Author Topic: o2 is the shit  (Read 19508 times)

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KrZ

  • Guest
Re: Let's look at the literature
« Reply #160 on: November 07, 2000, 12:57:00 PM »
The references seemed to indicate DMF was better.  All the patents etc. that I could find with IPA didn't have as good yields, absorption was definitely quick and noticeable.  The IPA/EtOH patents didn't have as high a selectivity as DMF or the sulfalone methods.

Beaker

  • Guest
Re: Let's look at the literature
« Reply #161 on: November 07, 2000, 01:35:00 PM »
Just to clarify, are you now sayimg that you never got acceptable results with IPA? What about your older posts with EtOH/50C/80psi O2?

placebo

  • Guest
Re: Let's look at the literature
« Reply #162 on: November 07, 2000, 01:50:00 PM »
Ok so....

01-14-99 11:18 AM Krz says...

In the beaker went;
3.5 g PdCl2,
45g CuCl,
295 g Safrole,
875 ml DMF

Pressurized it up to 120psi
50F.
285g MDP2P


11-08-00 05:31 KrZ says...

3.24g PdCl2
32.40g CuCl2•2H2O
324.36g Safrole
70mL H2O
500mL DMF

Pressurized to 35 psi O2.
60f
311gm MDP2P

So it seems from studying KrZ's figures that the O2 is not very fussy in regards to O2 pressure or water content and temp will probably only affect the rate of absorbtion.

The deciding factor is SOLVENT!
Now who has a good synth for DMF?


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KrZ

  • Guest
Re: Let's look at the literature
« Reply #163 on: November 07, 2000, 02:09:00 PM »
The DMF was 10% water in the PVC-a-ma-jig too, I just didn't write it in.  :-[  :-[  :-[  :-[

KrZ

  • Guest
Re: Let's look at the literature
« Reply #164 on: November 07, 2000, 02:11:00 PM »
I got acceptable results with IPA, just more polymerization on the distillation, same with EtOH.

placebo

  • Guest
Re: Let's look at the literature
« Reply #165 on: November 07, 2000, 02:46:00 PM »
Remember this KrZ?

Wacker - sort of, solvent volume was cut in half, and the surfacant was left out (500 muL of Dawn), DMF works w/o surf.


Care to elaborate? Am I deciphering this correctly, that you were using a surfactant/PTC from a detergent, or you had some detergent in the DMF that fucked things?

So do you think that the solvent is the key (and the water) and the reason for most fuck-ups?

Hmm...What solvent did Os use, and what was his yeilds?
Os?



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placebo

  • Guest
Re: Let's look at the literature
« Reply #166 on: November 07, 2000, 03:37:00 PM »
I have been doing some reading and found this bit of information.
If the solvent is the deciding factor between happiness and misery could this be the reason?


One of the advantages of dimethyl formamide
dimethyl amide and dimethyl sulfoxide is that
they are aprotic polar solvents and greatly
accelerate the rate of bimolecular nucleophilic
subsitution reactions since they solvate
cations but not anions. The naked anions
are thus highly reactive.

An example of an Sn2 is OH- + CH3CH2Cl -> CH3CH2OH + CL-.


Also did the old "UTFSE" (old board too) thing and found that DMF is "apparently" watched, and can only aquired through chem supply.

Can it be synthed?



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zooligan

  • Guest
Re: Let's look at the literature
« Reply #167 on: November 07, 2000, 03:44:00 PM »
Cebo's quote mentions DMSO as having some of the same properties as DMF.  Could it be used instead??

z

KrZ

  • Guest
Re: Let's look at the literature
« Reply #168 on: November 07, 2000, 04:27:00 PM »
There's some DMSO sitting here doing nothing, maybe we can see what's up w. it.

Semtex

  • Guest
Re: Let's look at the literature
« Reply #169 on: November 07, 2000, 08:29:00 PM »
placebo, I think Osmium used MeOH as his wacker solvent, but that's just a rumor...  ;)


::)  ::)

placebo

  • Guest
Re: Let's look at the literature
« Reply #170 on: November 07, 2000, 11:00:00 PM »
I sorta remember reading somewhere that Os used denatured but can't be bothered looking to confirm that right now.

KrZ, can you elaborate a little on the IPA/EtOH/MeOH deal?
Water not as important as with DMF?
...and you said yeilds not as good as DMF, in what range are we talking?
As bad as the others got, like 30%max?
Are you adding the water with these other solvents as well?

Just trying to figure if the solvent is what is making the difference, or the water addition, because I don't think others are adding water and if so, not that much anyway.

I think if one could reliably get 60-70% yeild (by weight), this method will be revolutionary.



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Antibody2

  • Guest
Re: Let's look at the literature
« Reply #171 on: November 08, 2000, 11:57:00 AM »
Antibody always wondered why there was never any mention of DMSO in relation to wackers, as it shares some of DMFs properties. It is also a bit easier come by. Hmmmmmm. Any other bees got opinions on DMSO as a solvent for this baby.



I’m gonna die when it’s my time to die. I’m gonna live my life the way I want to!

KrZ

  • Guest
Re: Let's look at the literature
« Reply #172 on: November 08, 2000, 03:46:00 PM »
Solvents make a world of difference when it comes to wacker oxidations, huge changes can occur by varying them.  Check out US patent 4,661,642.  They oxidize a number of items in tBuOH with a NO2-Pd type catalyst and get large predominance of the aldehyde.  However, when they switch the solvent to glycol, using the same catalyst and reoxidant, the molar selectivity towards the ketone becomes 100%!!  It's at the bottom of the data table, decene is the starting olefin.  They mention a book "Palladium Catalyzed Oxidations of Hydrocarbons" looks like a must have!

zooligan

  • Guest
Re: Let's look at the literature
« Reply #173 on: February 06, 2001, 04:49:00 AM »
Just thought it might be important to bring this thread to the top with the "successful DMF O2" thread.

z

LaBTop

  • Guest
Re: Let's look at the literature
« Reply #174 on: February 06, 2001, 08:05:00 AM »
Also, on the subject of changing solvents, did you know, KrZ, that the solvent for reducing the decomposition explosion risk in catalytic hydrogenation (according to Rylander) is 2-methoxyethanol (methylcellusolve); whether it would be compatible with reductive amination is unknown to us. LT/


WISDOMwillWIN

placebo

  • Guest
Re: Let's look at the literature
« Reply #175 on: February 11, 2001, 05:12:00 AM »
Is anybody in a position to try a little DMSO experiment or is it going to be left up to me to make the ground-breaking discoveries for the masses, like in the meth forum? I may just keep it to myself this time! Seems to be the way things are done around here! TAKE, TAKE, TAKE!


I could explain it to you, but you wouldn't understand!

Semtex

  • Guest
Re: Let's look at the literature
« Reply #176 on: February 23, 2001, 10:52:00 PM »
Does anyone have the solubility data for the glycol concerning the other stuff in the mix...? 


::)  ::)

PVnRT_NC8

  • Guest
Re: o2 is the shit
« Reply #177 on: February 24, 2001, 04:59:00 AM »
i maybe isso;ting the anhydride i thomk something 03-
seems to ssalt u[ e,,u;sion] ir al fe b etc? it goes attemps to go milky then cooled then warmed this is a look as ya go titration never is the same??  sometimes it just goes entirelly milky help then it fallls out over a few days???? etc??


Amethystium   See

Post 175370 (missing)

(LaBTop: "Fman Thesis, the Answer", Methods Discourse)
LT/

KrZ

  • Guest
Re: o2 is the shit
« Reply #178 on: February 24, 2001, 12:43:00 PM »
I'm with FMAN.  FUUUUUUUUUUUCCCCCCCCCCCKKKKKKK!!!!!!!!!!!!!!!!!!!!!!!!!!!!