This one is for all the homechemists out there, finally something u can replicate ;) Support my channel with patreon: / chemiolis Support my channel by becoming a member / @chemiolis
Happened across it in the Merck Index a while back. Once you know it, you'll never forget it. Another zinger: you can make acetone from vinegar and lime (and hard work)
You haven't been reading old enough textbooks of basic organic chemistry, I guess! I started reading older textbooks (chemistry, biology and electronics etc) as soon as I figured out how to read (basic university curriculum was available in the common libraries in the middle 1970s), and making aromatic rings from aceton or acetylene was atleast described in books from before 1960 ..
Whenever I have a bad day, I just watch the videos from this channel and drink a shot every time he says "short path vacuum distillation". It always works to lighten the mood
Just a friendly advice... Add the stirbar to the flask before placing the flask on top of the magnetic stirrer. The heavier stirbars pose a significant risk of cracking the flask or beaker when being pulled by the sirrer magnet. And in accordance with Murphys law this will happen at step 35 of the 37 step synthesis you have invested your life savings into. Trust me, I speak from experience. 😒
The ending was epic. Some real chemistry YT content there. And this is how you do a 100% yield, folks, take notes. Thank you once again for your entertaining content and hard work.
Only the thin (3mm) layer at the top was sand that is used to hold the column fill in place, if it was just sand it would just work as a filter. There are many different materials used for the column fill. Chromatography is used to purify many specialist chemicals because there are sometimes totally unavoidable side products in synthesis.
I am an azobenzene scientist, focusing in photoswitchability in condensed state. We think that tight packing due to pi-pi stacking usually inhibits photoswitching. That's why my research is focusing in how to allow this photoswitch in condensed state. Judging from your azo, it seems to be tightly packed. To confirm photoswitching I usually make solution, irradiate, and (1) do TLC (for quick confirmation) or (2) take UV-Vis spectrum (for formal photochromism report)
An alternative to the metal/acid reduction could be thiourea dioxide (TUDO). TUDO is available cheap from indigo dyer suppliers (it's now used instead of sodium dithionite, which cannot be shipped by air anymore) and it's a pretty potent reduction agent providing for a much cleaner reaction than dissolving metal. Procedure usually uses aqueous ethanol as solvent, nitro aromatic and NaOH are first dissolved, followed by TUDO and heating at 70°C for a few hours. The actual reducing agent is formamidinesulfonic acid, formed in situ from TUDO and NaOH.
Best nitration reactions that I’ve managed to do were with cold “over 100%” nitric acid. Over 100% nitric is just nitric acid with extra dinitrogen pentoxide (nitric anhydride) dissolved in it.
A nice fast trick to crash out amines as an HCl salt: Dissolve the crude mixture in ether. Take a test tube on the side and fill it half and half with concentrated HCl and ether. Then spray the top ether layer through the bottom HCl with a syringe and let it separate. The ether will take up some of the HCl. Then add the top HCl-in-ether layer to the flask with your crude mixture until the amine stops crashing out. Last step is filtration aaaand done! Keep up the awesome work man !
You're like "see it isn't crazy", well, that doesn't matter because it's damned genius, how you continue to come up with stuff that's original, I've never seen in school and could be done at home is absolutely amazing!
I've been making azo dyes in my research for my Master's degree for the last year, and I feel this video SO much. Weird tars, shitty yields... It is worth noting that we've found that the more heavily substituted the location for the azo coupling is, the harder it is to get any decent yield. 3% for a dye that has a 2,6- substitution around the aniline is pretty much par for the course. My PI actually joined me in the lab to help figure out an alternative... I'm not actually doing an oxidative coupling,, just traditional azo coupling, but I wouldn't be surprised if similar issues showed up even with the oxidative coupling. You still have to get the NH2s close enough to couple. Steric hindrance SUCKS and it seems like it shouldn't be that bad, but it IS.
when in doubt (metal) couple it out. some of those metal couplings stop at nothing. i'll always be shocked by the amount of bulk organometallic chemists manage to fit onto their tiny transition metal ions.
Whaaaaat. That's cool man. So commercial dye suppliers are only getting a couple percent yield in their processes? A few years ago a big supplier of chemical precursors in China had I guess an explosion or something in a warehouse, and for like two years there was this blue dye that was impossible to find because of it. Finally other people found different synthesisisis and we access again, but it being ridiculously low yield makes sense to me now as to why it took so long!
@@thatguy431 No, most of the commercial dyes aren't nearly this hindered. If you only have one methyl group next to the amine, yield goes up to 50-60% without too much trouble. Remove all substituents adjacent to the amine and yield is easily over 80%. The really hindered dyes aren't actually much use for commercial dyes, anyway, because they don't bind well to fabric.
@@christineg8151 Very nice how internet sometimes show some nice things. I work with azos for 6 years, and I really know the struggle with preparation of various derivatives. I am mainly focused on unsymmetrical diazenes, ones that cannot be made by azo coupling or Mills reaction :) We do this by sequence of Buchwald-Hartwig coupling of Boc-hydrazines and arylbromides, which are then oxidized. Nicely modular :)
Make the diazonium tetrafluoroborate salt of one aryl component and react it with a lithiated second aryl component. Think that's from a Ben Feringa article iirc. Very nice for asymmetric azoarenes. Warning though, as diazonium tetrafluoroborates are potentially explosive compounds. They're a whole lot more stable than e.g. the chlorides, though, so can in most cases be isolated safely, but proper caution is warranted. Also you need directed metallation, or alternatively lithium-halogen exchange to make the lithiated half. Haven't tried the exact Feringa procedure, but planning to do it soon-ish. And luckily, in my case the diazonium tetrafluoroborate seems fairly stable. At least enough for me to have made and used it without blowing up, lol
I like these videos! They remind me of old NileRed (not that there’s anything wrong with new NileRed, but it’s nice to see simpler reactions again). I live vicariously through these videos; I was gonna be a chemist, but I ended up going with a different major. I miss doing chemistry, but maybe some day I’ll come back to doing this!
A good alternative proceedure to prepare dry HCl in-situ for this specific application may be generating it from Acetyl Chloride/MeOH. It forms Methyl Acetate and HCl which would solubilise the compound and then simple distillation would remove excess solvents affording the hydrochloride salt.
I really like that you posted the worse method as well as the working one... so I don't have to wander what would happen if I added H2So4 and HNO3 combined etc.
Very nice synthesis! And pros for mentioning my beloved carbenes! Most anilines can be steam distilled which is a great method for separating them from tar. As for their precipitation, most often Et₂O is used as a solvent, one because dry HCl is sold as an ethereal solution, two to lower salt solubility (i suspect some ethyl acetate hydrolysed, air moisture everywhere, and alcohols dissolve amine hydrochlorides very well). As for column, just plug on silica on fritted funnel would be more than enough XD I agree with tin reduction, I never had luck with it and it is very messy, too much for my taste. As for oxygen source, better than exhaust from the pump (if it was diaphragm one it is ok, oil ones are horrible for this), washing the bottle with solid NaOH/KOH would help a lot, additional drying as well as CO₂ capture.
Hmm for nitration, we usually mix the nitric and sulfuric acid under cooling(SLOWLY!) before adding to our organic compound (also slowly holding the reaction under 25°C). Keeping in mind not to let the acid mixture ro get to warm since you gonna experience the the formation of toxic brown nitrousoxide gas.
Exactly. The mixing already creates so much heat that if happening in the reaction flask, would create local hotspots that create heaps of side products. Which is seen in the video 🥹
I mixed the acids normally without cooling (also did this before a toluene nitration) and did not see any gas, but yes it might be good practice to just mix them gradually to avoid any potential issues.
Great video! I have to agree with Thatchemist's advice to dye something after going to all that trouble synthesizing it.. It was a good contrast to see some "novice fabric dye experiment" shenanigans after all the legit informed chemistry :) I say that with all due respect - how many tie-dying channels are going to synthesize their own dyes? :D
Ok, so, these kinds of dyes are supposed to react with cellulose. So like cotton or natural fibers only. If used on polyester or something it will just wash out. Also, in order to ensure bonding happens, it needs to be in a basic environment, so us tie dyers will soak fabric in a soda ash solution before dyeing. It's cool stuff!
Concentrated sulphuric and nitric acid are not "home chemistry" in most of Europe. They're on the list of explosive precursors and you can't buy them unless you're a professional. There are even no common products containing them... BTW, the same problem with hydrogen peroxide, max. 12% :/
Your yields are always great. Very satisfying unlike most other chemtubers . Your yields are always great. Very satisfying unlike most other chemtubers .
What a masterpiece of a video! The jokes really made it too. Very thorough in all the trials and the procedure and improvements. Really good to see the whole process because it can be really disheartening when doing chemistry to see only success online and failure when you try it. One way you could have improved was during the steam distillation(s) of mesitylene was you could have used a dean stark trap / Clevenger apparatus. Also pretty sure that caking the dye on the sock isn't necessarily the best way to dye, there's probably a way to chemically bond lolz
Very nice job, sincerely congratulations. I have some considerations to do. Mesitylene synthesis can be seen as the cyclodehydration of three molecule of acetone. Using conc. sulfuric acid as dehydrating agent gives many side reactions because the acid react also as acid in fact. You can try others. The mess with nitration products can be easily solved with a good chromatography column and hexane, hexane : DCM as eluent. It is ever not so safe warm and distill nitrated compounds. Take care. As last that tar can be even more interesting than title compound. The amine can be precipitated dissolving in DCM and dropping carefully conc. H2SO4 until no more solid forms. Filter, wash and crystallize. There should be a direct reduction of nitroaromatic to corresponding diazo compound.
Btw if you really want strong bleaching that actually works, try powdered pool chlorine diluted in a bucket of hot water, then dip the clothes in it for a few minutes, then rinse thoroughly to get rid of the excess chlorine, otherwise it will start to attack the fabric and it will make it break apart very easily.
First of all, very nice video and I appreciate the amount of work you put in this video and in the synthesis. Your videos are very informative and in every video I learn something new. How do you analyse your intermediates and your products?
Speaking of sulphur dioxide, me and a high-school classmate accidentally made some when we were dehydrating (is that the correct term here?) one of those salts that contain water in its solid form. It turned out the little ceramic vessel we put the salt in to heat it contained some sulphur impurities. That gas is not play with, real nasty stuff and it took until the day after before my throat felt ok again. Also, as you can tell I'm not even close to a chemist, but I really enjoy your content! Feels like I learn something in every vid
One of the best chemistry channels doing things that may be ridiculous but are scientific. I love your videos and ideas. I'm a chemist like you, but maybe younger and without a lab :/ Regardless, these kinds of videos refresh my knowledge and perspective on chemistry. Go ahead and share your knowledge with the world. I wish you all the best :)
I'm not sure why Bechamp reduction fell out of favour. I used it on a number of arylamine substrates during my PhD and it almost always gave 95%+ yields. Because the yields were always so high, there were very low levels side products. I was normally able to simply extract, filter and then recrystalise my products to obtain high purity samples (again with yields upwards of 95% isolated). Before going the Bechamp route, I tried the more common hydrogenation over Pd/C but it consistently gave more impurities and lower yields. There were a few times where I had low yields but it was always because I produced too much fine iron(III) oxides that seemed to love forming an emulsion, trapping product, blocking filtration and becoming a nightmare to extract. Once I got the hang of it though, it became very reliable.
I'm not super sure how good I would feel about trying to distill over the di and trinitro mesitylenes. I could be wrong but something tells me that those two extra methyl groups aren't going to make a big difference between trinitromesitylene and its cousin, trinitrotoluene. -edit Wow. That is an insane amount of work. Kind of an "uh-oh" moment when you have a yield that has to be separated by column chromatography.
An alternative approach could potentially combine step 2 (Bechamp process) and step 3 (oxidative coupling) by coupling both in a reduction process going via an azoxy-intermediate (coupling of nitro- with amine-compounds).
You can find various methods in the following book chapter or by googling for "nitro amine azoxy coupling": "2.7 Reduction of Nitro Compounds to Amines, Azo Compounds, Hydroxylamines, and Oximes, and Reduction of N-Oxides to Amines" DOI: 10.1055/sos-SD-227-00139 (p.340ff) (from "de Vries, J. G.: 2018 Science of Synthesis, 2017/6: Catalytic Reduction in Organic Synthesis 2")
e.g. this one: "Preparation of symmetric and asymmetric aromatic azo compounds from aromatic amines or nitro compounds using supported gold catalysts" DOI: 10.1038/nprot.2009.242
Studying for JEE, i've seen only the reactions on paper Brings a whole new appreciation seeing how much more extensive and complex the actual process is
You could cool the sulfuric acid and nitric acid mixture before addition below room temp. That would probably suffice to keep the temps of the reaction mixture low.
As an operator of a public water system, bleach is my life. Everyone's indoor plumbing would become contaminated with bacteria and they'd all get sick. I'm actually heading out the door now to buy another 55 gallons.
Love the suggestion to conduct the last step with pure oxygen. Probably a 💥 of an idea flushing a flask with toluene and pure oxygen… 😏 Also: I wonder why you never use any analytics to check purity/characteristics. Looks like you’re working in a research lab, surely you have NMR/EI-Mass around? Additionally: The boiling temperatures always change with the pressure. As you’re using a vacuum pump for your destillations, it would be good to know the boiling points and the respective pressure your pump reaches. Especially for characterization as NMR/MS is not conducted. Lastly: I hope your pump survived the vacuum you put on a mixture containing conc. hydrochloric acid (and the hydrogen chloride it releases)… 🥹 Very entertaining videos!
I basically only check reactions with TLC, pretty much all the time. This is my own setup, thus I don't have any of such expensive analytical equipment. Sending it out is not possible since the companies are always booked full and I would need analysis on short notice. For the boiling points, I didn't measure with a vacuum guage since it isn't too important for this one. If I say vacuum, I use a membrane pump which will pull to about 20-40 mbar. If I say strong vacuum I'm using a rotary vane pump which pulls
I am writing this before watching the video (I only watched to 0:40, so I have not hear or seen what reactions are you going to do): condensation of 3 acetone molecules gives trimethylbenzene, then you will nitrate it, reduce it to make trimethylaniline, react with HNO2, and add thrimethylbenzene. Upd: I have watched the video. The last reaction was other than I thought
Could you include a little “supporting figures” thing with reaction mechanisms for some of the more complex rxns? Maybe in the description or at the end? I feel like having mechanisms helps us understand the process better.
I love how it's just like serious chemistry, then out of nowhere "it becomes as white as my ass in winter" xD love it. If teachers were allowed to talk like that, maybe there'd be more nerds 🤔
very nice! i tried the mesitylene synthesis a while back but it was in such a small scale that all the yield went down the drain, condensation reactions really don't yield well on small scale :P I might try this again but on a larger scale after i get more sulfuric acid and acetone, the orgsyn procedure i was following also was a little vague/ confusing in some steps so that also may have lead to no yield from me guessing things
i also suggest getting a overhead stirrer, these can be made with a cheap drill and a stirrer thing bought online (synthware has them but tbh cheap ones are fine), itd be perfect for stirring pasty mixtures and the iron powder
Could potentially get the temp lower during the acid addition by adding a condenser between the addition funnel and reaction flask and run chilled coolant through it. This way, the drops that actually reach the reaction are ice cold, or colder! (In theory, you could run it lower than 0c, since the acids are not even close to freezing at this temp.) Also, how many kiloliters of ethyl acetate do I need to do this exactly?
Pretty cool video! And dude, you seem to absolutely love your short path condenser xD Is this just because you don't have a rotavap, or is there something else?^^ And I like the difference from Tom to you: Tom: "Yellow chem bad" You crazy dutch chemist: "Just go directly to black tar and extract your pure product! Problem solved!" 😂👌 Edit: Oh and congratulations on your absolutely perfect yield of 100 %! From one off white sock to one orangy sock. Amazing. Amazing. Wow^^
I think u can get some azodye by just mixing aceton and ammoniaque, after a moth or so u get some red liquid that smels afule and has a strange yello phase. Idk i made it 2 mothes a go and now its just siting on my desk, witch is stubid becaus u can still smell ammoniaque and if it is some kind of azody its canceres to
iirc you can also use HCl to produce mesitylene from acetone instead of H2SO4, I haven't looked at the details but this could be a way around the SO2 byproduct.
If I oxidize mesetylene to it's respective tricarboxylic acid and then react it with a strong base under heat, will it form benzene? Then that would mean I can make benzene from acetone!
I like how at the end you have never used bleach, yet you have all these chemicals, and even better you had to ask your mom for bleach when you have all these dangerous chemicals. The bleach you used isn't that good, especially for chemistry, I always try and go for the stuff without any impurities like surfactants, colors, and smells.
