Small golden-orange cubic crystals of a potasium salt appeared (attachment), which behaved very energetic. So, also the solubility and colour of the potassium salt seems different than the product obtained from styphnamic diazotization. When touched by a glowing splint, it seems to make DDT in an even smaller amounts as the light yellow potassium salt of 2-diazo 4,6-dinitroresorcinol itself.

Although it is quite possible that the nitration of styphnamic produced a small yield of 2-diazo 4,6-dinitrophenol from the nitrous produced, it is tempting to speculate that a diazodinitrophloroglucinate resulted from the nitration by a putative 2-amino 4,5,6 trinitro resorcinol derivative!



[Edited on 21-12-2018 by nitro-genes]

One more post then...

Initially, I had some trouble using hydrochloric acid to diazotize the styphnamic (2-amino 4,6-dinitroresorcinol) to the corresponding 2-diazo derivative and determine whether this could possibly be an acid salt or the free diazoquinone. The free diazoquinone is very soluble in water and the alternative use of 50% sulfuric makes it impossible to dry the end product. As posted before, the solubility of styphnamic acid behaves somehwat peculiar in concentrated HCl (20-30%) and is prone to form a presumed acid chloride salt. The chloride salt of styphnamic is relatively insoluble at lower temperatures and prevents the full dissolution of all styphnamic when cold concentrated HCl is used. During diazotization, this leads to unreacted styphnamic in the end product.

Experimental:

0.25 grams of styphnamic acid was added to a 20 ml beaker. Then, 8 grams of 20% HCl was added and the solution heated slowly to about 90 deg. C.. All the styphnamic went into solution, forming a light yellow solution. Upon cooling this to 0 deg. C. in an icebath, beautiful light yellow/golden coloured leaflets started to form, presumably the chloride salt of styphnamic. Next, 0.1 g of sodium nitrite was added to a 5 ml beaker and 0.5 ml water added to dissolve. While in the icebath and keeping temperature below 10 deg. C. the sodium nitrite solution was added over the course of about 20 minutes. Most of the chloride salt redissolved during diazotization. After stirring for another 2 hours in the icebath, the beaker was transfered to a -20 deg. C. freezer and kept overnight. After filtering, the light yellow crystals were blotted dry as best as possible using filter paper and dried at 50 deg. C. for 3 hours. No change in colour was observed during drying, total yield was 0.21 gram.

Unlike using sulfuric, the product from diazotization in HCl did seem to dry completely, and was very flame sensitive, behaving much like a diazoquinone (videos attached). To test any possible presence of chlorides, 50 mg of the diazoquinone was transfered to a 5 ml beaker and a few drops of water were added to dissolve. Adding a dilute silver nitrate solution did not produce any silver chloride (or other) precipitate. When a few drops of a dilute HCl solution was added to the same solution afterwards, immediate clouding was observed. It seems the product is really 2-amino 4,6-dinitro resorcinol.

What remains strange is that I had heat tested the presumed diazoquinone from HCl diazotization before....I'm still 100% sure it detonated when a few mg were heated on a spatule when last tested :S....very strange....The only differences were that (1) the styphnamic was freshly prepared, (2) the precipitate after diazotization was filtered off after only a few hours and (3) a larger excess of sodium nitrite was used. Hmmm....there seems to be quite some carbon produced as well upon deflageration, maybe it wasn't completely dry, or part of the diazoquinone decomposed during the prolonged contact with HCl or upon drying at elevated temperature. The styphnamic was kept in an amber and airtight HDPE container at -20 in a freezer, so any decomposition seems unlikely.

Attachment: 2-diazo 4,6-dinitroresorcinol 1.avi (1MB)
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Attachment: 2-diazo 4,6-dinitroresorcinol 2.avi (706kB)
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[Edited on 7-1-2019 by nitro-genes]

Again, for anyone experimenting with the salts of DDNR, be extremely careful handling these compounds

Cited from US6946042B2 (Josef kohler):
"In the context of using diazinates, which are known from German Patent 391427 and German Patent 2806599, it must be mentioned for reasons of safety that the potassium salt of the dinitrodihydroxydiazobenzene in particular is not safe to handle and, similarly to lead azide, tends to self-detonate during production. This behavior is particularly observed during mixing of water-soluble potassium salts with a diazinate. Strontium diazinate also shows very high sensitivity to impact and friction in its pure form and therefore may also be poured and processed only with suitable passivators, in this case strontium sulfate. For reasons of industrial availability of the starting materials and simpler synthetic pathways, therefore, the non-toxic metal cations of 4-diazo-2,6-dinitroresorcinol are preferred."

The extreme friction sensitivity is is apparent from the table in US4246052 "SnCl2 reduction of Styphnic Acid and DDNP analogue therefrom"




What seems strange is that 4-DDNR is taken as example, while the reduction/diazotization described in this patent is very likely to produce 2-DDNR. The deflageration temperatures seem odd as well. It is likely that quantity, purity and heating rate of the sample will have a large influence on the apparent explosion temperature, though, there is a big gap between the 176 deg C from the patent and the 260 deg C, from the potassium salt I got.

It has been described before that the potassium salt precipitates as light yellow needles from concentrated solutions and brown triclinic blocks from diluted ones. When care is taken to only slightly heat the water solution (60 deg C or so) the potassium salt seems to crystallize as the light yellow needles irrespective of dilution. From boiling water the brown-blocks are formed again. I think the dinitropyrogallol decomposition product is maybe acting as crystal modifier, or maybe even form some double salt. It might be interesting to look at possible double salts and complexes for these compounds, not sure how stable these salts are during storage however. Noticed quite some patents mention the DDNR salts for use in lead free bullet primers, does anyone know if they are really used in practice? Could find some examples for SINTOX, though not for DDNR salts...

[Edited on 14-1-2019 by nitro-genes]

Last bit of isopicramic needed to get rid of...

Set out to make made some very pure p-DDNP (4-diazo 2,6-dinitrophenol) using oxidative purification (dilute nitric), after which it was thoroughly washed with dH2O, dried and recrystallized from cold acetone by slow evaporation in a beaker. The pure product is only a faint yellow-beige. Funny, all the diazophenols seem to form thin elongated plates or even hair like needles when recrystallized from acid, though both o-DDNP and p-DDNP form these almost cubic like blocks from acetone. Would these be orthorombic or triclinic, anyone any idea? (I have no idea how you could see the difference between these crystal forms)




Attachment: 4-diazo 2,6-dinitrophenol purified recrystallized.avi (980kB)
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[Edited on 15-1-2019 by nitro-genes]

Almost everything I made over the last couple of years was yellow of some sorts, which compound are you referring to exactly?

Quote: Originally posted by nitro-genes

Styphnamic acid!!! : The copper/ascorbic method of reducing picric acid to picramic acid seemed surprisingly specific in reducing one ortho nitro group (the method was posted on page 28 of this thread), even approaching the efficiency of the well known (hydro)sulfide reduction. I was curious whether the copper/ascorbic reduction would produce similar results for styphnic as for picric, as also mentioned by Rosco Bodine a while back. The product upon reduction of styphnic would be styphnamic acid, a pretty elusive compound, which is, (similar to it's diazo derivatives) only few times mentioned in literature. The diazo derivatives itself are of little interest as energetic materials in practice due to incompatibility/stability issues and the reported extreme friction sensitivities of their salts. The chemistry of both these selective reductions and diazo derivatives is still very interesting IMO. Basically the same approach for the reduction of styphnic was used as that for picric posted earlier. The styphnic was produced by hydrolysis of 3-aminopicric using 3 molar eqvts of NaOH and boiling the solution until no more smell of ammonia could be noticed (~30 min) followed by acidification using HCl. Overall, the reduction of styphnic seems to behave very similar as that of picric. Curiously, whereas the reduction of picric produced very dark brown solutions and produced a lot of gas during the reaction, the reduction of styphnic was without any noticable gas formation and no dark brown solution was observed near the end of the reduction. Yield needs to be measured, though might be at least as good or even better as that for picric. Experimental: Reduction of styphnic to styphnamic acid: 0.5 g of styphnic was added to a 100 ml beaker and water was added to 75 ml in total. Then, 0.27 g basic copper carbonate was added and the solution heated until all styphnic had dissolved into a dark yellow solution and no more CO2 was produced. A bit of undissolved copper carbonate remained because of the slight excess used. The copper styphnate solution was cooled to about 10 deg C. Next, 1.5 g ascorbic acid was weighed out and added at once. After the ascorbic had dissolved, I let the reaction stirr in the cold for another 10 minutes, though no clouding or precipitation was observed. The hotplate was turned on and the solution was heated slowly. When at 25 deg C. Slight clouding could be seen forming first, followed quickly by a light green precipitate (very similar to that observed for the picrate reduction). Heating was continued and slowly brought up to about 65 deg. C. The light green precipitate started to colour increasingly more yellow-greenish-brownish (also similar to the picrate reaction). After 30 minutes at 60 deg. C., the mixture was cooled down to room temperature and the precipitate left to settle. Most of the supernatant was decanted, then another 75 ml of cold water was added and most decanted/siphoned off again. The beaker was added to the hotplate again, 10 ml water was added and warmed slightly while dropwise additions of concentrated HCl were started. The greenish-yellow precipitate slowly turned a more orange colour and dark copper-reddish crystals of styphnamic acid started forming. The solution was cooled down in the fridge, filtered and washed with water to remove all of the copper and finally dried. The crystals of styphnamic acid look very similar to picramic, though with a more golden-brown note to it (See attached photo, some cuprous styphnate seems to still be present). A rough melting point was taken on the hotplate and had a much higher melting point as picramic acid at around 210-220 deg. C. (with extensive bubbling and decomposition). Diazotization to dinitro diazoresorcinol or DDNR: About 100-200 mg of the stypnamic acid was added to a 10 ml beaker together with 5 ml of 10% HCl. Some of the styphnamic acid dissolved, most remained as suspension. This was cooled to 0 deg C. in an icebath and 2 ml's of water with a spatule of sodium nitrite dissolved was added dropwise. Here is where it gets weird... Each drop of the nitrite solution produced a pretty dark colour (maybe due to residual copper?, or an N-nitroso intermediate?). After only a few drops of the nitrite solution were added, all of the styphnamic acid dissolved into a clear dark yellow-brownish solution. After stirring for another couple of minutes, a very light yellow precipitate started to from (chloride salt of DDNR?). Thinking it was the DDNR itself, I reasoned adding another 5 ml of cold water would probably precipitate more of the DDNR. To my surprise however all product dissolved again. Since there hadn't been any gas production during the diazotization itself, it seemed unlikely the compound had decomposed somehow, as could have been the case for styphnamic containing an amino group in 2-position. To precipitate any possible DDNR as the salt, solid sodium bicarbonate was added in small increments. When most of the HCl was neutralized, large amounts of fine dark yellow needles started to precipitate, presumably the sodium salt of some DDNR isomer. Since these salts are extremely dangerous (and I had made quite too much ) I saved a few mg's and dissolved the rest in warm water again. When dry it behaves very energetic though, detonating in tiny amounts, much resembling SADS. What really puzzles me is how the presumed internal diazonium salt of styphnamic acid (DDNR) can actually seem more soluble in cold HCl as the styphnamic acid itself...Also curious which isomer is formed during the reduction, maybe that could explain things....hmmm....It also doesn't seem like the same compound as was obtained from the nitration of iso-picramic acid....pfff, I was expecting to close the loop and connect all dots here, and then this?!?!?! ...if anyone has some thoughts on this, please share them!!! [Edited on 25-11-2018 by nitro-genes]

My guess would be that due to the nitro groups, the ring system is too electron deficient for formaldehyde to attack any of the aromatic carbons directly. My guess would be that the carbon of the formaldehyde would attack the outer nitrogen of the diazogroup bearing a slight negative charge. Then several things could happen (perhaps depending on pH and solvent used), electron transfer from the nitrogens of the diazogroup to the ring, forming a transient imine which would maybe hydrolyse leaving some hydrazone and dinitropyrogallol. Alternatively, it would lead to deamination of the ring by electron moving from the diazo group to the aldehyde, producing N2, formic acid and leaving 4,6-dinitroresorcinol as the product. The latter would be interesting as a route to the 4-diazo derivative of DDNR, as I am pretty sure I've seen at least one patent reagrding the resonably selective nitration of resorcinol diaacetate to the 4,6 dinitro derivative and mono reduction using hydrazine.

[Edited on 31-1-2019 by nitro-genes]

Might be worth checking reactivity of the soluble calcium DDNR with urea to see if a low soluble urea DDNR salt may exist. Bivalent / trivalent metals possibly could form complex "designer" salts .... Al (DDNR) styphnate or Pb (DDNR) picrate or basic salts or metal complexed salts might be another scheme to reduce sensitivity for a DDNR component in the compound.

Somewhat offtopic:

It seems the amino group of styphnamic acid (2-amino 4,6-dinitroresorcinol) is more suceptible to hydrolysis than I thought... While boiling of styphnamic with sodium carbonate only results in dark brown black resin formation, prolonged boiling of styphnamic acid in dilute acid seems to result in hydrolysis to 4,6-dinitropyrogallol (4,6-dinitro 1,2,3-trihydroxybenzene). Is picramic acid equally sensitive to acid hydrolysis?

Does make for a nice synthesis of 4,6-dinitropyrogallol though:

Experimental:

0.5 g of 2-amino 4,6-dinitroresorcinol was added to 80 ml distilled water and 1 ml 97% sulfuric was added. The suspension was boiled for 3 hours while covered with cling wrap upon which a light yellow solution had formed. Upon slow cooling, 1 cm long bright yellow crystals formed (attachment 1), that turned a more orange shade upon washing with water. It melts sharply at about 210 deg C (without visible decomposition), with immediate sublimation after melting. Presumably 4,6-dinitropyrogallol in nearly quantitative yield. Maybe some interesting salts or pyrotechnic mixtures could be made with this stuff. It does not behave very energetic, only burns slowly with a luminous flame when strongly heated (near it's melting point).



Also seems 4,6-dinitropyrogallol forms some interesting product when reacted with nitrous acid in concentrated HCl:

Experimental:

100 mg 4,6-dinitropyrogallol was added to a 10 ml beaker and suspended in ~1.5 ml 20.2% HCl. The beaker was added to an icebath and while stirring, an excess of sodium nitrite in water was added dropwise. Some of the 4,6-dinitropyrogallol dissolved and a pretty bright orange compound was formed instead (Attachment 2). I puffs off pretty violent when heated to ignition. The orange compound formed seems very unstable, already at ~50 deg C, it starts to blacken very fast, though it remains pretty explosive. It seems to form a tarry substance, as black as coal, when at 100 deg C, though it still remains pretty explosive. Finally it melts at around 120-130 C or so. maybe some dinitro dihydroxy quinone? An isomer of nitranilic acid maybe (that would be cool)? Some chloro derivative? The product seems pretty pure and crystalline, maybe just a mixture of something with unreacted 4,6-dinitropyrogallol? Any ideas?



[Edited on 8-2-2019 by nitro-genes]

Not sure how readily and stable nitro-nitroso substitution of the 5 position for 4,6-dinitropyrogallol would be. At first glance, both the 1,3 hydroxy and 4,6 dinitro groups seem to work against any presence of a nitroso/nitro. It seems likely that any transient nitroso addition compound would immediately be hydrolysed to leave the quinone that would be an isomer of nitranilic. IIRC, only the trinitro derivative of the trimethylether of pyrogallol has been described, though hardly any properties were given. On the other hand, benzoxazolones actualy favour the electrophilic substition of the 5,6 positions ....similarly, 5,6-benzofuroxan is more stable as the 4,6-isomer IIRC. Benzene chemistry is really strange... One thing that I do seem to remember reading in some book on quinone toxicity is that the isomer of nitranilic acid was insanely toxic, this is from a vague memory years ago and I cant find it again. Is there a good source for toxicity data of these compounds?

[Edited on 11-2-2019 by nitro-genes]

You know you want to put the orange stuff in some concentrated HNO3 to see what happens curiosity / cats

On toxicity nitroso compounds are a good bet to be toxic and carcinogenic

In my long experience, caveat emptor.... test the unknown sample first to see if it is finger licking good ......you just never know what you might be getting into there

[Edited on 2/11/2019 by Rosco Bodine]

Indeed, but then again...there aren't many things I wouldn't want to add to concentrated nitric.

The 2-diazo 4,6-dinitroresorcinol behaves very different in many aspects as the "others" so to say. Surprisingly, it seems the ammonium salt can actually be isolated and dried. When a solution of 100 mg of 2-DDNR was added to about 2 ml of water and slowly dripped in 5 ml of a 10% ammonium acetate at room temperature, everything stayed in solution first and no nitrogen was evolved at all. When cooling on ice for a few minutes, it precipitated almost quantitatively as long and glossy light yellow needles. It burns only weakly energetic in small amounts, though becomes increasingly more so with larger amounts, as can be seen from the video. On heating a few mg it just puffs off with white/yellowish flash. The ammonium salt is very soluble in warm water, and very insoluble at 0 deg C. I was so suprised to see how mildly energetic it was, that I was first thinking some internal rearrangement had taken place. When the ammonium salt is added to water again, and added to excess of a KCl solution, the extremely explosive potassium salt forms again. It really is a salt, maybe hydrate, amazing to see how that hydrogen bonding is able to stabilize the compound. Wonder how stable it would be on storage, one would think the ammonium would eventually react with the diazonium group right? If not, the ammonium salt or maybe the ethylenediamine salt might be used as a transfer reagent, similar to 5-NT.

If one is to draw the structure of the salts...how would it best be drawn? Does the cation combine with the delocalized negative charge of the ring, as sort of a meisenheimer complex, or just with one of the 2 hydroxy groups?

Attachment: Ammonium salt 2-Diazo 4,6-dinitroresorcinol - Copy.avi (929kB)
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Starting to wonder how unstable the salts of this thing are exactly, it happily sits at a pH of >12 with hardly any nitrogen gas formation. Wonder if it is more unstable at acid pH, which could be helpful for destruction. Maybe do a timed boil test in water and check for presence of potassium salt after fixed time intervals. Maybe sulfites would do better?

[Edited on 13-2-2019 by nitro-genes]

Quote: Originally posted by nitro-genes

If one is to draw the structure of the salts...how would it best be drawn? Does the cation combine with the delocalized negative charge of the ring, as sort of a meisenheimer complex, or just with one of the 2 hydroxy groups?

The diazo-oxy bridge is a dehydrogenated hydroxyl group so there is only one intact hydroxyl on DDNR and it becomes dehydrogenated also when a salt formation occurs and a metal or other cation replaces the phenolic hydrogen there.



Really while it is interesting to see what further can be done with the o-DDNR isomer that is more commonly known .....I still think the more obscure isomer p-DDNR derived from nitration of paracetamol acetate followed by hydrolysis and diazotization may gain enough stability by virtue of the 4-1 positions diazo-oxide bridge that the potassium salt will be less sensitive and more useful than the overly sensitive potassium o-DDNR. Acetic anhydride is the missing ingredient.

Two years ago I believe I had sorted this out concerning the structure.

http://www.sciencemadness.org/talk/viewthread.php?tid=439&am...

https://www.youtube.com/watch?v=q-0bQKoXD2k Do it Again

[Edited on 2/14/2019 by Rosco Bodine]

The electronic structure of diazophenols have been reviewed a couple of times. None of them mention a cyclic structure, although in this case it surely seems convenient indeed.

https://www.youtube.com/watch?v=hPvLYLQoN0A

Maybe only the para diazophenols behave more as a zwitter ion (more charge separation means more energy?) and the ortho more as quinones or cyclic, just don't know enough of physical chemistry to determine how convincing the data in all of them are as proof of their structure, it is an interesting topic for sure. The article from 1987 is the most modern review on this topic AFAIK, it mentions complete delocalization of the negative charge over the entire ring, which would be more in line with also the electronic structure of nitranilic acids and other salts of dihydroxyquinone IIRC. Still having trouble to see where that metal cation will end up exactly Other sources mention partial charges that change with the nature of the substituents and pH, I have really no idea where all these partial charges would end up to form the salts of the DDNRs though.

Kazitsyna, L. A., B. S. Kikot', and A. V. Upadysheva. "Quinone diazides and p-iminoquinone diazides." Russian Chemical Reviews 35.5 (1966): 388-405.
Kazitsyna, L. A., and N. D. Klyueva. "Electronic structure of substituted diazophenols." Russian Chemical Bulletin 19.1 (1970): 197-199.
Lowe-Ma, Charlotte K., Robin A. Nissan, and William S. Wilson. Diazophenols-their structure and explosive properties. No. NWC-TP-6810. NAVAL WEAPONS CENTER CHINA LAKE CA, 1987.

An other interesting reference in relation to the cuprous mediated reduction seems the one below:

Porter, Thomas R., et al. "Sterically directed nitronate complexes of 2, 6-di-tert-butyl-4-nitrophenoxide with Cu (II) and Zn (II) and their H-atom transfer reactivity." Dalton Transactions 46.8 (2017): 2551-2558.

Cuprous ions can maybe form some transient SET complex with the quinone-nitronate resonance form of styphnic to facilitate the reduction. Cuprous can form very strong ligand interactions (almost like covalent) so this explains maybe both the efficiency of the cuprous reduction as well as why the 2-nitro is selectively reduced? It would maybe also explain why styphnic acid seems more readily reduced at lower temperatures as picric using the cuprous method?

[Edited on 14-2-2019 by nitro-genes]

Quote: Originally posted by nitro-genes

The extreme friction sensitivity is is apparent from the table in US4246052 "SnCl2 reduction of Styphnic Acid and DDNP analogue therefrom" What seems strange is that 4-DDNR is taken as example, while the reduction/diazotization described in this patent is very likely to produce 2-DDNR. [Edited on 14-1-2019 by nitro-genes]

Where *exactly* do you get this stuff about *2*???- DDNR ????


Attachment: Diazophenols-their structure and explosive properties. NAVAL WEAPONS CENTER CHINA LAKE CA, 1987.pdf (1.3MB)
This file has been downloaded 730 times

[Edited on 2/14/2019 by Rosco Bodine]

Not 100% sure, though I'm not 100% sure the earth isn't flat either . The melting point of styphnamic is described as 190 C by Benedikt and Hubl, though as 219 C by the chinese article from 1933 (abstract link attached), which is alot more modern. The abstract (see link below) also mentions boiling in water produces dinitropyrogallol as proof of structure, something Benedikt and Hubl didn't provide. The melting point of the styphnamic from the copper/ascorbic reduction seems around 220 C as well, dilute acid hydrolysis produces quantitative yield of a yellow compound melting at around 210 (commercial mp. 4,6-dinitropyrogallol = 209-211C), the left over filtrate when all of the presumed dinitropyrogallol is removed produces an ammonia smell with NaOH, so likely an amino hydrolysed off. It is very unlikely that p-amino phenol derived diazo derivatives somehow form 2-amino resorcinol derivatives, and the 4-DDNR product from these seems much less soluble as the presumed 2-DDNR, as it precipitates from very dilute acid solutions (Klapotke), while the presumed 2-DDNR has an incredibly high solubility in water. Benedict and Hubl also described the diazo derivative from their reduction product to be only precipitated from concentrate solutions and concentrated acids, which also fits the observations of the compound I obtained. Combined with the likely preference for ortho hydroxy-nitro reduction described by Porter and the presumed quinone-nitronate structure mediated reduction, which fits the huge preference for the 2-nitro, this is the absolute most likely scenario, so without any constructive arguments I'll stick to the 2-DDNR. The only remote possibilities seems that the stannous chloride reduction of styphnic produces somehow the 4-amino reduction product and that the 2-amino of styphnamic may rearrange to take the position of one of the other hydroxy groups, AFAIK, this has never been described though for similar compounds.



[Edited on 14-2-2019 by nitro-genes]

Quote: Originally posted by nitro-genes

Not 100% sure, though I'm not 100% sure the earth isn't flat either . The melting point of styphnamic is described as 190 C by Benedikt and Hubl, though as 219 C by the chinese article from 1933 (abstract link attached), which is alot more modern. The abstract (see link below) also mentions boiling in water produces dinitropyrogallol as proof of structure, something Benedikt and Hubl didn't provide. The melting point of the styphnamic from the copper/ascorbic reduction seems around 220 C as well, dilute acid hydrolysis produces quantitative yield of a yellow compound melting at around 210 (commercial mp. 4,6-dinitropyrogallol = 209-211C), the left over filtrate when all of the presumed dinitropyrogallol is removed produces an ammonia smell with NaOH, so likely an amino hydrolysed off. It is very unlikely that p-amino phenol derived diazo derivatives somehow form 2-amino resorcinol derivatives, and the 4-DDNR product from these seems much less soluble as the presumed 2-DDNR, as it precipitates from very dilute acid solutions (Klapotke), while the presumed 2-DDNR has an incredibly high solubility in water. Benedict and Hubl also described the diazo derivative from their reduction product to be only precipitated from concentrate solutions and concentrated acids, which also fits the observations of the compound I obtained. Combined with the likely preference for ortho hydroxy-nitro reduction described by Porter and the presumed quinone-nitronate structure mediated reduction, which fits the huge preference for the 2-nitro, this is the absolute most likely scenario, so without any constructive arguments I'll stick to the 2-DDNR. The only remote possibilities seems that the stannous chloride reduction of styphnic produces somehow the 4-amino reduction product and that the 2-amino of styphnamic may rearrange to take the position of one of the other hydroxy groups, AFAIK, this has never been described though for similar compounds. The astract can be found here: http://delibra.bg.polsl.pl/Content/16820/P-321_1933_Oct.pdf [Edited on 14-2-2019 by nitro-genes]

That is 104 pages of abstracts so could you be specific or extract the page of interest. Thanks.

What I was thinking would be Styphnamic Acid on parallel to Picramic acid is what would generally result from a sodium sulfide reduction or other ordinary reduction .....like an ascorbate reduction on the Styphnic Acid Salt of a base, like sodium or magnesium styphnate and this would be a parallel to the ordinary reduction schemes for an alkaline base salt of Picric Acid.

So I had supposed the styphnamic acid analogue of picramic acid would be 4-amino (I think when I was looking at this 2 years ago) But then there is also possible the iso-styphnamic acid by working from a different precursor having the amino to be later diazotized in a different ring position, analogous to iso-picramic acid.

Now which one of the isomers you get could be pH dependent and could be reaction sequence dependent which could be co-dependent and also dependent on the ring position of the amino.

Speaking of what is and isn't flat on Valentine's Day

[inappropriate image removed j_sum1]


[Edited on 2/14/2019 by Rosco Bodine]

[Edited on 24-2-2019 by j_sum1]

Uploaded the relevant abstract, you were clearly busy...



[Edited on 14-2-2019 by nitro-genes]

Finally, good chemistry.......

Here is that extract again



Okay I see where you are getting the 2-amino for styphnamic acid and then that would provide a 2-diazo for the DDNR, with decomposition of the diazo to a 2-hydroxyl.....which would provide the 1,2,3 trihydroxyl for pyrogallol.

This clears up the matter of the other two possible DDNR isomers derived from nitration product of paracetamol acetate, later diazotized by two different methods, which would both have the 4-diazo structure, with one isomer forming a para 4-1 diazo oxide while the alternative isomer of Klapotke would form an ortho 4-3 diazo oxide preceded by hydrolysis decomposition of the nitro at 3 under the conditions for diazotization used by Klapotke. Applying the different diazotization method of Meldola which does not hydrolyze the 3-nitro results in the para 4-1 diazo oxide.

How this relates back to the compound of Benedikt and Hubl is something I would need to review to see which isomer is likely for that.

It appears there are at least 3 isomers possible by different reaction schemes, similarly as was the case of DDNP.

Quote: Originally posted by nitro-genes

Uploaded the relevant abstract, you were clearly busy... [Edited on 14-2-2019 by nitro-genes]

Lady was hitch hiking in the rain and just by coincidence the brakes suddenly locked up like a random mechanical failure ....these things just happen sometimes....it's an anomaly for sure.

[Edited on 2/14/2019 by Rosco Bodine]

Judging by the high solubility of the potassium salt they obtained (not much evidence though), it seems Benedikt and Hubl may have obtained something different than 2-diazo 4,6-dinitroresorcinol from their rather forcing diazotization procedure using an excess of nitrite in boiling sulfuric. My guess would be that they obtained a diazo dinitrophloroglucinate instead which would match the solubility of the potassium salt obtained for the product of the nitration of styphnamic. The Patents from Hagel et al. (US4246052) describes reduction and diazotization of styphnamic, but describe the product as 4-diazo 2,6-dinitroresorcinol, and also the patent from Kohler (US6946042B2) only mentions the 4-diazo derivative due to their ease of preparation, even though I can't see the logic of why they would talk about the 4-diazo derivative when the 2-diazo derivative is much more likely to be formed from the reduction/diazotization of styphnamic acid instead, is this a nomenclature issue or is styphnic really that different in reductions? Am I just dumb, or are these patent really wrong? What is strange is that the hydrochloric solubility of the reduction product described in US4246052 seems much higher than that of the product I obtained, and they do not mention the almost insoluble hydrochloric acid salt. If this is really all true, the salts of 2-diazo 4,6-dinitroresorcinol may have never been described, nor patented. Though, again... is the reduction of styphnic using stannous chloride really expected to yield 4-amino 2,6-dinitro resorcinol, I just can't believe it...

Starting to feel like Alice tumbling down the rabit hole....damn this is interesting!

[Edited on 16-2-2019 by nitro-genes]

Yes, been wondering the same. Similarly to lead azide, the potassium salt of 2-DDNR is described by Kohler to be notorious for its tendency to detonate when crystallizing from solution. From >5% concentrations of aqueous solutions of the diazoquinone, the potassium salt tends to instantly crystallize from solution upon introduction of a potassium salt solution, forming a felty network of very fine and long needles (Photo 1) that can turn the whole liquid into a solid gel-like consistency. It is likely that the described auto-detonation tendency during crystallization originates in part from this behavior, as is also the case with lead azide.

The needle crystal morphology can be completely eliminated when a 2% aqueous solution of 2-diazo 4,6-dinitroresorcinol is dripped slowly into a large excess of an ice-cold potassium acetate/acetic buffer at pH 6, that is completely saturated with KCl or KNO3. As such it forms small, compact and cubic crystals (Photo 2) that may exhibit better handling properties and may be less likely to self-detonate during its synthesis.

Then again, I think Kohler and Hagel were were no idiots and these patents originate from a time where the danger of the needle crystal morphology of lead azide was already known and described IIRC. Also pretty sure they read the article of Benedikt and Hubl... so...Would still be interesting to see the difference in friction and impact sensitivity between the two preparation methods of the K-salt described above though.



Regarding the preference for the 4-DDNR as energetic material, just a random guess (I know next to nothing about theoretical structural chemistry) would be that the 4-DDNR maybe behaves more as a zwitter ion due to the para position and more acidic 1-hydroxy group, while for the 2-DDNR the charge is more delocalized also over the nitrogroups, making that 2-DDNR behaves more readily as an oxidizer? If so, would this still apply to the salts?

[Edited on 17-2-2019 by nitro-genes]

When I go through this whole thread about DDNP, it seems that DDNP is worse in all parameters than CHP. (TeACP-hexamine clathrate) In production and explosive parameters. And even in next parameters. Or did I overlook something? Thank you for explaining from anyone.........LL

Well, for firearms use is DDNP sure better. Thanks for explanation........LL

Quote: Originally posted by nitro-genes

Yes, been wondering the same. Similarly to lead azide, the potassium salt of 2-DDNR is described by Kohler to be notorious for its tendency to detonate when crystallizing from solution. From >5% concentrations of aqueous solutions of the diazoquinone, the potassium salt tends to instantly crystallize from solution upon introduction of a potassium salt solution, forming a felty network of very fine and long needles (Photo 1) that can turn the whole liquid into a solid gel-like consistency. It is likely that the described auto-detonation tendency during crystallization originates in part from this behavior, as is also the case with lead azide.

A "diazoquinone" huh? How about a resorcinoquinone?

A massive precipitation of low density fibrous crystals is something that can also occur for picrates and styphnates as an intermediate product that requires further processing with very specific conditions of dilution and temperature and pH and stirring, to produce a more desirable and compact crystalline form that is a drastic difference required to provide a useful material. Under certain specific conditions the initial low density precipitate can form and can then be transformed to the high density material simply by manipulation of the conditions that redissolve the initial precipitate which may be a higher hydrate, and then recrystallize as a lower hydrate or anhydrous form at a higher temperature and different, usually lower pH. Sometimes the formation of a double salt will accomplish the dehydration if the double salt forms preferentially to a single salt hydrate.

Quote: Originally posted by Rosco Bodine

Speaking of what is and isn't flat on Valentine's Day [inappropriate image removed j_sum1] [Edited on 2/14/2019 by Rosco Bodine]

@ Rosco....Yeah, I get the feeling there may be some hydrates involved here and there after all. I wont be continuing with the salt of 2-DDNR though, think it is time to quit with eyes, ears and fingers still working and attached.

"A "diazoquinone" huh? How about a resorcinoquinone? " I don't get it, What do you mean by that?

Recrystallized some of the last completely dry 2-DDNR from acetone solubility in boiling acetone is about 1 g 2-DDNR /33.5 ml acetone....seems to work fine.




[Edited on 22-2-2019 by nitro-genes]

Attachment: 2-diazo 4,6-dinitroresorcinol recrystallized acetone.avi (769kB)
This file has been downloaded 952 times

Curiosity won again... Ok, one final experiment with the potassium salt!

The brown compact crystals of the potassium salt of 2-diazo 4,6-dinitroresorcinol as obtained from 2% aqueous solutions of the 2-DDNR (as in my writeup in prebub) present somewhat of a mystery it seems. I performed the exact same precipitation reaction again, the only difference only being that instead of the crude 2-DDNR, the acetone recyrstallized product was used. The KNO3 saturated potassium acetate/acetic buffer was exactly the same, as I made a large batch to make some comparisons and had quite some left. From a 2% aqueous solution of the acetone recrystallized 2-DDNR, there was still a lot of the the fibrous needle morphology material present. Only when the 2-DDNR solution was diluted further to about a 0.2% aqueous solution, the potassium salt precipitated as the small more compact crystals, only the colour was not a brownish, though a light yellow. Even from the 0.2% solution, some sporadic needles were present when looked under the binoc. With very high stirring rates (probably very dangerous) and very slow addition, the compact crystals can be also formed from a 2% aqueous solution of the pure 2-DDNR.

So:

It seems very unlikely the brown material is a hydrate, as Benedikt an Hubl suggest. To see if this is a double salt with some impurity instead (maybe dinitropyrogallol or some quinone/product derived from it?) one would have to do some large scale yield measurements on the crude 2-DDNR or qualitative tests on the brown material, so out of my reach. I must say, I don't think there is enough of any impurity present to form a double salt or explain the difference in crystal morphology by the lower true concentration of 2-DDNR in the crude product. The most likely explanation seems that some impurity is present in the crude 2-DDNR isolated directly from the diazotization that acts as a powerful crystal modifier and allows the compact crystal shape for the potassium salt to form from aqueous solutions of the 2-DDNR at a >10 fold higher concentration and minimal stirring as compared to the (presumably) more pure compound from acetone.
I've been wondering if some of these crystal modifiers act purely as by retarding the onset of first crystallization. Maybe dextrin would be effective for the pure compound...

[Edited on 23-2-2019 by nitro-genes]

In this thread, I feel like a student who listens to the debate of several university professors of chemistry........LL

Quote: Originally posted by nitro-genes

@ Rosco....Yeah, I get the feeling there may be some hydrates involved here and there after all. I wont be continuing with the salt of 2-DDNR though, think it is time to quit with eyes, ears and fingers still working and attached.

Quote:

"A "diazoquinone" huh? How about a resorcinoquinone? " I don't get it, What do you mean by that?

Final report on styphnamic and its diazoderivative...there, I'm all done!

There, I'm all done!


Attachment: Synthesis and some properties of 2-amino 4,6-dinitroresorcinol and 2-diazo 4,6-dinitroresorcinol.pdf (4.1MB)
This file has been downloaded 1334 times

[Edited on 28-2-2019 by nitro-genes]

Done huh? Hope springs eternal You aren't getting off that easy.

Page numbering ? Anyway on what would be numbered as page 5 if you beat me into submission proofreading and editing just above the pictures you wrote:

"Either 2-diazo 4,6-dinitroresorcinol itself or its salts have been tested for use in detonators and priming compositions, though were claimed to be incompatible with certain base charges [20,21]."

Who claimed? Federoff ???? Ha! Federoff even fell prey to the classic nitrite-nitrate alternate universe error ! Take the Federoff
summary blurb with a HUGE grain of NaCl !! Caveat emptor

The Federoff article is IIRC incorrect and references the Von Herz British patent along with a Chemical Abstract summary I don't recall ever having seen......So this is possibly not correct but is another Federoff typo. The structure of DDNR is also incorrectly identified by Federoff. These compounds were generally called
"quinone diazides" (incorrect) or "diazo-anhydrides" after the cyclic nature was identified for the diazo-oxy linkage displacing a phenolic hydrogen.

In my understanding what I would call this general class of compounds is:

diazo-nitrophenol-anhydrides or probably better
nitrophenol-diazo-anhydrides

Anyway it seems clearly an editing oversight in Federoff referencing a patent and "claims" that do not reconcile with what Federoff shows as "unstable" should read instead as "usable" or "useful" as *is* what the patent claims clearly state along with the measured weights of initiator found "useful" with several commonly used base charges.

Obviously it would be silly for a reputable chemist Von Herz to patent and make "claims" to publish at great expense the discovery of useless and unstable compounds in order to attest to their lack of value. More likely Federoff transcribers and editors simply screwed the pooch and left the pooch screwed for posterity.

Who was Von Herz anyway ??? Obscure chemist hardly ...IIRC
Von Herz invented cyclonite or RDX ....but somebody should probably check me on that since I am getting old and confused, probably the senility creeping up on me IIRC it was also Von Herz first filed for patent on the use of DDNP as an initiator.

A reference needed is the Chemical Abstracts (1924) Volume 18, page 1574 which may reference a journal article by Von Herz that a general search may find also, unless the abstract simply announces the British patent which is very likely.

Is there anything in the patent that is specific to instability or other issue related to "certain base charges"?



Here is an interesting compound where hexamethylene tetramine is shown to bridge complex 2 copper compounds, and such a scheme might work for copper DDNR similarly as it does for copper azide and may be useful as a desensitizer integrated on a molecular level. Other metal salts might also be susceptible.

For the complex if it would form with copper DDNR, there would be 4 of the mono-acid DDNR molecules in a compound having 2 copper atoms bridged by hexamethylene tetramine. If the hypothetical compound forms, it may be possible to use the benign ammonium DDNR as a precursor. Whether the speculated compound will form at all or whether any troublesome hydrate may be an issue is completely unknown, since the hypothetical compound is unreported and may be novel.

Glycine should similarly bridge complex 2 copper molecules, and may work better for the same purpose.



Edmund von Herz (from Vienna Austria) also invented Lead Styphnate primers



[Edited on 3/1/2019 by Rosco Bodine]

Hexamethylenetetramine (hexamine) and CuO and NH3 gas, I consider for the best substances for synthesis most powerful energy salts. After adding some suitable salt, in suitable solvent, always arises some, what has energetic properties. Is it an Holy triad.......LL

Glycine

Was confirmed (repeatedly) very easy D2D effect with TACP 86% + 14% glycine. ( OB glycine - 95,87, TACP + 14,5) Brizance is worse than CHP, but only slightly. Estimation is 10% down. Crystalls are more blue light, more monochromatic, similarly as wet TACP. Someones researchers has not available hexamine, but glycine yes. Among other things, glycine is a universal medicine for almost everything. If you get tired of banging, you can eat 1-2 g per day of glycine. Next interest thing: Glycine react with CuO in hot water 90 C immediately on copper glycinate (??) , which crystallized at 10 C (or less) from mother liquer. Also almost immediately. Copper-glycinate (??) not react with NaClO4 or NH4ClO4. Therefore is impossible create copper-glycine-perchlorate. It require HClO4 or else described procedure. On picture is tetraamine copper glycine perchlorate, as mixture. No copper glycine perchlorate as molecule crystals.......LL

Quote: Originally posted by Laboratory of Liptakov

In this thread, I feel like a student who listens to the debate of several university professors of chemistry........LL

It's like Russian to me too.

But they seem to be making progress

Quote: Originally posted by Rosco Bodine

Here is an interesting compound where hexamethylene tetramine is shown to bridge complex 2 copper compounds, and such a scheme might work for copper DDNR similarly as it does for copper azide and may be useful as a desensitizer integrated on a molecular level. Other metal salts might also be susceptible. For the complex if it would form with copper DDNR, there would be 4 of the mono-acid DDNR molecules in a compound having 2 copper atoms bridged by hexamethylene tetramine. If the hypothetical compound forms, it may be possible to use the benign ammonium DDNR as a precursor. Whether the speculated compound will form at all or whether any troublesome hydrate may be an issue is completely unknown, since the hypothetical compound is unreported and may be novel. Glycine should similarly bridge complex 2 copper molecules, and may work better for the same purpose.

Attachment: php0embtA (1.1MB)
This file has been downloaded 774 times Journal_für_praktische_Chemie 1943 pg 307-328 hexamine complexed copper azide



The solubility in ammonia makes this compound interesting for its potential to form a double salt or mixed salt with glycine or hexamine complexed copper perchlorate. Even a cocrystallized mixture could have interesting enhanced properties for incorporation of the azide content.

[Edited on 10/13/2019 by Rosco Bodine]

Dipicric acid or DIPAM can be obtained in low yield by direct nitration of 3'3-dihydroxybiphenyl or in very good yield by oxidation of 3,3'-Dimethyl-2,2',4,4',6,6'-Hexanitrobiphenyl. Reference: "ADOLPH, HORST G., JOSEPH C. DACONS, and MORTIMER J. KAMLET. Heat Resistant Explosives. XI. An Unusual Oxidation Reaction Leading to 3, 3'-Dihydroxy-2, 2', 4, 4', 6, 6'-Hexanitrobiphenyl (Dipicric Acid, DIPA). No. NOLTR-62-32. NAVAL ORDNANCE LAB WHITE OAK MD, 1962."



Would it be possible to selectively reduce a single nitro group on one of the rings using the copper/ascorbic acid reduction scheme due to immediate precipitation as the cuprous salt? Would the resulting mono or diamine derivative be able to diazotize forming a DDNP molecule bridged to a picric acid ring or two DDNP molecules attached to each other? Would the former be able to form salts? Or would the biphenyl bond in such a molecule be very unstable/susceptible to hydrolysis?

[Edited on 20-9-2020 by nitro-genes]

DDNP/Diazo

Quote: Originally posted by Raid

Is there any good papers for the deacetylation of picric acid? And DDNP synnthesis?

Thanks for the info

Quote: Originally posted by Raid

I am not sure if this info has been posted on another thread, but If you're looking for potassium or sodium nitrite for your DDNP synthesis then I have a solution for you! It's very simple. Get some potassium or sodium nitrate and heat it in a metal cup with a blowtorch under direct flame until molten and no more oxygen bubbles appear. I have not gotten the exact temp at which the nitrate salt decomposes to form nitrite but it is said to be from 550c to 790c. A blowtorch should be able to get to that temp with no problem. Also if you're wondering what gas I was using it was just propane without any added oxygen. Some more things to consider when making the sodium nitrite. make sure you use a METAL reaction vessel aluminum will not work because it would react with the molten KNO3 or NaNO3 and decompose further than it should have. Also make sure to clean your reaction vessel very very very well. If there is even a small amount of contaminants it will show up in your final product and will be very hard to get out. Personally I think this method is much better then all of the other methods on the thread about nitrate reduction and is MUCH faster and will save you loads of time and reagent because the yield is nearly 100%, probably around 97% or something. Note to Admins and Mods: I'm guessing someone will try to move this post over to the thread about nitrate reduction, but I would appreciate it if you kept it here or made a copy and put it on that thread. I'm saying this because I think this is valuable information to the people that are wanting to make DDNP and are having a hard time getting or making a nitrite salt. Also the thread about nitrate reduction is old and hard to find. This info would be much more convenient for people to look on here and find what they are looking for.

Quote: Originally posted by ManyInterests

Edit: just some questions about para and ortho-DDNP. Can they be loaded into stainless steel bodies? Also when loaded. How sensitive are they to being pressed by a vise? I did hear from a user that a few drops of methanol is needed to desensitize them before pressing and allowing them to cure in the cap before inserting a fuse/electric match. Is this correct?

Quote: Originally posted by Raid

you can use RFNA or WFNA

Quote: Originally posted by Raid

you can use RFNA or WFNA

Quote: Originally posted by Raid

Some more things to consider when making the sodium nitrite. make sure you use a METAL reaction vessel aluminum will not work because it would react with the molten KNO3 or NaNO3 and decompose further than it should have.

Quote: Originally posted by fx-991ex

Quote: Originally posted by Raid   Some more things to consider when making the sodium nitrite. make sure you use a METAL reaction vessel aluminum will not work because it would react with the molten KNO3 or NaNO3 and decompose further than it should have. What about a glazed porcelain crucible? is it ok? [Edited on 22-6-2023 by fx-991ex]