DDNP & related compounds: The über thread!

Thanks for the patent, the dinitro acetaminophenol/H2SO4 solution was almost brown/black/red in colour and was put in the fridge, nothing has crystallized out yet. I'll check it tomorrow, about to hit the sack.

[Edit] suddenly remebered that picramic acid is soluble in h2s04, after caustic soda (main part) and sodium bicarbonate neutralization a rustbrown powder was obtained, it is more brownish red as opposed to picramic acid which is more red than brown, with sodium hydroxide the colour is an amazing deep red, with hint of violet. Will do the diazotisation tomorrow, as its drying now. Also will make some pictures :-)

[Edited on 19-5-2015 by nitro-genes]

Yes pictures are good and keep careful notes.

Here's some insight into the chemistry involved.

There are some subtleties involved about the color transitions involving the behavior as a dye indicator for pH observed for picramic acid or isopicramic acid. These amino acids like glycine, (aminoacetic acid) can function both as cation with a stronger acid to form a salt like glycine nitrate, or can function as an acid anion with a more basic cation to form a salt like sodium aminoacetate. That's amphoterism. The aminoacid can form a salt going or coming, can be the locomotive or the caboose. Or it can stand alone neat as the free aminoacid.

So there are 3 distinct forms in which we can see the aminoacid appear. Depending on the conditions, all of the aminoacid may be present as one distinct form, or as more than one form in mixture. The color changes and conditions can identify which of the 3 forms is present at the time when only one form should exist, defined by the conditions.

The dye indicator property usually applies to the picramate or isopicramate salt when a base is the cation and the picramate or isopicramate is the anion, for example sodium picramate or sodium isopicramate. To the limit of their solubility such salts function as powerful intensely colored dyes, more intensely colored in the more basic range and fading to the more pale color of the free aminoacid when the base cation is displaced by a stronger mineral acid, when that base migrates and associates with that stronger acid, leaving the lower solubility and less intensely colored picramic or isopicramic acid as the free aminoacid in the solution, probably in part precipitating as a solid residue, due to low solubility in the solution which is becoming increasingly acidic with the mineral acid.

However as the mineral acidity increases further, the free aminoacid being amphoteric can also function as a cation in association with a stronger acid than itself, and begins to dissolve and probably exhibit a different order color change as
for example occurs with formation of isopicramic sulfate, which will remain in solution even after being diluted, and will not return to free isopicramic acid and precipitate, until acted upon by a base to associate with the stronger acid and displace it.

How the color change occurs in this second scheme where the amphoteric isopicramic sulfate forms increasingly soluble and concentrated solution is something I do not know. So you will have to "ball park" guess what are your neutralization equivalents based on how much of what strong acid/s you are using and undershoot the bulk neutralization and titrate manually to produce the color changes and precipitations which should be logical when you observe.

The attached (again) article from Chemical World describes the de-benzoylation procedure which is possibly applicable also to the de-acetylation. It describes a spot test used to monitor the progress of the reaction by solubility on dilution of a sample and this may be a useful test also for the deacetylation.
Because of the volatility of acetic acid the de-acetylation will likely proceed more easily than the de-benzoylation.

A vacuum and/or passing through a bubbler inert gas, or riskier ordinary air might help strip away the volatile acetic acid and speed up the de-acetylation.

Earlier I speculated that this compound may be an example of "lost art" that has been gathering dust for a hundred years and has become an academic obscurity, and I think that's right. But I also think this iso-DDNP could be an oldie but a goodie.

The iso-DDNP may prove superior in significant ways to the usual DDNP in both explosive properties and storage stability. For example in thermal stability tests at just above the BP of H2O, 110C, the iso-DDNP has 6 times the stability of the usual DDNP. At lower temperatures more consistent with natural environmental storage temperature ranges, the iso-DDNP could easily be dozens or more times storage stable than the usual DDNP. If the initiating properties are also better as expected for the iso-DDNP, then it can be appreciated how the iso-DDNP would be the superior initiator.

Also speculated earlier about the potential for a mixed isomer cocrystallization with the better known DDNP, and am still intrigued what may occur there as a potential for better crystalline form and density, and potential improved properties if such a mixed isomer crystal does form.

AFAIK there is nothing in the literature about this, and very little about the iso-DDNP either.

So this is follow up experimental "re" search with some new aspects as a bonus and it also involves a green energetic.


Attachment: Pages from The_Chemical_world pg327.pdf (247kB)
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[Edited on 19-5-2015 by Rosco Bodine]

The acetylated isopicramic acid obtained directly from nitration of the paracetamol could very possibly be amphoteric also. Good point. Given your observation that the acetylated isopicramic acid precipitates from the diluted nitration mixture which is very strongly acidic for its unreacted sulfuric acid content, it is indicated however that any amphoterism would be very much lower for the acetylated isopicramic acid, than has been reported as a distinct property of the deacetylated isopicramic acid which readily forms a soluble sulfate.

You will learn by observation during the reactions and manipulations what are the visual "markers" that may be indicators of progress of the reactions. Temperatures are included markers usually for where things are going and when effective endpoints have arrived.

There are Chinese followers of this forum so I would expect they are looking at this iso-DDNP now if they haven't already done the research. The cost for the iso-DDNP production may be a little more, but the quality may offset the cost.
It could come down to simple economics where only costs alone are governing.

During the past years when many manufactured items available in the world are coming from China as a result of the massive industrialization there, it has been for me a mixture of admiration for the technology and quality for some things, and a displeasure for other things where slight changes could greatly improve the durability and serviceability for equipment that has been deliberately made "disposable" and difficult or impossible to maintain or service or repair, so that disposal and replacement has been made necessary. That is my "pet gripe" about the "progress" represented by some designs for more expensive manufactured goods from China. In fairness however it seems to be a global trend, and is definitely not an ecologically sound "design strategy" but is a greed motivated kind of "engineering". This should never be a design strategy applied to appliances or vehicles, to make difficult their maintenance or repair, but it has sadly become the routine to encounter such design and engineering being deliberately implemented by various product manufacturers. It may serve company profits to implement such designs but it is detrimental to the consumers and to the environment. There, I've said my piece. Engineers have a kind of ethical credo, just like medical doctors. First do no harm.

The few reported properties of the iso-DDNP definitely look promising. If it does simply detonate from heat instead of requiring a larger mass to undergo a DDT like is the case for the usual DDNP, that would tend to make it much more efficient as an initiator. The improved stability could also make it useful as a component in ammunition primers, depending upon the sensitivity and crystalline form. The economics involve more than just the difference in costs for the two isomers purely on a weight basis.

[Edited on 19-5-2015 by Rosco Bodine]

Redid the synthesis today, only double the amounts and without neutralization

Photo 1: 20 grams of ethanol extracted acetaminophen was added to 120g 98% H2SO4 and heated to 70 degrees for 15 minutes to dissolve and sulfonate yielding a golden caramel brown solution

Photo 2: 24 grams of AN was dissolved in 60 grams of H2SO4, cooled to below 0 deg C and slowly added to the SA/Acetaminophen while keeping temperature between 5-10 deg C. Halfway through the nitration a deep yellow/red, almost black solution was obtained

Photo 3: After all of the AN/SA was added, the nitration mix returned to an orange/brown colour

Photo 4: The nitration mix was crashed in ice/water and fut in the fridge. After settling the dinitro acetaminophen settled to the bottom of the beaker as yellow/orange solid

Photo 5: After filtering and washing three times with cold water, the product was transfered to a beaker containing 50 ml 98% H2SO4 and 50 ml of water

Photo 6: The beaker was put on the hotplate while stirring and heated to a temperature just below the boiling temperature of the water/SA solution (120 deg. C)

Photo 7: Deactelyation after 45 minutes, very pronounced acetic acid smell, solotion turned a very deep orange/brown

Next, After cooling the solution was neutrailized using cooled NaOH solution and bicarbonate, precipitating a large amount of rust brown powder (forget to take picture, srry ) The colour during neutralization changes very suddenly and dramatically when the pH comes below a certain point. The difference really is a few drops of bicarbonate solution, amazing to see :-)

Photo 8: final yield after drying, 20.3 grams of putative isopicramic acid.

The staining power of this compound appears even stronger than that of o-picramic acid. Producing a deep red with blueish tone in basic solution. Less than 1 mg under basic conditions produces a very strong colour in a glass full of water. When strongly diluted, the colour almost becomes in between purple and pink.

The isopicramic acid was diazotized according to COPAE method and is drying now :-)


[Edited on 19-5-2015 by nitro-genes]

Well, the p-DDNP is dry, I dried it over a hot waterbath. It flashed pretty fast, but not as fast as the o-DDNP I made and leaves more residue. Because of this I suspected that the isolated isopicramic acid was made up of multiple compounds, and Irecrysallized the isopicramic acid from ethanol. It crystallized very peculiar, like small spherical goblets attached to each other, which may be another indication that some other impurity is present, as can also be seen from the picture (yellow and red stuff). There are several probabilities, 1 is that simply deacetylation was incomplete, the colour of the impurity resembles that of dinitro acetaminophenol, although reheating part of it with SA produced no smell of acetic acid. Whatever it is, unforntunately it co-crystallizes with the isopicramic acid, also seems so with the second crop of crystals although much less. Other possibillitites are that the nitration produced a mix of mono and dinitro compunds, partly oxidized stuff resulted from the nitration, the deacetylation may have been to rigourous resulting in decomposition or some stuff from the tablets is still present. (Although the latter is unlikely IMO) Anyway, close, but no cigar.



[Edited on 19-5-2015 by nitro-genes]

[Edited on 19-5-2015 by nitro-genes]

Bad quality o-DDNP from some experimental crystallization techniques, I didn't want to do the synthesis again. Still... p-DDNP is much faster! Both are 50 mg amounts the left is o-DDNP ignition, the right the p-DDNP. By the sound of the flash I would say that the p-DDNP wouldn't need much more unconfined to make DDT. Wow, nice!

Attachment: o-DDNP and p-DDNP.avi (3.2MB)
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[Edited on 20-5-2015 by nitro-genes]

It is known that DDNP does not make DDT unconfined unless more than a few grams or so are ignited. Impure or not, I'm positive that 100-150 mg of the p-DDNP would have made DDT.

Maybe you could make a video of 50 mg of your DDNP on white paper, just curious how much faster DDNP is when completely clean, would be a nice comparison. Maybe I should recrystallize the DDNP like you did to get rid of the sublimated sulfur contamination from the S/vaselin heating, maybe that would clean things up

[Edited on 20-5-2015 by nitro-genes]

The ammonium salt of the acetylisopicramic acid has low solubility in cold water and good solubility in hot water and can be used for initial purification by recrystallization.



From this information it may be known that sulfonation is not required, nor is sulfuric acid. Paracetamol may be dissolved in the minimum amount of glacial acetic acid and nitrated in the cold maintained by an ice bath, gradually adding a nitrating mixture containing twice the amount of theory of d 1.5 HNO3 diluted with twice its volume of glacial acetic acid. The nitration completes in the cold in a few hours.

[Edited on 20-5-2015 by Rosco Bodine]

yes, acetaminophen is very soluble in glacial acetic acid as opposed to cold SA, I've found no listings of incompatibilities for acetaminophen with concentrated sulfuric acid nor did I have any indication for this during the synthesis. Acetylation of salicylic acid is generally performed using acetic anhydride with H2SO4 catalyst at 100 degrees, although this is more dilute though. I'm pretty sure that the decreased yield is either from the nitration or from only partial precipitation after crashing in ice. Next time I will save the filtrate and neutralize this to see how much is left in here. Maybe using only -20 cold ice to crash the mixture in will also precipitate more. I added substantially more water/ice than anticipited to keep the mixture below 10 deg C upon dilution, which is also a probable cause of yield loss. The ammonium salt may be a good alternative for recrystallization from water as opposed to ethanol, thanks!

Quote: Originally posted by Hennig Brand

You are right, it may just take a little more mass for the p-DDNP to make DDT.

I understand. My earlier post was edited, but I am leaving the description for the isomers for possible usefulness to others. There is actually at least one more isomer of DDNP reported, but we can save that one for later and not derail this more interesting discussion for what is probably the best of 3 known isomers.

From what I have gleaned from the literature, this p-DDNP should prove superior to the o-DDNP. If nothing else it is an alternative initiator at least as good as o-DDNP and is possible to synthesize from a commonly available precursor which is paracetamol. No reduction of a nitro compound is required to produce the amino acid precursor for diazotization, which simplifies things in that regard.

The synthesis from paracetamol should not present any unsolvable difficulty. But there are probably details and refinements for the manipulations which may be worked out to optimize the procedure. It is already known that the end product purity has great bearing on the performance of the material, so it can be expected that fine tuning of the synthesis should lead to a better performance for the highly pure end product, and that crystalline form and density may be important also.

The reactions which are known for DDNP to produce azide and tetrazeno type derivatives could also be investigated to see if the p-DDNP analogues have better performance.

A eutectic low mp mixture forms for picric acid and o-DDNP and may likewise occur for p-DDNP. What may be the effect with styphnic acid is not known, but such mixtures could result in a more sensitive, more powerful mixture for a base charge in compound detonators.

A possible candidate solvent, other than acetone, for purification of DDNP is nitromethane, to which might be dropwise added methanol or toluene or xylene or naphtha as a solubility decreaser to cause gradual slow crystallization forming larger crystals instead of a crash precipitation of small crystals as a low bulk density material, as would be obtained from a diazotization where crystal growth does not occur unless the diazotization is optimized for crystal development.

On a lighter note. It occurred to me that the nanny state regulators of hobby chemistry experimenters are presented with a kind of double whammy migraine for the proposition of p-DDNP from over the counter acetaminophen. As if ordinary aspirin isn't already a concern as a "strategic raw material" hmmm.....now here comes tylenol as another "headache remedy"

The reaction of extra special agent Gumby charged with the official duty of tracking unauthorized off label use from diversion of benign OTC materials is probably something like this







[Edited on 20-5-2015 by Rosco Bodine]

NP, I was not after a whose ding-dong is bigger discussion, is was genuine interest because I've never seen videos of DDNP ignited on white paper, which is very revealing and the exact reason I did it this way . I don't know how very pure DDNP flashes, so this would be really interesting to see. The DDNP I produced flashes very similar to other DDNP videos I've seen though.

I'm not doing anything with larger charges anymore, so I never really got a good reason to make my DDNP very pure by recrystallization for example. Moreover, this is tough because any residual sulfur forms an incredibly fine precipitate which is almost impossible to filter IMO. If you could make a movie of a 50 mg amount flashing on white paper that would be really appreciated, seriously. I thought about doing the sulfur/vaselin heating, but was afraid of the sulfur sublimate contaminating the NaOH solution, which would result in a bright orange solution instead of pale yellow for normal Na2S solutions.

I'll make a new movie clip since I produced both o-DDNP and p-DDNP exactly the same way for a better comparison, the colour from the p-DDNP is almost the same, although is has a slightly more purple/pink tint to it. Also planning to make some dextrinated pellets, like Rosco suggested earlier, to see whether the compressed p-DDNP is able to make DDT. Regarding the synthesis from acetaminophen, the optimization of the synthesis from AN/SA really requires a lot of effort since there a several steps involved and the starting material is a complex mix of all kinds of stuff. For all I know it may be that a certain brand of paracetamol tablets produces less impurities from ethanol extraction, although it may be that the nitration using AN requires different conditions and reaction times indeed, or maybe deacteylation of the dinitro acetaminophenol requires a different protocol. If more people could perform the synthesis and share their experiences that would be great!

This has so much potential and possible follow up experiments that it is impossible for one person to do anyway.

[Edited on 20-5-2015 by nitro-genes]

There are alternatives to H2S generation which do not involve thermal cracking of hydrocarbons. Simply treating with H2SO4 a "lime sulfur" or sodium polysulfide produced from NaOH and sulfur will evolve H2S which can be bubbled into an NaOH solution, tracking the neutralization by weight gain for the vessel containing the solution being neutralized. The free sulfur byproduct stays in the H2S gas generator and does not sublime at ordinary temperature. I think there were several schemes described earlier for producing the sulfide reducing agent.
And there are alternative schemes for reduction that involve no sulfur at all.

@nito-genes I am predicting that Hennig is going to require a new witness plate.

A random musing kind of thought is that either isomer DDNP might make an interesting third component in AP putty.

[Edited on 20-5-2015 by Rosco Bodine]

Nitro-genes, Rosco, no big deal, from the other side of the computer screen it can sometimes be hard to tell if I have insulted someone or not.
I will see about digging out some sodium picramate tomorrow. I should read up a little more and give this new isomer a try soon too.

Your old witness plate looks like a typical witness protection program success story You can stop shooting it any more, it looks like you got it Maybe retire it as a wind chime. We are taking up a collection to get you a new one.

Cycling the acetylisopicramic acid through a recrystallization of the ammonium salt for isolation and purification could be a benefit. And this might work for the isopicramic acid following the deacetylation as well. Some other salt like the potassium or sodium could work as well for aqueous recrystallization and purification.

That witness plate brings back good memories. It really is time for a new one though, 'tis true. The funny thing is I have at least two or three more of that same type, without holes, but it is always old holey that surfaces first some how or other. Even though I have admitted to having other witness plates, please everyone feel free to send me money and toys, don't hesitate.

You should keep it, like I also do with most of my witness plates, one day you'll be old and grey and you open a dusty box at the attic and remember the fun you had while doing this kind of stuff. Some things, like explosive imprints of leaves and other organic stuff would be almost art in a way.

Anyway, p-DDNP really offers a nice OTC synthesis of a potentially world class primary, even the nitrite can be prepared easily from lead and KNO3 or NaNO3 (quoting myself ) -->

"
Potassium nitrite synthesis

Outside and wearing gloves, 250 grams of lead (20% excess) was melted in a stainless steel vessel after which 100 grams of KNO3 was added at once. The mixture was stirred until all the KNO3 had melted and formed a clear layer floating on top of the molten lead. Some yellow/brown PbO started immediately to form, however, upon prolonged heating there was little to no further formation of PbO.
I decided to heat the mixture stronger and within about 10 minutes a strong exothermic reaction became evident. In a beautifully controlled manner and without any gas formation, the entire mixture became red hot. The mixture was well stirrable and this was done so for another couple of minutes to ensure reaction of all the KNO3 present. (The lead has a tendancy to sink immidiately to the bottom again)
It is important to keep stirring to the point of solidification, since it makes extracting the KNO2 much easier! The mixture was ground together with several additions of water, until all the PbO was present as a fine powder at the bottom and filtered to remove any PbO. The light yellow filtrate was then boiled to dryness (takes long time, due to hygroscopicity) and yielded about 65-70 grams of KNO2, minor plumbate contamination can be removed by bubling through CO2 for some time."

[Edited on 21-5-2015 by nitro-genes]

@Philou: 3-diazonium, 2,4,6 trinitrophenol must exist, since it is used as an intermediate in the synthesis of KDNBF, mentioned earlier. I've only seen it used to prepare the azido compund and uses very strong diazotising conditions at low temperatures, I reckon it would't be very stable.

What was your idea about the synthesis of 3,5-diazido-2,4,6-trinitrophenol, sounds interesting

Quote: Originally posted by nitro-genes

@Philou: 3-diazonium, 2,4,6 trinitrophenol must exist, since it is used as an intermediate in the synthesis of KDNBF, mentioned earlier. I've only seen it used to prepare the azido compund and uses very strong diazotising conditions at low temperatures, I reckon it would't be very stable. What was your idea about the synthesis of 3,5-diazido-2,4,6-trinitrophenol, sounds interesting

Sorry had some syntheses mixed up I think...Done to much over the last few weeks, and my reading is not up to date

Can't get the p-DDNP flashing without carbon deposits, so I started over from scratch and not skipping any steps. Tried crystallizing acetaminophen from ethanol, but it has the nasty habbit of forming very stubborn supersaturated solutions form ethanol and ethanol water mixtures..

The cleanest and still fast method with the brand of tablets I used is to extract 25g of acetaminophen (weight of tablet junk not included) with 125 ml of boiling methylated spirits. After stirring for about 5 minutes the solution is filtered hot and then added to another beaker. Then I boil it down with stirring to about 50 ml at which point slight clouding of the solution can be observed. Then I added 50 ml of water and keep boiling. When nearly all the ethanol is evaporated (takes about 15 minutes with hotplate on highest setting), there is a sharp induction point for crystallization to commence, within about 10 minutes nearly all of the acetaminophen precipitates as a reasonably course sand like precipitate, it is left ot cool and then filtered and washed generously with cold water. The filtrate is a really slightly yellow (p-aminophenol from hydrolisis?) and milky, I suspect that the stearic acid and other junk may have formed some emulsion which can be washed away. It is most likely an emsulsion of the waxes/stearic acid etc since it doesn't settle on standing a long time. The crystals looked very clean and glassy under a binocular, I will try to make a picture of it, which is kind of impossible with a full frame DSLR.

This method may result in hydrolysation of some of the product, but it doesn't smell acidic, is snow white, free flowing and looks really clean under the binoc. Picture attached



[Edited on 21-5-2015 by nitro-genes]

It were most likely impurities from the tablets, I redid the whole procedure with the newly isolated acetaminophen and there is a huge difference in the intermediate product appearances. The dinitroacetaminophen is a really orange colour instead of yellow/orange and no sticky residues are present after crashing in water, the deacetylation mix becomes a deep red instead of brownish red and upon neutralization a brick red powder separates quantitatively as a fine crystalline glistening product.

The problem with evaporation is that stearic acic, wax, plegmatized starch and povidone are all to some extent soluble in methanol/ethanol/water which would contaminate the product upon evaporation. Crystallization of acetaminophen using OTC solvents is problematic sine it is one of the most stubborn supersaturation compounds I've seen. The procedure outlined above works, I tried 3 times in a row, producing the same clean product every time. It probably works because the impurities form a milky emulsion that can be washed away, although this procedure may work not with all tablet brands. I bought several packages and weighed 10 pils to see which contained the least amount of rubbish. Surprisingly, after extraction with boiling ethanol, the insolubles filter really easy, yielding a completely clear solution.

The article about the solubility of paracetamol can be found halfway true this thread --> https://www.sciencemadness.org/whisper/viewthread.php?tid=62...

I'll make a detailed writeup soon, going true all the steps.

[Edited on 22-5-2015 by nitro-genes]

I am not one to criticize success. What works for you works for me.

Sorry I missed that before and see you have already been there, done that. The same issue can be encountered for aspirin being cleaned up for nitration. The mystery impurities after nitration can appear in picric acid gotten from aspirin also. Red goo is better avoided and more easily avoided at the beginning than is it easy to get out the mystery goo impurity later.

With aspirin the binders seem low solubility in the nearly saturated warm solution of the aspirin in denatured alcohol, and simply settle out as a dust fine sediment in the warm solvent. If a tall cylindrical jar is used and the jar of hot solvent is tilted, the sediment collects on one side of the bottom of the jar and nearly all the solvent can be decanted in one clean pouring away almost down to the last 20 ml or so of liquid.

I look forward to the writeup sorting out the finer details. This is very interesting what may turn out to be an "improved" performance and improved stability variant isomer of DDNP.

The topic of p-DDNP came up over 10 years ago but was never really given a good look. It has been like an itch that needed to be scratched for a decade now receiving attention

Another one of my old "itches" is guanidine perchlorate as a base charge initiated by triaminoguanidine perchlorate used as a primary. I like the obvious chemical compatibility and simplicity for that pair of materials which should have very good energy output also and would seem difficult to go wrong.

One thought I wanted to reiterate is concerning the water content for the nitration mixture which would be present with the described by patent and literature described nitrations where sulfuric acid was present as a component of the nitration mixture. Water content and warm temperature work against the formation of nitrosyl sulfuric acid, which is a diazotization agent, and the nitration product in this case is vulnerable to diazotization. The issue that could arise in a sulfuric acid containing nitration mixture is that a partial diazotization of the nitration product could occur while it is still in the nitration mixture, which could cause losses since the conditions are also favorable for decomposition of that diazo product as soon as it is formed. So water content to a certain extent that does not hinder the dinitration but does hinder the formation of nitrosylsulfuric acid, could actually result in a higher yield for the dinitration product, compared with what may be produced by a more aggressive and lower water content nitration mixture. There is a tradeoff about the nitration mixture which probably has a "sweet spot" kind of optimum water content which leads to maximum yields for the dinitration product, avoiding the nitrosyl sulfuric formation which would probably attack the newly formed acetylisopicramic acid and decrease the ultimate yield.

In the alternative nitration using glacial acetic acid and fuming nitric acid, where no sulfuric acid is present, the complication presented by nitrosyl sulfuric acid is eliminated so that alternative method of nitration would likely produce a more pure product.

[Edited on 22-5-2015 by Rosco Bodine]

Yeah but just because d 1.5 HNO3 is specified doesn't mean it wasn't white that they used RFNA is actually not all HNO3 even though it may be d 1.5 or more.
All you need to convert WFNA to RFNA is a little sunshine.

Good to remember light sensitivity for HNO3 that when nitrations are done outdoors, or when HNO3 is being distilled. Ain't no sunshine when she's gone (colorless)

File this under "the safelight imperative" regarding the predictable decomposition of HNO3 favoring formation of the nitrosyl sulfuric acid or "nitrous fumes", which is STRONGLY favored by direct sunlight, and even distinctly present but to a lower extent in shaded indirect daylight. Outdoors is good but keep it in the shade like the deep dark woods as much as possible.

https://www.youtube.com/watch?v=E6emVq0RZec

<iframe sandbox width="640" height="480" src="https://www.youtube.com/embed/E6emVq0RZec?rel=0" frameborder="0" allowfullscreen></iframe>

Aqua Fortis Latin "strong water"

Chemistry has its roots in mysticism and alchemy

The most ancient priests and oracles of science are not modern cosmologists and physicists

We are the ancients of ages past, present, and yet to be

https://www.youtube.com/watch?v=eqcWztXpVa4

<iframe sandbox width="640" height="360" src="https://www.youtube.com/embed/eqcWztXpVa4?rel=0" frameborder="0" allowfullscreen></iframe>

[Edited on 22-5-2015 by Rosco Bodine]

Well, regret to say...but maybe it's is not the holy grail after all, I thought it would DDT in about 100-150 mg amounts, but lighting 500 mg is a big Oempf, but no detonation. P-DDNP may actually be very similar to o-DDNP in properties, although how it reacts under confinement and different recrystallization techniques remains interesting. Anyway, photo of isopicramic acid attached, weird thing is that it looks much more yellow when strong light hits it, I'll take daylight picture tommorow. The video of the ignition of 500 mg is also shown.



Attachment: 500 mg p-DDNP_Trimmed.avi (1.7MB)
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[Edited on 22-5-2015 by nitro-genes]

I am not convinced there is not some yet to be revealed difference based on the earlier side by side comparison of the o-DDNP and the p-DDNP. However that could be a misleading comparison in the same way as the result for the potassium tetrazeno derivative of the o-DDNP, with o-DDNP which is still puzzling.

Will confinement kick the p-DDNP beyond what confinement does for o-DDNP ?? Or will the snakebit gremlin appear as occurred for the potassium tetrazeno derivative of o-DDNP??

Life is like a box of chocolates, you never know what you're going to get, says the mother of Forest Gump!

It seems the lower critical mass to DDT unconfined would have translated to higher performance confined. And we observed it is mysterious what happens, not only there in that test but for the reported higher performance of basically the same compound with only an added hydroxyl. It could be the confinement related performance differs for the o-DDNP and the p-DDNP. Or the only advantage for p-DDNP may be the greater thermal stability. I am still puzzled by the reported detonation at 190C with "extreme violence". Similarly vague descriptions exist for other materials without any sample quantity or conditions being specified which is not helpful to really understanding what is the actual performance, like weight tests for an initiator where the actual story becomes more clear.

[Edited on 22-5-2015 by Rosco Bodine]

250 mg ignition (has some cool frames)

100 mg semi confined (aluminium bowl)

2-5 mg confined in aluminium foil (didn't want to make too much noise)

A video of some clean o-DDNP would be really welcome



Attachment: 250 mg p-DDNP_Trimmed.avi (1.2MB)
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Attachment: 100 mg p-DDNP semi confined_Trimmed.avi (1.4MB)
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Attachment: About 5 mg confined aluminium foil_Trimmed.avi (1.8MB)
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Oh, almost forgot, and an side by side comparison of o-DDNP (left) and p-DDNP (right). Both were made using exactly the same diazotising conditions.

Attachment: 250 mg o-DDNP (left) and 250 mg p-DDNP (right)_Trimmed.avi (2.9MB)
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[Edited on 22-5-2015 by nitro-genes]

I was hoping for p-DDNP to be an unequivocal primary explosive like lead azide, but at the same time I wasn't overly optimistic either.

Here is a video I took of about 10mg of o-DDNP deflagrating. Sorry for the video being out of focus. This particular batch did leave some pretty heavy carbon residue, maybe I remembered wrong and the earlier batches did as well. Yield of DDNP based on sodium picramate monohydrate(?) was only about 86%, which I believe is because I wasn't careful enough to keep the temperature low enough during the diazotization reaction. I used the method from "DDNP a Detonating Explosive" outlined here:
http://www.sciencemadness.org/talk/viewthread.php?tid=439&am...





Attachment: DDNP Deflagration.avi (3.8MB)
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[Edited on 23-5-2015 by Hennig Brand]

Thanks for uploading the video! Really nice to see other peoples results. The first comparison video I uploaded was a really bad experimental batch. It seems p-DDNP does not significantly accelerate faster as loose powder, maybe confined there may be a difference. Little dissapointed, standing there with ear and eye protection, expecting a bang. Was a lot of fun though and both the dinitroacetaminophenol (sort of grapefruit colour, very strong dye) and isopicramic acid and it's salts are amazingly colourfull dyes.

Saw the mention of p-DDNP exploding with extreme violence at 190 deg C, but conditions and quantities were not mentioned. Almost all primaries accerate faster when strongly heated, their already not to strong bonds trembling from excitement, only the slightest push suffices. In the article, maybe they slowly heated the stuff, had it confined or used a really large quantity, back in the old days these things were used as intermediates for dyes and I seem to remember reading that it's explosive nature was discovered much later after it was first synthesized. Could be they made 100 grams of the stuff and just had no idea...

[Edited on 23-5-2015 by nitro-genes]

Some stability testing of mixtures of DDNP and lead azide would be interesting. I really question how incompatible o-DDNP and lead azide really are. One thing was obvious from earlier testing, even relatively tiny amounts of lead azide used to initiate DDNP could make DDNP perform at least as well or better as a similar weight of lead azide. In fact when used to initiate picric acid I would say DDNP is more efficient than lead azide, when initiated by lead azide.

Yes there would seem to be a composite similar to ASA which uses p-DDNP as the bulk component instead of lead styphnate as functions in ASA. With the stability improvement of p-DDNP, if the initiating power of the p-DDNP is comparable to the o-DDNP, then tandem charges or synergistic mixtures could similarly be very useful and should have no long term storage deficiency.

Using pharmaceutical grade acetaminophen neat and unmixed with any adulterants would eliminate the purification step that complicates a small scale synthesis so that on a commercial manufacturing scale p-DDNP would be very economical and simple to manufacture.

The international market price for paracetamol is very low since so much of it is made by so many manufacturers for a large market. So obviously the p-DDNP would be cheap to manufacture, maybe cheaper to manufacture than the o-DDNP that is more predominately used now. And if it proves to be as good as or better than the o-DDNP then what is up with that?

Is the p-DDNP something that has been overlooked?

I should patent p-DDNP for use as an explosive if nobody else will Somebody should make a buck or two on this, it only seems fair I could say I didn't really invent p-DDNP, but maybe I stayed at a Holiday Inn last night, so there.

[Edited on 23-5-2015 by Rosco Bodine]

There is still another third isomer of DDNP that is less stable than o-DDNP. so it could be that o-DDNP occupies a middle ground sort of peculiar niche in terms of median chemical stability related to initiating ability as a kind of tradeoff, where it has the right combination of chemical and thermal instability that gives it a little better initiating power, but the liability inherent to that initiating ability is won at the cost of necessarily having a chemical stability that is not optimal.

Maybe o-DDNP became popular and accepted because the o-DDNP was the first diazo compound to be discovered, and though it was the first isomer to be known, it may not necessarily be the best of the several isomers later known.
The o-DDNP coincidentally could be the best of the known isomers, or it may not be the best, but is simply the isomer that was popularized by being first to be known.

What is the incremental difference in initiating ability for p-DDNP as compared with o-DDNP will tell the tale about what exactly is the reason why p-DDNP was evidently not adopted for use as an initiator. The literature found so far has not been helpful explaining what may be any deficiency about the p-DDNP.

Urbanski was certainly aware of the p-DDNP but gave no commentary to help understand why the p-DDNP would not be the better initiator.

It would seem we have a handloaders riddle to solve more than any conundrum.

It is a good mystery, what's up with p-DDNP ????

Who comes up with this stuff ? Hehehe ........me.

Checking the market for paracetamol the stuff is very cheap.
The tableted form USP grade can be gotten for less than 20 dollars per kilogram including shipping.

If the p-DDNP is highly soluble in nitromethane, then it might make an interesting explosive fuel and sensitizer for soaking into NH4NO3 or NH4ClO4 as a binary composition guaranteed to have high energy.

So do you think such a binary composition would surpass kinepak or rack-a-rock? You betcha! By a mile!

p-DDNP might also form an interesting plastique with nitroglycerin, or a third component in a triple base with nitrocellulose. An extremely fast burning gunpowder useful for small caliber rimfire and pistol use could result where the powder charge approaches near to detonation.

I can be optimistic about p-DDNP being useful as an explosive fuel and sensitizer useful in high density, high velocity emulsion explosives which could be cap sensitive and permissible in mining applications. Given the cheap precursor substrate and simple manufacture, even if the performance of p-DDNP as an initiator by itself turns out to be deficient, there are certainly other applications where p-DDNP could function as a sensitive explosive fuel in mixture with oxidizing explosives.

https://www.youtube.com/watch?v=qGaOlfmX8rQ

<iframe sandbox width="640" height="480" src="https://www.youtube.com/embed/qGaOlfmX8rQ?rel=0" frameborder="0" allowfullscreen></iframe>

Attachment: Diazo initiators from Urbanski 3.pdf (232kB)
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[Edited on 23-5-2015 by Rosco Bodine]

Quote: Originally posted by PHILOU Zrealone

It is logical that DDNP produces carbon traces owing to its bad OB...just like many other nitroaromatics.

Quote: Originally posted by PHILOU Zrealone

If p-DDNP is more thermally stable than o-DDNP, there is a chance it perfoms less good as an initiating explosive by heating... For most explosives, there is an evident correlation between heat sensitivity and impact sensitivity. It seems logical that between two primaries the more thermal sensitive one will D2D in lower quantities since the activation energy is less thus each decomposed molecule will generate energy that will trigger more molecules arround it; the propagation of the energy wave and acceleration of it will be higher.

I get pretty enthusiastic about such things too, but I don't know if I would go quite that far.

The lady comes into the armory asking what is that sweet smell like bananas, and I say it is the Hoppes #9 bore solvent, but she should keep thinking about bananas, cause it's nature's perfect food, and she might be gettin' hungry.

Ok, here the complete overview of how to produce iso-picramic acid (rough version):



Synthesis of 4-amino-2,6-dinitrophenol (iso-picramic acid) from acetaminophen


Notes: Look for the cheapest brand of Tylenol/Paracetamol tablets, containing the highest amount of acetaminophen (usually 500-1000 mg). Weigh 10 tablets or so to determine the percentage of fillers present and compare different brands for the lowest percentage. Additionally, this extraction procedure may not work equally well with every brand of tablets and would depend on the composition of the binders/fillers. If the nitration produces some sticky residues there are likely remaining impurities present from the tablets. Alternatively, pure acetaminophen is also available commercially, which would eliminate the extraction procedure.

Extraction of acetaminophen from Tylenol or Paracetamol tablets

Collect a number of tablets, translating to a combined weight of 25 grams of pure acetaminophen, (so weight of fillers not included) and grind as fine as possible using a coffee grinder. Transfer the powder to a 250 ml beaker and add 125 ml of denatured spirits. Heat the mix under reflux to the boiling point on a hotplate or boiling water bath and let it stir for about 5 minutes with gentle boil to extract the acetaminophen. Filter the solution hot into a 250-500 ml beaker, which will remove most of the fillers.

Next, put the beaker on a hotplate and put it on the highest temperature setting and let the solution boil while stirring. The ethanol fumes are very flammable and potentially explosive so do this outside! When the solution has evaporated to about half of its original volume, add 50 ml of water while keeping at boil. When nearly all of the ethanol is evaporated (takes about 15 minutes) the acetaminophen will precipitate over the course of 10-15 minutes as a course sand like precipitate. Take the solution from the hotplate and leave it to cool to room temperature. Add another 50 ml of cold water and filter the suspension. Wash 3-4 times with cold water and filter to collect the acetaminophen. The filtrate will have a slight yellow tint and appears milky, this is normal. Let the acetaminophen dry at room temperature for 24 hours, to obtain pure crystalline acetaminophen as a free flowing powder. (21-22 grams)

Nitration to dinitro acetaminophenol

Prepare a large cooling bath containing crushed ice and water, containing at least 500 grams of crushed ice. Put a 100 ml beaker on a scale and poor in 73.5 grams (40 ml) of 96-98% sulfuric acid. Transfer to the ice bath and let it cool to 0-10 deg. C. Then add 24 grams of dry ammonium nitrate in small portions, keeping the temperature below 20 deg C. Swirl or stir for about 5 minutes to dissolve all the ammonium nitrate and keep on ice.

To a separate 500 ml beaker, add 128.5 grams (70 ml) of sulfuric acid and also transfer to the ice bath, let it cool to 0 deg. C. Add a stirrer bar and thermometer, and put the ice bath on a stirrer plate, set at 125-250 rpm. Weigh out 20 grams of the acetaminophen and add small portions to the sulfuric acid, while keeping temperature below 10 deg C. Let it stir for an additional 10 minutes after the last addition. (Not all of the acetaminophen will dissolve, but during the course of the nitration, the remaining lumps will dissolve eventually.)

After the acetaminophen/SA solution has reached 5 deg C, slowly start adding the ammonium nitrate/SA solution. It is best to keep the temperature between 5 and 10 deg C during the additions. The nitration responds very rapidly upon the additions, about 2-3 ml with each addition is about the maximum that can be added for the first additions, resulting in a jump from 5 to 10 deg C. Above 15 deg C, foaming starts to become evident, probably due to decomposition of the acetaminophen.

Depending on the efficiency of the cooling bath, the total addition will take about 30 minutes. Halfway the nitration, the solution will attain a dark brown color with each addition, which will fade to a more orange color again after some time. After the final addition is made, let the solution stir for another 1-2 hours while keeping on ice. Finally, ad 250 grams of finely crushed ice to the nitration mix. Some foaming will occur, let the solution stir for another 20 minutes while in the ice bath until the foam has mostly dissipated. The dinitro acetaminophenol will settle as an orange precipitate to the bottom of the beaker, is filtered and washed with ice cold water from the ice bath. Wear gloves while handling it, as it is a very strong dye! Under acidic conditions it gives a bright orange/grapefruit like color, while a deep red/violet is obtained when adding a base.

Note: Yield can be increased by neutralizing the filtrate with concentrated ammonia solution and leaving overnight in the fridge precipitating the residual dinitro acetminophenol as the ammonium salt.

Deacetylation to iso-picramic acid

After filtering, the dinitro acetaminophenol can be directly transferred to a 500 ml beaker. Set stirring to a low setting of about 100 rpm and add 50 ml water + 50 ml of concentrated sulfuric acid. (25 ml's of water and sulfuric acid might suffice) Set the hotplate to 150 deg C and heat to 120-125 deg C. for about 45 minutes. The solution will gradually go from orange to a deep red over time and the initial suspension will form a solution of the soluble iso-picramic acid sulfate. Continue heating until no more smell of acetic acid can be noticed. Take the beaker from the hot plate and allow to cool down. Add 100 ml water, filter, and transfer the filtrate into a 1000 ml beaker, and put it on the stirrer again. Set stirring to 500 rpm, and add small portions of household ammonia over the course of 15-30 minutes, until the solution is just slightly acidic. When too much ammonia is added the solution will turn a very deep red color and a little acid can be added to return a slightly acid pH. The iso-picramic acid will separate as 18-21 grams of a brick red glistening crystalline precipitate that filters very easily from gravity alone.

[Edited on 24-5-2015 by nitro-genes]

It is a little more complicated due to the very low temperatures needed during the nitration and the need to get really pure acetaminophen. From there however, the whole procedure can actually be done in a few hours, waiting steps not included.

[Edited on 24-5-2015 by nitro-genes]

It may be available in its pure form from drugstores, but where is the fun in getting something from the supermarket and turn it into a word class primary?

[Edited on 23-5-2015 by nitro-genes]

True, it really is an efficient and easy to scale up procedure, although the volume of the ice bath would also need to be really large. I've done the synthesis as outlined above multiple times to be sure it works, but the results are pretty much the same every time.

I'll try the diazotization protocol as outlined in Urbanski that you posted, which is very similar to the Chinese paper posted earlie, to increase density of the product. Also looking forward to making the tetrazeno derivatives again, though my hopes are not to high.

the ability of the diazogroup to couple with amines is interesting, any ideas for more energetic amino derivatives?

[Edited on 23-5-2015 by nitro-genes]

For you biochemist over here, one of these makes a really good adjustable dropper. Make the smallest hole possible in the conical bottom using a hot needle, adjust by screwing the endcap on less or more tight. Dripping rates can be determined and marked on the tube.





[Edited on 24-5-2015 by nitro-genes]

The idea of using the soluble sulfate salt occured also to me, I'm experimenting with this at the moment. Also tried the diazotization procedure as listed in Urbanski, but the higher temperatures utilized are not suitable for the production of p-DDNP. Up until now I had used the procedure from COPAE at 0 deg C, however, diazotization at higher temperatures produces a dark brown soluble filtrate and bad quality p-DDNP. Likely, iso-picramic acid is much more susceptible to oxidation by HNO2 than o-picramic acid.

Another thing convenient for larger batches, where the exotherm takes longer to calm down during nitration of the acetaminophen, is to freeze the nitration vessel containing the SA into a solid block of ice at -20. Almost as efficient as a salted ice bath.

Also, a first experiment was performed using diazotization using SA to produce the soluble picramic sulfate first. Never seen any references concerning SA mediated synthesis and crystallization of DDNP. Have this kind of studies ever been performed by your knowledge?

Anyway, 3 grams of iso-picramic acid were added to 40 ml of water, this was heated to 90 deg. C and conc. SA was added drop wise until all the picramic acid had gone into solution. Hard to estimate, though I think it needed about 3 ml in total to do so. Then at 0 deg C., a solution of 1.1 grams of sodium nitrite in 20 ml water was added drop wise over 30 minutes.

The p-DDNP produce this way is reasonably free flowing, higher density and is an more deep orange/brown in colour than the COPEA method. It flashes equally well compoared to earlier btaches, similar carbon deposits and no signs of degradation. It does cake somewhat and a look under the binoc suggests agglomerates of more tiny crystals, but to small to really see (only 4x mag). I think the Urbanski method at 0 deg C. may produce better results.

Quote: Originally posted by nitro-genes

Also, a first experiment was performed using diazotization using SA to produce the soluble picramic sulfate first. Never seen any references concerning SA mediated synthesis and crystallization of DDNP. Have this kind of studies ever been performed by your knowledge?

No, to my knowledge anyway, (if that is any measure) we are doing something possibly "new and improved" so far as anything publicly shared about the synthetic details for p-DDNP as being done here. The broadly general and basic concept for p-DDNP has been published a hundred years ago, and further experiments suggested by reading between the lines in some of the published journal articles and patents. But I don't believe this particular methodology as a step by step process has been ever before described explicitly or published in extensive detail for o-DDNP and certainly not described for p-DDNP.

I think we are probably breaking new ground here so far as publishing anything that would turn up any Google search hits regarding p-DDNP, so it may be entirely novel what experiments you are doing. Actually it is difficult to find any references at all regarding p-DDNP much less to find detailed information. It is likely information that doesn't exist in any published form to be found. So this is an area of obscure research that has possibly been overlooked by the mainstream science of academia, now receiving long overdue attention by "fringe" science or "mad science". Geniuses are us.

Did formal research long ago recognize and study the potential value of p-DDNP as an easily and cheaply made green energetic material, but then just failed to publish the findings?

I think we missed it.

Well once again, it seems sometimes if you want something done right ......you just got to do it yourself.

Not meaning to count unhatched chickens, but p-DDNP could be like a lucky lottery ticket.


[Edited on 25-5-2015 by Rosco Bodine]

Nature certainly is full of wonders

Order of ignition, all made from recrystallized p-DDNP:

1. Acetone-evap recrystallized p-DDNP (orange/brown platelets)
2. Hydrazinium tetrazeno salt of p-DDNP
3. Potassium tetrazeno salt of p-DDNP

I just couldn't believe it, who would have thought!



Attachment: Recrystallized p-DDNP, hydraziunium tetrazeno, potassium tetrazeno.avi (4.9MB)
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Thanks to solo for the attached reference.

Our friends in Munich have been looking at p-DDNP but have used a more difficult synthetic route than isopicramic acid which is the more direct route we have been discussing here.

The synthetic method involving direct nitration of paracetamol to form acetylisopicramic acid followed by deacetylation and diazotization is IMO a simpler and better route to p-DDNP.

Even so, there has been done some testing which shows decreased friction sensitivity and confirms increased temperature stability for p-DDNP compared with o-DDNP while impact sensitivity is about equal.

Density difference for p-DDNP and theoretical power calculations predict a 5% greater detonation pressure and velocity for p-DDNP compared with o-DDNP, so the theoretical analysis predicts better performance as an initiator, but actual testing is yet to be done.

It looks like we are very probably onto something new (novel invention) with these experiments involving p-DDNP

p-DDNP has definite potential usefulness as a green energetic.

Edit: I have reduced the file size for the attached article

Attachment: Synthesis & Energetic Properties of 4-Diazo-2,6-dinitrophenol and 6-Diazo-3-hydroxy-2,4-dinitrophenol.pdf (286kB)
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In the article compound [4] is p-DDNP

In the article compound [5] is acetylated paracetamol corresponding with the diacetylaminophenol of Reverdin and Meldola

excerpt from the article:

Jesus, this paper is from June this year, coincidence?!

Thanks for looking up that reference Rosco and Solo! Holy shit, I knew it, compound 6 exists and is reasonably stable, though obtained only in moderate yields. The possibilities in combination with the Japan paper......headache...need more acetaminophen. Could be compounds 7 and 8 are actually impurities in the p-DDNP from paracetamol. Does make me wonder what would happen if 3 mole eqv of AN are used for the nitration.

And true, route from acetaminophen would be better to scale up, extra benefit seems that there are no high explosive intermediates in the synthesis of isopicramic, like for picramic from picric acid for o-DDNP. There is one thing I still want to look into. It occured strange to me that the p-DDNP tetrazeno derivatives are so much less energetic than it's o-DDNP cousins. There also seems more N2 gas produced when reacted with hydrazine. Since DDNP is destroyed very fast by OH-, and p-DDNP tetrazeno derivatives resemble the parent isopicramate salts, either the ortho position is nesseccary for the tetrazeno formation...or...p-DDNP is MUCH more sensitive to destruction by a base, which would mean potential problems with moisture at long term storage. Haven't seen any references in which that was tested.

[Edited on 12-6-2015 by nitro-genes]

Yeah, you're right, forgot... They probably obtained the trinitro derivative though NO from desructive oxidation of part of the product, similar to diazotization of picramic using HNO3,explaining reported moderate yields. Possibly, yield can be improved by performing nitrite nitration under neutral conditions via viscinal acetmino group (japan paper) and then nitration. Curious what the product of compound 7 would be after refluxing with hydrazine and then using 3 mole eqv of nitrite... Long shot maybe, but could this possibly produce the first benzene structure bearing both a nitro, triazole (N-oxide?) and diazo group in one?!

[Edited on 13-6-2015 by nitro-genes]

The diacetyl derivative is the starting point for the trinitro derivative. But there are stability issues. You would have to further acetylate the phenol on the ring of paracetamol which is a monoacetyl (N-acetyl) and the nitration method differs.
You can't add the diacetyl to sulfuric acid which splits off the acetyl from the OH and reverts the substrate being nitrated right back to paracetamol.

See the articles attached here

http://www.sciencemadness.org/talk/viewthread.php?tid=28533&...

I haven't compared the syntheses carefully yet but there could be a 2,3,5 trinitro compound there for [7] instead of the 2,3,6 as it is being identified.

See the early publication page for this work in progress
http://onlinelibrary.wiley.com/doi/10.1002/ejoc.201500465/ab...

Edit: I just noticed that in the abstract for the article, compound [7] is identified as the 2,3,5 trinitro but in the article itself is identified as the 2,3,6 trinitro .....so it evidently is a misprint, or typo, or else it is still being sorted out ......in which case they have my sympathy May I recommend the ancient literature, for clarification

I really hate the convoluted IUPAC nomenclature convention usage and having to translate it back to what seems the more simple and eloquent nomenclature of the past. This is confusing enough to follow without the fashionable new names for phenol derivatives which dare to not assign ring position 1 for the hydroxyl of phenol derivatives if they can be called a hydroxylated alternative compound as semantics.

p-acetaminophenol or N-acetyl-4-amino-phenol became the IUPAC convention named N-(4-hydroxyphenyl)acetamide.
In my humble opinion such new naming is pure garbage semantics that is change for the sake of change, not clarity.

I don't like the inverted ring diagrams either that place ring position 1 of phenol at 6 o'clock instead of 12 o'clock. I understand it is conventional for the reaction scheme shown for the halogenated benzoic acid starting material and for the aniline derivative intermediate, but why use a long way around more difficult synthetic route for the p-DDNP is something not understood. It seems to be an overly complicated synthetic path that is just not necessary nor good economy. As our friend PHILOU Zrealone would likely say, to kill a fly you can use a fly swatter or a small amount of pyrethrin or a nuclear weapon, and all will kill the fly equally dead, but the lesser complex approach may serve better the intended purpose.

Last but not least, the computer predictions on energy for the experimental compounds are interesting theoretical analyses. However, I think there may occur test result evidences which may show those models may need revision. How good are the models remains to be seen. Certainly this provides a good opportunity to test the models and see their worth.

[Edited on 6/13/2015 by Rosco Bodine]

The Dabney paper was a nice read, thanks. "subjecting the solution to a winters cold"...doesn't that sound much better than "the solution was shoved in a freezer". Have to remember this sentence for future papers. Also thought about a route from salicylic acid, TCCA may be used to chlorinate the salicylic acid in 5 position (relative to acid group, p relative to OH). Most likely, only one chloro group would be added and since the chlorination presumably goes via an intermediate TCCA-phenyl complex, it would only produce the para derivative, as opposed to chlorination using nascent chlorine. TCCA gives no chlorinated products with benzoic acid, but salicylic acid was not tested in the paper that was posted on SMDB. Also not sure how 5-chloro salicylic acid would behave under strong nitrating conditions.

Also interesting from the Dabney paper: It seems that iso picramic can be recrystallized from water very well, this is something I will try somewhere in the future. They also mention surface oxidation of the isopicramic acid, wondered about this as well and kept it in an airtight container. Wouldn't this be a major drawback for the synthesis of p-DDNP on a larger scale?

Quote: Originally posted by nitro-genes

Jesus, this paper is from June this year, coincidence?! Thanks for looking up that reference Rosco and Solo! Holy shit, I knew it, compound 6 exists and is reasonably stable, though obtained only in moderate yields. The possibilities in combination with the Japan paper......headache...need more acetaminophen.

Actually we have been poking around about p-DDNP for a year now since June of last year, so the discussion was bound to get noticed sooner or later

That bottle of paracetamol quietly hides chemical history and mystery like a genie in a bottle awaiting a rub from Japanese or German chemist alike, to send them back to school and test their mettle and ask the question "What do you really know about organic chemistry?"

Rumor has it the only sure headache cure is more accordion music and more beer It is like musical chairs around the benzene ring .......the music stops and there you are!

It will require reviewing the literature but on preliminary reading it seems possible there could be structural identification issues in the early online version of the article. For [7} that is obvious as an issue, with contradiction in the abstract and maybe a typo, but [6] also definitely needs review, and I will look at [8] some more too. On first glance they seem worth a closer look to double check those structures. Frankly I am dubious about the instrumental analysis and would prefer old school proof of structure.

Klapotke may have to hire a psychic to channel the ghosts of Reverdin and Meldola I didn't notice their names credited in the references and that is possibly an omission, unless they are included and superseded by some of the later references. There was some passing commentary in articles by Meldola not providing complete details for understanding variations on nitrations, which would possibly be covered in more detail in the book written by Meldola about his experiments.

[Edited on 6/13/2015 by Rosco Bodine]

After referencing the literature and reviewing the reactions described in the Klapotke article I found that the Abstract description as the 2,3,5 trinitro for compound [7] is indeed a typo, and the article description identifying compound [7] as the 2,3,6 trinitro is correct. Melting point with decomposition at 119C also identifies the 2,3,6 trinitro as distinct from the 2,3,5 mp 145C.

Likewise the article descriptions for compound [6] appears correct.

Compound [8} is also correct and is interesting. It appears likely there is an unstable and soluble diazonium salt intermediate which decomposes on dilution to form the diazo phenol. Compound [8] may also form salts which could be interesting.

If I get a headache from looking too much at all these structures, I'll probably have to dig into my economy size bottle of acetaminophen.

There has occurred an overlap once again with the other thread, with regards to further usefulness of paracetamol as a precursor. See the following post for references, of interest.

http://www.sciencemadness.org/talk/viewthread.php?tid=62204&...

For convenience I will attach the most pertinent reference here
The alternative approach to nitration of paracetamol to form 3-nitro-4-acetamidophenol provides a high yield of the precursor for nitration to produce the 2,3,5 trinitro derivatives, including a diazo-oxide which retains all 3 nitro groups, or may be easily converted by boiling in alcohol to a dinitrohydroxyquinone diazide which forms salts, and is isomeric with compound [8] of the Klapotke article.

Also made accessible by the 2,3-dinitro-4-acetamidophenol, after deacetylation is a second variant isomeric p-DDNP that is the 4-diazo-2,3-dinitrophenol which is distinct from the 4-diazo-2,6-dinitrophenol derived from the isopicramic acid of Dabney.

There exists both an Alpha p-DDNP as we have been discussing, but also there is a Beta p-DDNP possible.

So several energetic materials, at least 4 different diazo compounds are obtainable from paracetamol without requiring its higher acetylation to paracetamol acetate.

The p-DDNP from isopicramic acid is 1 of the 4 identified.

It is likely the safest and most stable of the 4.

Attachment: A NEW NITRATION PRODUCT, 3-NITRO-4-ACETAMIDOPHENOL, OBTAINED FROM ACETAMINOPHEN WITH NITROUS ACID.pdf (178kB)
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Attachment: article Meldola and Hay JCS Vol95 pg1378.pdf (1MB)
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Attachment: Pages from Journal_of_the_Chemical_Society pg1935.pdf (423kB)
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[Edited on 6/15/2015 by Rosco Bodine]

The 1989 Chemical and Pharmaceutical Bulletin article attached above for producing 3-nitro-4-acetamidophenol in 81% yield from paracetamol is most interesting because it makes possible the use of the more convenient N-monoacetyl compound that is paracetamol by way of conversion to 3-nitro-4-acetamidophenol, to avoid the requirement of the diacetyl compound, ( paracetamol acetate ) as a precursor which may be nitrated to the trinitro compounds.

It is already established that direct nitration of paracetamol by several different nitration schemes will lead only to the 2,6-dinitro compound which is acetyl-isopicramic acid.

However, if a different approach to an alternative nitrite nitration scheme is applied to paracetamol to produce 3-nitro-4-acetamidophenol, this makes possible further nitration to the trinitro derivatives and also makes accessible the 2,3-dinitro derivatives. It is clear that the 2,3,5 trinitro derivatives are accessible via the further nitration of 3-nitro-4-acetamidophenol.

Also interesting, is it seems likely that the 2,3,6 trinitro derivatives may be produced, based upon this interesting footnote in the Meldola and Reverdin article on journal page 1492. If I understand clearly this information, use of a sulfuric and nitric acid mixture for further nitration of 3-nitro-4-acetamidophenol leads to the 2,3,6-trinitro-4-acetylaminopehnol which is the compound [6] of the Klapotke article, by a different synthetic route requiring no acetic anhydride for producing a diacetyl precursor for nitration.

Note: The IUPAC nomenclature for compound [6] is N-(4-Hydroxy-3,5,6-trinitrophenyl)acetamide
This is synonymous with older nomenclature that is 4-acetamido-2,3,6-trinitrophenol or
2,3,6-trinitro-4-acetylaminophenol or
2,3,6-trinitro-p-acetylaminophenol

By using different nitration schemes, applied to 3-nitro-4-acetamidophenol produced easily in high yield from ordinary paracetamol, it appears sulfuric acid mixed with nitric acid will lead to the 2,3,6-trinitro derivatives, while in the alternative the 2,3,5-trinitro compounds will be produced by nitrations of
3-nitro-4-acetamidophenol using nitric acid or nitric acid mixed with acetic acid, in which sulfuric acid is not contained.

If my understanding of the footnote is correct, the presence or absence of sulfuric acid in the nitration mixture applied to 3-nitro-4-acetamidophenol will determine which isomer trinitro compound is produced. With sulfuric acid present in the nitration mixture the 2,3,6-trinitro-4-acetylaminophenol is the result. Absent sulfuric acid in the nitration mixture for 3-nitro-4-acetamidophenol, then 2,3,5-trinitro-4-acetylaminophenol is the result.

This would need to be confirmed by experiment, testing the melting points for the deacetylated products, the 2,3,6-trinitro-4-aminophenol mp 117-120C and for the 2,3,5-trinitro mp reported 145C with decomposition.

Thus far nothing found in the literature sheds further light on this possible selectivity for the trinitro isomer produced.

Aside from the diazo derivatives that are possible, of particular interest is the reported reactivity with hydrazine for the trinitro compounds, and what may be the results of subsequent derivatives possible for such hydrazides. An assortment of potential green energetics could be possible.

I, or we, welcome any commentary or feedback on any of this subject material from our readers in Munich. A penny for your thoughts These synthetic approaches using ordinary and cheap paracetamol provide more direct and economical paths to not only the compounds [4], [6], [7], [8], as described in the Klapotke article, but to a portfolio of similar related compounds which have potential usefulness as green energetics.



Thanks to solo for article attached providing helpful data for 2,3,5 trinitro compound further identification by salts

Attachment: Salts and Ethers of 2-3-5-trinitro-4-acetyl-aminophenol-Meldola 1910.pdf (840kB)
This file has been downloaded 609 times

[Edited on 6/15/2015 by Rosco Bodine]

Nice overview of references Rosco. As for the possible mechanism for SA selectivity for the 2,6 trinitro; could a contributing factor be the steric hinderance of the sulfate group due to formation of the isopicramic sulfate? Water content, oxidation f product and reduction of NA to HNO2?



[Edited on 16-6-2015 by nitro-genes]

Hold the phone on the distinction between the 2,3,5 and 2,3,6 compounds as have been showing in the literature. When I began this research about a year ago I expressed skepticism about some of the structural identifications and surmised some confusion and uncertainty about some of the writings and such skepticism has been borne out as justified.

Evidently some or all of the structures identified as 2,3,5 trinitro may actually be 2,3,6 trinitro.

Here is the link for the paper. It appears that Meldola and Reverdin went around in circles on this.

There was also what amounts to an errata declaration made by Meldola AND Reverdin in Proceedings (Royal Chemical Society) 1912 for which I have made a screenshot. So it looks like they were not in disagreement but were joined in error discovered later. And it does appear the other work apart from the structural confusion remains valid.



Some of my earlier analyses will need revision with regards to 2,3,5 trinitro structures which were misidentified probably by Meldola. I am still sorting this out. I think the reactions described and data are probably correct other than the early researchers confusion about structure.

I recall mentioning Federoff shared my skepticism and referred to the authors writings about what they called a trinitro 2,3,5 compound , yet Federoff called it a 2,3,6 trinitro in PATR essentially correcting the authors See PATR Vol. 2 pg B-60

http://pubs.rsc.org/en/content/articlelanding/1914/ct/ct9140...

Thanks to solo for the attached article

Attachment: Meldola and Hollely, JCS 1914, 105, 977 to 990.pdf (884kB)
This file has been downloaded 582 times

From what I can make of this discrepancy about structure, there is disagreement between Meldola and Reverdin and Meldola is "surrendering" to the views of Reverdin and
basically "leaving the matter in the capable hands of Reverdin" as an unfinished business.

I tend to believe the synthetic procedures and analyses and measurements and observations have validity, but for the theoretical aspects about structural identification of the differing isomers there was not a meeting of the minds for Meldola and Reverdin. The work at synthesis done aside from the ambiguity about structural identity still has validity and since there are only two possible isomers for the trinitro compounds of p-aminophenol it is like a coin toss and a guess if the sample compound is the 2,3,6 trinitro or the 2,3,5 trinitro. There could be mixed isomers of course. But these chemists were not novices and should know when they have isolated pure compounds, even if there was disagreement about that sample being one isomer or the other.

It could be sorted out on a case by case basis what is the result produced by a synthesis even if no definite general rules can be established for predicting exactly what isomer should be produced.

I would have to laugh if my speculation above about the presence or absence of sulfuric acid did turn out to be the variable which predicts the isomer that will result. It was a reasonable conclusion assuming the information being reported was accurate. Did I see something simple hiding before them in plain view which they somehow overlooked?
Hmmm now there's an idea.

It appears there was study of these compounds for 10 years without conclusive results about positively identifying the two isomers, if Meldola is understood. So if you make the trinitro compounds then it is probably the 2,3,6 but not certain.

Hopefully the observations not related to identifying the isomer correctly are still valid.

And hopefully some of the more modern references have provided clarification about the isomers and what determines which isomer or if a mixture is produced.

[Edited on 6/16/2015 by Rosco Bodine]

Iso-Picramic Acid Synthesis

Well I have what I hope is iso-picramic acid. It has been drying for the last day or so, so I will include a picture of the dry yield and attempt to make some iso-DDNP using it.



Extraction of Paracetamol (acetaminophen)

Forty extra strength 500mg Tylenol tablets were put into a Mason jar and an amount of methanol was added which was at least the height of the pills over and above the pills (very scientific measurement ). An oval stir bar was added and the mixture was stirred using magnetic stirring at room temperature until dissolution and erosion caused the pills to break up. The stirring was ceased and the mixture allowed to settle for several hours before pipetting off the clear paracetamol in methanol upper layer. More methanol was added to the pill residue and it was again stirred up and left to settle before removing more solution. This could have been done at least once more, but it wasn't. The combined methanol solution was next heated, below the boil with stirring, until most of the methanol was gone before adding 30-40mL of cold water (the remaining methanol could have easily been evaporated, but the water may have served a function over and above reducing solubility, it may have dissolved some of the trace amounts of water soluble impurities from the pills which made it through the extraction.





Dinitration of Acetaminophenol

Nitro-Genes posts were used as a general guide. The following numbers were used which were suggested by Rosco:

"
[A] For each 1 gram of paracetamol to be dinitrated, dissolve in 4 ml H2SO4

[B] For each gram of paracetamol to be dinitrated, use 1.4 gram of NH4NO3 mixed with 1.5 ml H2SO4

Add gradually with stirring B to A maintaining about 5C

The quench / dilution mixture should have about 15 grams ice for each gram of paracetamol.

It would possibly benefit the nitration mixture to sit for a couple of hours in the ice bath with continued stirring before quenching."

I used the following method because I was lazy, busy and very low on ice. 14.4g of paracetamol was started with and 91% sulfuric acid was used throughout. The powdered paracetamol was added to the sulfuric acid in a Mason jar in about six increments with swirling and in between additions the solution was cooled down in the fridge. The ammonium nitrate (fertilizer grade recrystallized from water) was added to sulfuric acid in another Mason jar and left to dissolve over night in the dark at room temperature. The paracetamol in sulfuric acid was kept in the fridge while the nitration mixture was not, though they both probably could have been. A large oval stirrbar was added to the vessel holding the solution of paracetomol in sulfuric acid. When making an addition about 3-5mL of the nitration mixture was added with swirling before placing the mixture back into the fridge to cool. Starting the nitration in the morning I made additions randomly, about once an hour. By early afternoon the additions were complete. It wasn't until the next morning that the nitration mixture was removed from the fridge and quenched with crushed ice and filtered and rinsed with water.





De-acetylation to Iso-Picramic Acid

About 15mL of 91% sulfuric acid and 15mL of water were mixed and added to the still damp dinitro acetaminophenol in a beaker with stirrbar. The temperature was raised gradually and at about 70C the smell of acetic acid was very noticeable and by 80C the fumes were very strong, almost choking. After about 45 minutes and with the temperature at 100-105C no more smell of acetic acid could be detected. The color change from light to dark occurred mostly in the first 10 minutes or so of heating. About 80mL of water was then added. Filtration was attempted but was then aborted, as a test, but also because not everything was in solution (does it matter?). The amount of acid and water used was likely not ideal.





The solution was next allowed to cool and then household ammonia was pipetted in with stirring unit the color change to red became apparent and then a couple drops of 31.45% HCl was added to bring the pH back down slightly (I was going to use sulfuric acid, but the HCl was much closer to me at the time and it was just a couple of drops). The reddish brown iso-picramic acid was easily gravity filtered. The yield is now nearly dry. I will post a picture of the dry yield soon and will attempt diazotisation to iso-DDNP. There were many transfer losses, etc, so the yield may not be great.




[Edited on 16-6-2015 by Hennig Brand]

Quote: Originally posted by Hennig Brand

De-acetylation to Iso-Picramic Acid About 15mL of 91% sulfuric acid and 15mL of water were mixed and added to the still damp dinitro acetaminophenol in a beaker with stirrbar. The temperature was raised gradually and at about 70C the smell of acetic acid was very noticeable and by 80C the fumes were very strong, almost choking. After about 45 minutes and with the temperature at 100-105C no more smell of acetic acid could be detected. The color change from light to dark occurred mostly in the first 10 minutes or so of heating. About 80mL of water was then added. Filtration was attempted but was then aborted, as a test, but also because not everything was in solution (does it matter?). The amount of acid and water used was likely not ideal.

Nice to see others experimenting with p-DDNP as well, it's looking like you have isopicramic and indeed the procedure is not that complicated as it looks at first glance. Methanol seems to work well, surprised to see no supersaturation like for ethanol, where adding water doen't precipitate the acetaminophen at all. In methanol, acetaminophen is even more soluble than ethanol and most impurities probably less, so thats a good thing. How many pills were used for the extraction? Thought about using it, although methanol is harder to obtain. Did you see any clouding of the solution while evaporating to a lower volume? Was the filtrate milky? No sticky residues at the bottom of the beaker after nitration? Curious why you chose to increase the mol eqv of AN to about 2.4 instead of 2.1-2.2 as generally used. Interesting experiment, but I'm not sure if this is benefical, especially with the O/N incubation time used.

Also interesting what the increased amount of ice does to the precipiation of the DNAc after nitration. Never did any experimentation with that and used the ratio from the patent Rosco posted. On the one hand, extra dilution may dissociate any possible soluble salts formed, while on the other hand solubility of the free acid may increase. I usually add the ice directly from the -20, by which the diluted nitration mix actually goes to -5 Deg C, which precipitates more than using ice water. Still, I noticed that upon ammonia neutralization of the filtrate, there is a substantial amount of the red ammonia salt precipitating when subjected to a O/N winters cold.

Btw, you were right not do the filtration after the deacetylation, like you said, the water acid ratio was too high, causing dissociation of some of the isopicramic sulfate to the free acid. Further depends on the temperature, but adding about an equal volume of dH2O to the 50% H2SO4 after deacetylation is about the maximum that can be added without causing precipiation of the free acid.

Would be nice to see a video of the p-DDNP after diazotization!

[Edited on 17-6-2015 by nitro-genes]

There shouldn't be any issue with disassociation of the isopicramic acid sulfate upon dilution, IIRC the description from one of the early articles, it stays intact on dilution, unless it is deliberately titrated with a base to disrupt the soluble salt.
It was that information on which I was basing the 2-3% solution strength dilutions suggested for direct diazotization of the isopicramic acid sulfate believing it would remain in solution diluted once it had formed in a more concentrated acid solution. I even had a passing thought that instead of diluting the isopicramic acid sulfate with distilled water, to use 4% acetic acid, white vinegar and diazotize that to see if better crystals would result.


The nitration ratios I suggested in a U2U after crunching the numbers from the patents and your own described process, making a guess what might improve the yield with some slight changes to see which direction up or down it took things based on yield.

If the nitration was pretty benign and well behaved then you could easily scale up 300% in the same reaction vessels. Was there any foaming or other issues whatever? Also if the nitration yield still comes in at about 70% then another nitrate or use of HNO3 should raise the yield into the 90% range. Every substrate to be nitrated seems to have a preference for a special nitration mixture that works best. So the NH4NO3 and sulfuric could be one of the combinations that is not necessarily best, even though it does work to the extent it does, it may be yield limiting by nature.

That virgin witness plate is pining away for attention. Need to break her in right

[Edited on 6/17/2015 by Rosco Bodine]

This thread has evolved into what is absolutely state of the art cutting edge Vanguard kind of beaker clinking stink up the backyard blue ribbon world class mad science IMO this thread ought to be stickified.

Thanks. Forty 500mg pills were used, from which I only obtained about 16g of paracetamol. I only used 14.4g for the nitration, leaving about 1.6g of more powdery material behind. The extraction efficiency could be improved. Even one or two more extractions may have helped. Also, I didn't grind the pills, how much that matters I don't know.

When the paracetamol solution in methanol, from the extraction, was heated driving off the methanol it stayed nearly completely clear basically until the water was added then a fine white powder was produced and the solution went a bit milky. The amount of methanol left was only ca. 5-10mL prior to adding the water. Prior to adding water the crystals of paracetamol were almost clear like glass, large and well formed. I wasn't sure if the water should be added or not and eventually decided I would. In the above picture under the bit of white powder coating the paracetamol is in large nearly clear crystals. The paracetamol was ground up prior to adding to the sulfuric acid. No sticky residue from what I saw! Methanol (99.9%) is cheap and easy to obtain here by the gallon jug, while ethanol can be a challenge to even locate and is usually much more expensive and usually adulterated heavily.

During the nitration there was no foaming at all, the only indication that anything was happening at all was an approximate few degrees Celsius rise in temperature with each addition. Yes, the last couple of 3-5mL nitration mixture additions caused almost no temperature rise. The extra nitration mixture may not be optimized for economy but it probably didn't hurt much either, at least I don't think so.

Yippeeeeeeee!

https://www.youtube.com/watch?v=Ah_a5-oU7gM

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