Brominating an Alcohol using Phosphorus Tribromide (1-pentanol)
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- Опубликовано: 17 окт 2024
- Hello everyone! In this video, we will be brominating 1-pentanol using PBr3 that was made in a previous video. I will use the product, bromopentane, in a future video to make my biting insect attracting chemical.
I am going to try and edit all of my 1080p stuff and dump it all as fast as I can. There are 15 of them and I hope to drop them all in the next month or so.
Phosphorus Tribromide video: • Making and Playing wit...
I plan to do an FAQ video, so if you have any questions you'd like me to address in the video, leave them in the comments.
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I dont know why but watching these videos is really relaxing, even though i know zip about chemistry
i agree
its never too late to learn
I really like the combination theory/practical format, awesome video as always
+Rob Mckennie thanks! Ill keep doing it
Tfw after a long night of re watching Nile red videos and you're about to sleep but RUclips tells you he uploaded a new vid. :)
+The Herb haha :)
I'm very impressed by the quality of your videos. It's obvious that you devote much time and effort to editing them.
I love to see the previous compounds you've made be used to create new ones. I just love the building blocks method of at home chemistry. I'd love to know more about what exactly are your starting materials. What were your first basic chemical purchases that got you started?
+lightvsdark21 Hello, that question is way too broad to answer! I honestly don't really know what to say. I guess the stuff I started with was the stuff that was easy to get at the store and just worked my way up. I really don't remember though :(
+Nile Red Haha no worries. I figure it's probably mostly stuff at Home Depot or the like. Just wondered if you remembered like your go to things you always bought when you first got started. Love your vids by the way. Really really well done. Lidocaine had to be my fav so far hahaha!
lightvsdark21 thanks! And yeah, I dont really remember. I just slowly collected stuff over time.
@@NileRed 10:00 what’s going on with the stir bar? Was there another magnet close by?
Phosphorous acid => foss-FOUR-us acid. From the old nomenclature of the suffixes -ous and -ic to indicate lower and higher oxidation states in compounds, just unfortunately it sounded silly to make it "Phosphorousous acid" so it ended up being spelled exactly like "phosphorous" the element, but the pronunciation should shift to indicate the compound.
Brilliant videos, by the way!
I like how I learn this reaction on paper in OChem and then watch these videos to see it done in real life.
Cool!
Great vid! You really deserve your subs, the quality of your vids is so outstanding. I really like the depth of field and the sharpness :)
Great video as always! I really enjoy watching you.
I have a suggestion for a next synthesis: How about making acetylacetone via Claisen-Condensation of acetone and ethylacetate? It has a nice smell and forms very colorful komplexes with many transition metals.
Keep up the good work!
+Manuel Oelschlegel Interesting. Do you have any more information on this?
What happens if you don't control the temperature when adding the PBr3? Are there a bunch of side products?
I ask because I received a shipment of 500 g of it from a sketchy Russian guy on ebay and yesterday just kind of added it to some sieve-dried 1-pentanol, without thinking about how exothermic it would be. I did at least know that lots of HBr was going to be released, so I did it outside. It produced a really impressive geyser of HBr, boiling 1-pentanol, and some sort of weird brownish salt-like stuff. I didn't check youtube until now to see if anyone else had done it on here before, and it didn't occur to me to actually do this carefully and keep an ice bath handy.
Anyway, I got a decent yield of bromopentane (or what I believe to be it - maybe there are side products?). I will soon try to use it with lithium t-butoxide made from reacting lithium and t-butanol in order to make pentene through an E1 reaction, then probably brominate that with elemental bromine because brominations are fun and alkenes are hard to find.
For the next vid: any one of cleaning sulfuric acid, cleaning mercury, or iodine from povidone. For the future: Nitrous!
+Barnekkid Its going to be 3-nitrophthalic acid (luminol precursor), then cleaning sulfuric acid!
cleaning sulfuric acid :)
+Nile Red cleaning mercury would be nice. It sounds like a good filler episode
cleaning mercury or iodine-: -:
another really awesome video as usual. nice work sir
Really excited for the acrolein and 1-octen-3-ol videos!
Really great video 👍👍. Great for students as they only read and remember the chemical equations, but your videos make Chemistry fun for them. I too am a student and learn a lot from your videos. just one question- I suppose that the structure of phosphorous acid at 3:59 is incorrect.
As always, great content! You've brought interesting ways to introduce chemistry to the masses. Please Please Please show us the Denatonium benzoate as soon as possible! ..Maybe even some Denatonium saccharide?
+Stephen Fabiano thanks! The denatonium will come in due time. I am going to be dumping all my videos filmed with my old camera first (denatonium benzoate was with the new one). I will be working fast though...so it should't be too long.
I was about to ask whether or not you'd be doing an iodomethane video, and then your future videos outro started playing. Glad to see it's on there! Might be some controversy on its uses, especially on the substances from your previous video series that was taken down (understandably).
If you don't think it's too in-depth for your intended audience, I think explanations of stereochemistry in the mechanism explanation would be useful to gain some insight on the reaction. Great video as always.
+Jake Bender Thanks! Yeah I do plan to make it because there are completely legitimate uses for it.
when i started my degree i made physics my main focus with chemistry my 2nd major was neglected ..... after a while chemistry became more fun due to the better practicals my university offered ....... now chemistry is my my primary focus and physics took a back seat ..... however i do like the theory of physics over chemistry thou ..... due to Quantum mech in physics
I vote Recrystallization tutorial, sulfuric acid, or luminol. For future videos, make potassium carbonate from wood ashes! It's a good drying agent for organic bases.
your videos got me in to chemistry. ty
In your phosphorus tribromide video I posted a comment predicting that the sulfuric acid reacted with your phosphorus tribromide producing hydrobromic acid which caused the yellow tint. For this video, the hydrobromic acid would also react with the alcohol to replace the OH group with a Br group but via a different mechanism (protonation of OH). So your contamination had no effect since all your bromine would still react to brominate the alcohol as desired.
Hey Nile, I would love to see the Cleaning sulfuric acid from drain cleaner, I've been waiting for that one, then I would like to in the future see common acids on your hand (or my chem teacher does), (sorry) that or Vanillyamine.
Love your videos, keep it up. Also thanks for getting viewer input and having us let ya know what we would like to see, again thanks for the videos, stay safe
+CaptinCCat The next one is a precursor for luminol, but i just finished editing the sulfuric acid one, so itll come after that!
Nile Red Thanks, that's aswome
What properties did your side product have? My thought is whether it's tripentyl phosphate/phosphite, or dipentyl ether.
If you have access to triphenylphosphine, you can save yourself a lot of hassle in the workup by swapping your PBr3 for PPh3.Br2, which you can make in situ by adding Br2 to a solution of PPh3 in dichloromethane. Adding dropwise, you will get an off-white suspension, which buffers toward yellow. You'll see when you've added enough bromine because it wil immediately go dark yellow; I usually let it stir for another 15 mins to cool down again at this point. Add your alcohol dropwise (really important to avoid side-products) in an ice bath, and allow it to stir for 30 mins. Dilute your DCM solution with twice its volume of hexane/pet ether, filter off the PPh3O, remove the solvent and you're done.
You can triturate it with ether or pet ether if there is still residual PPh3O, but in around an hour, you have gram-quantities of alkyl bromide in high yield (usually >90%, but as low as 30% if you add the alcohol too quickly), high purity (>95% by NMR) and without having to use PBr3. Worth looking at, and might help you avoid high-boiling side-products, and phosphine gas evolution in distillation.
+Nick Butler that is really cool to know. I actually have like 100g of pph3
I know that the video is old, but you might have lost at least 10 to 20% of your yield during the workup.
Your organic phase was your product neat. You should have used some solvent like DCM to dilute your compound.
Most likely, a lot of your compound was emulsified in the aqueous extractions, and you didn't extract the aqueous phases at all eith solvent.
Also, the distillation could've consumed a good 10-20% of your yield. It is preferable to distill under vacuum to a lower boiling point to prevent side reactions. Again, most probably, you consumed some product in an Arbuzov reaction to male the phosphite ester like you described.
I come out as very critical (and as a long time subscriber, i know that you didn't have lots of experience back then), but it's a good tip for beginner chemists to understand the importance of a good workup and a good purification on the yield.
Regarding making my own phosphorus tribromide, does it have to be elemental bromine and elemental white phosphorus or does any elemental phosphorus do, also how violently does it react, I could imagine doing it in a closed vessel to avoid oxygen and having
*problems* ,
can it be done in a solvent and what would you recommend? Preferably something very cheap or that I could also make myself if needed...
you didn't even tell the viewers that alcohols make a bad leaving group.... which is the whole point of using PBr3 in order to carry out a nukleophilic subsitution instead of just using any other nukleophile...
Also, PBr3 can't actually be used on tertiary alcohols.
I'm not a teacher, but you could have just used a primary/secondary alcohol instead of a tertiary for presentation purposes...
Nile, pls
Hi Nilered, i love your videos! I was wondering if you could make a video on reductive amination using formic acid instead of metalhydrides? thank you for all the work
Would this be the same process of using a different alcoholic say ethanol? Could I I drop bromine slow into the ethanol in a ice bath? Then add sulphuric acid?
Hey, i know this video is quite old but i recognised a little mistake there: You always metioned phosphorous acid (P(OH)3), but this doesn't exist (maybe a few ppm of it). The main P(III)-acid is the tautomeric form phosphonic acid HPO(OH)2 with one (not acidic) hydrogen atom bonded directly to the phosphor atom and one oxygen atom bonded by a double bond to the phosphor.
One of the first SN2 reactions they taught at Orgo 1 ;D
I mean, these kind of brominations don't yield spectacularly but 39% using PBr3 you might as well used HBr and got around the same. I think you could push your yield a bit by washing with smaller amounts of water/brine/bicarb generally and doing at least one back extraction with Et2O if you're gonna distill anyway.
Since the bromo is denser than water, i'd go with DCM for work up (WU).
Also, extracting the aqueous with DCM during WU.
Also, if using DCM, using even more water will prevent emulsions (the bit when both phases were opaque, meaning that there was an emulsion).
The aqueous and organic phases should be completely clear during WU (not colorless is ok, but opaque is no good)
Love your videos.
nile red when you add an alkyl halide to water in the seperatory funnel shouldnt it go back to being an alcohol? my university proffessor said an alkyl halide is unstable and reacts with water to become an alcohol
When will the fan page be ready?
where did you get your 1-pentanol? i would like to get some.
maybe its gasoline but im not sure because my proffessor mentioned gasoline is a mixture containing alcohols if my memory serves
+Nile Red great video and ammonium formate,nitrous oxide (with a way to tank it)
I think your structure for phosphorous acid is wrong. I'm pretty sure it only has 2 OH groups (making the acid diprotic), a double bonded oxygen to the phosphorus, and the last hydrogen bonded directly to the phosphorus.
+Ocean Junkie It is in equilibrium with it. upload.wikimedia.org/wikipedia/commons/6/6c/Phosphorous-acid-tautomerism-2D.png
Cool, didn't know that.
You should do some liquid/solid column chromatographic separations. That would be cool.
+Hume820 I really should. I just hate them :p
how was the mixture stirred in the flask? I see it spinning, but how does that happen?
+Nikola Tesla there is a magnetic stir bar that spins via a motor in the base. its a clever way to mix stuff up!
Why do you know so much abpur chemistry ?
Did you study it or do you work in a lab or something like this ?
+Zock4 What's interesting is that most of what i have learned is from making these videos. I have a background in chemistry, but having to apply it practically has been the most educational.
+Nile Red I can understand it's like a drawer who learns how to draw but never actually draws a picture
10:55 phosphorous acid not phosphorous tribromide (since esters are formed via condensation of alcohol and acid). Just wanted to mention it, maybe a little annotation could be put there.
Couldn't you have just used HBr and a catalytic amount of H2SO4 to protonate the hydroxyl, instead of PBr3?
I was starting to wonder what you were going to need 1-bromopentane for...
Literally every video I watch somehow links to 1-octen-3-ol
I really want to see bromination of phenol!!
Will you make a video testing the effectiveness of the attractant on mosquitoes?
Where do you buy your 3 neck roundbottom flasks? The site I've looked at doesn't sell those ;-;
+Mr.chang cooler go to the nurdrage channel he has a link to a site that sells them
Couldn't you have distilled the water out of it instead of adding all kinds of stuff and funneling it so many times, losing more and more yield? If it boils at 130 the water, which boils at 100 should go out and leave the clear product behind
How did an ice bath keep it below 0 degrees.
Most words used in Videos so far: "Separatory funnel" and "real pain"
For the next video I vote recrystallization tutorial.
Pop off stoppers and have you searching for 5 minutes to try and find the stopper?
Maybe the next time add twice as much alcohol because maybe this reaction creates phosphite esters apart from alkylbromide so you woud made a theoretical yield of 50% 6ROH+PBr3=3RBr+P(RO)3+3H2O this water that is created woud also lower the yield
where did you buy the white phosporus and the red phosporus
Can you Boronate an alcohol? Or a lipid?
? Can you give us sulphonation , acylation reactions
My vote goes to cleaning sulfuric acid drain cleaner.
I saw a very big error in the video... at 1.00 you put a sobstitution SN2 using a tertiary substate! That is impossible cause in that case there is a carbocation formation and than a sobstitution. Please be carefoul the next time.
+RealChemistry Technically you are right, but I will save myself with 2 answers. a) SN2 still occurs on tertiary substrates (to some extent) and b) R groups can also represent hydrogens :)
+Nile Red R group hydrogens? Please no xD
R means radical
RealChemistry Lol yes, radical.
+Nile Red Indeed a radical is everything apart an hydrogen... I never seen using R for hydrogen in any of my books. (My favourite brown)
RealChemistry R is often used for H. I see it a lot in papers. It isn't technically proper because R is supposed to be an alkyl chain...but it is done anyway.
Petition to make 1-Octane-3-ol commonly known by the name Nibbol (nibble+ol)
Why is sodium bicarbonate so good at neutralizing acids?
+Liamthepyro It is a base. It forms carbonic acid which decomposes to CO2 and H2O.
its a cheap and weak base
It can also act as an acid right?
So it's both a base and an acid, I'm pretty sure there's a fancy name for it.
How are you planning to make acrolein? Acidic thermal decomposition of glycerol?
+Bill Smathers Pretty much. Just mix glycerin and magnesium sulfate and heat
+Nile Red Huh, I was under the impression that that reaction only proceeded efficiently if an acidic sulfate was used. Guess you learn something new every day!
Bill Smathers MgSO4 is slightly acidic, no?
+Nile Red I thought you needed something at least moderately powerful, like a bisulfate, to initiate the dehydrogenation of glycerol to 3-hydroxyl-propanaldehyde, which then dehydrogenates at the high teperatures to acrolein. It needs to protonate a hydroxyl group, after all.
Bill Smathers I just found some papers that say all your need is MgSO4 and glycerin. When I try it, ill if it works are described.
That has to be the smallest filter flask I have ever seen.
Curtis Dorris Size doesn't matter. It's how you use it, that counts.😎
@2:45 - Y E L L O W C H E M I S T R Y
Tungsten tribromide and tungsten floride arsnic☣️ znon
Cleaning potassium metal
Not sure i would do any chemistry after 3 PBR 😄
Can you post a video on producing Butyric acid using fermentation of putrefying cheese?
That would be great... Thank you.. :)
+Ananth Kalyanasundram It's easier to oxidise 1-butanol with let's say permanganate.
+DrakorioTheDragon I want to prepare it at home..I dont have a permanganate salt :P
Just go to a chemist's and ask for permanganate. If they ask what for, you're just going to wash your throat. :) Small amounts and a bit expensive too but still.
guys why is the H3PO4 an acid? I would have though it would be a base since it has the OH things? I only do 10th grade chem so i am not really that good at this stuff :(
These OH groups are bound to a very electron deficient central atom (the P). That's why the hydrogen is "allowed" to leave so the P can have more electrons to itself.
Denatonium benzoate please!!
What does it mean, bro?
An only child goes through life alone and lacking siblings, forever pondering the question: What does bromine?
Can u make PENT and acetone peroxide please? :D
So the reaction is a SN2?
+misticanmaster No, it is an electrophilic aromatic substitution. The product of the reaction will be used in an SN2 reaction. I am sorry if that wasnt clear.
make phosphoric acid
Dose it get you more pissed?
Alcoholating my Bro is funnier ! ;)
chemistry
FFS use molar ratios
and can you make a vid on how to concentrate h2so4
+The classroom maniacs Yup that will be uploaded soon. Not the next one, but the one after. So probably will be posted like on sunday.
Thanks a lot because i made h2so4 by sulfer dioxide method and cuso4 method and i dont know how to concentrate it thanks alot from malta ps search on google earth to see where it is
upload vanillin oxime
Álcool hollics
that PBr3 so sexy
help me repel the insects lol
+nuclearthreat545 haha i should make insect repellent and not attractant...
I Actually Think It Not Worth It. The HBr Gas That Released Is What Made The Esters. It A Lose, But It Could Be Recovered. It Tripentylphosphite. Their Two Reaction That Occured:
1: Hydroxy Is Replaced For Bromine, Produced Alkyl Bromide & Phosphorus Acid.
2: Hydrogen Of Hydroxy Group React To Produced Hydrogen Bromide & Alkyl Phosphite Ester.