The Vespiary

The Hive => Methods Discourse => Topic started by: legionbob on June 26, 2002, 04:38:00 PM

Title: Lazy man's wacker continues...
Post by: legionbob on June 26, 2002, 04:38:00 PM
Into the standard 2 liter pop-bottle/tubeless tire valve pressure chamber:

1 g PdCl2
5 g CuCl2 (anhydrous if it matters)
150 ml MeOH
1 ml dH2O

    Prestirred/dissolved, then:

50 ml safrole

     A word of warning, solution must be acidic for the wacker to run, so test the pH and adjust as needed.

    Plugged and sealed, pressurized to 40 psi with pure O2 from a tank (regulator hose hacked to accept a tire fill adaptor).   Vigerously shaken by hand for a few minutes for good measure, then left on it's side to maximize the O2/solution surface area.   Come back and shake the hell out of it on a few occassions say once every half hour for a few hours, details dont seem to be important.  At about the 4-5 hour point the bottle was purged, repressurized with more O2, and left at room temp on it's side for a total of about 20-24 hours.   The sides of the bottle should be noticeably 'soft', much less hard than when first pressured.   In the past when I screwed this up it was due to lack of proper pH or lack of patience, this batch size will draw about 25-30 psi down total.

     Workup:

     Dump the reaction mix and about 100 ml of 10% HCl into a sep funnel.   Realy don't need to shake, the ketone/oil will precipitate out by itself.    After draining off (and keeping) the bottom organic layer, extract the remaining aqueous layer a time or three with a non-polar.   Toluene or xylene work better at getting all the tar and shit out of the aqueaous layer IMO, which is important for later.   Keep both layers.

     So, you have the toluene/ketone/crap fraction in one container, and the water/acid/alcohol/catalyst in another.   Wash the organic layer with distilled water and add that water to the other aqueous stuff.   This should leave you with most/all of the catalyst in the water/alcohol.

    Vac distill the organic layer to get the ketone, a water aspirator is good enough.   On my rig the light yellow spicy smelling ketone comes over at about 145C.   Yield:  Consistently 38g MDP2P from 50 ml safrole, almost certainly higher if you have a better vac source/still.   If the reaction was allowed to run to completion there shouldn't be more than a few drops of saf/isosaf.  Likewise, no real sign of the aldehyde...except for some polymerized crap the reaction seems to run very clean.    OK, got the goods...now to the catalyst.
     If you properly extracted the aqueous layer there isn't going to be much in there besides the metal salts, HCl, water, alcohol.  Distill/boil off the volatiles to leave a residue of our happy catalyst, ready to be reused.   So far I'm up to three re-uses with no signs of quitting, should be almost indeffinately reuseable (after all, where can it escape to?)    Just make sure you extracted that aqueous layer well or you'll get a tarry mess when you boil off the water/MeOH.

    And there you have it.   Shit easy, pretty much full catalyst recovery, decent yields...and if you pay attention to pH and use O2 it seems to be very very very reliable and reproducible.  For what it's worth, it seems to work equally well increasing the saf to about 75 ml.   Al/Hg amination, the honey is sweet (I get about 14 g honey.HCL for 20g ketone, some bad procedure I think.)    Happy cooking.

    Oh yah, where to get an oxygen tank?   Just go to a bulk gas place, the sort that sells gasses for welding and blow-torching.   Tell em you need it for your propane blowtorch if they ask, O2 is completely unwatched so no worries.  Usually rent the tanks on a yearly basis plus fill/refill costs.   Figure $60 for a year and a fill.  Another $150 maybe for a regulator, you can figure out hacking the hose.
Legion Bob
"We're Everywhere!"
Title: Anyone willing to try this out and compare the ...
Post by: Osmium on June 26, 2002, 05:13:00 PM
Anyone willing to try this out and compare the resulting ketone by some analytical means to the real deal?
I'm not fat just horizontally disproportionate.
Title: Seems about right
Post by: Chromic on June 26, 2002, 05:35:00 PM
Stellar work, and everything seems about right.

If you had, say, 35 psi uptake the first time, and 25 psi uptake the second time on an air space of 1.8L (2L - 150ml MeOH - 50ml safrole) that would mean a total of 4 atmospheres were taken up, or 7.3L of oxygen. That's about 0.327 of a mol O, and you put in about 0.340 mol of safrole (50ml = 55g)... so that seems a touch low on the oxygen uptake. Perhaps consider letting it run a bit longer (but since my calculations are likely plus or minus a bit, maybe you really are letting it run long enough).

Your yields from amalgamation are rather low, suggesting a ketone with impurities (but at least 75% pure)... did you fractionally distill your ketone?

38g of mdp2p is 0.213 mol, so you got a yield of 63%. Not very high, but perhaps with more practice on the technique you can bring it up some.

Now, and most importantly, some other bees will be able to verify your work and the quality of the ketone. This is because, if I remember correctly, alcoholic oxygen/palladium wackers have been failures for a # of bees.
Title: Please elaborate...
Post by: weedar on June 26, 2002, 05:40:00 PM
legionbob wrote:

Plugged and sealed, pressurized to 40 psi with pure O2 from a tank (regulator hose hacked to accept a tire fill adaptor).



Sorry,but I have trouble understanding how to hack this
thing and pressurize..Could you be more verbose or possibly
give us some pictures?(Everybody loves pictures :) )

Weedar

Weedar contains 2,4-D dimethylamine salt,apparently
Title: Pictures!
Post by: Chromic on June 26, 2002, 05:45:00 PM
I second the vote for pictures! E-mail them to another bee and politely ask them to put them up (eg ueruma, rhodium, etc) if you don't know how to get them up on a web page anonymously. We absolutely need pictures of your apparatus!  :)
Title: O2 Wacker analyses
Post by: Ritter on June 26, 2002, 07:38:00 PM
Osmium:

SWIM used to run this rxn frequently and has seen the nMR's of the product.  It was usually 85:15 MDP2P/MDP3P with no traces of the propiophenone present.
Title: Something doesn't seem right
Post by: lab_bitch on June 26, 2002, 07:55:00 PM
I have trouble seeing how enough oxygen could have been supplied to the system.  Molecular diffusion between two stagnant phases is extremely slow.  That is why fish will die if the aquarium isn't aerated.  The solubility of O2 in water is 0.004g/mL, and is of the same magnitude for methanol.  You need about 5g of O2 to get the yields that you claim.  Assuming that diffusion is negligible while you aren't shaking it, you would have to completely saturate the methanol about 500 times to get the required amount of O2 needed.  Mabey I'm wrong about the negligible molecular diffusion, but it just doesn't seem very reasonable.  Also, do you predissolve your catalyst?  This is a must for good yields.  The soln. should be transparent when held up to a light.
Title: I knew that it worked (since I came up with that ...
Post by: Osmium on June 26, 2002, 07:57:00 PM
I knew that it worked (since I came up with that thing many years ago), but never had an opportunity to test the product.
Great news Ritter!  ;D
I'm not fat just horizontally disproportionate.
Title: Where would one find info on that
Post by: Bubbleplate on June 27, 2002, 04:41:00 AM
2 liter pop-bottle/tubeless tire valve pressure chamber? (not in TFSE)
Sounds simple, but what exactly is it?
Title: bike tire
Post by: RoundBottom on June 27, 2002, 05:07:00 AM
man, use a bike tire valve... they are so much more prevelent.
i learned a thing or two from charlie dontcha know.
Title: alright, you say it's a 'lazy man's wacker', but ...
Post by: El_Zorro on June 27, 2002, 08:40:00 AM
alright, you say it's a 'lazy man's wacker', but there's still a lot of shakin' goin' on.  IMHO, that's too much work if you're gonna use that title.  What I think you could do would be to find the kinds of 2L soda bottles with the round bottoms.  They have a black plastic base glued on, but if ya yank that off, it's just like a round-bottomed flask.  So just nigger-rig yourself up a clamp for it, drop in an egg stirbar, and crank up your mag stirrer until the stirbar's about to go flying, and there's thousands of little air bubbles flying around in the solution.  That should keep your solution fairly saturated, and with absolutely no work required.  (Well, you do have to turn the rpm knob on the stirrer.  Hmmmm.  Gimme a day or two. ;) )  Just repressurize as needed, and you have a procedure worthy of the title you gave it.
Do not go gentle into that good night.  Rage, Rage, against the dying of the light.  --Dylan Thomas
Title: You're missing the point
Post by: weedar on June 27, 2002, 09:21:00 AM
El_Zorro,the whole idea with this "lazy man's wacker" is
that you don't need any expensive glassware/equipment..

Weedar

Weedar contains 2,4-D dimethylamine salt,apparently
Title: Title should be cheapman's wacker then.
Post by: pickler on June 27, 2002, 04:15:00 PM
Title should be cheapman's wacker then. If you wanna put a few dollars out you could get one of those paintcan shakers like Home improvment stores have.
We'll soon find out if I'm a chemist or not!
Title: What pH exactly should it be?
Post by: Bubbleplate on June 27, 2002, 04:49:00 PM
What pH range is workable, and I assume one can use HCl to adjust?
I too was going to suggest taping the bottle to one of those shakers like they use in bio labs. I guess a paint can shaker would work just as well.
Title: True, pickler.
Post by: El_Zorro on June 27, 2002, 08:42:00 PM
True, pickler.
Do not go gentle into that good night.  Rage, Rage, against the dying of the light.  --Dylan Thomas
Title: Literature states that an HCl concentration of 0.
Post by: lab_bitch on June 28, 2002, 02:05:00 AM
Literature states that an HCl concentration of 0.1 M is the best for the ethylene oxidation.  You may want a higher pH, though, because ketone undergoes side reactions in acidic solution.
Title: Information VS. misinformation what a pain.
Post by: SPISSHAK on June 29, 2002, 11:09:00 AM
There's a lot of good info on this reaction here problem is it's mixed with a lot of misinformation.
Like that pop bottle for example, does'nt ketone eat through some plastics?
Title: Plastic Soda Bottle Material
Post by: Bubbleplate on June 29, 2002, 10:03:00 PM
I believe that most plastic soda bottles are made from PET (polyethylene terephthalate) and should be immune from ketone.
If someone wants to use other plastic containers in the Lab, one can look for the Plastic Code on the item's bottom, and check this reference for its composition:

http://www.designboom.com/eng/education/pet/recycling.html (http://www.designboom.com/eng/education/pet/recycling.html)


Anyway, always test the plastic item before hand with a small amount of the chemical it will be exposed to.
Title: Thanks for the hint.
Post by: SPISSHAK on June 29, 2002, 11:36:00 PM
Good advise, SWIM like the idea of the PVC pressure vessel in  the O2 is the shit thread.
Title: Bear With Me Here...
Post by: Bubbleplate on June 30, 2002, 05:46:00 PM
But did I read this correcty?: Add Safrole NOT Iso-safrole to the mix? No need to convert safrole to iso first?
Question: CAN Iso-safrole be used?
Title: I know this one
Post by: weedar on June 30, 2002, 09:27:00 PM
Bubbleplate:You should read more about the Wacker on
Rhodium's or maybe UTFSE..The Wacker Oxidation doesn't need
iso,plain old safrole will do,but isosafrole will actually
be a part of the "impurities" resulting from this reaction.

Weedar
Weedar contains 2,4-D dimethylamine salt,apparently
Title: Pictures
Post by: Chromic on July 19, 2002, 06:38:00 PM
Can you please give us pictures of a typical run? I'd like to see a picture with everything loaded, and then what everything looks like after the run is over.
Title: hmmmmm.....
Post by: hellman on July 23, 2002, 06:22:00 AM
Well done, let's see some pictures,.
Title: rubber tire valves
Post by: platcat on July 23, 2002, 05:44:00 PM
Available at any auto parts store. several varieties. a higher pressure one for truck tires and mag wheels is a bolt in valve stem.Those caps are thin (2 ltr), swip would prefer the bolt in variety. And the  tire inflater hose is just cut and spliced into the oxy hose.  oxy acytlene is a much more common form of cutting/welding that  oxy/propane.Buy used tanks cheap. the est i got on rentals ran from .60d a day down to .16d a day. if u walk in with your tank they will trade it  for a full one or refill it.under 20.d us. depends on size.You have to open a acct and a credit app at the bigger places. to rent that is. You can get small bottles of O2 at  large stores in the hardware dept. they are near the propane and mapp gas cylinders for use in the mapp gas/ oxy portable units. they dont hold much and are not refillable. but its an alternative source. and its very OTC. :)
"The crux of the biscuit is the apostrophe"FZ
Are we there yet?