Making 18-crown-6 - Crown Ethers
Vložit
- čas přidán 16. 07. 2022
- Check out The Column! A free e-mail newsletter about the chemical industry.
www.thecolumn.co/?...
Procedure for 18-crown-6: www.orgsyn.org/Content/pdfs/pr...
In this video I am making 1,2-bis(2-chloroethoxy)ethane using the Appel reaction with carbon tetrachloride and triphenylphosphine. This reaction is relatively uncommon nowadays due to restrictions on carbon tet, therefore I followed my own procedure which I put together from general statements online (due to its simplicity). Afterward, I used this product while following an orgsyn procedure to make 18-crown-6.
Support my channel with patreon:
/ chemiolis
Support my channel by becoming a member
/ @chemiolis - Věda a technologie
![Making [1.1.1]Propellane](http://i.ytimg.com/vi/iTlRvQuIyqE/mqdefault.jpg)
When you use KOH, it not only provides the base needed for the ether synthesis, but the potassium ion is the correct size to act as a template, around which the cyclic ether can form instead of favoring a polymer.
that's super cool actually
Very good observation! When you make 15-crown-5 you use sodium hydroxide as sodium is the best template for 15-crown-5.
ah i was going to ask how you make rings of the right size
@@morgan0
The bigger the ring the bigger the cation you use.
12-crown-4 - lithium
15-crown-5. - sodium
18-crown-6. - potassium
(sodium will also work)
dibenzo -24 crown-8. - potassium
@@karlbergen6826 So, if you wanna make 6-crown-2, you use hydrogen hydroxide?
Up to now I didn´t know you could actually make them this easily. Anyways great video!
But the yields are not so pretty. A testament to their price.
Macrocyclizations like this are usually done at high dilution. Im equally surprised that there's a useful amount coming out.
@@orange422
The template effect brings up the yield which is why potassium hydroxide is used. If your yields are low of if you get a mysterious blue color on distillates try making the tryethylene glocol dichloride from tryethyline glycol yourself. Some tryethylene glycol dichloride that you buy just doesn't work properly. Use phosphorus trichoride as your source of chlorine and stay out of the fumes.
Easily? how can you easily get Carbontetrachloride nowadays?
@Damn Good Very easily and even cheap when you know where to look.
@@damngood8476 yeah I mean this is a whole topic in Xplosions & Fire's channel right?
I was thinking "easy? ha... sure IF you can get the carbon tet.” 🙃
i recommend posting pictures of the mechanisms on screen, nile red does this and it makes it easier to follow
I used to make 18-crown-6 by reacting tryethyline glycol with tryethylene glycol dichloride and potassium hydroxide. This was done on pilot plant scale. Distilling it was tricky. As if air got into it it would explode. When the distillation was done we turned of the heat, and left the vacuum pump on and went home.
runaway reaction moment, generally its good to assume reactions as exothermic and keep an ice bath handy, and a thermometer in the flask. all that tet boiling is horrifying
I think it's so cool that you have a sponsor for these last 2 videos. You deserve it because you are funny and your chemistry is very fun to watch!
"these royals are actually useful" got a good snort out of me
When you put the stopper on I said to myself "that's not good, but ok". Yeah, never do a reaction in a closed system unless of course that is your intention and you know exactly what you are doing and are sure that you have the appropriate presure vesel. PV=nRT always have your apparatus open to the atmosphere . PV=nRT
i really loved the video . Even though i dont have the chemicals to sythesize it . I loved first time on youtube someone attempted to make it and was successful . I have studied about crown ethers and they are interesting in their own way.
does it have to do with the flower of life
and 6ether
Props for the short and related sponsor.
I just did your procedure with a condenser and it was still super violent and sprayed reagents all over my fume hood. I would highly recommend keeping this in a water bath or ice bath to anyone attempting this again. I'd also recommend using a 1L rbf for more head room.
Yes it takes off suddenly! Nice of you to verify, definitely some additional measures should be taken to tame it down. Will you also make the crown? Let me know how it went, and make sure to use magnesium sulfate when drying, cacl2 made it really messy.
@@Chemiolis Yes, my coworker needs some for an experiment and I intend to make it instead of purchasing it. I'll let you know how it goes.
@@babybeater12 how did it go
Poor guy 😢
Very elegant and straight forward.
Years ago I used to make I8-crown-6 from triethylene glycol and the corresponding glycol dichloride in a 72 liter flask. I also made dibezo-18-crown-6 from catachol and the dichloride of diethylene glycol. I used n-butanol as my solvent and and sodium hydroxide. I recryalized the oroduct from toluene. Most of it was hydrogenated to a mixture of anti and syn dicyclohexano 18-crown-6. The catalyst was Ruthenium on alumna. The pressure was 1000 psi.
Really nice video, i really enjoy your channel keep it up !!
Oh the pain... *pop* "what was that?" Shit shit shit shit! *turn off stirring* and then that lovely feeling of having nothing left that you can do to stop the incoming trainwreck but to just sit back and watch. I so know that feeling.
Nice synthesis like always
Very cool channel, love from the Netherlands/Poland
Very well done. Your videos are of good quality and extremely interesting. Appreciate the fact that you attempt to demonstrate the mechanism (when it is known). Lewis structure diagrams would be even more informative for those who do not have a degree in organic chemistry. At any rate, thanks for posting and keep up the good work.
Great video :D
Good video AND good volume ;) thanks!
Very interesting video! Crown ethers are very cool and useful in the lab
Really Enjoyed
Awesome! That was a lot of work, thank you for that. sorry about your glassware.
Can you substitute bromine for carbon tet? Get different crowns with different x-ethylene glycol ethers?
Nice work 👏
Pretty cool synthesis!
It is a shame, that sealing glassware with a stopper is always such a high risk. I have heard many stories about shattered glassware due to unforeseen pressure building up. It would be nice having a stopper, that has some sort of safety mechanism in place to prevent this, however that would be pretty complicated to implement.
Actually that exists and it isn't very complex. Every pressure cooker in the kitchen has such a thing.
I mean, there are ways to prevent the stopper from shooting out, but the glassware sometimes doesnt take the pressure and decides to explode. Some kind of rupture disc would be nice but they are usually made of metal and not very inert. Also a valve would be nice to releave the pressure before opening again, otherwise it would be hard to open without the stopper to shoot out. At that point it would probably already be easier to avoid a pressurised system entirely by just using a condenser instead (for reactions like in this case). However for storage, glass stoppers are primarily used. When storing things, the pressure shouldnt change too much if the substance has been handled correctly, so maybe we dont need those exotic stoppers I was proposing earlier :)
The easiest thing to do is to just put a clamp on top of the stopper (with about 1 cm space) so that when it pops out due to pressure buildup, it won't shoot off completely, but will still allow gas to escape before dropping back down. I'd also recommend to use a plastic stopper as a glass stopper might shatter.
Use a bubbler filled with mineral oil. Can be improvised with a hose connection and a beaker if you don't have one on hand. Just make sure that the descending part of the tube has a higher internal volume than the liquid in the beaker. Otherwise you get suck back.
Pressure differences get equalized by gas streaming out/in, eg during heating/cooling but for the most part it's sealed.
what you want inst like, just a stopper with a teflon check valve?
that would be hard to do
Good vid! Thanks a lot!
Cool stuff! Any chance you will try to synthesize alkalides or electrides with it?
Thanks!
very usefull video! thanks bruh
Do you think you lost a lot of product to polymerization of the chlorinated triethylene glycol rather than cyclization?
I didn't know they made cross shaped stir bars. Another thing to add to the list of things to get.
Dude this is so cool.
Could I ask that you include links to the literature you mention?
I will put the procedure i followed in the description
Undergraduate chemist here,
Does this technically make the crowned ethers molecular cages? Or are they a separate classification because they only trap those specific cations?
Awesome video!
Is that a Dutch accent I'm hearing?
Nice video btw! it's exactly the type of way I want to learn more about chemistry
This is so cooooool! I’ve been waiting for years for someone to do it on CZcams. One question though: what was the final yield?
0,5 g - approx 5-10% (lit. 60%)
@@Chemiolis Oof
Awesome!
Lovely, so envious of all your cool stuff. How can you afford septa, flasks, and organometallics, among others? I wish I could do that! Anyway the Appel reaction is also quite an interesting reaction, shame that CCl4 is so toxic and gets so little attention because of it...
I pay pretty much all of it out of my own pocket, from savings. Adsense, patreon and now sponsors help but they don’t cover all of the expenses yet. Appel reaction is definitely interesting, there are some modified versions that use a slightly different halogenated methane to avoid tet. I also saw a catalytic version that uses chlorinated oxalic acid as Cl source and PPh3O as catalyst.
CCl4 was banned for the same stupid reason CFCs were banned.
you can do an appel reaction with other chloride sources - also wouldn't the tosylate suffice?
Could the crown 6 compound make complexes with cobalt, iron, manganese, copper and other salts? Nice video.
I don't think it will, the size is quite specific and therefore the interactions are too weak if the atom is too small and thus too far away (or too big and it doesn't fit).
I think it would be ok to add some sodium iodide during Williamson ether synthesis. Iodide is a good catalyst for this. Wonder what is the yield, looking at the amount obtained it seems that you formed a ton of PEG instead of crown, unfortunately
I followed an orgsyn protocol for this. www.orgsyn.org/Content/pdfs/procedures/CV6P0301.pdf I kept it pretty much the same, I only changed the drying agent. But I also made my own reactant which I don’t know the purity of. The CaCl2 was kind of messy honestly, maybe it had some effect, it made it really thick. Anyhow my final yield of pure crown was 0,5 grams which is a yield of about 5-10%. In the procedure they mention ~60%. I couldn’t achieve the same high vacuum as them though which troubled distillation slightly as well, but it was still do-able with higher temperatures.
damn good video
Great video! Would be nice if you could show the full set-ups as well as the close-up shots too :)
I wonder how well the 1,2-bis(2-chloroethoxy)ethane would participate in a blanc chloromethylation of benzene.
Oh my god
Carbon tet!
why is your buchner funnel so small relative to your erlenmeyer flask? where is your chemistry feng shui?
In 32 years as a synthetic chemist, I don't think I ever ran a reaction in a stoppered flask unless that's what was called for.
SOCl2 probably is the best reagent for the 1st Rxn.
Next you can make cryptand 222 which can make the sodide ion(Na- ion)
is there a reason for using the appel reaction? why not simply use PBr3 or thionyl chloride?
I had the chemicals already and it is usually high yielding
I knew as soon as you stoppered the Appel reaction that you were in trouble. As you observed, they can be quite exothermic.
that carbon tet spray cannon was something from my nightmares. my god.
Please record something with NaH use
I noticed that you usually fill flasks too full. My preference, it should be less than 50%. You could try 500ml rbf more often.
Cool
Never stopped unless you're making Kool aid, and you went. 😂
Make a complex using transition metals and you will have an excellent catalyst for making metalorganic compounds. 🤓
How did you know you have only that crown, not others or just linear ethers?
Only the 18-crown-6 will complex with the acetonitrile and crystallize out. Linear ethers will dissolve in the acetonitrile and get washed away, other crowns aren't really produced afaik. If they are, it is really an insignificant impurity.
@@ChemiolisHow do you make 12 crown 4 because I’ve been looking through the web for a while trying to find a good free article on the synthesis of 12 crown 4 and there is basically nothing on the synthesis of 12 crown 4
"Despite their royal looks these royals are actually useful"
Well that confirms that you are Dutch 🤣
CCl4 Fountain!
How are you dealing with EU regulations regarding chemicals? They're some of, if not _the_ strictest in the world for amateur chemists.
I can buy pretty much every chemical by using a company when buying it. Though the carbon tet I have extracted myself.
@@Chemiolis Yes, carbon tet is hard to get hold of, because it definiely shouldn't get into the atmosphere.
For the other things I thought of registering my own business, or creating a chemistry club, raising some funds and rent some space where people can do chemistry together
Much work, low yield, but at least successful this time! 👍
BTW: Isn't CCl4 banned worldwide by the Montreal-protocol? 😕
Yes. That doesn't mean that you are not allowed to use it for science or education purposes.
@@call.me.heisenberg6990 Yes, in universities and research institutes. But it doesn't give me the impression, that we are dealing with either of them here...
Carbon-tet is one of the worst solvents that someone could mess around with...
@@call.me.heisenberg6990 as far as I'm aware it's not even allowed in universities here in Australia
No it isn't. It is a routine solvent in Russia for example and you can buy it here without any paper or something like
@@markshort9098 Australia is nearest by the ozon hole... 😉
Nevertheless, Tom from E&I extracted it from the same source as this channel...
1:51 It is difficult to visualise the chemiclas just by hearing their names. Molecular drawings over the flasks as you read out the names would make it easier. -- We are her to learn a little, or refresh some chemistry in an entertaining way. (To just watch something explode we would have visited channels with less potential.)
Invest in some keck clips and no more broken stoppers
If too much pressure builds up, it will still fail. Or if your keck clip is stronger than the glassware, the RB itself will break. Best to use an open container (tall condenser) or an adequately sized bomb/pressure flask
Neato burrito
>carbon tet
i have decided not to attempt this one myself.
loved the video!
this guy came to make good videos like nilered used to make. now he only do stupid shorts
Is this drugs?
I like how you skipped the most irrelevant alkali metal, rubidium
This is a horror movie