Author Topic: O2 Wacker  (Read 9601 times)

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pickler

  • Guest
O2 Wacker
« on: December 20, 2002, 01:33:00 PM »
Swim is thinking about trying the O2 wacker and still has a few questions about it. Swim has already tried TFSE and Rhodium's page but the confusion still persists. There seems to be a lot of different info about the whole wacker. Now using pure O2 is a given, but swim's questions are more around the reaction times and shaking and purging. How long is this reaction supposed to run? How long to shake for and let sit before purging and refilling with O2? Swim has seen everything from 4 hrs to 1 day. Any help would be appreciated.

I went into the business for the money, and the art grew out of it.-Charlie Chaplin


hCiLdOdUeDn

  • Guest
Heh, why dont you try it and find out!
« Reply #1 on: December 20, 2002, 01:36:00 PM »

pickler

  • Guest
I put in a post to get an answer to a question, ...
« Reply #2 on: December 20, 2002, 02:06:00 PM »
I put in a post to get an answer to a question, not a smart ass response from you hidden cloud.

I went into the business for the money, and the art grew out of it.-Charlie Chaplin


carcrash

  • Guest
I am curious too on the o2 wacker
« Reply #3 on: December 20, 2002, 03:16:00 PM »
I spent a good chunk of a day on tfse looking at the o2 wacker.  Meoh, 1 gram CuCl2, 1 gram PdCl2 per 50 grams safrole and pre stirring were the only definite.  But very inconsistent results were about all I pulled up.  What pressure and temperature with pure o2 gives consistent yields? For temperature I read everything from icebath to cool to 70C. Wondering about using either an abs or pvc schedule 80 pressure vessel with the reaction done in glass with an hdpe cork screw to keep things from spilling out. I know pvc is more likely to shatter so it would be wrapped in duct tape. Schedule 80 pvc is harder to find but more pressure ressistant. Also would a baby rocker work instead of a shaker? Seems more effective than stirring but less than shaking. And might be able to put the stirrer in the rocker too.

Some 6 foot o2 tank that I really would love to put to good use has been following me around.  

Not a chemist I just follow directions on the box mix

hCiLdOdUeDn

  • Guest
Heh, ok no need to get angry!
« Reply #4 on: December 20, 2002, 04:40:00 PM »
Heh, ok no need to get angry!

Post 382528 (missing)

(TheBlindGenius: "Yes", Newbee Forum)

Post 382529 (missing)

(pupilage: "Answers", Newbee Forum)

Post 383204 (missing)

(scram: "I have success using 0.8g pd per 99g olefin.", Newbee Forum)

Post 382489

(pupilage: "Ever heard of the O2 Wacker?  It works!!", Chemicals & Equipment)

Post 364110

(placebo: "I agree with Rhodium, this could have been an ...", Methods Discourse)

Post 362669 (missing)

(pupilage: "Put PdCl2 in a real wacker of some sort..", Newbee Forum)



Alot of success stories. Yields from 60-80%. Try it yourself by adjusting the PdCl2:safrole:O2:temperature/time. You can atleast expect some yield. Dont use PVC, as ketone is pretty reactive and might break cheap PVC under pressure. Try to find a thick walled glass container or teflon coated metal container. 


Sink or SWIM

carcrash

  • Guest
Glass inside the pvc
« Reply #5 on: December 20, 2002, 05:04:00 PM »
Keytone will eat the pvc unless its in a glass container. Pvc or abs to contain the pressure not the reagents. Ideally an 8 or 10 inch pipe with o2 inlet, pressure release and a gauge or better yet an over pressure release gauge valve, with a threaded union near the top so you can remove the glass. Or a reducer could be used with a T at the top for a ball valve for presure release and hardware for o2 inlet on the other end of the T. Use epoxy steel putty to make the connections air tight for the gauge and gas inlets if they are not coming off the T.  Great stuff handy for lots of things.

Not a chemist I just follow directions on the box mix

gabd

  • Guest
after reading a lot I get the feeling that
« Reply #6 on: December 20, 2002, 10:09:00 PM »
glass is the only way to go. Stainless steel is a no-no with palladium chloride. HPDE is quite resistant to ketone and not so porous for oxygen.

Any other polypropylene seems not so resistant to ketones attack. HDPE can wear out, I guess it makes a potential bomb or some nice mess.

I have yet to try this but I had an idea, that I feel like trying.  Using a rb flask with 1 neck and temp inlet, secured in a stainless steel vessel. Through the temp inlet goes a gas dispersion tube, that bubbles oxygen, to pressurize the system. The neck is plugged in with a small diameter tube, just enough to let oxygen through but not to favorize liquid spilling out(maybe a coiled tube of some sort). Everything is closed in the stainless steel vessel. Then when you start pressurizing, you do it slowly, bubbling O2 trough your liquid. The pressure equalizes in the stainless steel vessel and your rb flask is safe because its no taking any of the pressure(its even on both side, the purpose of the opening in the neck). I guess along with shaking, this could dissolve more O2. I like the idea but I still have to figure out what vessel to use. Any inputs would be appreciated.
I guess the bigger your rb flask, the better(more surface area) which could mean a pretty big metal vessel.

But after reading this patent

Patent US3365499



I'm not sure I want to try the O2 wacker!

SPISSHAK

  • Guest
gabd
« Reply #7 on: December 20, 2002, 11:52:00 PM »
I read a lot about that reaction too I can tell you to look at the patents (the original patents) and go from there, in the patents they mention this reaction requires heating, so you want to do that, and other details that are important.
When in doubt always refer to the literature.

carcrash

  • Guest
Speaking of bubblers
« Reply #8 on: December 21, 2002, 01:22:00 AM »
I have been thinking about running a serious fish pump inside the pressure vessel that bubbles into the solution contained in glass. Run an hdpe tube into the solution. Wondering how bubbling and stirring might compare to shaking. 

Not a chemist I just follow directions on the box mix

goiterjoe

  • Guest
isn't it pressurized?
« Reply #9 on: December 21, 2002, 07:52:00 AM »
If the vessel is pressurized, it will blow the contents back into the bubbler.  Bubblers don't create much pressure, they just push air along gently.

If at first you don't succeed, try, try again. Then give up. There's no use being a fool about it.

gabd

  • Guest
I think is refering to
« Reply #10 on: December 21, 2002, 09:24:00 AM »
the bubbler inside the vessel, just recirculating the pressurized O2 in the glass flask, which is enclosed in a closed stainless steel vessel. The pressure is 40 Psi but the glass doesnt "feel" it because there is no pressure difference. The bubbler should work that way, shouldnt it?

goiterjoe

  • Guest
as long as it's sparkless
« Reply #11 on: December 21, 2002, 09:38:00 AM »
that might be quite entertaining to watch from a distance if it wasn't completely sealed. ::)

If at first you don't succeed, try, try again. Then give up. There's no use being a fool about it.

carcrash

  • Guest
nix the fish pump idea
« Reply #12 on: December 21, 2002, 01:15:00 PM »
Any spark at 40 psi in pure o2 will repeat Apollo 1. I am sure that fish pumps are not marketed for being sparkless.

Not a chemist I just follow directions on the box mix

gabd

  • Guest
Good thinking
« Reply #13 on: December 21, 2002, 03:11:00 PM »
What an explosion that would make. But I still think that bubbling the O2 in the solution while pressurizing should dissolve more oxygen.

So somehow hook up a hose on the gaz inlet that would send the O2 in the mix, bubbling. I still have to figure out whant vessel could hold such a setup.

gruns

  • Guest
alu min ium
« Reply #14 on: December 30, 2002, 09:16:00 PM »
Would it be dangerous to run the wacker in a cast aluminum
container?  You know.. like a pressure cooker, so you could
magstir through it. 

Does anybody know if oxygen would treat a pcooker's
pressure gauge badly?  If it did I suppose you could
change it out with a scuba gauge somehow.

I was also looking around at solenoid-controlled high
pressure air valves and was wondering if anybody know if
oxygen would eat brass.  Those valves ran for like $30, btw.

Another thing I was looking for but I couldn't find, that
is an oxygen pressure gauge with an output you could use
to log on a computer, does anybody know about one?


Also, if you take apart those little pumps (I'm an insatiable
tinker) you'll find that it's just a permanent magnet next
to a little solenoid, I'm fairly sure it'd be tough to
get it to spark.  Of course, then you'd have to run 115v
into your pressure chamber :)



Rhodium

  • Guest
I would expect all the metal salts to ...
« Reply #15 on: December 31, 2002, 05:24:00 AM »
I would expect all the metal salts to precipitate as the metal if you ran the rxn in an Al container. Bad idea.

gruns

  • Guest
hehe...
« Reply #16 on: December 31, 2002, 01:04:00 PM »
Hehe.. I meant, glassware inside an aluminum container,
not running the reaction directly on aluminum, sorry, shoulda
been more specific...

Would the fumes coming off the reaction corrode the aluminum?
(/me shows his ignorance of the reaction)



Osmium

  • Guest
No pain - no gain!
« Reply #17 on: December 31, 2002, 01:59:00 PM »
This is funny. Everyone is already planning to build semi-industrial reactors for bulk manufacture of ketone before they have done even a few small scale experiments.

You know how you will get most of your questions answered?
Get a PET bottle, hook up some O2 line to it, dump in 50ml of play-safrole (e.g. dimethoxyallylbenzene from eugenol), some PdCl2 and Cucl2 dissolved in MeOH a day beforehand, pressurise the shit out of the SRV with O2 and start shaking that sucker for a few hours while occasionally sticking the bottle in a hot water bath. Monitor the internal pressure with a manometer and find out under what circumstances O2 absorption is highest, figure out a quick and dirty workup procedure and then, after your biceps have grown by two inches on each arm after you ran 10-20 trial runs you will have figured it out.



Daphuk_up

  • Guest
pressurized O2 and MeOH...
« Reply #18 on: January 04, 2003, 07:16:00 PM »
Just a quick newbie question got my first post.  I have done a bit of research, bit still cant find any data regarding this question.  The question is thus:  At what pressure of relatively pure O will methanol spontaneously combust?  Will it at all?  My instincts tell me probably not, at least not up through 200psi (~7 atm) or so.  Any opinions on the matter?

Secondly, I would like to speak out loud to myself here, and remind myself why it is that it is so important to fully understand a reaction rather than just following a recipe.  My friend SWID had even gone to the trouble to create a 2" PVC container for the O2 wacker, complete with calculations of the molar amount of gas vs ketone present at various pressures.  Figured out he did that in a 2" diameter, 18" long piece of PVC with appropraite quantaties of ketone and MeOH that approx. 200psi would supply enough oxygen (based on 100g of ketone = .617mol, and 6.8 atm of O2 in the remaining space = .3668mol of O2 or .734 mol of O).  Then, after learning that PVC and ketone are no good, and that the atmospheric oxygen is not used in the reaction, he is totally stumped. :o   No need for a UTFSE on this one, I can find my own way to it, still got plenty of research to do for my imaginary buddy. ::)

I am still curious about the pressure thing though.

Wait a minute, if atmospheric O2 isnt being absorbed, then why does the pressure drop?  That makes no sense...


pupilage

  • Guest
Ok answer of sorts.
« Reply #19 on: January 05, 2003, 09:31:00 AM »
I reserve the right to be totally wrong on this one but this is what I think occurs when just atmospheric air is used. Air is made up of mostly nitrogen 78% and Oxygen 21% all other gases make up the other 1%. In the PdCl2 mix we are asking an oxygen atom to link with our favorite Olefin to produce the ketone we seek.
In the vessel nitrogen combines with oxygen and forms the gas nitric oxide (NO)The simplest reaction possible. So what you will see from the pressure indications is decrease in pressure due to Oxygen converting to the nitric oxide.
No or almost no ketone produced.