Chlorination of Isobutene: 1-MCP ep02
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- Опубліковано 28 чер 2024
- We take our previously made isobutene and pump some bloody chlorine through it in order to make the molecule methallyl chloride. This is the molecule needed before the super-base cyclisation to form 1-methylcyclopropene, the magical apple chemical.
- Наука та технологія
There's a lot of thought that I'd add the chlorine to the double bond, but the literature says that I should get alpha-chlorination instead. It's a slightly more complicated mechanism but yeah... it shouldn't just simply add to the double bond.... it shouldn't.....
It does attack the double bond, but that's actually what gives you your product!
According to this paper, the mechanism goes as follow :
-Electrophilic attack of the chlorine on the double bond :
(CH₃)₂C=CH₂ + Cl₂ --> [(CH₃)₂(CClCH₂)]⁺ (isobutene chloronium, that last bit is a 3-membered cycle with a Cl in it) + Cl⁻
-Proton elimination :
[(CH₃)₂(CClCH₂)]⁺ ---> (CH₃)(CH₂Cl)C=CH₂ + H⁺
So the double bond shifts to another carbon (which loses a proton), and that's how you get the methallyl chloride and HCl!
pubs.acs.org/doi/abs/10.1021/ja01153a549
(Notice that they've used ¹⁴C-labeled isobutylene! You gotta love the fifties...)
piranha031091 thanks for this insight!! Very interesting.
And yes, a lot easier to track than 13C if you've got shitty 50s detectors I suppose haha
What is your yield?
Extractions&Ire ah yes, rearrangement, the bane of every chemist. Theory will tell you one thing but then charge shifting will change to stabilize that transition state :/
@@piranha031091 ........i do not have time RIGHT NOW to read more than the first paragraph of that paper you mention but it said the methylallyl MONO chloride was made at ZERO CELSIUS and they got a 83% yield. I was under the impression that the reaction sucked in the cold. I think the guy who wrote your paper and the guy who wrote my paper should be forced into a boxing ring and fight it out to see who is right. Sure it is not scientific but it would make me feel better cause at least the guy who is wrong will get punched alot since both of them will get punched a lot probably.
Best channel ever (other than ex&f): smells like a marshmallow that’s been cooked in a war gas
War Gas is a great name for a band.
Idk, I think this channel is actually better than his main channel. More Chemistry, more detailed.
@@jhyland87 is this not the main channel it has more constant uploads
Mate you need to build yourself a roof on some stilts, a shed without walls if you will. Keeps the rain off but lets you be essentially outside for any nasty fumes. Cheaper than a fume hood too.
I think you "steam-distilled" off a lot of your product by not having a nice fractionating (or at least a refluxing) column above the boiling flask, and then dumping hot water into the water bath, which caused the DCM to violently vaporize and carry other relatively volatile components over the short neck and into the condenser.
EDIT: Also, avoid ALL UV (the sun, fluorescent lighting, etc) to stop chlorine radicals from halogenating your double bond... Even a single, dim fluorescent lighting up an apparatus, which was almost completely wrapped in foil, is able to produce enough side products to make separation VERY difficult.
The extension cord just chillin in the rain is a n x i e t y
So, I feel like you need smaller glassware setup. Even a single shortpath could be really useful. And the heat could have polymerized it, you could pull a partial vac and distill at a lower temperature
Please don't give up!
Thanks for the support!
love it. I'm part of the process, figuring the possible mistakes and improvements as we go
Over chlorination or polymerization is possible. It’s also possible you made a chlorohydrin as the set up is not water free. Hard to say what happened. Try to get a hold of N-Chlorosuccinimide, this is a solid chlorine source which will help with the stoichometry problem. Keep it out of light. Try to dry the DCM with magnesium sulfate right before the reaction.
en.m.wikipedia.org/wiki/Halohydrin
mrmax35 The DCM is pretty dry, it's stored over a whole bunch of molecular sieves too.
But you make a very good point. I got very excited because I saw that often DBDMH can be used as an alternative to N-bromosuccinimde (I could make the bromo instead of the chloro, should be all good). This is exciting because DBDMH is readily excessable to me as a brominating thing for spas. Unfortunately, it doesn't look like that chemical can do alpha-brominations like we have here, and will over-brominate the double bond.
I could perhapppsss try to make N-bromosuccinimde?? Would extend the project out a little haha
Yeah, nice job (or really, effort) man! Hyped to see more :D
"I'm so. I'm a bit pissed off." Might as well be the motto for orgsyn.
I wish I could say something helpful here. Good effort though. Keep persevering. Gas phase reaction sounds like it might be worth a go. Doing stages 1 and 2 as a single process sounds like a headache to set -- especially controlling the gas streams. But at least you avoid playing with cryo temperatures.
I had to prepare 1,2-Dibromocyclohexane back then, which also turned black when distilling it. So it had to be washed by adding a third of it volume of a 20% solution of KOH in Ethanol and then the mixture was added to the same amount of water. Then it was washed with water until residues of the base where removed. So I guess that maybe unreacted chlorine is present which then reacts in the heat. According to the rule (sorry for very bad translation from german) "Sunlight, heat, sidechain. Cold, catalyst, core.".
Random Experiments Int. - Experiments and syntheses distilling it in the sunlight probably didn't help at all yeah, possibly triggering it to polymerize.
A comment suggestion was that perhaps the byproduct of HCl was interfering, perhaps during the distillation with the heat. So that's maybe the reason for the KOH wash?
Don't you risk substituting the chlorine for an OH when heating stuff like this with potassium or sodium hydroxide?
Colin Ries yeah there's that risk, so maybe carbonate wash would be better. Would have to wash out all the base before distilling
I apologize if none of what im brainstorming is useful, it's been years since I've seen a chem class/lab. But if your byproduct is HCL and H2O, and you need Cl2 to make it go, doesn't either sodium or calcium hypo do the trick? Sulfuric and sodium hypo would also make chlorine, and sodium sulphate, which i think would then be inert, same with calcium hypo, but calcium sulphate.. plus if water is an issue maybe h2s04 is of some use. I've completely lost myself at this point but best of luck and thanks for the vids :D
I'd say the KOH is to remove acid and the excess of halogen, if present. Like I said in the beginning the base has to be removed for sure, before heating it again.
Marshmallow Cooked In War Gas... Thanks for my new band name!
Boiling and not getting anything over can be due to large system volume. Too large bottle has a large gas volume. It can all condense and drop back before getting over.
Smaller bottles and short path distillation head would help in those cases.
Extraction&Ire .......I may know your problem. Free radical ALLYLIC chlorination is done with HEAT. In the cold the equillibrium is shifted to the other reaction where the chlorine creates a halonium (chloronium) ion with the double bond and then another chlorine adds anti addition so each chlorine adds on each side of the bond (anti). You know like you are testing for double bonds and you use bromine in some DCM. You MIGHT need to apply pressure to get the temp up since the boiling point of isobutene is so low. But then how do you get the light in the reaction? Heat also forms chlorine free radicals so maybe you would not need the light .......just pressure to build up the temp. I do NOT know but i do KNOW that free radical ALLYLIC chlorination sucks in the cold. Maybe that is why your product has such a high boiling point cause you added 2 chlorines to the double bond and not just 1 to the allylic position(keeping the double bond). Also it looked like you put foil on the reaction pot for a lot of the time. You need the sunlight to do the ALLYLIC reaction and if you block the sun the chlorine will DEFINITELY add anti on the double bond. Cause adding to the double bond is so easy it is spontaneous. No energy is required like with the allylic addition
"Smells like a marshmallow that's been cooked in...a war gas."
I stopped midway through the video so you know this is urgent.
I really appreciate the funky background music about three minutes in. Just wow.
Also, Have you contacted Cody yet?
I appreciate the urgency! It's an Aphex Twin song, part of his unofficial 'soundcloud dump' that happen like, wow nearly 2 years ago now.
And yes, well actually he found me amazingly. He commented on the first video so he's in! We just have to get there
The fact that your DCM is in an old beer bottle makes me laugh! :)
DISCLAIMER: Or at least is used to be...
Oh my. What have you made? Some kind of halogenated isobutene oligomer?
The outdoor conditions won't have helped, the UV levels will be way too high - radicals a-go-go.
Extract&Ire.........JUST MY OPINION BUT .......... i think it is best to use LED blue light for making chlorine free radicals. Chlorine only needs 494 nm green light to cleave their bond homolytically. And LED blue light is 450 to 480 nm which is PERFECT. I am going to buy a blue LED flood light to use. I have to use blue light for benzyl chlorination cause the benzyl carbon/chlorine bond that is formed is broken with UV light and violet light shorter than 421 nm. So i am forced to use LED instead of the sun. But i am going to use it for all my free radical chlorinations in the future. Even when i make tetrachlromethane from DCM. Cause i know the benzyl carbon/chlorine bond is PROBABLY the easiest carbon/chlorine bond to break so i know the blue light will not break ANY carbon/chlorine bonds no matter what i am making
Why not just get a pop-up tent canopy to keep your set up dry?
Time to get the NMR machine!
Hey hou, you should try the Wohl-Ziegler-reaction, this reaction will selectively chlorinate the Allyl- Carbon.
or chlorinate the alcohol via free-radical Halogenation, distill (124-128 °C(lit.)) and then eliminate hydroxyl group.
Dr.Satan that named reaction is a good one, but the reagent for it is hard to get. Also, assuming I have it, I'm not sure what the experimental setup would be as it's usually done in refluxing chlorinated solvents, which we can't do because of the low boiling point of the compound
I wonder if it wouldnt come over because that boiling flask was too big or had a leak? maybe it was re condensing and refluxing instead of making it all the way to the condenser.
Damn. i know that feeling all too well. still as annoying as it is, don't give up!! maybe the choice of acid in the Chlorine generator had something to do with it. HCl gas may have come over with the chlorine and reacted with the isobutene.
Why don't u make a simple refrigeration system using fridge compressor from scrap yard and copper tubing...u can use propane as refrigerant and you will get - 42*C temperature at evaporator
Dollar Projects he isn't codys lab
I think that’s not his strong point...
almost any compound with a c-1 double bond polymerizes on heating when impure and under light. I've never been able to destill styrene, methacrylic acid or anything like that without strong vacuum at low temeratures.
Shroom Lab Yeah, things seemed to go bad on heating. It was only 60 C...... But yeah. How can I get around this? Vacuum distillation? That's a real shit for me to do honestly
Vacuum destillation is difficult I agree. Additionally you probably don't have the data of bp under reduced pressure. As the mp of your product is so low, crystallization even whith dry ice gets a nightmare. I'd try to find a high yielding procedure with low side products boil off excess the isobutene at -5C or some and check the refractive index if you can if the purity is ok without further processing
8:30 this is happening to me with acetone, it wont distill anymore...
aphex and chemistry, my fave things
You really should have a fume hood, doing experiments outside is way too much to handle....
And how did that unprotected power strip manage not to short in the rain?
looking back on the footage, I had that exact thought honestly. I've been meaning to replace it with something a bit newer and something less rained on, probably a wise thought
Surprisingly it takes a lot of rain to penetrate the sockets on a power board. Not recommending you to test this theory especially if the circuit isn't protected by an rcd
That paper says the light is also causing over saturation and your getting dichloride. You need to try this with an oxygen free atmosphere in the flask.
cannagorilla ah oxygen free, gross. If that's required, it'll never work, I just can't do that well currently. I'll definitely exclude sunlight next time though
@@ExtractionsAndIre You were working with dry ice, just vent the offgassing from that into the flask. "Pure" CO2, if that's not in itself a reactant in this situation.
how do you avoid chlorinating the double bond?
nickt; By not exposing to to any UV (so basically doing it in complete darkness, or by using browned glassware, or with only low-energy lighting like they use in semiconductor manufacturing.).
Have you considered using N-chlorosuccinimide? I've read that it is used to chlorinate in the allylic position.
David Yes, but N-chlorosuccinimide is not an easy chemical for a person like me to get. I've been looking up how to make it or its friend N-bromosuccinimde, it's not easy but definitely possible. Will extend out the video a bit though
Extractions&Ire is it so hard to get? Here in Austria, I can just order it in the internet.
Other idea: Could you use N-chlorphtalimide?
Burned it ? OK. Put on the anvil. Not works? You use bigger hammer. Will works.
LOL yes bigger hammer. :)
Haha........Too much questions in video. Only anvil shows exact results. Hit, done.. :-)
MAKE THAT STUFF! FUCK YEAH! i have no idea >.
Pyridine? Organic base. Its not a strong base. But easy enough to make
Now that's not just a good suggestion, that's an excellent suggestion. It would scavenge the hydochloride without interfering with the reaction product. Does it react with chlorine gas though? hmmm
onlinelibrary.wiley.com/doi/10.1002/recl.19390580808/abstract
Apparently at 270C in the gas phase. So. Not easily
I tracked down that paper too, looks good! They mention stuff about free radicals promoting it too, so i'll have to shield it from light but the current thinking is that i'll have to do that anyway really
Try it Its only time and money.
If pyridine is too nucleophilic then reduce it to piperidine Not as easy. But it would be a great additional step. You need more of those. Haha
G'day from sucky England!Watching some mind-numbing intellectually vacuous celebrity drivel on the idiot box or satisfying your chemical curiosity by doing some 'matter manipulation' - what would you rather be doing? ;)
I u want to make ur own cooler as permanent substitute for dry ice.. Then i can help you... It doesn't take more than 2 hours to build
What is your yield?
qwerty qwerty it's hard to give a yeild seeing as we didn't really get our correct product, so I'd say the yield was 0% for this attempt :(
negative experience - is the same result.
we respect your work !!!
thanks mate!
Maybe you were degradating the product while trying to distill it?
War gas!!
8:40 me trying to bootleg vacuum distill hash oil. Burned all my product >.>
Sorry I had to dislike. This video so hard to look at due to the - what seems like - 10 fps framerate and the horribly shaky camera.
Can you software stabilize it please?
You can leave a comment without disliking you know :P But yes, moving forward, I actually have a lot to say for this.
There's been a big issue with my rendered clips for a while now. Initially I thought it was because of the render settings I was forced to chose, I can't chose the highest highest settings because my internet is too slow and I can't upload real big files. This video for example took over 18 hours to upload, so if I maxed out the settings (assuming my laptop could handle it without crashing; which it can't) we're starting to talk 3 days of upload. But yes, I can work around that by uploading at uni for example.
But that's not the issue. The issue stems from the fact that I use two cameras with slightly different frame rates. This has been made worse recently because I had to change the camera app I film on my phone with, because the standard camera app on a Pixel does not support external mic like say an iPhone does (just because the developers decided they didn't want it) and the new app films at 30fps and the other camera films at 24fps. (I got an external mic, so you might have noticed how much the sound quality has improved from say a month or two ago, but nevertheless). Anyway, i've been letting the issue slide because I didn't know what to do about it. That's my error, I should've been looking more into it.
This issue is apparently called 'ghosting'. You might think the footage is unwatchable because of the shaky camera, but there's something worse going on that's causing the unwatching-ness. Pause the clip at any point where i'm doing the mobile footage, especially where there's movement, and you'll see its not a clear frame, but a blend of two frames together, there's like a ghost image. The output render is not matching the frame rate settings of the clip, making it hard to watch.
Anyway long story, i've spent today doing research after reading your comment, really looking into it. And finally, buried under some settings is a thing called 'smart Resample'. I turn that off, and what do you know?! The issue resolves.
To make it clear, here are two clips from this video with and without resample:
ua-cam.com/video/vZO7Z1B1ADs/v-deo.html
ua-cam.com/video/e-OCLu-C0Rc/v-deo.html
So in short, I can't fix this video. But from now on, it'll be fixed! I'm very glad I solved it, it's been pissing me (and you!) off for a while, so, thanks I guess.
I didn't expect THIS response. XD
I'm glad you solved this ghosting. I paused those two videos on the same frame and your hand looks crazy with resampling. While watching this new video I found two things you can improve: The Background with all the shadows on the fence is really the main culprit, I'd say. It's worse when it's shaky. Then the bright and dark stripes rapidly switch places and strain the heck out of my eyes. xD
The other thing might help with that too: Use googles stabilize function for videos before uploading it to the laptop. Maybe that doesn't take SO long. Or try interlacing. 1080i could look better Edit: But maybe that is what that ghosting was in the first place. :/ Try?
I liked your video again, BTW. xD