Sciencemadness Discussion Board - Check out this synthesis video!

Check out this synthesis video!

driveby40 - 21-6-2013 at 11:30

Hey all,

I'm new to this forum, someone on Reddit thought you guys might enjoy my YouTube channel. I've been putting some videos together that showcase some of the work I do in my lab (I'm a grad student at UCLA). My latest video is a Skattebøl rearrangement to form a cyclic allene. Here's the link, lemme know what you think!

http://youtu.be/EVDQgjFu9BU

Sublimatus - 21-6-2013 at 11:42

The "in the trenches" format is refreshing. There aren't too many other channels like that on YouTube as far as I'm aware.

Made me nostalgic for the days when I was doing research at university. Ohhh the joys of air-free chemistry.

Keep it up.

bfesser - 21-6-2013 at 11:54

Interesting video, thanks for sharing. I'm a little disappointed that you used a calculator for that simple subtraction, but it's forgivable. I'm also not particularly impressed with the cleanliness of your work space. Perhaps for future videos you could give the hood sash and the scale display a little cleaning? It's nice to see some air-free work. I've read a lot about it, but haven't seen any performed in person, and there is little on YouTube.

Magpie - 21-6-2013 at 11:57

I enjoyed watching this nice example of air-free work. You have a lot of nice toys that won't be found in many home laboratories. It's great that your professor and the UC helped you with this and allow posting on the internet. Also I see you have the throbbing rock music background during slow periods: so necessary for today's short attention span audiences.

driveby40 - 21-6-2013 at 12:10

Thanks for your comments, I did try to tidy up a bit but obviously there is room for improvement. Unfortunately whatever is on that scale screen doesn't come off, believe me I've tried.

[<a href="u2u.php?action=send&username=bfesser">bfesser</a>: removed unnecessary quoting]

[Edited on 7/8/13 by bfesser]

bfesser - 21-6-2013 at 12:15

You could always polish it off with progressively finer grit abrasive papers.

Sublimatus - 21-6-2013 at 12:16

hah! The fumehood wasn't clean enough? If anything, it's too clean! A clean bench means a lazy chemist.

driveby40 - 21-6-2013 at 12:32

I would rather be labelled as lazy than unsafe; excessive clutter is considered a safety hazard (and also distracting) so I'm always sure to tidy up before filming.

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[Edited on 7/8/13 by bfesser]

bfesser - 21-6-2013 at 12:32

Or a meticulous chemist. The hood was fine, the sash could have been cleaned for filming.

Sublimatus - 21-6-2013 at 12:36

It was a joke.

Of course you're both right.

I wonder if the marks on the sash are actually damage due to solvent being splashed against it. Is it made of glass or plastic?

[Edited on 6/21/2013 by Sublimatus]

driveby40 - 21-6-2013 at 12:47

It's glass coated with some sort of adhesive film. I cleaned the outside but there's some crud on the inside of the sash from various splash ups (like the time I neutralized acetic acid in the sepfunnel with bicarb... oops). I should have taken care of that before filming but it slipped my mind.

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[Edited on 7/8/13 by bfesser]

Magpie - 21-6-2013 at 12:56

Quote: Originally posted by Sublimatus

hah! The fumehood wasn't clean enough? If anything, it's too clean! A clean bench means a lazy chemist.

The above is on good authority:

A tidy laboratory means a lazy chemist.
— Jöns Jacob Berzelius

Jöns Jacob Berzelius (1779 –1848) was a Swedish chemist. He worked out the modern technique of chemical formula notation, and is together with John Dalton, Antoine Lavoisier, and Robert Boyle considered a father of modern chemistry.[

Sublimatus - 21-6-2013 at 15:08

I worked with a Russian postdoc that had two double-wide fumehoods just packed full of to-be-worked-up or stored samples in beakers and flasks. You couldn't actually do chemistry in them. The bench opposite the hoods was completely cluttered as well. How he knew what was what I could never understand.

Despite the mess, he was the most prolific member in the research group, and quite good at organic manipulations.

I tend to keep my lab pretty clean and organized. That must be why I'm not rich and famous.

sargent1015 - 21-6-2013 at 15:23

While I am working up reactions or in the middle of projects, my bench and hood are quite messy, but it is organized chaos. The satisfaction at the end of a synthetic sequence is uncluttering and refinding my labspace, only to start in on something new, and the vicious cycle continues.

Cleanliness means you are spending more time on looks than the chemistry!

bfesser - 21-6-2013 at 16:51

Quote: Originally posted by Magpie

A tidy laboratory means a lazy chemist.
— Jöns Jacob Berzelius

argumentum ad auctoritatem

Quote: Originally posted by sargent1015

Cleanliness means you are spending more time on looks than the chemistry!

Some people are just more efficient than others. For example; cleaning your lab space and preparing it for the next procedure while waiting on a reaction.

sargent1015 - 21-6-2013 at 18:03

Quote: Originally posted by bfesser

Some people are just more efficient than others.

Efficiency is getting more products out and meeting deadlines rather than cleaning. Extract, column, dry, set-up, repeat. Organized chaos keeps your tools within arms reach when you are juggling multiple reactions at a time

Btw, I do very much enjoy the video, which is what this thread is ultimately about. Pyrophoric material is a challenge to work with.

[Edited on 22-6-2013 by sargent1015]

Magpie - 21-6-2013 at 19:32

Quote: Originally posted by bfesser

Quote: Originally posted by Magpie

A tidy laboratory means a lazy chemist.
— Jöns Jacob Berzelius

argumentum ad auctoritatem

argumentum ad exemplar

Recognize this lab? I dare you to find a more productive chemist on this forum.

adamsium - 21-6-2013 at 21:08

Quote: Originally posted by sargent1015

Efficiency is getting more products out and meeting deadlines rather than cleaning.

I actually have to disagree with this to an extent (not trying to be antagonistic - this is just something that comes up a bit for me). For me, it is always much more important that my work is top notch, even if I take a little longer. I might take longer, but I then sit back and smile while others do it all over again, or have a minuscule yield of brown crap instead of a pile of fluffy white crystals with a near perfect IR (or whatever) spectrum. Faster is not always better; better is always better! Being fast is easy, doing patient, careful work of a consistently very high standard is not easy for most.

Edit: I forgot to say that I do agree that it's not about being clean. As long as your actual work is clean, you clean up the workspace when you're done and any mess is not overly hazardous, the focus should absolutely be on what's in the flask(s) and the rest of the apparatus, not next to it.

[Edited on 22-6-2013 by adamsium]

sargent1015 - 21-6-2013 at 21:59

Quote: Originally posted by adamsium

For me, it is always much more important that my work is top notch, even if I take a little longer. [Edited on 22-6-2013 by adamsium]

And for me, it is about more products (products do not constitute brown crap in flasks) and more research in shorter periods of time. I will agree to disagree, but my lab will stay in the same messy functioning capacity as it always has.

adamsium - 22-6-2013 at 00:07

If you're talking about getting more done instead of wasting time on things like having your work area looking pretty and sparkly, I absolutely agree... as long as my workspace is safe, all that really matters is doing my work properly and getting the best outcome I can get; I would definitely describe my style of work as 'organised chaos'. I was talking about not rushing procedures and being careless. Also, sorry if it sounded like I was insinuating that you do this - I wasn't. I was referring to people who I have seen do this, to their own detriment. I can never understand why people are so hell bent on saving a few seconds/minutes only to mess everything up.

I don't even know what people were talking about in regard to the OP's 'messy' work area. It looks fine to me. Nice video, by the way! :cool:

Hopefully you'll make some more.

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[Edited on 7/8/13 by bfesser]

Magpie - 22-6-2013 at 07:31

My own philosophy and modus operandi is that of adamsium. My argument in defense of messy work spaces is merely one of observation. My wife is one of the messiest cooks around. But she can turn out a delicious meal faster than anyone I've seen. Also, I worked a few summers with an uncle who was a farmer. When working in the shop and finished with a tool he would just drop it on the floor. The shop was a complete mess. But he was a mechanical genius and received a patent from John Deere for a major revision of the combine for wheat harvesting.

plante1999 - 22-6-2013 at 07:42

Quote: Originally posted by Magpie

My wife is one of the messiest cooks around.

So, magpie, you didn't had told us your wife was into clandestine chemistry. Ha ha ha

In my point of view, I try to be the cleanest possible in my work space, but when you lack of space, it is a bit hard to put everything at there place, when they got none.

bfesser - 22-6-2013 at 08:01

This is a futile argument. Those who take part will never concede to the reason of the opposing view. Let's all just agree to disagree and stop spamming. There's no need to take this thread any further off topic.

driveby40, I enjoyed watching your other <a href="http://www.youtube.com/watch?v=Z-0EnES_OS4" target="_blank">video</a> on the preparation of 2-chloro-1,3-dimethyl imidazolidinium chloride (DMC), but it would be nice if you defined the acronym before just jumping into using it—sorry, this is one of my pet peeves. I'm a little disappointed that you glossed over your solution to the ring of impure solid product stuck in the Schlenk flask. What did you resort to?

I've <a href="viewthread.php?tid=19098&page=19#pid289005">requested</a> the paper you cited in the video.

[Edited on 6/22/13 by bfesser]

adamsium - 22-6-2013 at 08:07

Argument? There hasn't been any 'argument' nor any "reason of the opposing view" (whatever the 'opposing view' is) presented. I guess you just don't like people disagreeing with you. That's your prerogative, but isn't it a bit ironic that you then accuse people you don't know anything about of refusing to accept an opposing view/argument in this context? Think about it.

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[Edited on 7/8/13 by bfesser]

bfesser - 22-6-2013 at 08:19

<a href="https://en.wikipedia.org/wiki/Argument" target="_blank">

Quote:

In logic and philosophy, an argument is an attempt to persuade someone of something, by giving reasons for accepting a particular conclusion as evident. <img src="../scipics/_wiki.png" />

</a>
I re-iterate, stop taking the thread off topic, please.

[edit]
<a href="http://www.youtube.com/watch?v=kQFKtI6gn9Y" target="_blank">>This isn't an argument.
>Yes, it is.
>No, it isn't.
>Yes, it is.</a>

[Edited on 7/9/13 by bfesser]

adamsium - 22-6-2013 at 08:51

I, too, can re-iterate; no argument was made. I was quite clear that this was my own view and made no attempt to persuade anyone of anything. No argument, per se, was presented by me, by your own definition. You, also, have not made an argument, but merely unsubstantiated, presumptuous assertions.

[<a href="u2u.php?action=send&username=bfesser">bfesser</a>: removed unnecessary quoting]

[Edited on 7/8/13 by bfesser]

mr.crow - 22-6-2013 at 09:02

Quote: Originally posted by driveby40

Hey all,

I'm new to this forum, someone on Reddit thought you guys might enjoy my YouTube channel. I've been putting some videos together that showcase some of the work I do in my lab (I'm a grad student at UCLA). My latest video is a Skattebøl rearrangement to form a cyclic allene. Here's the link, lemme know what you think!

http://youtu.be/EVDQgjFu9BU

Nice! I love seeing stuff like this! I have to live vicariously since I can't do this stuff in real life very often

BTW why is everyone arguing and talking about philosophy? Knock it off

driveby40 - 22-6-2013 at 10:41

Quote: Originally posted by bfesser

This is a futile argument. Those who take part will never concede to the reason of the opposing view. Let's all just agree to disagree and stop spamming. There's no need to take this thread any further off topic.

driveby40, I enjoyed watching your other <a href="http://www.youtube.com/watch?v=Z-0EnES_OS4" target="_blank">video</a> on the preparation of 2-chloro-1,3-dimethyl imidazolidinium chloride (DMC), but it would be nice if you defined the acronym before just jumping into using it—sorry, this is one of my pet peeves. I'm a little disappointed that you glossed over your solution to the ring of impure solid product stuck in the Schlenk flask. What did you resort to?

I've <a href="viewthread.php?tid=19098&page=19#pid289005">requested</a> the paper you cited in the video.

[Edited on 6/22/13 by bfesser]

Yeah I felt bad about that. I think the stir bar stopped spinning for some reason during the reaction and caused that ring of crap (it was as hard as a rock!). I had done the reaction before and that didn't happen. I tried poking at it with various needles, injecting more solvents, etc. I ended up breaking off a piece of the flask in the process so I just quickly capped it and cut my losses by saving what material I managed to collect. It was kind of embarrassing breaking the glass and whatnot so I edited that out. Haha. Got plenty of pure DMC nevertheless to get to the next step of my synthesis, but then the subsequent step failed miserably so I gave up on that route. I eventually succeeded making my target compound via an alternate pathway.

bfesser - 22-6-2013 at 19:20

Thanks to solo, <a href="viewthread.php?tid=19098&page=19#pid289064">here</a>'s the paper for the rest of us.

Funkerman23 - 22-6-2013 at 22:45

I agree with Magpie: you have some damn fine equipment at your disposal. Teflon pump, rotovap and that Schlenkline setup was beautiful. Seeing real air free work was eye opening as well and you seem to know your stuff. If I may ask what degree are you working on? Please make more videos if you can/ want to!!( subscribed as well). Consider me very impressed.

amazingchemistry - 23-6-2013 at 17:44

I'm sorry if this is rather obvious (look at my sig for an explanation

) but how can you be sure of the weight of your product to up to three decimal places if your balance seems rather messy and without a draft shield? what is the error in your yield?

Magpie - 23-6-2013 at 17:56

But he rounds all that uncertainty off to 2 decimal places in the end, ie, "88%."

12AX7 - 23-6-2013 at 18:03

Nice. The music is a nice touch (90s campiness notwithstanding

).

But just what *does* it smell like?

Tim

amazingchemistry - 23-6-2013 at 18:17

plus or minus what? The thing is, an error of +.01g would have resulted in a 1% increase in yield. You can call this nitpicking, but why teach things like error analysis or significant figures at school if we're just going to round our numbers and call it done? I once watched a physics lecture by Walter Lewin, and one thing he said left a deep impression. He said: "Any measurement that you make without a knowledge of its uncertainty is completely meaningless." So what's the uncertainty in his measurement?

driveby40 - 23-6-2013 at 19:52

Quote: Originally posted by 12AX7

Nice. The music is a nice touch (90s campiness notwithstanding

).

But just what *does* it smell like?

Tim

It smells strong and penetrating, detectable at even dilute quantities. Very unique smell not found in nature as far as I know. It's similar to gasoline, with an almost cloying sweetness and even an onion-like finish. Similar to dicyclopentadiene if you've ever smelled that.

driveby40 - 23-6-2013 at 19:59

Quote: Originally posted by amazingchemistry

plus or minus what? The thing is, an error of +.01g would have resulted in a 1% increase in yield. You can call this nitpicking, but why teach things like error analysis or significant figures at school if we're just going to round our numbers and call it done? I once watched a physics lecture by Walter Lewin, and one thing he said left a deep impression. He said: "Any measurement that you make without a knowledge of its uncertainty is completely meaningless." So what's the uncertainty in his measurement?

Keep in mind that I was doing the experiment to produce a maximum amount of product, not to determine the exact yield. In order to use the more accurate scale, I'd have to use a smaller, lighter flask and face an inevitable loss in yield during the transfer. 88% on that scale, might very well be off by 1% (probably moreso due to temperature variation than air currents). I've calibrated that scale and its usually accurate within 0.005g for my calibrated weights.

bfesser - 24-6-2013 at 07:30

Quote: Originally posted by amazingchemistry

You can call this nitpicking, but why teach things like error analysis or significant figures at school if we're just going to round our numbers and call it done?

For Analytical Chemistry—this is Organic Chemistry.

amazingchemistry - 24-6-2013 at 18:47

thank you for the answer

I realize now that it does depend on what one is trying to accomplish. Though I'm sure you would want to calculate your overall yield at the end of the process, and 1% errors pile up fast in multi step synths.

bfesser - 25-6-2013 at 07:13

From one batch to the next, yields can very widely in organic chemistry. Physical losses can be minimized, but some reactions are just plain temperamental. It's often a lot more about what you synthesize/isolate than how efficiently. That's left to the chemical and process engineers.

Magpie - 25-6-2013 at 12:48

Those engineers are going to want to know how efficient the process can be before they spend millions of dollars on building a plant. So they will do optimization and pilot studies first.

I would like to ask the OP where he obtained the cyclopropane dibromide precursor. Was this made in-house or purchased? If made in-house, what were the steps?

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[Edited on 7/8/13 by bfesser]

driveby40 - 25-6-2013 at 22:37

The dibromocyclopropane is made in house from very cheap, commercially available chemicals. Just mix cyclooctene, potassium tert-butoxide, and hexanes together at 0°C, then add bromoform dropwise. Let it warm and stir overnight. Like the Skattebol rearrangement, the mechanism also involves a carbene intermediate. Ive attached a pdf to show this explicitly.

Attachment: MECH.pdf (339kB)
This file has been downloaded 544 times

[<a href="u2u.php?action=send&username=bfesser">bfesser</a>: removed unnecessary quoting]

[Edited on 7/8/13 by bfesser]

Magpie - 26-6-2013 at 08:07

Thank you for explaining this and showing the mechanism. I find it amazing that a cyclopropane, with all its ring strain, can be made so simply. That shows the power of a carbene, I guess.

[<a href="u2u.php?action=send&username=bfesser">bfesser</a>: removed unnecessary quoting]

[Edited on 7/8/13 by bfesser]

Heuteufel - 29-6-2013 at 15:35

Nice.

But I don´t like the way you drew the addition of the dibromocarbene to the double bond. The addition of a singlet carbene is a [1+2] cycloaddition and as such a concerted reaction (one step) ... and the representation of the carbene with partial charges is also very misleading. Sorry for the nitpicking, but I could not resist.