Author Topic: LiI  (Read 1908 times)

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sYnThOmAtIc

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LiI
« on: August 15, 2002, 08:42:00 PM »
Ok was reading the isomerization with LiI in the electroepoxidation procedure and it said the equipment was purged with n2. Is this nessecary for epoxide isomerization? If so what will happen with its absence? Low yields, side reactions? If not what was the purpose?

Also someone posted a chart with the molecular weights of safrole iso epoxide ketoen and amine but it was scaned and canot find it with and keywords since it had no words really. Anybody know what thread or number it was? As i'm not having much luck today finding chemical formulas on google.

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Chromic

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MWs
« Reply #1 on: August 16, 2002, 01:26:00 AM »
>Ok was reading the isomerization with LiI in the electroepoxidation procedure
>and it said the equipment was purged with n2. Is this nessecary for epoxide
>isomerization? If so what will happen with its absence? Low yields, side
>reactions? If not what was the purpose?

Probably not. The main purpose is to remove oxygen and humidity from the reaction. And if you're looking on a high yielding OTC way to the ketone... might I convince you to look some more at Ritter's work with tosic acid?  :)

>Also someone posted a chart with the molecular weights of safrole iso epoxide ketoen and
>amine but it was scaned and canot find it with and keywords since it had no words really.
>Anybody know what thread or number it was? As i'm not having much luck today finding
>chemical formulas on google.

I've got a spreadsheet with all of the data for all alkenes of interest. Here's the data for isosafrole:

isosafrole & safrole 162.2g/mol
epoxide 178.2g/mol
glycol 196.2g/mol
ketone 178.2g/mol
ketoxime 193.2g/mol
pseudonitrosite 238.2g/mol
nitropropene 207.2g/mol
nitropropane 209.2g/mol
3,4-MD-benzaldehyde 150.1g/mol
3,4-MD-nitrostyrene 193.2g/mol
3,4-MDPEA 192.3g/mol
3,4-MDPEA.HCl 201.7g/mol
3,4-MDA 179.2g/mol
3,4-MDA.HCl 215.7g/mol
3,4-MDMA 193.2g/mol
3,4-MDMA.HCl 229.6g/mol

I could also make structural diagrams of all of the above too. I always used to confuse me.

Ritter

  • Guest
Thanks Chromic!
« Reply #2 on: August 16, 2002, 02:27:00 AM »
Thanks for calculating all those molecular weights and posting them in one place Chromic!  I appreciate the time you put into that handy little post.

sYnThOmAtIc

  • Guest
Ditto to that Ritter. Thanks for the help ...
« Reply #3 on: August 21, 2002, 08:02:00 PM »
Ditto to that Ritter. Thanks for the help chromic.

Yea just trying to calculate the highest yielding procedure for the least money and time.
 
BTW anybody know anyting about the RuCl3 isomerization? Can the catalyst be reused as it is after isomerization? Or does it get converted to a useless Ru compound that isn't worth or even possible to reuse?


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Rhodium

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LiI oxidation and Ruthenium isometization
« Reply #4 on: September 02, 2002, 12:28:00 PM »
LiI + O2 -> I2 + LiO may happen, that's why the air is purged. It may not be necessary at all, but that's the rationale.

The RuCl3 isomerization hasn't gotten anything else but good reviews. The Ru complexes left in the post-isomerization tar should be good for another run (but I haven't seen anyone posting about doing this yet), if you do not let the tar harden and trap the Ru compounds inside after you have distilled the iso-compound, but instead dilute your tar with a little THF, ether, petroleum ether or whatever suitable solvent you have, and then distill this solvent off after adding your next batch of allylbenzene compound.

I'd say that it would be a very good idea to use very pure feedstock of safrole (distilled and recrystallized) in this procedure, and also to keep the temperature as low as possible (while still keeping it high enough for the reaction to take place, experiment some here), all this as to minimize the formation of tars, which may inhibit the activity of the Ru complexes towards further runs.

Would anyone care to guess about how to isolate the metal salt out of the reaction matrix afterwards? If that would be possible, that would be an even better option than reusing it together with the tars.

foxy2

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Ruthenium Chloride Info RuCl3
« Reply #5 on: September 02, 2002, 11:20:00 PM »
Merck Index says
RuCl3 occurs in two forms.
alpha, which is black lustrous crystals. Insol in water and alcohol.
beta, dark brown fluffy hexogonal crystal. Soluable in Alcohol.

Prep: Fletcher et. al., Nature 199, 1089 (1963)


This looks promiseing!

Regeneration of ruthenium catalysts.

Patent DD146251


Abstract
An economical method for the regeneration of Ru or Ru compd. catalysts consists of treating the spent catalyst in a mineral acid at room temp. to the b.p. of the acid.  Thus, RuCl3 was digested in 40% H2SO4, filtered, washed, and dried with acetone at 253 K.  This catalyst was used to hydrate 4,4'-diaminodiphenylmethane at 303-313 K under 14.7 MPa to 100% efficiency vs. 6% for an unregenerated catalyst.


Ruthenium chloride catalyst for hydrogenation.

Patent FR2526782


Abstract
Catalysts for the hydrogenation of sugars are prepd. by impregnating solid supports (preferably SiO2) with pure aq. RuCl3, drying, and reducing in H.  Thus, Ru and NaCl in Cl at 600-650° gave Na2RuCl6 which was extd. with alc. in a Soxhlet app. to give pure RuCl3.  Si02 was impregnated with 1% aq. RuCl3, dried, and reduced in H.


Reactions of sulfuryl chloride with metals.  II.  Platinum metals.    
Dillamore, I. M.; Edwards, Dennis Arthur.
J. Inorg. Nucl. Chem.  (1969),  31(8),  2427-30. 
Abstract
The Pt metals are converted to chlorides by reaction with SO2Cl2, in some cases the chloride isolated being dependent on reaction temp.  b-PtCl2, PtCl4, b-Pd-Cl2, IrCl3, a-RuCl3, b-RuCl3, and OsCl4 have all been prepd. in virtually quant. yields within a reasonable reaction time, but RhCl3 is only formed extremely slowly from the metal by this method.


Isomerization of hexene-1 catalyzed by ruthenium(III), rhodium(III), and palladium(II) chlorides.   
Hirai, Hidefumi; Sawai, Hiroaki; Ochiai, Eiichiro; Makishima, Shoji.
J. Catal.  (1970),  17(1),  119-20. 
Abstract
The times required to reach equil. in the isomerization of BuCH:CH2 were RhCl3.3H2O 15, (PhCN)2-PdCl 150, and RuCl3.3H2O 1000 min.  The Ru catalyst re-quired an induction time of .apprx.1 hr, during which Ru(III) was reduced to Ru(II) before isomerization began.  The action of the Rh catalyst is attributed to the formation of (BuCH:CH2)4-Rh2Cl2.  In Pd complexes, various ligands decreased the ac-tivity in the order Ph3P > Et3N > pyridine > quinoline > 1,3-cyclooctadiene.  

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sYnThOmAtIc

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Thanks rhodium and foxy.
« Reply #6 on: September 07, 2002, 10:24:00 PM »
Thanks rhodium and foxy. SWIM will start experimenting some time once he gets into germany and post results..


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