Sciencemadness Discussion Board

Simple melt-cast carrier 2,4-dinitrophenoxyethyl nitrate (DNPOEN)?

UndermineBriarEverglade - 18-12-2025 at 15:33

Quote: Originally posted by KFeNAT  

As an alternative to TNT for amateur casting, 2,4-Dinitrophenoxyethyl nitrate could be tried. It is said to have a melting point of about 64 degrees Celsius and can be prepared simply by nitrifying Phenoxyethanol with mixed acid at low temperatures.


I can't find much about this compound. Wiley's Explosives 7E gives it as "dinitrophenoxyethylnitrate":
Quote:
Dinitrophenoxyethylnitrate
pale yellow crystals
empirical formula: C8H7N3O8
molecular weight: 273.2 g/mol
energy of formation: −236.8 kcal∕kg = −990.6 kJ∕kg
enthalpy of formation: −256.3 kcal∕kg = −1072.2 kJ∕kg
oxygen balance: −67.4%
nitrogen content: 15.38%
density: 1.60 g∕cm3
solidification point: 64 °C = 147 °F
lead block test: 280 cm3 ∕10 g
detonation velocity, confined: 6800 m∕s = 22 300 ft∕s
at ρ = 1.58 g∕cm3
deflagration point: over 300 °C = 570 °F
impact sensitivity: 2 kp m = 20 N m

The compound is insoluble in water, but soluble in acetone and toluene. It is prepared by dissolving phenyl glycol ether in sulfuric acid and pouring the reaction mixture into mixed acid at 10–20 °C (50–68 °F).

It is a nitrocellulose gelatinizer.


It appears to be a good candidate for melt-cast explosives: good power, sensitivity between RDX and TNT. Unfortunately they don't say where the data is from. Dettx.com lists it under "DNPOEN" but has little information.

US Patent 3037057, 1962, gives a very cold mixed-acid synthesis with 60% yield and says it's soluble in methanol:
Quote:

To a solution prepared by admixing 83 grams of concentrated sulfuric acid and 41 grams of 60 percent nitric acid, contained in a reaction flask, there were slowly added with stirring 20 grams of 2-phenoxy-1-ethanol. During the addition, the temperature of the reaction mixture was not allowed to rise above -10° C. by means of a Dry Ice and acetone bath surrounding the flask. Upon the complete addition of the alcohol, the nitrated product was poured onto ice and filtered. The crude 2-(ortho, para-dinitrophenoxy)-1-ethylnitrate thus obtained weighed 24 grams. The nitronitrate ester product was then purified by recrystallization from methanol and exhibited the following properties: melting point: 68 C.


Phenoxyethanol is available to consumers as a cosmetics preservative for $30/kg. Has DNPOEN been tried in an amateur setting? Seems too good to be true.

Microtek - 20-12-2025 at 08:17

Any info on the trinitro derivative? It seems an obvious thing to try, so maybe it doesn't have a suitable melting point.

KFeNAT - 20-12-2025 at 09:18

Quote: Originally posted by Microtek  
Any info on the trinitro derivative? It seems an obvious thing to try, so maybe it doesn't have a suitable melting point.


Yes, it is recorded on page 364 of the same book mentioned above (Wiley's Explosives 7th). Its melting point is 104.5°C, its detonation velocity is 7600 m/s at a density of 1.65 g/cm³, its expansion value of lead casting is 350 cm³ (10 g), and it is slightly less sensitive to impact than RDX (7.9 N•m). The method described in the book is that it can be obtained simply by re-nitrifying the dinitro compound.

However, I think it might be possible to use a combination of high-concentration nitric acid and sulfuric acid, or sulfuric acid and KNO3, to directly digest phenoxyethanol into trinitrophenoxyethanol nitrate. The electron-donating effect of the ether group is stronger than that of methyl and hydroxyl groups, making the benzene ring easier to nitrate. Therefore, compared to TNT and TNP, its trinitroation should have a lower requirement for reaction temperature. It is possible to obtain the trinitro product within the temperature range where the nitrate ester is not oxidized and destroyed.


Attachment: Explosives (Rudolf Meyer, J_ (Z-Library).pdf (4.2MB)
This file has been downloaded 46 times

Axt - 20-12-2025 at 09:33

US1560426A is the patented trinitro analogue https://patents.google.com/patent/US1560426A/en?oq=us1560426

It seems the nitration conditions are pretty mild, for the lower analogues low temperatures are used to prevent over nitration. Interesting find, I never knew it was so available. I checked the price it was the equivalent of $20 US a litre here.

vol. 8 P236 PATR2700 is its entry. There is discrepancy for the sensitivity for the dinitro, in there its far less sensitive >120cm vs >40cm for TNT.

KFeNAT - 20-12-2025 at 09:35

Phenoxyethanol is available to consumers as a cosmetics preservative for $30/kg. Has DNPOEN been tried in an amateur setting? Seems too good to be true.[/rquote]

I haven't actually tried synthesizing or testing this substance yet. It seems very suitable and easy to synthesize, which is very exciting. However, I'm also puzzled as to why so few people have used it; at least in the discussions I've participated in so far, no one has actually tested it. It's worth mentioning, though, that in my area, phenoxyethanol is only $6/kg. When I have time, I'll definitely try it myself and see if it really works.

UndermineBriarEverglade - 20-12-2025 at 12:40

Wiley's Explosives 7th also says the trinitro variant is "very stable", and the patent reports that it's soluble in benzene. It is slightly less suitable for amateur melt-casting since it can't be done in a hot water bath. Without solubility numbers it will likely take some experimentation to separate them, but a mix might be fine for practical purposes. If I attempt a synthesis, I will probably start with KNO3 + sulfuric acid and measure the melting point of the result.

The precursor has been commercially available since the 30s, so I don't see any good reason why these haven't been explored. Maybe "phenyl cellosolve" used to be much more expensive. My worry is that DNPOEN/TNPOEN have some hidden downside: dangerously high sensitivity while liquid, chemical incompatibility with common explosives, a tendency to weep nitric acid or form dangerous salts, toxicity, etc. I wish there was literature on their practical use.

Microtek - 21-12-2025 at 00:42

If you really want to use a water bath for the melting, you could just add salt or ethylene glycol to the water to raise the boiling point. Or you could mix in a little of the dinitro derivative to lower the melting point.

I would imagine that the abundant availability of toluene from the petrochemical sector is the reason why TNT won out. At any rate, I suppose it falls to the members of this forum to do the exploratory work.

Synthesis

UndermineBriarEverglade - 5-1-2026 at 23:45

Performed my first small-scale synthesis of DNPOEN & TNPOEN with potassium nitrate. I intended to prepare primarily TNPOEN and then tweak the parameters to produce DNPOEN, but obtained a significant fraction of the dinitro and a very low overall yield of <25%. I will vary the temperature and acid quantities, and maybe distill some nitric acid.

Both compounds are highly soluble in acetone. Only the minimum quantity must be used, or it'll take a lot of water to precipitate them again. They are like ETN in this respect. DNPOEN's solubility in acetone is on the order of 27g/100mL.

I have also learned that separation is easy. In hot ethanol, DNPOEN will melt while TNPOEN remains in solution.

----

Target: 4.995 grams TNPOEN (0.0157 mol, "1 part")

Inputs:


Yield:


Procedure:
  1. A chilled beaker of H2SO4 was placed in a water-ice bath with magnetic stirring. KNO3 was added in scoops, with temperature kept to 15-20°C.
  2. Then phenoxyethanol was added dropwise. Some white gas, presumably nitric oxide, was released along with an objectionable sweet/antiseptic smell (phenoxyethanol does not smell good by itself). Upon addition to the mix, the clear phenoxyethanol turned to a very dark beet red. The reaction mixture looked like raspberry syrup: almost black in the center, and red visible in thin sections. During and after phenoxyethanol addition, the mixture thickened enough to stop the stir bar, requiring repeated additions of sulfuric acid.
  3. After 30 minutes, addition was complete. After some time, the mixture was removed from the cooling bath and allowed to rise to ambient temperature (17°C). There was no further evolution of heat. It did, however, continue to thicken, requiring the addition of 9mL of sulfuric acid (16.52g 93.2%) in total.
  4. After a total of 85 minutes, the reaction mixture was drowned in 900mL of cold tap water to yield a cloudy orange solution.
  5. This solution was filtered to yield an orange scum, some dark red/brown crystals, and a vibrant orange filtrate. The filtrate was deeply colored but unclouded, and despite chilling and dilution nothing more could be extracted from it.
  6. Solids were dissolved in 20mL of acetone and crashed into ~2-400 mL of water, but precipitation was not complete. More water was required, which yielded small orange crystals in a milky yellow solution resembling limoncello. These were filtered and the filtrate discarded.
  7. The solids were dissolved in 20mL of denatured alcohol warmed in a hot water bath. Most of the solids dissolved, but a dark red part melted and remained at the bottom of the beaker. Then, the mixture was cooled to obtain 3 substances:
    1. Solidified dark red puddle of DNPOEN
      This was removed with tweezers and rinsed in water to remove the orange crystals stuck to it. Then, it was dissolved dropwise in the minimum necessary acetone (1.46g) and dumped into ~250mL of water. This precipitated round solids that dropped to the bottom and stuck together, created an oily sheen across the top that quickly solidified, and left clear water in between. 0.42g of solid DNPOEN was obtained by vacuum filtration.
    2. Reddish liquid, unrecoverable D/TNPOEN in alcohols
      The liquid component was poured off into water to yield a milky white solution. Filtration yielded almost nothing, just a few straggler orange crystals.
    3. Orange crystals of TNPOEN
      Finally, the orange crystals were dumped into water. They remained undissolved and the water remained clear. 0.82g of TNPOEN[?] was obtained by vacuum filtration. The crystals are short spikes with a crunchy texture, denser than nitroguanidine's fluffy hairs.


I used a Thiele tube to measure the melting point of the DNPOEN and found a range of 63-66°C in accordance with the literature. I compared against two digital thermometers and found that, at least around 65°C, my glass thermometer reads 5° low, so the earlier reaction temperatures may not be correct.

I haven't yet tested the melting point of the presumed TNPOEN, or any explosive properties of either substance.