I would never have the balls to switch that heating element on without running the apparatus under positive pressure of inert gas. Kudos on your immense testicular fortitude.

Well done, brave man, and a great account of the synthesis, thanks. I would recommended using a second bubbler to eliminate residual ketene in the exhaust though.

Doug, you're suggestion to use a smoke bomb to test the ventilation in the smoke hood and lab area is well taken. If there are problems evacuating the smoke out of these areas you need cross ventilation, what is known as "make up air". Particularly and most commonly if you are in a basement in the winter you will have negative air pressure the indoors relative to the outdoors, this negative air pressure must be dealt with. Cross ventilation will make the space colder but it will provide you with the essential fresh air. The way to test for negative air pressure in the lab area is to open a window or door to the outdoors or turn off the fan in the fume hood and see if air rushes in through the openning, if it does you have negative air pressure. Hood fans, which are exhaust fans, can't overcome negative air pressure because the more air they pump out of the room the more negative the air pressure, the vacuum, becomes. By the way, sometimes you don't need a second fan, all you need is to leave a window or door open to the outdoors across the room to let the air in. We love our chemists and we want them safe.

I always thought ketene lamps were stories chemists use to scare their children!

Couldn't help but wear my safety squints while watching.

Well I don't think I'd do it myself, but it was great to see it done! Very interesting process.

I might have missed it, but it looks as if the reaction and work-up were done without an inerting gas. Granted, the volume of the system is fairly small but best practice would be to inert the system prior to introduction of reagents. This is something that I have to do often at work (chemical plant operator) for safety reasons. Great video, I really enjoyed it.

Wow this looks dangerous.. I seem to remember him talking about an inert atmosphere. Heating a NiCr wire in the presence of acetone.. Not for the faint hearted. Really cool video and I've honestly never heard of Ketene. Learn something everyday.

You can make a useful smoke pen out of nothing but tightly rolled paper towels. It doesn't exactly plume huge quantities of smoke but it naturally smells terrible, being burning cellulose, and you can use the scent as an indicator of fume hood failure while still getting the benefit of being able to accurately test small cross sections of the flow path.

Very Impressive, you have given me great impetus and making my own Ketene lamp. I’m just waiting for a 500 mill chromatography reservoir and then I’m going to get busy too. Vogel shows a ketene lamp but it varies a bit from your design, you showed me that it doesn’t have to be 100% equivalence. And my design certainly is not like yours, I’ll let you know how my first acidic anhydride turns out. Thanks Doug, you are quite the chemist. I have always been drawn to physics, but of course had taken my share of chemistry courses. Most of them had been in organic let’s face it most of the interesting things are in the realm of organic chemistry. The fact that a Nobel laureate described the blue color of an alkali metal dissolving in anhydrous ammonia as the solvated electrons from the metal just blows me away. Everybody had seen it, but the person who secured it out that’s figured it out, won the Nobel prize.

Smoke bomb is a good tip, I use the big 6 inch ones you can pick up at any fireworks stand. I had to use that trick to make sure my hood is good enough for me to safely work with phosgene. I still used a respirator though

Dude you're smart. Thanks for the video !

Awesome video. A proper walkthrough of the safety precautions you had in place would be neat.

You're mad. Absolutely fantastic, though. Have you considered deliberately producing diketene? Ethanolysis gives ethyl acetoacetate which otherwise needs to be made through the low-yielding and laborious Claisen condensation.

Careful. I made one of these when I was 16 and the DEA came to my house (not joking). Turns out acedic anhydride is exactly what you use to convert morphine to heroin and i had googled so much stuff about it they came knocking. Because my parents are rich and we had a really nice house they thought we were heroin kingpins. I just explained to them i was interested in chemistry and they were actually really cool, i cant remember if they told me officially it was illegal to make or not but basically told me i would be fine as long as I didnt sell it or, of course, start making heroin. One of the guys left a coffee mug that says DEA on it so I have proof.

Amazing! BTW, I hope to never live downwind of you... Ever!!! LOL

Great video! Out of curiosity, what was your PPE for this video? Given that you were dealing with such toxic substances were you using any form of respirator? If you were, what canister did you select? Cheers! keep up the great work!

I've been looking forward to this!

" to show that this is really acetic anhydride, I've got some morphine mono-hydrate here and we'll just reflux that in just enough anhydride to cover it...mmmm thats a tasty little treat mama....the final product is so good that it was used to stop babies crying, to treat alcoholism, oh and just about any other pain you could think of, not to mention being used as a CURE for morphine addiction..hahaha..yes it's true....that's the crazy crazy world around the 1900's..ever get the feeling we are deprived from having the freedom to try new and different things?

One of your best videos!

Absolutely inspiring.

after seeing this working, I have got to admit I was quite surprised at just how fast it was working ! It got me thinking, I reckon there is an even easier way to do this, provided you already have the bare minimum of glassware to do normal distillation, here's what I propose. Set up your boiling flask in the electric heating mantle with a reflux condenser ( a Liebig type, just the tube, no spiral like the Graham type) on top in the vertical position as you normally would for reflux. Now, instead of having a coiled Nichrome wire inside a glass bulb, you could probably just have a carefully designed single length of Nichrome inserted through the top of the condenser running down the center of the tube, you could have a couple of little supports made of glass wool or mica from an old toaster etc. to keep it in the dead center so as not to touch the sides, you could use your "T" adapter at the bottom between the boiling flask and the condenser to lead the copper wire out of that will attach to the Nichrome, goo it up with silicon sealant, that stuff will work really well for that because you are only boiling acetone, 56 degrees Celsius. The copper wire that the Nichrome attaches to at the top end of the condenser can also be sealed in place with silicone sealant, the clear stuff, with the addition of a plastic tube of around 5mm diameter that is also sealed in place, the tube would lead directly into your acetic acid or if you want to be extra picky you could just have extra meter or so if tubing coiled up and submerged in an ice bath to condense out and residue then bubble your ketene into some acetic acid

I like the idea

A very useful compound indeed

Excellent, I really enjoyed this

If I ever try this (which I doubt), I am pretty sure I will use flame to burn the methane and traces of unreacted ketene and als will flush the setup, when the reaction is done, with some butane, which I will also burn. Ketene is no joke.

I admire your courage. Would the cyclohexane to 1,3-butadiene reaction be any safer to try?

I can’t wait until the day I can have my own lab, that is not under threat from raids.

Great video Doug. It's hard to see the layers of acetic anhydride and water on the video. Do you think you could add a small amount of dye to the water? Maybe it would help with the visualization of the two layers? I'm not sure.

Awesome stuff man! SO glad I started subscribing to your channel!

you can buy inert welding gas from any welding shop that way you can fire it up without the step of "turn it on and hope the acetone displaced enough oxygen

Hey if you can find a way to get your percolation to form smaller bubbles, and used a taller/thinner collection vessel, you'd likely increase the ketene absorbtion

So it makes water into 70% acetic acid but stops at some point and if you start with high concentration it makes glacial acetic acid into the anhydride. It seems to me you could combine the high purity product with the low purity product and bring it all the way to anhydrous. You could probably use a separatory funnel and a claisen adapter to gradually dilute the product dropwise as you're bubbling the ketene into it.

Ok. So if you suddenly stop producing new videos, we'll know why...

I made ketene by utter mistake when i was a kid. I used air over acetone as a bunsen burner and it had some steel wool as a flame arrester, well it didnt work like that, the iron worked as a catylist and oxidized the acetone to ketene and formaldehyde ☹😵😵😵

You got some cahones brother. Geez! Would love to have a chat with you tho. Obviously you know a few things

Bro , you have a very detailed warning about how dangerous Ketene is . Now, I've seen quite a few videos about Copper Catalytic Pyrolysis of Acetone done at home , in schools , shows / presentations , etc. Didn't see anyone dropping down dead yet. Is it possible that they are all morons ? And if so, how come no one died inhaling that stuff ? Don't get me wrong, we can all see that you've done your homework and the quality of your videos is top class . The question is just out of curiosity and not a critique of the video.

For safety I'd have bubbled what was coming out though a large container of water with a pH indicator. Provided the reaction with ketene is 100% or close to that then when the water colour changes, I know the reaction has fiinished.

wouldn't this synthesis be a lot safer under argon or nitrogen flush ?

Bhopal, baby!

1:00 no worries even though I like doing dangerous stuff I'm really not planning on attempting this (especially with my chemistry lab being my kitchen at the moment), but I find the "ppm" unit absolutely non intuitive. I have no idea what "1 ppm" represents in practice. I know it is very little but how much so? I guess the point I'm trying to make is that I think it could be useful to express these thresholds in a way we can relate to, like (just an example, dunno if it is the correct order of magnitude at all) "this is the equivalent of 1ml uniformly spread inside of a football stadium" or something like that. Imho it would help convey the danger level better cuz I'm not sure if many people have an intuitive representation of what "1 ppm" is. I know I don't.

Giant sacculence...respect

Xcellent very nice stuff

I like watching these types of videos out of curiosity. I came here because i watch a lot of nile red. Bur when i seen Phosgene its was at the moment i knew, DONT TRY THIS AT HOME KIDS. Thanks

So before turning on the filament / heating element, you can be assured that there is no more oxygen in the lamp (or at least not enough for an ignition event) just by the flowing acetone vapor? That part scares me more than the muffkin' ketene as I can shield myself from the ketene gas with a proper vent hood and respirator, but an exploding ketene lamp is harder to shield from. For educational purposes only; m0rphin3 is bad enough WITHOUT being tampered with.

Good work sir the system is totally close.methane and other products like methylene and CO may generate pressure within the system

Thanks.

yeah, I've seen the Vogel set up, and I suppose as long as the reaction tube is rated to handle those high temps, and you expell the oxygen from the atmosphere, is should,nt go kaboom. Personally...I'd be using a stainless setup for something that, err lively..and not starting with glacial acetic is just madness.

Cool video but you are crazy to make such a toxic compound in a home lab!

Whenever you have electric heaters with exposed connections, it is safer to use an isolation transformer between the Variac and the load. Even better would be a 120 to 48 volt transformer. Wouldn't moisture in the air quickly destroy escaping ketene as fast as it escapes?

If you used larger ketones would it work just as well? Say propanoic anhydride from methyl ethyl ketone. Also do you plan to use this apparatus for other pyrolysis reactions? There are a lot of interesting synthesises (sorry) around pyrolysis but proper apparatus, particularly apparatus that gives good yield, is hard to make/come by.

I would be shitting myself turning on that nichrome in case it ignites the acetone vapor.The upper flammability limit of acetone is about 13% so it's not a problem but it would still be on my mind. This is a very cool video, I love seeing big glassware setups like this. What can acetic anhydride be used for?

I am amazed at the number of people who believe that this is some super dangerous experiment. Breathing your car exhaust is massively more dangerous. It’s just KZfaq BS.

Can you use this aperatus to produce acrolein from glycerin?

I live in Australia and have tried this experiment many times as per this video's instructions precisely, with locally purchased ACS grade acetone, but unfortunately could not get any gas production, could anyone offer any suggestions as to why no ketene was produced?

very nice Doug this is amazing! chemistry is very awesome i would love to chat with you an pick your brain some day please

Dear sir.I did that process carefully and step by step as you did.but the result liquid solved easily in the water.The question: Should I purefy it by distillation?

I’m imagining you filming this in a scuba suit

I read that carbon disulfide is normally used as a catalyst for the thermolysis of acetone into kethene/ethenone. How come you're getting decent yields without using a catalyst ?

Also is this purely to show how to produce ac2o or do you have further plans for a compound using the anhydride you made.

What is the heat required for distillation?

Please mention about the quantity of the chemical to be used for producing acetic anhydride will be waiting for reply thank

i think you got the chemical formula of keten wrong its H2C2O not C2O,besides that great video keep up the good work

Just stumbled on your channel by accident- great video!(I subbed instantly!!!) You've got a fantastic setup there dude! It puts most of my lab equipment to shame! Have you purchased all your lab aparatus and chems yourself?(Privately, I mean?) Do you hold any kind of licence that enables you to purchace labware, chems, etc? Appart from just being interested,(nosey!) I'm curious because I've found it quite difficult to buy (even very common) chemicals from chem supply places here in the UK, more often than not having to resort to finding substitute chems/chems that are used for other purposes... It's a *huge* pain in bum,(!) so much so that I often end up having to give up on a project before I even start it! :'( Really looking forward to having a look through some of your videos! Cheers!

How isolation mix a acetic acid and acetic anhydride? And whate is test acetic anhydride in laboratory? Thanks for this video

Amazing. I've been designing my own but alas it likely will stay just a design as I have no fume hood currently. Where did you get the acetic anhydride? I've been trying to get my hands on some for a video on acetylsalicylic acid but the only way it seems possible is to go all the way from urea and acetic acid through acetonitrile (thanks to Chem Player's fantastic video on the subject), but it would be super nice to just be able to buy some (I don't have a business or company i.d. so, unfortunately,​ that doesn't work entirely).

Any chance you're going other to make other crazy chemicals in the future? Like SO3 and reacting with HCl to make ClSO3H :D

Interesting how Wikipedia doesn't have squat on the toxicity of ketene, such as its IDLH value you mentioned.

New subscriber. Great stuff! I've read that taking essential oils or aromatics from roses is challenging. Do you care to tackle that?

What is the immediately dangerous level of nitrogen dioxide? Because that you can readily sense and unless you are locked in a lab you wouldn't let yourself get poisoned by it because it burns.

Hey Doug, One more important question I forgot to ask, what glass tubing " borosilicate, flint?" and size " inner diameter, wall thickness, outer diameter?" did you use to insulate the "12 gauge??" copper lead wires...

To: Doug's lab At the very end how cold or warm is the distilled water in the 3 tubes ? I'm curious cuz I'm wondering if it matters like if it was hot would that mess it up the same with cold or warm,its probably room temperature.

doesn't the flask that holds the hot wire have to be quartz for safety?

Phosgene is not that toxic, I have breathed it from burnt refrigerant. It wasn't much good but not IDLH

Correction: it looks to be a Friedrichs-type condenser you're using at the first stage reflux? In short, I'm asking are they better performers than the regular,(read cheaper;) )kinds one could use? Thanks.

is adition of ketene to hypochlorous acid resulting in chloroacetic acid ?

Hola, para comprarte 1 o dos litros. O hacer donación??

So if one filled a vape tank with acetone, then inhaled helium and blew through the vape while holding the fire button, one would expel deadly gases into the atmosphere?

Are those weight figures correct? 30.9gms to 52.5gms? Shouldnt it be 32.5gms? Gaa is 1.03gm/ml and a.a. is 1.05gm/ml

If you want to make glacial acetic acid vie this method, what temperature would you distill at, and would it have to be fractional? Also, would it be possible to make the generator out of steel pipes that would be welded together for minimal gas escape?

Hi Doug, a quick question: what was the temperature of the acetic acid before going up to the reflux?

What gasmask filter type are you using?

I'm retired chemist and agree never do this at home...so you should do it? BTW, is this your mom's home?

Would like tout se you synthesis acetylacetone with your lamp.

its toxic, but will it not be quicly hydrolysed in air to acetic acid? as long as the hydrolysys isent in your lungs ur fine

Hey Doug, I have a few questions, if you would be so kind to take the time to answer them, it would be greatly appreciated.. What type of respirator cartridge do you suggest using on a full face respirator when generating ketene? What gauge nichrome wire did you utilize for the filament? Can this be used with other species of ketones for example, Methyl Ethyl Ketone, to generate propionic anhydride? I think it's great that you've utilized standard apparatus to assemble a ketene lamp, I have contemplated doing the same but have yet to have the chance to set it up and work out the kinks myself. I look forward to your insight, thanks

What are the side products when making acetic acid via this method?

The book Doug references at 3:30 is _A Textbook of Practical Organic Chemistry_ by _Arthur Vogel._ Below is a link to a PDF version of the books _3rd edition_ (published 1956) hosted on Science Madness. On _page 373_ (or 396 of the PDF) you will see the apparatus that Doug's using. www.sciencemadness.org/library/books/vogel_practical_ochem_3.pdf#page=396 *Edit:* Here's a newer version of the same book (5th edition) also in PDF, and I would link to the page with the same apparatus, but this version can't be searched via the browser like the 3rd edition... So if you want it then you may actually have to read through the index yourself :-P But I'm sure it's in there. Additionally, here's another PDF that shows some useful information: www.sciencemadness.org/talk/files.php?pid=111392&aid=4257

Hello Doug - this video is awesome, more than great :)) I'm trying to buy some commercial Anhydride Acetic like the one in your video (wiki says it is low cost) but it is hard to find an online shop, can you tell me where to buy that cool liquid?

God damn it doug, what are the sideproducts. If you are trying to not get me killed by not giving me info, I tell you that I have already run the generator to produce acetic acid, none died, but I still need to know the sideproducts if I want to get the acid glacial.

From which book did u get the set up? What sort of metal is the wire?You said NiCr or Chromel i think. Kanthal should also work?

where does the exhaust of the fan go? Is there a filter on it? Or is 5 ppm no too important when released outside?

Why in the flask is a golden color ?

And Afghan tribesmen do all this over open flames in caves. I’ve based out some mst & cooked it in the oven with acetic anhydride & the results are very hit & miss….Damn it all!.

I thought my hobbies were all over the map.

FYI, Doug, the Patreon link from this particular video is broken.

Great video! But there is a mistake in ethenone structure, one of the carbons lack two hydrogen atoms :c

Does ketene feel like phosgene? I inhaled phosgene once, it was rough LMAO.

Doug, is a "lamp" the only way to achieve thermolysis? If you used a steel tube heated by a flame or electric resistance to pyrolyse the acetone vapor, could it be made to work as well ?

Best way is 100ml of spirit viniger and 10ml of hydraulic acid