AllChemystery - 2017-02-23
Making picric acid via a nitration of Acetylsalicyllic acid or more commonly known as asprin. We use Ethanol to extract the ASA which is separated via filtration through celite. the filtrate is evaporated to give us the starting product. The reaction must be done in a well ventilated area and in a tall form beaker. overflows will result otherwise. Next we sulfonate the ASA in hot concentrated sulfuric acid for an hour and upon slight cooling we begin to add the correct amount of sodium nitrate. this nitrates the ASA firstly into the mono and dinitro forms of ASA and upon the last of the nitrate additions and heating we get the third nitro group attached giving us the trinitrophenol product. The crude product is then recrystallized from boiling water. The yield from this was 47.2g from 45g of the ASA Starting material so it is pretty high yielding usually 80-85% if done correctly. i didn't quite get that however still pretty pleasing. Music: Crunk Knight by Kevin MacLeod is licensed under a Creative Commons Attribution license (https://creativecommons.org/licenses/by/4.0/) Source: http://incompetech.com/music/royalty-free/index.html?isrc=USUAN1400044 Artist: http://incompetech.com/ Impact Intermezzo by Kevin MacLeod is licensed under a Creative Commons Attribution license (https://creativecommons.org/licenses/by/4.0/) Source: http://incompetech.com/music/royalty-free/index.html?isrc=USUAN1100620 Artist: http://incompetech.com/
Great video, good reaction detail and explanations. I think including safe handling and storage would be beneficial. I know safety is boring but sometimes it’s important.
if people wanna do the reaction they shouldn't just blindly follow it, because that's a way to get your fingers blown off, and I don't think safety instructions will help, if you don't know safe handling procedure or can't be arsed to look it up then you shouldn't make it, just my opinion
Another thing .How much time did you dissolve the crude acid before crystallization ? 2 hours 4 hours ?
Mucho gracious for ur rapid reply, I bow to ur greater knowledge.I look forward to seeing more video's from u, chemistry is magic.
Very good tutorial. Can potassium nitrate be used in place of sodium nitrate?
There are methods with KnO3 but the yield isn't quite as good. It works though.
@Chemistry of Questionable Quality I have used both, plus Ammonium Nitrate and prefer Ammonium Nitrate as the liquid is much less thick and it seems to nitrate and stir much easier. I believe the end yield is actually a little better also, i think only because it is a thinner liquid, doesn't foam as much and this probably allows it to nitrate easier. I find clean and dry Ammonium Nitrate the preferable salt in all my nitration's, such as ETN and even gun cotton.
It's funny, by that I mean odd, how the soundtrack makes this so much more serious, even if it sounds like an old legend of Zelda game on pure mdma
Add the cooled nitration mixture slowly with stirring to a crushed ice / water mixture. No NOx is produced this way.
Thanks, I normally find background music really annoying but you had a good choice it seemed to lend that medieval alchemist feel.
please add reaction formula to your videos.
So the ASA is just hydrolyzed and decarboxylated in situ? That's rather elegant.
Where have you bought your hot plate? I wanna buy one which is reliable and won't stop heating or stirring after a few reactions, that's why I'm asking.
Why is it important to sulfonate the aromatic ring first and then nitrate it? Why not just use mix of HNO3 and H2SO4 directly?
the yield will be much less as unwanted side products will be more like mono,di nitro phenol and oxidised product.
Would dirty sulfuric acid drain cleaner work for this reaction? Or would the picric acid react with the red stuff in the sulfuric acid?
Concentrated sulfuric acid loves to suck water out of stuff. It will even decompose organic compounds to water + other products just to hydrate itself. A classic example of this is the charcoal column experiment, where you fill a small beaker about 2/3 full of sugar, the rest of the way with concentrated sulfuric acid, and watch. It decomposes the sugar to water + elemental carbon. The heat produced boils some of the water, which expands the carbon into a foam, which rises up out of the beaker.
If there are traces of any oxygenated organic compound (anything containing C, H and O) in the flask, then the acid could be dehydrating it. Depending on what it is, you could get numerous by-products from this, some of which may be coloured. If it is turning black, you are probably generating some microcrystalline elemental carbon, which is suspended in the liquid.
If your acid is red, that means some of your sulfuric acid is behaving as an oxidizing agent. So the coloured products could well be oxidation products of whatever contaminant is present.
You could use it for this reaction, and probably get some kind of a yield, but its likely that it would be very dirty, and without knowing exactly why your acid is red, I personally wouldn't waste time or money....
Perhaps it would be advantages to perform a simple distillation of your dirty acid, that is if you are competent and experienced enough to perform this procedure safely, as it poses several potentially high risks.
Will you show us how to make Pentaerythritol tetranitrate (PETN Synthesis) with diluted nitric acid, Doc?
I second this!
@J H I third it!
Percentage yield is 82.45%
Is the same process required to crystallize ETN?
No ETN isn't soluble enough in hot water for that to be practical. Also you absolutely do not want such large crystals of ETN. You'll need some other solvent such as acetone, methanol, or ethanol to dissolve ETN and then it can be precipitated by dumping into cold water.
Good job on the recryst, nice big needles
Wouldn't using nitric acid result in a better yield at the end?
Is it worth to use nitric acid instead of sodium nitrate?
this synthesis has already been optimised by one of the best hobbyists out there and i know he tailored it to work perfectly with sodium nitrate. KNO3 won't give anywhere near as good a result. using nitric acid is a workable method too but requires a different approach and it fumes a lot more too. not entirely sure about higher yield though. i may visit the procedure in a future video.
This synthesis of TNP from phenol using nitric acid I got from COPAE (Chemistry of Powder and Explosives). It is very time consuming though, and very expensive, if you're planning on making larger quantities.
You can find it on http://www.prepchem.com/synthesis-of-picric-acid/ and also by downloading the book directly.
The book contains valuable knowledge.
yeah i'm quite familiar with COPAE. it is probably the first book one should read even before experimenting. there are many other books on the subject. as far as an explosive picric acid is pretty respectable but there are obviously better options. you should avoid HMTD and other organic peroxides.
I deleted the first reply I made. I thought you were talking about another synthesis of TNP that wasn't related to this video.
HMTD isn't chemically stable. It degrades with time.
I was thinking about silver acetylide double salt or DDNP for pimary. Or maybe ETN if it will make the deflagration to detonation transition when confined.
How well do you think ammonium nitrate would perform as the nitrate salt? I have read a paper that said that hot sulfuric acid and ammonium nitrate produce less nitric acid and just react to make other byproducts. I have KNO3 and used it before (I got lots of lower nitrates but I'll try again with better amounts of reagents) but I have over 5 pounds of NH4NO3 that I need to get rid of. I would like to do some very extensive testing on dunnite (ammonium picrate) since one guy was claiming that it can behave as a primary. Even after finding some common ground I still find this to be bullshit and want to test its properly myself with many many tests and two varying re crystallization solvents and using different particle sizes. Your thoughts on this would be greatly appreciated.
fdnjj 6 honestly you’d be wasting your time and picric acid. Testin ammonium picrate in that manner. It’s even difficult to fire picric acid by impact.
But using the nitrate to make HNO3 by distillation is the way to go. You get a thick slurry of ammonium sulfate which interferers withheld reaction and makes it hard to stir.
It is unsuitable for making picric acid. Not sure exactly why but it is. KNO3 will work better. NaNO3 is most suitable here.
@AllChemystery Okay thank you. I was planning on making dunnite anyway. I won't just be doing impact tests I'll also do a multitude of tests. I might just skip the the part where he recrystallizes with ammonia and just test my dunnite which was on the agenda anyway. I've got my synthesis planned out and decided to go with KNO3 because I heard lots of people have runaways with NH4NO3. I pulled my ratios from a different site. The synthesis also doesn't go above 90°C but he reported to get good yields and product so hopefully I'm not about to waste my salycilic acid. Last time I made picric acid I did my own calculations for reagent amounts and got only partial nitration with lots of lower nitrates. The highest my temps went was 100°C anyway so that may also be a factor.
Just convert the ammonium nitrate to sodium nitrate using sodium hydroxide and make ammonium hydroxide solution as a bonus.
@Chemistry of Questionable Quality Ammonium Nitrate works fine, but yes, it can be converted to Sodium Nitrate if you are worried. \good suggestion.
Is Picric acid fairly stable?
Would it be practical to make 500g of it?
It’s very stable and surprisingly insensitive despite being given a bad reputation over the decades as sensitive to store,.
500g is questionable- experience is needed with this and obviously you also need the raw materials and large enough glassware to cope with foaming.
Personally I’d do 500g over 2-3 batches.
Pretty impractical and why’d you need that much anyway?
@AllChemystery Thanks for your reply,
I need a reliable booster explosive to detonate anfo, it can be set off with a large amount of primary explosive but that is risky business
it is pretty stable but I'd really take care and not make that much, even if it is stable if you have half a kilo of something of essentially the same magnitude of tnt in terms of possible damage would you really wanna store it in your house? idk, probably can but 500g is wayyyy too much imo
Nice channel hombre, glad I found it
could you use potassium nitrate instead of sodium nitrate?
Yes
11:20
Remember my previous question about acid CuNTZ wet to extract a sample with metallic teaspoon submerged inside moist mixture. Cross contamination, beware.
And you use a METALLIC teaspoon in contact with strong acids? (picric acid even diluted with distilled water, Ph around 1 or 2, I believe) you know very well that crude picric acid in the presence of metal except tin form picrates.
(lid beaker cover /stainless steel teaspoon video)
Beautiful needles crystals PA extra pure. Congratulations!
Cabrondio VITRIOLVM the end product where I used the metal spatula the product is 100% dry and very briefly so no problem.
Chemically.. can you use denatured alcohol?
Do you think that I could get away with using filtered tap water instead of distilled water? I will be casting it later
Yes, but you could get side reactions that inhibit yield. I don't think there is and danger in it, but you should always use distilled water for chemistry. If working with energetic, you should always do everything exact and never cut corners. If so you really have no business getting into this field of chemistry.
Can I use 85% sulfuric acid of I compensate the lower concentration by adding more? And can I use denaturated ethanol as solvent?
I don’t think that will work. The purpose of H2SO4 is to dehydrate the reaction so by doing that you would just be putting more water into the system and it would fall.
Shit, now I have to distill sulfuric acid :/
@AllChemystery , what about denatured ethanol?
BackYard Science 2000 as solvent for recrystallising? No water is best. But it will dissolve the ASA from the tablets. Most alcohol works for that
@AllChemystery , ok. Thanks. I should have been more specific. I meant for dissolving the ASA.
deep side of youtube type stuff, when your this deep you can find how to make everything from drugs to firearms to explosives
would nitric acid be an even better option than NaNO3?
the point of NaNO3 is to produce nitric acid in situ, so I guess you could replace it with pure nitric acid, but why? I can't see it would give a much better yield and it being more aggressive could cause unwanted side reactions
I thought the dry crystals at the end are dangerous/sensitive when dry?
Picric acid is explosive when dry but its sensitivity is extremely exaggerated by most people. Large crystals make it more sensitive but 95% of the time not even repeated hard hammer hits can detonate it. Also it needs strong confinement to reach high order detonation so in all honesty it's pretty safe as far as explosion hazard.
Nice video, will you show us how to make %100 Ethanol? (200 proof)
Philip Bender molecular sieve 3A?
Distill over sodium or azeotropically with benzene
Excellent all around 5* Video.Can I ask if KNO3 will substitute for NaNO3?????
naturalbornfool not really. I mean you can but you won’t get as high yield or purity as shown here. You’d just need to adjust the molar ratio.Ammonium nitrate won’t work either. This is just one of those synthesis where sodium nitrate is required.
it will form percipitate as potassium picirate
@AllChemystery Ammonium Nitrate does work, i have done it with numerous nitration's, and not just for picric acid. I find it works just as well as sodium nitrate, but use ammonium nitrate because i have lots and is convenient for me. but works great and gives a thinner liquid for nitration to allow higher yield. just my 2 cents, but great video!
Do you know that you can actually purify picric acid by distillation? Just heat it up and it'll vaporize!
Alex Besogonov
Are you sure? But anyway no thanks... heating it in a confined space is just inviting disaster and knowing my luck it would probably explode.
Plus with this method, twice recrystallised acid gave extremely high purity and quality crystals which were huge, well formed and nearly clear upon viewing single crystals and titration gave a result of 98% purity.
So I’m good...
But only 20g of ASA are soluble in Ethanol?
Yes but the ethanol is heated to increase the solubility
Супер!
Do you think the wonderful music helped too produce the stuff man? You know, the spiritual vibrations and all.
I did some last week I think.
Wow!
After watching hundreds of Kerbal Space Program videos I was convinced that no piece of music by Kevin MacLeod would ever surprise or impress me. I was wrong.
could you use potassium nitrate instead of sodium nitrate ?
Not really. Sure it will work however you yield will be very low. NaNO3 is simply best suited for this synthesis. NH4NO3 will not really work either.
@AllChemystery Do you know why the yield is lower when KNO3 is used? Is it because of solubility issues or something else?
christianvn1 not entirely sure. I guess that from my experiments and others we have found that NaNO3 works better than other nitrates. If you have it or can synthesise it HNO3 works the best.
@AllChemystery Thank you for the reply, NaNo3 is eazy to make and/or cheap to buy.
Wouldn't this be easier if you were starting with phenol? The aspirin has impurities and all this complexity seems to be to overcome those limitations. And shit, phenol is crazy cheap compared to aspirin. (For those in the comments, yes, phenol is what they make aspirin out of, and many other medicines, and bakelite...)
Cool vide, but what did you do with the starch in from the original aspirin
Just discarded it. I don’t know exactly what fillers were used so it’s useless really.
Is it possible to replace sodium nitrate with ammonium nitrate ?
No. The ammonia produced would neutralize the acid.
@BackYard Science 2000 Ammonium Nitrate does not neutralize the acid. It works great for all nitration's. I have done many successfully and yield has always been good.
I’m glad to see this riskae chemistry that I am sure the “Martyrs” know quite well. But that works both ways? ;-)
Is it possible to start from Salicylic acid?
111 also you won’t have a reduced potassium in your solution nor sodium. It would be terribly dangerous. It doesn’t work like that. Sulfates are a possible by product as well as CO2 and acetic acid
Hi!
I will be using a detonator made with steel tubing and SA/DS. I don't know what is the critical diameter of PA, I will have to dig more to find out. But I think it will initiate reliably.
111 maybe. You will need a lot of it though. TNP is quite insensitive. You will likely need a booster. Look int ETN. It’s precursors are cheap,it’s easy to make and pretty powerful. A compound detonation device is going to be needed I suspect. Or a large amount of SA/DS-500mg plus which is not particularly ideal.
Yeah, I figured I must've been wrong. Sodium will react violently in contact with water.
Oh, I made the stoichiometric calculations. I decided to go with 40g of salicylic acid and 210ml of 98% sulphuric acid.
I just don't know if by using a smaller amount of salicylic acid (compared to acetylsalicylic acid) will result in a inferior yield. If it won't, its way cheaper than using ASA.
I can get salicylic acid for 12 dollars a pound.
I can synthesize ETN if needed.
500 mg is a very unsafe amount for a primary explosive, indeed.
How much ETN should I use as a booster though? 4 or 5 grams would be enough if the TNP is at critical diameter?
I need a lot of testing to achieve perfect initiation.
very good
How can you be sure it's picric acid and not 2,4-dinitrophenol? did you make any analysis to confirm that?
DarkF4k3 I followed a procedure written by one of the most knowledgeable energetic materials hobbyists around. His method is the best one written that I know of. A good test on purity is the fact that you have large needle shaped crystals which won't grow in a DNP solution. Upon close inspection the individual crystals are almost clear.Also during the recrystallising there was no red goop in the bottom of the beaker. DNP is more orange in solution. This stuff did detonate when put into foil and struck with a hammer on steel and it also did detonate when set off with a No8 detonator. I have also formed other explosive picrate salts with this batch. This is 2,4,6 TNP without a doubt.
DarkF4k3 Pretty much as long as it’s above ~80C, the third nitro group is pretty likely to go one there.
@Henry Jiang I believe to attach the third nitro group you need 100 degrees Celsius or hotter. DNP will definitely be all you get at 80. DNP when recrystallised forms globuals and forms at the bottom, unlike the long crystals when the third nitro group is successful. It is easy to see the difference.
Wow, careful with those beautiful dry crystals please!
It's usually kept damp and essentially inert! If you got reagent grade TNP from Merck - it would be with about 5% distilled water and it'd be sort of a paste.
Yea the bigger the crytals the greater the sensitivity. Also he used a metal spatula which is not advisable because of the whole sensitive salt thing.
No it doesn't have to be absolute ethanol. Isopropanol Methanol and acetone will also work.
Waht are you from
Can i start with SA instead of ASA?
BiG ᗷOSS Agar.io yes. You could. Just use the correct molar amount to the acid.
AllChemystery It hast toll be absolute Ethanol Or not?
nice :)
Why do we get CO2 gas.. What is degrading here? Carboxylate group? and why?
Would 2N02 react whit 4H to make 2H20+N2
David - 2018-06-29
Have you ever tried making 2-azido-3,6-dinitrophenol?
I haven't encountered it yet but maybe it's quite interresting.
Synthesis: Picric acid (reduction)-> Picramic acid (diazotation)-> 3,6-dinitrophenol-2-diazoniumchloride (+NaN3)-> 2-azido-3,6-dinitrophenol