Sciencemadness Discussion Board

Chloropicrin and its Odor

DDTea - 18-5-2003 at 04:40

This morning, I performed the reaction between Nitromethane (mine was 30%, with castor oil and methanol- keep this in mind), and 6.00% Sodium Hypochlorite Bleach.

The way I went about doing it was rather crude... I simply heated up a Mason Jar with hot water, poured in 50 mL of Nitromethane, and then added an excess of bleach. I then stirred for 20 minutes.

A reaction definitely did take place, because there was an immediate color change (from the Nitromethane mix's original blue) occurred and heat was given off.

As I performed this reaction, a strange smell was given off, which I suspect was that of Chloropicrin... but I have never smelled Chloropicrin, and nor can I find any specific details about its smell. It was a sweet odor, but not terribly pungent. However, whenever I smelled it, irritation of the eyes and throat promptly followed. The smell was not painful to breathe, like Chlorine or Ammonia, but it did really irritated the felt like Onions. It also caused coughing, and later slight wheezing.

What I need to know is, what does Chloropicrin smell like?? I mean, specifically- not just "strong and sharp and irritating," because that is not very descriptive...

Also, could any side reactions have taken place? I mean, could the Methanol have reacted with the NaOCl, or the Castor Oil with the NaOCl, to produce another compound that has a sweetish odor?

Also- I would like to describe to you what my reaction mixture looked like after the 20 minutes: It was mostly reddish/brown, and at the top of it there was a clearish/bluish looking oily liquid, but not much. Also, there was some flaky compund. I suspect that this would have been the NaOH that is formed from the reaction between Nitromethane and the Hypochlorite.

Anyone want to help their old buddy Samosa? :) Not just for me though; perfection of this method offers an EASY and CHEAP way to Chloropicrin, with 95% yields! Keep in mind, I did this reaction in Mason Jars with impure chemicals...

[Edited on 5-18-03 by Samosa]

Haggis - 18-5-2003 at 07:15

Sorry Samosa, but my book only says, 'stinging, pungent odor'. I can give your some other 'stats' on it though to help you figure out what it is.
Real name : Nitrotrichloromethane.
Physical state: Colorless oily liquid
Boiling point: 112 C
Non-flammable. Soluble in organic solvents but not in water. No hydrolysis in water. Decomposes under the influance of light (UV). "Irritates nose and throat; causing tearing; irritates lungs at higher concentrations; causes nausea and vomiting; can cause skin lesions" It's also very soluble in fats and oils, so organs can absorb it.
Well, I'd hate to get this stuff stored in my lungs.;)

Krypton - 18-5-2003 at 09:53

The vapours of chloropicrin are extremely
acidic, the best with gas-mask or a fume-box when maked.

DDTea - 18-5-2003 at 16:52

After reviewing the patent, I see three things that I did incorrectly in my synthesis.

First, there was supposed to be a slight excess of Nitromethane, not the Hypochlorite.

Secondly, I was to add the Nitromethane to the Hypochlorite, I did it the other way around.

Thirdly, I was supposed to add the NM gradually, I did it rather quickly.

a_bab - 18-5-2003 at 23:39

I tried with the picric acid/CaOCl2 method, without having any references but the fact that these are the reactants. I did the reaction in in an aquous sollution, with mild heat, and I can tell you that the smell of chloropicrine is somewhat like chlorine smell, a little bit sweet and you feel it in the throat instantly. And yes, with copious amonts of tears. I cannot decribe it better as I never felt a similar smell. On the other hand, I'm sure you've got chloropicrine with your reaction.

I suggest you to try the chloroform/nitric acid route. Chloroform is piss easy to make. The drawback is the fact that the reaction is sustained in an enclosed tube, and it takes some time to perform.

DDTea - 19-5-2003 at 05:16

Copious amounts of tears you say? Hah. That's what I am suffering through as I type- I'm redoing the reaction with my previous mistakes corrected.

As I add the Nitromethane mixture to the Hypochlorite, I get that sweet smell, and that is promptly followed by coughing (irritation in back of throat, and in chest too!) and lots of tearing.

I am now confident that I have CHloropicrin, now the problem is just separating it out :(.

Success! (Pretty sure, at least)

DDTea - 19-5-2003 at 05:43

I am pretty confident I have had success. A distinct, oily, clearish-bluish (i suspect the blue is caused by the Nitromethane's coloring), liquid formed at the bottom of my reaction mixture. This layer was obviously denser than the rest of the chemicals, and was insoluble in water. Furthermore, it caused profuse tearing and severe irritation to my throat. I could barely do anything but cough for a full 2 or 3 minutes. I was coughing so badly, I thought I might vomit from it... Yields were small, but that could be attributed to impurities and to rushing. But, clearly this is an effective, easy pathway to Chloropicirn.

vulture - 19-5-2003 at 06:20

Chloropicrin can also be made by reacting TNP with KClO3 and HCl apparently.

I don't know anything about yields though.

rikkitikkitavi - 19-5-2003 at 08:51


cloropikring is enlisted on UN list of forbidden chemical weapons (CWC directory) so beware that the Bush doesnt come down with a Thomahawk...


Nick F - 19-5-2003 at 12:22

Haha, ouch. It fucking works, doesn't it? I just put a few spatulas of TNP into 5% NaOCl bleach at room temp. There was a faint odour, hard to describe... like a cross between CH2Cl2 and really strong English mustard, with hints of chlorine... but whereas CH2Cl2 and chlorine both smell quite "clean," this smelled "dirty." Hence the inclusion of mustard in the description. BUT I really don't know if you have any idea of what I mean by a "clean" or "dirty" smell... I would like to describe the smell as "mottled brown, lumpy and rough," but then I really don't think you would have any idea of what I was talking about. That's what I think the smell would look like if you could see it. I covered the vessel with some cling-film, and went back ten minutes later. The solution hadn't changed in appearance, it was still just a bright yellow, clear solution, but tiny droplets of condensation had formed on the cling-film. Carelessly and foolishly, I peeled back the cling film, and at arms length I tapped the top of the film with my finger, to send a gust of air from inside the beaker towards my face. I didn't think a significant amount had formed, there was no sign of it in the liquid and the solution looked no different. Then suddenly it felt like someone had actually poked me in the eye with a stick that was covered in sand paper. It's VERY strong, especially considering the small amounts I was exposed to!! I bet this stuff clears blocked sinuses fast...
Strangely, I did not notice any coughing... maybe because there was little in the air in the room, I just got a quick burst of it.

(Note to self: be more careful with chemical weapons.)

a_bab - 20-5-2003 at 03:11

I read somewhere that because of the chloropicrine the victims commited suicide. That was back in the WWI.
Hey, Samosa, beware. It would be pitty to loose such a good member ;)

DDTea - 20-5-2003 at 03:52

No worries mate, I only have a little bit of the stuff (less than 10 mL), and it is securely sealed off.

However, now I will list some of my personal observations with Chloropicrin...

The odor reminds me of the smell of some Halocarbons, somewhat like Acetone, but with the strong smell of Chlorine mixed in. About 1 or 2 seconds after smelling it, the eyes feel like they would after cooking with Onions- basically, you're forced to close them. This is also accompanied by tearing. If you stay in the presence of the vapors longer, and actually inhale them, it irritates the back of the throat and causes coughing. However, I never noticed any upper; respiratory irritation, as would be caused by straight Chlorine.

After exposure, coughing continues for a few more minutes; but not too long. The chest gains a slight feeling of tightness, but not so much that it is uncomfortable. This tightness lasts for about a day.

That's all for now! Basically, I've summed up all the symptoms of acute exposure; but I hope to have made it seem more realistic, you know? Reading this off an MSDS sheet just doesn't have the same effect.

All in the name of science! :D

a potent weapon

DDTea - 28-5-2003 at 14:54

The Chloropicrin/Castor Oil that I was using in the day's experimenting had hardened onto some of my glassware (measuring cup and jam jars ;) ). So, knowing that Chloropicrin is very soluble in Ethanol, I used that to clean off my equipment.

That was well and good, but then I went to pour out the Ethanol in the washroom (closed area). What I suspect happened is that the Ethanol made the Chloropicrin much more volatile, so that as I poured it down the drain, the concentration of Chloropicrin in the air climbed very rapidly. Naturally, it did what it is designed to do to the body: coughing, eye pain, tearing, throat pain, upper respiratory irritation (surprisingly, this part did not hurt so much, just a tingly feeling in the nose), chest pain, and vomiting (did not actually vomit, but felt like I was about to). So, I rushed to another bathroom to be near a toilet in case I did vomit. There, I noticed a feeling in my chest as if I'd swallowed a huge air bubble, and my heart rate increased.

But now I am good, after breathing some fresh air :D.

Now, what is to be learned? NEVER dispose of chemicals in the bathroom! Or at least, don't do it without a gas mask on.

What else is to be learned? That this is a potent weapon, should that be what you are interested in... Chloropicrin dissolved in a volatile solvent, such as Ethanol. Ether or Methylene Chloride would be even better.

But, experimentation with the Chloropicrin is finished for today! ;)

[Edited on 10-21-03 by Samosa]

Darkfire - 29-5-2003 at 14:12

Chloropicrin isnt suposed to be all that reactive, even to the activated carbon in gask masks sure im not sure they would even help...


DDTea - 29-5-2003 at 18:40

Activated Carbon filters are very effective against Chloropicrin. In fact, Chloropicrin is one of the chemical agents most easily protected from by activated carbon.

However, you will want a full face mask, because it still will irritate the eyes- making it near impossible to work.

Darkfire - 29-5-2003 at 19:16

Hmm... I read in more than one place it is un reactive, i found this odd at first because of the chlorine but i ended up taking the word of the web...

Krypton - 29-5-2003 at 20:31

The hot vapours of chloropicrin can harm your
skin in very short time when maked careless
with a open equipment, or the caustic
vapors of the overheated reaction mixture.
I think the storys of half dead persons
are enormous exaggerated, the concentration
in the air must be high to cause seriously

PHILOU Zrealone - 2-6-2003 at 05:05

No doubt a little CCl3-NO2 has been made!
But to ensure a better yield you need to neutralise a little the bleach with a little HCl to get a little Cl2 and thus freshly made HOCl.Basic media helps dissolving Cl2 and allow Na nitronate formation what is indispensable for chlorination.
In the industry, they make NM/NaOH/H2O mix and then bubble exces Cl2 in it!

Why CH3-OH is in your reaction?
CH3-OH + bleach --> CH2=O + ClCH2-O-CH3, HCO2H, ...all are lacrymators.

Last weekend when attempting a CTeAP synthesis (tetrameric instead of trimeric) I mixed 100ml H2O2 (200V/50%) with Aceton (100 ml) with 30 ml HCl (35%)... the batch was not cooled and products were at ambiant temperature...I added the catalyst (Sn IV chloride) and the batch heated until aceton was bubbling...then my brother and I were really irritated (nose, eyes)...I believe the catalyst had free a little Cl2 in HCl with aceton to yield boiling CH2Cl-CO-CH3 (strong lacrymator).

A later trial was made by dilluting twice the amount of H2O2 with water and all ingredients were freezing cold...I got moderate heating to ambiant temperature..a trouble appeared and cristallisation started; soon I got a solid wet cake (I think the yield is near 100%).

Funny to see the same reaction produces two different effects!And now on will I can make 5 liters lacrymator gas with a very long remanence smell in less than 20 sec!The 300 ml batch that runnaway and sprayed all over the place had stayed lacrymator for a complete day in open air.

DDTea - 20-10-2003 at 22:45

Two or three days ago I got around to checking on my box of chemicals, which had been terribly neglected over the summer. Guess what I find? A jar of left-over Chloropicrin/NM/other stuff mixture left over from my tests in this thread. I've learned, though, not to try to store the stuff-- it seems to attack the lid of my mason jar, which of course was some metal... But the strange part was, on the outside of the lid, some weird crusty substance was forming which mildly irritated/burned the skin.

On the note of the Nitromethane route to Chloropicrin, I don't think it is the best "Jam Jar" route. The best source for Nitromethane OTC is from hobby shops, and is sold as race car, helicopter, and boat fuel. The problem is, you can expect ALL of them to contain Methanol, Castor Oil, and other Synthetic Oils in addition to the desired NM. These impurities cause real pains during the synthesis of Chloropicrin. As such, I am eyeing the Picric Acid route- the way Nick F went. It's a bit more involved, but judging from Nick's response, you get a high quality product (and for significantly less cost than the NM route- though, comparatively, the NM route is much easier).

Philou- have you tried your uncooled synth of CTeAP again? Reading over it again, it is suddenly very interesting to me... Going off topic a little bit, do you suppose one could synthesize Chloroacetone by combining AP with HCl? That is, would the AP (strong oxidizer) cause the release of straight Cl gas which, in turn, would react with the AP and hopefully form Chloracetone?

Theoretic - 10-11-2003 at 07:45

I think the crusty stuff was a trichloronitronate of the metal of the lid (or a mixture of trichloronitronates if the lid is made from an aloy). The chloropicrin vapours that seeped out probably reacted with moisture and the metal.
The trichloronitronate ion is CCl3NO3H-. The nitronate ion is CH3NO3H-.

Haggis - 10-11-2003 at 12:04

As of late, I have also played a bit with chloropicrin (PS). What I did was place .25 gram of TNP in the bottom of a beaker. Then 50 ml of 6% bleach was poured on. I remember somewhat of a fizz or effervesence as the bleach hit the TNP. I stirred it around some and there was still some TNP in the liquid, so I added 50 more mls. This was poured into a 250ml flask and stoppered. The next morning...the flask was opened. I smelled the stopper, and, yes, there was a horrible scent I've never smelt before, although it is vaguely reminiscent of a pesticide or poison I either smelled or imagined smelling as a child. Then, I sniffed the mouth of the flask, and I felt the pain/stinging/irritation in the back of my throat. Also, upon another 'hit' of the PS, I got a higher dosage, and was reeled back in my chair, eyes and throat stinging. My eyes had pain, and I instinctively started rubbing them, but I'm not sure if that helped or hindered the effects. The eyes stung for arund 5 seconds, while the stinging in the throat subsided after around 3. Also accompaning was an increase in heartrate, either from the shock of being teargassed, or the agent itself. Also keep in mind this was from .25 grams of TNP, and is diluted to 5% or more. Not having a single want to distill the stuff, I plan on purchasing some xylene, swirling in the flask, separating the xylene/PS solution, then evaporating off the xylene. Can anyone see any difficulty to this procedeure? I was thinking that as Samosa said the ethanol sped up the vaporization of the PS, the xylene could too, lowering storable yields. This is one concern of mine. I plan to also experiment later with 68% Calcium Hypochlorite from pool chlorinator, for less solution to hassle with. Ugh, even while typing this, I get 'sensory flashbacks' and imagine that I am smelling the agent, when I am quite far away from it. Fun stuff!

DDTea - 10-11-2003 at 19:32

Haggis - you get those "sensory flashbacks" too?? Lately, I've been getting it a lot- I can smell the Chloropicrin in my nose, and on occasions I feel an irritation in my nose/throat (though not pain)... Interesting effect, I wasn't sure if it was just me.

Chloropicrin is very insoluble in water. I'm not sure about TNP, but I know Sodium Hypochlorite is soluble. Would it not be possible to separate it simply by pouring it into a large volume of water? Volatilizing Chloropicrin even further is the absolute last thing I'd want to do.

Do you have any idea how much Chloropicrin you made? Try adding the Hypochlorite to the TNP, but more slowly. Aim for complete addition in about 20 mins or so-- see how that affects yields. I know when I added the Hypochlorite to to the Nitromethane right away, yields sucked and I had a lot of Chloropicrin vapors (not easy to work with)... But on adding more slowly, though I still had the vapors, it was a bit easier to work with- and I actually had visible yields.

On these trichloronitrate salts... The only information I can find to something similar to these is on straight Nitronate salts- as produced by reacting a base with Nitromethane. Do you suppose that, by leaving the resultant NaOH in the Chloropicrin mixture, it reacted to form a Trichloronitronate salt?? Also, keep in mind that it was irritating to the skin-- this could prove to be an interesting group of bioactive chemicals, so long as they are just irritating and not actually corrosive. There are plenty of corrosives in this world, and one more would not be very interesting.

[Edited on 11-11-2003 by Samosa]

Mongo Blongo - 11-11-2003 at 10:34

I made it ages ago and I remember getting those flashbacks. It wasn't painful but I could smell a hint of it every now and again. I would discribe the smell as painful chlorinated Liquorice :D
Also I remember yields being very bad using TNP and sodium hypochlorite.

Theoretic - 12-11-2003 at 07:33

I do think that by reacting alkali with chloropicrin, you get trichloronitronates - especially as chloropicrin is described as "extremely acidic". I think the raction is just kinetically hindered, so heating could help ( if you are looking forward to this reaction as a way of storing chloropicrin).

vulture - 12-11-2003 at 15:51

For the people that are using the TNP route:

Don't forget to add HCl. HCl + NaOCl will produce free chlorine and greatly speed up the reaction.

Madog - 12-11-2003 at 17:01

ah, thanks. i was thinkig about the reaction earlier and realised that there must be H+ for the to procede.

i added about 100ml of chlorox onto .1-.2g TNP. after about 7 hours the presence of chloropicrin was evident. several days later the solution whent off-yeloow-clear and there is a few drops of translucent-off-yellow liquid on the bottom of the flask :-D

DDTea - 17-11-2003 at 20:00

After reading through the section on Chloropicrin in War Gasses again, I have found some information regarding the supposed Trichloronitronates and the interaction of Chloropicrin with metals...

"...chloropicrin attacks steel slightly and copper and lead very energetically. American publications, however, assert that chloropicrin attacks all metals."


"On treatment of Chloropicrin with an aqueous solution of sodium or potassium hydroxide there is no reaction, but if alcoholic soda or potash is employed, a gradual decomposition takes place and after a time crystals of potassium chloride separate."

Trichloronitronates have caught my interest though, and I can find almost no information about them- much less their potential bioactivity. Perhaps they can be synthesized by chlorinating Nitronate salts?

Darkfire - 14-12-2003 at 20:37

If you want to dispose of this stuff, how can it be done besides the toilet or letting it evaporate?

Topics changed a bit since first page, this is in relation to CP.

[Edited on 15-12-2003 by Darkfire]

guaguanco - 15-12-2003 at 09:04

Concentrated alkali would me my first idea.

DDTea - 15-12-2003 at 18:30

Sodium Hydroxide should decompose Chloropicrin to less aggressive molecules. As for me, I've always taken the flush-it and forget-it route :D. May the fish forgive me :(.

Darkfire - 15-12-2003 at 19:24

That would work for me exept in still a stay at home highschool student, parents wouldnt take to kindly to trying to being rudely taken away from a good shit because they had a chemical weapon just splash up their ass...

Im gonna do the mix with naoh then flush and forget method.

Mumbles - 15-12-2003 at 20:20

Man, I just hate getting a spash with chemical weapons. It takes all the joy out of a nice long relaxing sit on the john.
They have a few more methods. Hydroxide seems pretty easy, and cost efficient. Bisulfate to if you don't have any hydroxide handy(but by the sounds of it you do).

DDTea - 16-12-2003 at 11:36

Be careful with the sulfates and bisulfates. Reactions between Chloropicrin and these compounds can produce nasty decomposition products, such as Nitrosyl Chloride and Phosgene. I would go with the Hydroxide route because the decomposition products are less aggressive.

Darkfire - 16-12-2003 at 17:52

Yeah making phosgene, kinda defeats the point of destroying the CP.

DDTea - 16-12-2003 at 19:34

That's alcoholic Sodium Hydroxide, btw, as stated in an earlier post concerning reactions with Chloropicrin. Since Sodium Chloride will gradually precipitate out, it puts the Chlorine into a safe form-- as opposed to Phosgene or NOCl. Not sure where the C and the -NO2 will go...

Theoretic - 17-12-2003 at 02:12

I think that chloropicrin + sodium hydroxide =. Sodium chloride + water + sodium nitroacetate. The nitroacetate ion could then be alkalysed into sodium nitrite and sodium carbonate.
I made a mistake previously, stating the nitronate ion as CH3NO3H-. It's actually CH2NO2-. Can't see how trichloronitronate is possible, maybe the hbydroxide can join across the molecule?

Organikum - 17-12-2003 at 05:52

Reduce the chloropicrin with ironfilings from cast iron and HCl (aqueous) to methylamine and ammoniumchloride. If only so much HCl is added that the solution stays SLIGHTLY acidic all time predominantly methylamine is formed, if more HCl is added mostly ammoniumchloride will be resulting.

I added "aqueous" to the HCL and "iron filings" instead of Zn, also I believe Zn to work also.

[Edited on 30-12-2003 by Organikum]

DDTea - 17-12-2003 at 07:29

:o Reduction of Chlorpicrin in an Acid Environment is very dangerous!! That will not safetly decompose Chloropicrin, it will form much more dangerous Phosgene Oxime. That is actually the synthesis route of Phosgene Oxime: Chloropicrin is dissolved in an Aprotic solvent, HCl is bubbled through, and it is reduced with Tin or Zinc.

Organikum - 17-12-2003 at 07:35

The procedure is plain from the article "chloropicrin" from the old ftp. It is said to produce methylamine in quantitative yields. The use of HCL - aqueous and no aprotic solvent may make the difference so I added the "aqueous" to my post before to avoid endangerment by misinterpretation.

[Edited on 17-12-2003 by Organikum]

DDTea - 26-1-2004 at 21:43

This has been delayed much too long-- I've finally got back to my experiments in Chloropicrin, and this time I've had more success than ever. I have found a way to produce high-quality Chloropicrin from OTC Nitromethane Fuel solution. Mine was 30%.

I found that I wasn't using nearly enough NaOCl solution relative to the amount of NM I was using. But, I will excuse those early experiments as "preliminary." I don't have my actual procedure and calculations with me, as it was contaminated, and thus not brought inside the house.

Here was the procedure, out of memory:

25 g of 30% Nitromethane is added rapidly to 415 mL of 6.00% NaOCl solution, quickly stirred (I stress quickly-- don't want to be around it too long), and covered. It would now be prudent to leave the area, and to let the reaction go for about 10 minutes. After this time, add 30 mL of 30% HCl to the mixture, and stir. The Chloropicrin will sink to the bottom and little globs of saponified Castor Oil will float to the top/cling to the sides. The other impurities will dissolve in the water. The mixture can now be decanted off, being careful not to pour out the bottom layer of Chloropicrin.

It's incredibly simple, but I should give some warnings. Friends, like you, I don't believe in k3W|_ warnings, but I cannot give the procedure without some words of advice. DO NOT try to see if the Chloropicrin is there... trust me on this, it is there; so no wafting and NO SNIFFING. If you feel your eyes watering, leave the area immediately-- you don't want to inhale too much of it or it WILL ruin your day. I think that the chances of it actually killing you are low, but it can make you wish you were dead. Easily the most dangerous part of this reaction is decanting off the impurities...this will be the part where you are exposed to the most Chloropicrin (as there will be less water between it and you), so be forewarned. Hold your breath, if you don't have a gas mask or good ventilation, and do it as quickly as possible.

The HCl proved to be the key ingredient here, in that it neutralized the NaOH that would otherwise destroy the Chloropicrin, together with the alcohol. If you are using 5.25% bleach, you will use 475 mL of NaOCl to 25g of 30% Nitromethane. The Chloropicrin looks like a blob at the bottom of the reaction vessel... Mine came out red, probably from various impurities and coloring. But no doubt, it was, in fact, Chloropicrin. From the size of the blob, it looks like I got very good yields (this is based on the amount of NM I used... I could not actually weigh it, due to some concerns for safety/chemical hygiene).

I did not have any vessel that I could seal and store the Chloropicrin in, so I simply poured Ethanol on top of it and added NaOH-- alcoholic bases can be used to decontaminate this.

There you have it. Happy crying, and happy coughing. I would not try to upscale this, simply because of the danger of it.

vulture - 27-1-2004 at 08:46

You could always dispose of it by detonating it....

DDTea - 27-1-2004 at 09:37

I haven't tried detonating Chloropicrin... But, because of its properties as a lachrymator, it's best used as a gas. For explosions, Picric Acid would be more useful. In any case, the situation was rather dire-- more of it had vaporized than I thought-- and late night detonations attract far too much attention.

KABOOOM(pyrojustforfun) - 29-1-2004 at 20:46

<blockquote>quote:<hr>You could always dispose of it by detonating it....<hr></blockquote>IIRC I read somewhere it's undetonable (I'm not sure @all). any info on this is greately appreciated..

Haggis - 12-3-2004 at 13:40

For some reason I have been bit by the chloropicrin bug again, and decided to produce a small amount via the TNP route.

First, 1g of TNP was measured out into a 250ml Erlenmeyer flask. This was taken out into the garage along with 200ml of 6% bleach. I was going with .004 molar amounts for each chemical, and this ratio is near stoichiometric. I donned my respirator and added the bleach to the TNP. Upon contact, the TNP fizzed a bit with what I remember to be reddish bubbles. This subsided soon as the rest of the beach was added. What I had now was a orangish liquid in the beaker.

I then walked away, leaving it on the garage floor to react. I just wandered around the garage for a while, looking at some the chemicals we have on the shelves, wondering what I could use them for. I remembered the chloropicrin, so I walked over to the flask. My eyes started twinging when I was near it. Suprised, I jumped back. I stepped around 20-30 feet away, removed my mask a bit and carefully sampled the air...and about choked. I had filled my garage with chloropicrin vapors, and had not noticed it because I was wearing my respirator. I only noticed when it started effecting my eyes as I approached the flask. I quickly ran over and stoppered the beast. The garage doors were opened to flush the toxic gas from my house.

That night, I checked on it, and it appeared that nothing was formed. I initially suspected the small amount of PS formed went into solution. I know PS was formed, however, from the odor that escaped the flask when it was unstoppered.

Flash to today, around 47 hours after reaction, I decided to check on the vessel. I was suprised to find an opaque white, dense liquid sitting ominously in the bottom of my flask. Upon seeing the liquid, it gave me the same feeling one would get from going to the bathroom in the middle of the night, then turning on the light to find a rather large spider on the toilet. I stopped in my tracks, startled, then went to inspect it.

There really isn't much to say about it, I am going to see if I can get some more from the reaction. The surrounding liquid now is more of a bright yellow color, opposed to the orange from the beginning of the reaction.

Overall, the TNP route is more time consuming due to the nessesary production of picric. I decided that the NM route would prove better yeilds, but I do not have access to NM at this time. One could cut down drastically by using a higher concentration of hypochlorite, and one needs large amounts of bleach for small batches, and the volume could be a hassle.

109_0903.JPG - 114kB

thunderfvck - 12-6-2004 at 02:43

Sorry. Another dead topic resurrected.

Now some of you may understand why I was so interested with picric acid ;)

OKay! What the hell? How is CCl3NO2 made from (NO2)3-(C6H2)-(OH) and NaOCl? This one really has me boggled. Where does chloropicrin get its carbon from picric acid? Wouldn't this break the aromatic ring? What's the equation!! There has got to be a multitude of products.

Anyone care to enlighten me?

Thank you kindly.

menchaca - 12-6-2004 at 10:29

chloropicrin can be synth otc from chloroform and HNO3 :

CHCl3 + HNO3 --> CCl3NO2 + H2O

and the choloroform can be make from acetone and bleanch:)

vulture - 12-6-2004 at 11:24


The nitroacetate ion could then be alkalysed into sodium nitrite and sodium carbonate.

Acidify the nitroacetate solution, distill over a column and you have your nitromethane back. :)

EDIT: According to Organikum (the book)Nitroacetic acid should decarboxylate when distilled...

That is, if the other components do not interfere.

If it works, you have a way of converting TNP to nitromethane...

[Edited on 12-6-2004 by vulture]

[Edited on 12-6-2004 by vulture]

garage chemist - 29-8-2004 at 22:35

Sorry for bringing up this old topic again, but the chloropicrin thread will surely never die.

I also have read the german book "Die Chemie der Kampfstoffe" and I understand it because I am from germany. This book is extremely valuable and informative, it gives a fully outlined laboratory synthesis for every war gas used in WW1. Including a synthesis of dichlorodiethylsulfide from disulfur dichloride and ethylene.

I have read about an undiscussed way of destroying chloropicrin there. Chloropicrin reacts readily and rapid with a solution of sodium sulfite (Na2SO3) to form the sodium salt of nitromethane disulfonic acid. The reaction must be carried out at elevated temperature and occors in alcoholic and in aqueous solution.

CCl3NO2 + 3 Na2SO3 + H2O ---->

CHNO2(SO3Na)2 + 3 NaCl + NaHSO4

This is a far better method to destroy CP than alcoholic NaOH.

I am also wondering about the equation for the formation of CP from TNP and NaClO.
I have not been able to find this out!!!
It would be very helpful if someone could post this equation.

I can also say that aqua regia + acetone is not a good method of preparing CP, the reaction is very violent and can get out of control quickly.

When I have time and some bromine, I will try to make bromopicrin! (NaBrO + TNP)
It is a stronger lachrymator than chloropicrin but about ten times less toxic.

[Edited on 30-8-2004 by garage chemist]

ordenblitz - 30-8-2004 at 15:44

I made some chloropicrin today employing both TNP and NM routes with sucess both times.

The TNP route left a few plastic'ish looking foaters similar in color to TNP that appeared after adding the hcl even though all TNP went into solution upon the addition of the bleach. Curious. as all the starting chemicals were commercial except the clorox.

I have never smelled CP before but it was really very similar to chlorobenzylidene malonitrile (CS agent) which I have smelled on many occasions.

The only difference I can think of was the CP description of hints of "licorice" smell, was really very accurate whereas the CS has a peppery note in it's flavour.

Mmm I'm getting hungry!

DDTea - 30-8-2004 at 17:12

I find the Sodium Sulfite route of destroying PS (this is the NATO designation for it and proper abbreviation) to be very interesting. Do you know how long this reaction takes or how high the reaction temperature has to be?

I have personally tried the NaOH/Alcohol destruction method and it does not work very well. I had the PS flooded in the decontamination mixture and after several days, there was still the detectable and irritating odor of PS. And on the note of odors, CS definately has that "peppery" odor while PS has that "thick" and "penetrating" and "irritating" odor. However, from my experience, PS causes a more painful reaction that makes you feel like you will pass out; CS's throat and chest pain didn't feeel the same to me (i felt it a while ago...I might test it again to give a more accurate description).

Also, what is this book "Die Chemie der Kampstoffe" (or should it be "Kampfstoffe"?) ? Is that simply "The War Gases" in German? Who is the author? Is it an online e-book for us all to see? :D

garage chemist - 31-8-2004 at 04:53

The reaction occurs at 90- 100°C IIRC and this is strange because of the boiling point of ethanol.
Maybe it is better to carry out the reaction in aqueous solution, you can see that the reaction is complete when the blob at the bottom has disappeared.

"Die Chemie der Kampfstoffe" is an e- book, it has been scanned by PAC from the E&W.
Here is the link:

I haven't seen the book "The War gasses" so I don't know if the "Die Chemie der Kampfstoffe" is just the german translation of it.

DDTea - 31-8-2004 at 11:16

Ah, this is actually "The War Gases" in German. Same author and such.

JohnWW - 1-9-2004 at 14:36

Unless some valuable byproduct can be recovered for other uses, disposal of chemical warfare agents, and similar toxic surplus or condemned chemicals, by reaction with other chemicals (which may themselves be costly) is usually uneconomic compared to simply burning in a special incinerator, with the emissions being scrubbed out with water-spray scrubbers in the flue. Another possibility is deep burial in a remote area designated as a hazardous wastes dumping area. The toxicity of the substances also militates against trying to chemically deactivate them.

Explosives are usually too dangerous to try to treat chemically e.g. with a reducing agent, and unlike war gases they cannot be safely incinerated. As in Iraq, they can be disposed of safely only by controlled detonation in a pit (then filled in) in a remote area, or by deep burial in a remote area. After WW2 a lot of explosives were dumped at sea in deep areas, especially the deepest trenches, in the North Atlantic ocean. Unfortunately, some were dumped in shallower places in fishing areas, and as the result are occasionally dredged up by trawlers. The rusting steel shell and bomb casings make them dangerous to handle.

John W.

garage chemist - 6-9-2004 at 06:07

Now I've made some bromopicrin.
(NaBrO + TNP)

It smells very sweet and is much less painfull to breathe than chloropicrin.
It caused almost no tearing and no coughing.
The smell is not too similar to chloropicrin, it is easy to distinguish those two by the smell.

Reverend Necroticus Rex - 6-9-2004 at 06:48

Has anyone tried making iodopicrin, or maybe the fluorine analogue, fluoropicrin should be much more toxic due to the F- ion:cool:

fvcked - 6-9-2004 at 15:25

Who wants to test smell flouropicrin:P

garage chemist - 6-9-2004 at 16:46

I wonder how to synthesize fluoropicrin?

I mean, hypofluorites don't exist because fluorine reacts violently with water to form HF and O2.

Maybe by reaction of sodium fluoride with chloropicrin? (Finkelstein swap)

I don't know about fluoropicrin but it could be either extremely toxic or not toxic at all.
Some organic fluorine compounds are very toxic (simple alkyl fluorides, Perfluoroisobutylene, Sarin) while others are non- toxic (freon, the fluranes).

I think iodopicrin would be rather harmless, most likely not too different from iodoform.

I was actually surprised at how harmless bromopicrin was. I could directly sniff the reaction mix and only got some mild eye irritation. It also smelled rather pleasant.

BromicAcid - 6-9-2004 at 17:23

CF3NO2 appears to be found under the name trifluoronitromethane rather then fluoropicrin for which I got zero results. It seems rather difficult to synthesize as all the results that I found cited a rather recent source for a direct synthesis of this chemical:
Lu, N; Thrasher, J. S. “The Direct Synthesis of Trifluoronitromethane, CF3NO2,” J. Fluorine Chem. 2002, 117, 181-184.

Although there is possibly an indirect method to achieve it that was used previously. It does appear to be quite the rarity though.

Edit: I've heard that hypofluorites can be made by running fluorine gas over a surface that has been prevously wetted with an aqueous alkali.

[Edited on 9/7/2004 by BromicAcid]

Reverend Necroticus Rex - 6-9-2004 at 17:42

Could you perhaps post a direct link to the article you mentioned Bromic, I don't know how to access journals like that from when a name/title is cited:(

BromicAcid - 6-9-2004 at 17:47

Sorry but I don't have the article, all I found were citations to it :(

Edit: Searched around and found an abstract of it.

[Edited on 9/7/2004 by BromicAcid]

DDTea - 7-9-2004 at 11:35

Trifluoronitromethane seems like it would be an extremely aggressive compound. Wouldn't the three Fluorines would create a hyperactive electrophilic Nitro group?

I'm going to make a conclusion here, based on the assumption that Bromopicrin is NOT as aggressive as Chloropicrin (you may want to check that again--perhaps you just didn't have a high enough concentration in the post-reaction mixture to cause significant irritation?). The greater the electronegativity of the CX3, the more electrophilic and aggressive the NO2 is and thus the NO2 causes the irritation. This would explain why Chloropicrin is significantly more aggressive than Bromopicrin. And continuing this, Trifluoronitromethane ("Fluoropicrin";) would be even worse!

DDTea - 8-9-2004 at 11:17

Continuing what I said above... I find that Nitro-Halogen compounds and Cyanide-Halogen are fairly comparable. As such, to consider the effect of a more electronegative Halogen on the aggressiveness of the compound as a whole.

My hypothesis is that the more electronegative the Halogens in Trihalonitromethanes, the more electrophilic and aggressive is the Nitro group. So, let's take into account the Cyanogen Halides and their irritating properties, according to "The War Gases."

Cyanogen Chloride: "Concentrations of 2.5 mgm per cu. m. of air produce abundant lachrymation in a few minutes. The maximum concentration which a normal man can support without damage for 1 minute is 50 mgm per cu. m. of air."

Cyanogen Bromide: "Concentrations of 6 mgm. per cu. m cause strong irritation of the conjunctiva and of the mucous membranes of the respiratory system... the maximum concentration which a normal man can support for a period of 1 minute is 85 mgm per cu m., according to Flury, and 40-45 mgm. per cu. m. according to Ferrarolo"

Again, the same trend, at least judging by these two compounds. The more electronegative halogen seems to cause greater irritation. So I'm going to make the assumption that it works the same way with compounds like Chloropicrin.

Strange though; Cyanogen Fluoride and Cyanogen Iodide are both included in The War Gases, but no details to their aggressive properties are given.

Reverend Necroticus Rex - 10-9-2004 at 09:08

My guess would be, cyanogen fluoride=HIGHLY toxic, more so due to the toxicity of the F- ion.

Cyanogen iodide would be perhaps less so than the bromide, but still unpleasant stuff to be around:D

Such a shame astatine doesnt have a longer half life....:o

JohnWW - 10-9-2004 at 09:47

Because of the greater stability of the C-F bond compared to that of other C-halogen bonds, it would be more resistant to metabolic processes. While FCN would be more volatile than cyanogen chloride or bromide, it may be less poisonous because of this greater bond stability.

Here is a section from the U.S. Army manual FM8-9, at the web-page :


515. Introduction.
Cyanogen chloride and cyanogen bromide after absorption react in such a way that hydrogen cyanide is eventually released. Their effects on the body are essentially similar to those of hydrogen cyanide, but, in addition, they also have local irritant effects.

516. Physical and Chemical Properties
a. Cyanogen chloride is a colorless, highly volatile liquid. Although only slightly soluble in water, it dissolves readily in organic solvents. Its vapour, heavier than air, is very irritating to the eyes and mucus membranes. Cyanogen chlorides pungent, biting odour is marked by its irritating lachrymatory properties. Normally cyanogen chloride is non persistent. (See Table 5-I.)
b. Cyanogen halides are rather poorly absorbed onto charcoal, especially if the charcoal is damp. The cyanide group, not being ionised, does not react well with the metal salts found in respirator charcoals.

517. Detection.
Automatic detectors are available which detect attack concentrations of vapour. Draegertm tubes are also available, as are water testing kits.

518. Decontamination.
See hydrogen cyanide. [oxidants e.g. permanganate]

519. Mechanism of Action.
Cyanogen chloride acts in two ways. It systemic effects are similar to those of hydrogen cyanide but it also has local irritant effects on the eyes, upper respiratory tract and lungs.

520. Pathology.
Cyanogen chloride injures the respiratory tract, resulting in severe inflammatory changes in the bronchioles and congestion and oedema in the lungs. Very low concentrations (e.g., 10-20
mg. min. m-3 ) produce eye irritation and lachrymation.

521. Signs and Symptoms.
The signs and symptoms caused by cyanogen chloride are a combination of those produced by hydrogen cyanide and a lung irritant. Initially, cyanogen chloride stimulates the respiratory centre and then rapidly paralyses it. In high concentrations, however, its local irritant action may be so great that dyspnoea is produced. Exposure is followed by an immediate intense irritation of the nose, throat and eyes, with coughing, tightness in the chest and lachrymation. Afterwards the exposed person may become dizzy and increasingly dyspnoeic.
Unconsciousness is followed by failing respiration and death within a few minutes. Convulsions, retching and involuntary defecation may occur. If these effects are not fatal, the signs and
symptoms of pulmonary oedema may develop. There may be persistent cough with much frothy sputum, rales in the chest, severe dyspnoea and marked cyanosis.

522. Treatment.
Cyanogen halide poisoning should be treated in the same way as hydrogen cyanide poisoning as regards its cyanide-like effects. [with amyl or sodium nitrite, vitamin B-12]. Pulmonary irritation should be treated in the same way as
phosgene poisoning.

523. Course and Prognosis.
Recovery from the systemic effects of cyanogen halide poisoning is usually as prompt as in hydrogen cyanide poisoning. However, a higher incidence of residual damage to the central nervous system is to be expected. Depending on the concentration of cyanogen halide to which the casualty has been exposed, the pulmonary effects may develop immediately or may be delayed until the systemic effects have subsided. Early prognosis must, therefore, be guarded."

These war gases (only chloride and bromide mentioned) thus owe their toxic effect to the CN- group as in HCN (which is more volatile), and additional lachrymatic and vesicant effect to the halogen part, requiring dissociation in metabolism for both effects. Dissociation would be probably too slow in the case of FCN. The chloride and bromide do not persist because they are slowly hydrolysed by water; FCN would be resistant to hydrolysis. The greater molecular weight of ICN would make it insufficiently volatile for easy dispersal, the iodine also being less hazardous, although it is even more easily dissociated. HOCN is also much less volatile because of hydrogen-bonding.

John W.

sylla - 19-10-2004 at 05:01

Originally posted by PHILOU Zrealone
In the industry, they make NM/NaOH/H2O mix and then bubble exces Cl2 in it!

I tried it and something really strange had happend.

I first mixed nitromethane with some NaOH 1M, it was quite exothermic so I added ice. After a few minutes it went dark brown/orange. Then I've bubbled excess Cl2 into it and nothing special appeared... so I decided to add the nitromethane/NaOH (does it really form sodium nitronate or maybe the water break it to another thing ?) directly to the hypochlorite solution (12°) slowly.

At first the solution was cloudy and white but after having added all the solution of nitromethane (or derivate) it became orange and some crystals began to precipitate.

After a few minutes my solution was covered by those crystals (beige and with density <~ 1). Of course there was no chloropicrin at all (if I do the same synthesis without NaOH I get lots of chloropicrin)...

So I'm wondering what I actually made :| Does someone here have an idea ?

[Edited on 19-10-2004 by sylla]

DDTea - 23-10-2004 at 18:50

You added the NaOH directly to the Nitromethane? That in itself should have formed Sodium Nitronate, yes... I have no idea what chlorinating such a mixture would give. It seems more sensible to make a hypochlorite mixture w/ NaOH and HCl, and then add Nitromethane to that. In fact, according to the patent, NM is added to the Hypochlorite, not the other way around. Doing that simply change really made my yield a lot better when I did this (or at least made it easier to see/extract).

Another interesting route to Chloropicrin is Nitromethane + Cyanuric Chloride. Adding 1 mole of Cyanuric Chloride per mole of Nitromethane should form Cyanuric Acid + Chloropicrin. The mixture would then be treated with 3 moles Sodium Bicarbonate and poured into a large volume of cool water. The Chloropicrin, not being water soluble, could be easily extracted while the sodium cyanurate solution would be disposed of.

I like this method more than the Hypochlorite method since it involves working with smaller volumes of liquid--making extraction a lot easier. It might lend itself better to making PS from impure (35%) Nitromethane mixtures, too.

Anyone care to try it? :)

garage chemist - 24-10-2004 at 07:57

If I only had some nitromethane...
Making picric acid is so time donsuming and expensive, and it doesn't always work.
Actually, there is an auction on 2 Liters of NM right now at ebay, but it's very expensive and 2 Liters is WAY too much for me. I don't make any HE charges so it doesn't have any uses for me other than making chloropicrin.
I most likely won't buy it.

Is cyanuric chloride the same as trichloroisocyanuric acid?

chemoleo - 24-10-2004 at 09:07

Sylla, I also don't quite understand what you did.
First you mixed a solution of 1M NaOH (how much) with how much NM? Then, you bubbled Cl2 directly into it? Or did you make the hypochlorite solution by bubbling Cl2 into it? Where does the 12 % hypochlorite solution come into this?
Then, what did you do with the crystals? Did you subject them to flame, or whatever?

garage chemist - 1-12-2004 at 08:57

Finally, I found something about the actual smell of chloropicrin, now the thread title has its justification.

WW2 Gas identification posters

Here is the poster for chloropicrin:

Although I never smelled flypaper...

sylla - 21-1-2005 at 03:32

Originally posted by chemoleo
Sylla, I also don't quite understand what you did.
First you mixed a solution of 1M NaOH (how much) with how much NM? Then, you bubbled Cl2 directly into it? Or did you make the hypochlorite solution by bubbling Cl2 into it? Where does the 12 % hypochlorite solution come into this?
Then, what did you do with the crystals? Did you subject them to flame, or whatever?

Actually I did two things :

I first bubled Cl2 intro the sodium nitronate (or watchever it is) solution which yield nothing ; no chloropicrine and no insoluble salt or colour change.

I then tried to add another solution of sodium nitronate to hypochlorite solution (12° chlorometric, so 5% not 12%) which gave me the strange crystals.

I didn't tried to filter them ; I'm too scared about chloropicrin toxicity :(, aren't you ?

garage chemist - 23-6-2005 at 07:54

I had succes with a new route to chloropicrin which is much less time consuming than the TNP or NM route. No bleach is used, since I hate using bleach because of the large reaction volumes.
Also no fuming nitric acid is needed.

I got the idea from the article "Chloropicrin" from the FTP (thanks to whoever uploaded it).

2 ml of 65% nitric acid were mixed with 3 ml 37% hydrochloric acid, in a 30ml pear shaped flask. A slightly yellow, warm aqua regia was obtained.
0,5ml acetone were added at once and the contents of the flask swirled to ensure mixing. The yellow color of the acid vanished and it became clear and fizzed a bit. Then I heated it. It quickly became yellow, then brown, and a reaction set in and the mix boiled violently, evolving NO2. I quickly placed the flask in a cooling bath, which moderated the boiling. I took it out again and slowly heated with a bunsen burner, the mix had a dark red color and was cloudy. Some more NO2 was evolved, and the reaction was left to continue on its own until it had returned to room temperature.
20 ml of water were added to the mix and a red drop of chloropicrin (approx. 0,1ml) seperated out. It was extracted with a pipette and washed with water, which turned it clear.
Note that the chloropicrin dissolves in the hot acid, only the dilution of the acid precipitates it completely.

Don't try to make a much larger batch than the described one, because the reaction is violent and can get out of control easily.
An attempt with fuming nitric acid produced no significantly larger yield, but the reaction was even more violent.

[Edited on 23-6-2005 by garage chemist]

IrC - 23-6-2005 at 11:27

Garage Chemist, do you know any other links to "Die Chemie der Kampfstoffe"? The link above is either dead, or I have a really crappy ISP?

garage chemist - 23-6-2005 at 13:07

You can find the english version in the SCM library under the name "The War Gases: Chemistry and analysis" from Mario Sartori (near the bottom of the list).
Note that the production of chloropicrin from aqua regia isn't covered there.
Also look in the FTP, if "Die Chemie der Kampfstoffe" isn't up there, then I could upload it.

[Edited on 23-6-2005 by garage chemist]

IrC - 23-6-2005 at 16:50

Thanks. I looked around a while in axehandles ftp and looked at the file lists, but did not see it. Since he has such a large amount of stuff in there (I put a few hundred MB's there myself in the last 2 months) I may have missed it but no matter, I went to the SCM book section and D/L'ed the english version you mentioned.

12AX7 - 23-6-2005 at 20:46

What I'm left wondering is, what does chloropicrin have to do with picric acid or vice-versa? What would be dechloropicrin and why does it have a different name?


The_Davster - 23-6-2005 at 21:15

I believe it is called chloropicrin as it was first prepared from picric acid and bleach. Don't question archaic nomenclature, the naming logic used then is so much different then todays nomenclature systems, and the chemists of old did no have the ability to determine the exact composition of most compounds so they were often named based upon their precursors. I believe your "dechloropicrin' would just be nitromethane

[Edited on 24-6-2005 by rogue chemist]

The_Davster - 28-8-2005 at 17:42

I found out today that chloropicrin can also be prepared by the action of bleach on styphnic acid. I used around 40mL of 11% bleach and a 1/4 spatula of styphnic acid. Allowed them to sit for a few min, then added an eyedropper of HCl, then after a few hours a puddle of liquid had collected on the bottom on the testtube around the size of 3 .177 BBs. Smelled kinda like chloroform, but made my eyes sting:).

garage chemist - 9-12-2005 at 12:01

I found the equation of the reaction of picric acid with hypochloric acid:

C6H2(NO2)3OH + 11 HClO -----> 3 CCl3NO2 + 2 HCl + 3 CO2 + 6 H2O

So the aromatic ring is indeed completely destroyed.

Eclectic - 9-12-2005 at 13:26

I don't think pure chloropicrin has an "odor". It gives pain and copious tearing on inhalation. Imagine taking a good snort of hot chinese mustard. Now imagine 1000 times as much delivered straight to your sinuses with a sledge hammer. In very high dilution it has a peppery, acrid, teargas smell and was added to the soil fumagant methyl bromine as a warning agent.

DDTea - 23-12-2005 at 23:37

On what Eclectic said...

Chloropicrin has a definite odor. You will catch it on initially inhaling it, just before the pain reaction kicks in. It is very unique and very different from any impurities (as you know, I made it from bleach, which has a Chlorine smell, and Nitromethane, which is odorless).

Going off memory now (although I still remember the smell quite clearly--sorta burned into my nose :P ): It has that chlorocarbon smell, like Methylene Chloride or Chloroform. Actually, the smell of Bromine in Methylene Chloride reminded me a lot of Chloropicrin; but I've yet to find anything that has quite the same smell. Some perfumes have reminded me of it, though, which I find funny.

But if you want to know how Chloropicrin feels, I can tell you very easily. It's like cutting an onion when it comes to the eyes (not surprising since onions contain a lachrymator). The only thing I can find that made me cough as badly as Chloropicrin was CS (I sprayed myself). It's not a painful cough, but a persistent and intense one--as if there's something stuck in your chest that you can't quite reach with your coughing. There is a definite pain in your whole respiratory system though; it feels like it's [thermal] burning. It really affects your whole body; I know a guy who caught a whiff of it and fainted instantly. I felt weak after I got a whiff of it

As I recall, it's mixed in with Methyl Bromide more for its irritating properties than its smell.

With that said and in retrospect, I'd strongly discourage home chemists from making Chloropicrin. The synthesis is too easy, so you might regard it as some fun for the weekend; but that's treating it too lightly. PS really isn't any more dangerous than a lot of other lab reagents. In fact I don't even know why I'd discourage you from doing it. I'm trying to think of reasons to, but I'm falling short. Most of us are pretty gung-ho with safety; but don't forget those around you or the environment, please. :)

[Edited on 12-24-05 by Samosa]

hinz - 28-5-2006 at 16:37

I had sucess with the trichlorisocyanuric acid method, Samosa:D:D:D:D:D:D:D!

I was destilling some modell aircaft fuel, to get some metanol. Later I collected the nitrometan, there were around 20% in it. So I had some nitrometan and no use for it.

Just for interrest I took some trichlorisocyanuric acid (C3N3O3Cl3)and added it to the nitromethane but nothing happened. Now I went inside (took my test tube with the mixture with me) and read this threat. I also read that you have to add a base. So I took my Ca(OH)2 (the single base I have) and added it, the reaction was quite vigorous and the stopper blew out. Now I have to sleep in a tear gassed room.:(

About the reaction mechanism: I think the OH- ion shifts the equillibium of nitromethan to the "enol" form of it:

CH3NO2 + OH- <===> - CH2-NO2 + H2O

The "enol"-form can act as a nucleophile with the as intermediate formed hypochlorous acid (hypochlorite) The hypochlorous acid forms slowly when the electron deficient clorine leaves as a Cl+ and gets captured immediately by a OH- This may react to hypochlorite or be used up by the "enolised" nithromethan.
The whole reaction:

CH3NO2 + OH- <===> - CH2-NO2 + H2O

- CH2-NO2 + HOCl <===>>> Cl-CH2-NO2 + HO-

C3N3O3Cl3 + 3 Alkali+ + OH- <===> C3N3O3Alkali3 + 3 HOCl

I'm tired now my eyes are tearing a bit, I hope the reaction mechanisms are more or less true, anyone who finds misstakes is wellcome:)

The_Davster - 28-5-2006 at 17:37

I was just thinking about the mechanisms behind this earlier today, what I came up with was almost the same as you.
NaOCl+ H2O-->HOCl + NaOH
HOCl--> OH- + 'Cl+'

CH3NO2+ NaOH--> H2O +CH2=NO2- (nitronate)
nitronate goes to the 'enol' form of -CH2-NO2
Cl+ + -CH2-NO2 -->CH2Cl-NO2
Two more nitronate and subsequent rxn with Cl+ and you have the chloropicrin.

3NaOCl +CH3NO2--> CCl3-NO2 +3NaOH
And the NaOH will eventually react with the chloropicrin(forgot and am unable to find the products of this reaction), so soon after the mixing of NM and bleach one must neutralize the base formed with some acid

I would be really interested in the mech of formation of chloropicrin from picric acid, I was not able to come up with anything really plausable.

Also, the reason Samosa had such fun when washing the glass with EtOH is that Chloropicrin and ethanol form an azeotrope that boils at 77C(35% chloropicrin).

DDTea - 28-5-2006 at 18:08

I've been neglecting this topic for a while due to some legal issues I ran into with it. Without saying too much, it was a major shakeup in my life and have just now gotten things back in line.

And I've also finished a year of Organic Chemistry ;-) .

Yes it's time we talk about the mechanism of this reaction. You guys nailed it--it's almost identical to the Haloform reaction (e.g.: chloroform from acetone), only there is no Chloroform cleavage in this reaction. Remember, NaOCl is essentially Chlorine dissolved in Sodium Hydroxide solution...

So here we are: CH3NO2 ---(NaOCl)--> CCl3NO2
Step 1: CH3NO2 is deprotonated by OH- : (-)H2C-NO2
Step 2: The nucleophilic carbon then reacts with the Cl+ (from NaOCl) and bonds with it. This, in turn, makes the remaining Hydrogens *more* acidic (electrophilic Cl withdraws electron density from them) and thus will react even more readily with another OH-, then Cl+, a second and third time.

This would explain the "mix and forget" nature of the reaction--it speeds up as it goes along!

Now that we understand this mechanism, it just may have other synthetic use to us. The only difficulty is that it will be near impossible to stop the reaction with a mono or dichlorinated product, since each reaction results in a more reactive product. But the way this is overcome in Alpha halogenations is using an *acidic* medium and Halide ion. So for example:

CH3NO2 --(Acetic Acid/Br2)--> CH2BrNO2

The reaction is stopped at the monohalogenated product! This could definitely have synthetic value, since here we have a Nitro group behaving analogously to a Carbonyl. Perhaps we could extend it further for example, an unsaturated nitro compound, possibly even the infamous "nitroacetylene"

O2N-CH2-CH2-N2O ---(Br2/Acetic acid)--> O2N-CHBr-CHBr-N2O ---(NaOH) --> N2O-C=C-NO2

I might be getting too ambitious here though.

I'm very pleased to hear about the Trichloroisocyanuric Acid method being successful! Shall we try to find a mechanism for this reaction? Who knows what can grow from some juvenile recklessness in a garage!

EDIT: just took time to reread what you wrote, Hinz.
I had sucess with the trichlorisocyanuric acid method, Samosa:D:D:D:D:D:D:D!

I was destilling some modell aircaft fuel, to get some metanol. Later I collected the nitrometan, there were around 20% in it. So I had some nitrometan and no use for it.

Just for interrest I took some trichlorisocyanuric acid (C3N3O3Cl3)and added it to the nitromethane but nothing happened. Now I went inside (took my test tube with the mixture with me) and read this threat. I also read that you have to add a base. So I took my Ca(OH)2 (the single base I have) and added it, the reaction was quite vigorous and the stopper blew out. Now I have to sleep in a tear gassed room.:(

[This will be difficult to convey with text...but I'm too lazy to draw nice mechanisms :) ]

Here is my proposed mechanism. From other experiences, we've found that reacting Nitromethane with Sodium Hydroxide leads to "Sodium Nitronate." I believe it is this Nitronate ion that reacts via electrophilic addition:

1. CH2=NO2(-) Na(+) + C3N3O3Cl3 --> C3N3O3Cl2-CH2-NO2 + Na(+) + Cl(-)
This results in charge cancellation and the nitronate ion forming a complex with Trichloroisocyanuric acid--shall we call it "Nitromethyl Dichlorisocyanurate." Dichloroisocyanurate looks like a spectacular leaving group and Cl- a great nucleophile; thus I see an Sn2 reaction occurring on the Methylene.

2. C3N3O3Cl2-CH2-NO2 + Cl(-) ---> CH2Cl-NO2 + C3N3O3Cl2(-)

These two steps repeat twice more, leaving the two products: Chloropicrin and Sodium Isocyanurate (since we used NaOH).

This is just my hypothesis. I say this because Hinz said that no reaction occurred between the Nitromethane and Trichloroisocyanuric Acid until a base was added, which is why I believe it is the Nitronate ion that reacts.

[Edited on 5-29-06 by Samosa]

Quantum - 7-8-2006 at 13:34

I just made some for the first(and last) time today - I used a methanol solvent to carry it into the air(like perfume) and dumped it into the sink and then poured hot water over it and put my face above it.

All I had time to smell was a sent that was sharp like HCl but more "organic" like a solvent before I was bent over hacking away.

It didn't make me cry that much - I could still see but I was incapacatated.

DDTea - 7-8-2006 at 20:05

Originally posted by Quantum
I just made some for the first(and last) time today - I used a methanol solvent to carry it into the air(like perfume) and dumped it into the sink and then poured hot water over it and put my face above it.

All I had time to smell was a sent that was sharp like HCl but more "organic" like a solvent before I was bent over hacking away.

It didn't make me cry that much - I could still see but I was incapacatated.

For those wondering how it feels to be gassed by Chloropicrin: It's almost like being punched in the face and having the wind knocked out of you simultaneously.

It's not just a lachrymator; its effects are truly incapacitating (temporarily). It makes your muscles feel weak, so it becomes hard to get up or walk. Doing what our friend Quantum did (and what I have done) will basically lead to you fainting (not necessarily losing consciousness, but collapsing and hacking/choking until your face is blue).

Keep it safe, and trust that it is, indeed, an incapacitant. Keep self-testing to a minimum :P

Quantum - 8-8-2006 at 16:42

That is a very apt description Samosa - its almost like Liquid Knuckles in Snow Crash(sort of) - Really knocked me for a loop

NBK and others would(and do) have a feild day with this stuff. Of course this is a chemistry forum but there are many applications for this chemical expecially combined with a second agent.

It's powerful! I'm not going to expose myself to it again.

Edit: Change KBK to NBK

[Edited on 9-8-2006 by Quantum]