posted 07-21-99 08:47 PM         

A FOAF of mine, loved the benzowacker, as its results were much good.
He had ran it sucessfully numerous times, but just this once, he thought it was time to change the solvent,
His hatred of purchasing this product(DMF), made him feel anxious and controllably sick inside..blah,blah..
Controllably, yes, ultimately his mind was in controll of his body,.
What shit, sorry, its that bud...

So he had two solvents laying around,
100% Ipa and 100% xylene, and some dmso, (which he hasn't been tried yet.)
He understood, as far as he thought the mechanism's of a good solvent,.

Do you know what happened when he substituted with these 2 solvents.

Yes, He now no longer feels controllably sick any more.

P.S.

He doesn't mind so much with the P-benzo, as he has a genuine interset in photography chemicals.

Hypothetically speaking, I believe DMSO will work (2).

posted 07-21-99 08:52 PM         

sorry man
anyways,...
Seya

posted 07-21-99 11:09 PM         

What ratio IPA to Xylene?

posted 08-01-99 11:55 AM         

Are you saying that one can substitute either IPA [i]or[i/] xylene instead of DMF, or are you saying one can use a mixture of those two in some proportion (please give the ration if it's the latter).

posted 08-01-99 01:25 PM         

Why the hell would you want to impersonate me?

PS

posted 08-01-99 07:38 PM         

The Wacker oxidation has been done many times in MeOH, EtOH, iPrOH, DMF, DMSO, etc. As for alcohols interefering, this isn't much of a problem. Yes, Pd2+ species can catalyze alcohol oxidation, but not significantly under the conditions you're likely to encounter when oxidizing olefins. For that matter, they catalyze the Bayer-Villiger RxN, if you let them, but to date, that hasn't been a problem.

Barring olefins or amines from usage as solvents, the only practical limitations here really regarding solvent choice is the solvent's ability to dissolve both the catalyst(s) and reagents. Fer crissakes, using a PTC and the right ligands on palladium, you can actually even get away with even less than THAT -- by dissolving the olefin and PdCl2 in something like DCM, and adding an aqueous layer of H2O2, then a PTC to shuttle the oxidizing species from the aqueous phase into the organic phase, you can successfully perform the Wacker in an ultra-clean cutting-edge way (ref's available upon request.)

No yields, reaction time, conditions, concentrations, general observations, or even molar proportions with your report? No mention of the solubility of your catalysts in your solvents system, or the actual proportions of the two solvents, for that matter? You didn't even tell us what catalyst or catalysts you used. Hmmm. Well, I guess its the thought that counts. Sorry to be such a party-pooper, but you haven't actually told us anything. I don't mean to sound harsh, but I feel you have the potential to do some amazing practical research. This still could be handy, provided you were kind enough to supply more complete details.

Patiently awaiting useable details,

posted 08-01-99 09:45 PM         

Actually, what I am thinking, is that if we work on it, we can have a cheap, high yielding, practical Wacker. What about using another metal besides Pd? I know that Pd is the perfect catalyst for this, but what about a mixed catalyst? Cu with something else?

How about this. Olefin and catalyst in a cheap organic solvent, H2O2 as Oxygen source, and a PTC to cover the aqueous -> organic phase transfer.

Even if this does not have the best yield, have you seen PdCl2 prices these days? We can use allot of catalyst (cheap) and run it for a long time. A traditional Wacker, with PdCl2, CuCl2, and O2, cost a fair amount to run. Especially in large amounts. A 20L reaction (~1000g olefin) would cost well over $1000.

posted 08-01-99 10:38 PM         

I'll be back

hellman
Methyl man- No, use either solvents, not both together, although, it really woudn't matter

posted 08-01-99 11:01 PM         

If you have some other solvent, say meoh, impress yourself and disslove it in that,
Small increments in time and heat will dissolve it,.

posted 08-02-99 07:46 PM         

There are plenty of metal catalysts for epoxidizng olefins, but only one PRACTICAL one that'll consistantly give you the alpha-methyl-ketone. If you're willing to settle for that, then the worlds your oyster.

I've wondered, if you sued something like a cobalt, titanium, or nickel complex to catalyze the odixation to the epoxide, and coupled it with LiBr or equiv. catalyst to isomerize, would this work? There may be some contentions of competing sulubilities between the catalysts, but it looks kinda interesting.

Hellman,

Glad to see you didn't take me the wrong way. Solubility can be helped by 1: crushing things exta-fine, 2) sonication. What was your yield? Keep fightin' the good fight!

posted 08-04-99 01:16 PM         

Math is not Methyl's strong point (somewhat of a handicap for an aspiring khemist), but he perseveres anyway. Calculators rule!

posted 08-04-99 02:07 PM         

You could just use this tool:

http://www.chemfinder.com/

to see out that the weights for 1 mole of each are:

IPA = (C3H8O) = 60.096 grams
Xylene = (C24H30) = 318.50 grams
DMF = (C3H7NO) = 73.094 grams

Or, you could refer to a Periodic table like this one:

http://www.shef.ac.uk/chemistry/web-elements/

to see how those numbers are actually derived, using the atomic weights of the individual elements comprising each compound. For example:

if IPA = C3H8O (meaning 3 carbon, 8 hydrogen, and 1 oxygen atom)

then you would refer to the periodic table to come up with the following equation:

1 mole of IPA = (3 x 12.0107) + (8 x 1.00794) + (1 x 15.9994) grams, or...

1 mole of IPA = (36.0321) + (8.06352) + (15.9994) grams, or...

1 mole of IPA = 60.09502 grams

(looks like I’m off by a thousandth gram for some reason, but you get the idea, right?)

Oh yeah, almost forgot, a "mole" is just a fancy name for a gazillion (6 x 10^23?) molecules of a given substance. Some egghead named Avogadro came up with this concept a long, long time ago. 1 mole of every element has the same number of molecules in it (a useful concept, for lots of reasons), but weighs a different amount, due to the differences in the total atomic weights of the atoms comprising it.

posted 08-04-99 10:02 PM         

IPA: 61g
DMF: 74g
Difference: 13g (~18%)

It would thus take 18% more IPA to equal the mole-weight of a given amount of DMF. The scale of benzo wacker that the guy in the bar said he favors calls for 388mL of DMF, if memory serves (and it often doesn't), so that would mean I'd want to use about 458mL of IPA to do the same job.

Am I way off base here?

posted 08-04-99 10:44 PM         

Your close, damn close.
I can't work the math out for you today, but if you can't work it out by next week, I post my secret wepon,.
I'm not at home you see.

To go by what the man in the bar said, you'll need to know how much 388ml of DMF weighs, or even better how much 1ml of dmf weighs,unfortunately it was written on a volume basis, not a weight basis.
For that matter i haven't even got a calculator here, so...

For example if say 1ml weighed 1g(Hypothetical)
1 mole of dmf would be 74mls(or 74*(weight of 1 ml)
then divide 388 by 74(or whatever you calculated the volume of 1 mole of DMF)

which is around 5 mole of dmf roughly in 388mls of dmf,.
Then all you do is measure out 5 mole of IPA
which is around ~304grams

Don't forget this is all based on the fact that 1ml of dmf weighs 1 gram, which i am sure it doesn't. goooooood luck.

I help you if your still stuck, later dude.

posted 08-05-99 11:30 PM         

MeOH, EtOH, IPA will all work just fine. The reason DMF was quoted is because various papers use DMF <I>because it used to be an extremely popular organic solvent in the lab!</I> Real labs back in the old days wouldn't have had the supply problems that bees hypothetically have.

posted 08-08-99 10:11 PM         

It's not critical to molarize the solvent system, But that doesn't mean to say it's not the right thing to do,
For me, I like to have those interactions happening at roughly the same rate and energy as strikey bar post.
Just don't forget too much solvent takes longer, to little takes shorter,
How much variance, how fast's your stirrer, what shapoe your pot,( Just kidding, have fun, you can't fail with this baby..>!)
Well that's why it doesn't hurt to use molar quant.

But as we are all a little rough on the edges, and this is clandestine chem,.

Fuck it and have a good time,
Tell me your results when you're through,

GOOOOOOOOODLUCK