stoichiometric_steve
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Performic Acid Oxidation Solvents...
reading about this in the rhodium mirrors, it seems that DCM is the solvent of choice, as it limits the reaction temperature.
does anybody have experience with this kind of reaction and could thus tell me if it is possible to substitute tert-butyl-methyl-ether (TBME...not
MTBE  ) for DCM for environmental reasons?
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leu
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Ethers can be oxidized by peracids to glycols and/or oxiranes so using ethers as a solvent for Swern oxidations is unproductive and can be even
possibly quite hazardous in the case proposed 
[Edited on 31-8-2007 by leu]
Chemistry is our Covalent Bond
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solo
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Related Reference Information (Good Reading )
Execution of a Performic Acid Oxidation on Multikilogram Scale
David H. Brown Ripin,* Gerald A. Weisenburger,* David J. am Ende, David R. Bill, Pamela J. Clifford, Clifford N. Meltz, and James E. Phillips
Organic Process Research & Development 2007, 11, 762−765
Abstract:
In order to run a peracid oxidation on multikilogram scale in
a pilot plant facility with an acceptable level of risk, an extensive
study of the thermal characteristics of the reaction, reactants,
and quench was undertaken. A number of features were
engineered into the process in order to confidently run the
process without the potential for a thermal or pressure excursion
on scale.
Attachment: Execution of a Performic Acid Oxidation on Multikilogram Scale .pdf (141kB)
This file has been downloaded 1447 times
It's better to die on your feet, than live on your knees....Emiliano Zapata.
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roamingnome
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| Quote: |
DCM for environmental reasons
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well if the enviroment is the concern, get a deicated solvent recorvey still for DCM
i think the montra around here these days is... try it and tell us the results
DCM works, is available, and is choice during workup....
just dont go out for a cigarette break when you think the addition part is threw and come back to find it all bubbled up threw the condensor...
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leu
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| Quote: | | there is no way you could possible oxidize TBME to a glycol or an oxirane. and the oxidation mentioned is no Swern oxidation, either...are you drunk?
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No, but apparently you are ignorant of the dangers of mixing an alkyl ether with a peracid  Organic peroxides are rather hazardous, if you want to try it on a small scale please do it in a manner that won't kill you so you let the
forum know that you survived your folly
Chemistry is our Covalent Bond
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leu
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| Quote: | | TBME does not form peroxides. |
The chemist who wrote the wikipedia article actually said this:
In chemistry
Being an ether, MTBE is a Lewis base. However, unlike other ethers such as diethyl ether or THF, it does not coordinate well enough with magnesium to
be used for making Grignard reagents. The tert-butyl group is easily cleaved off under strongly acidic conditions (forming a moderately stable
carbocation), particularly if heated (isobutylene is lost), something which can limit the use of MTBE as a solvent. However it possesses one distinct
advantage over most ethers- it has a much lower tendency to form explosive organic peroxides than most ethers. Opened bottles of diethyl ether or THF
can build up dangerous levels of these peroxides in months, whereas samples of MTBE are usually safe for years (but they should still be tested
periodically).
The author said that MTBE can form peroxides but didn't contemplate anyone being foolish enough to add a peroxide former to MTBE and then use it a
solvent in an organic reaction In your first post in this thread you said:
| Quote: | | does anybody have experience with this kind of reaction and could thus tell me if it is possible to substitute tert-butyl-methyl-ether (TBME...not
MTBE ) for DCM for environmental reasons? |
which demonstrates your lack of understanding of the nomenclature of ethers, and more importantly the dangers implicit in handling them Please use plenty of sandbags when you conduct your first experiment as without them
you aren't likely to be able to tell the forum about your folly 
Chemistry is our Covalent Bond
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S.C. Wack
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| Quote: | Originally posted by stoichiometric_steve
are gonna post more off topic BS? it's you who is not familiar the nomeclature of organic compounds. but i will explain, so your
folly has an end:
(tert) is not included in defining the order of the substituents, and (B)utyl comes way before (M)ethyl in the alphabet, which is what IUPAC says. so
the correct nomenclature is tert-Butyl-Methylether. Hence, TBME. |
OK then, let's talk about who is familiar with IUPAC nomenclature: Not you. Try 2-methoxy-2-methylpropane.
Even the most cursory search of the web shows that MTBE is clearly the preferred name in the literature, reference books, and suppliers, though TBME
(spelled out) gets a good showing at ACS with 35% of the total.
The acidic hydrolysis and oxidation with various oxidizers to t-butanol is not a secret. Nor is its reaction with H2O2 and acid to form peroxides: US6225510. But then they call the ether MTBE in that patent, so maybe they have it in for you.
Why leu is worried about you and your other_aliases getting blown up, I don't know. He's a nice guy, maybe too nice.
[Edited on 1-9-2007 by S.C. Wack]
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Sergei_Eisenstein
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You rule. Now try to order a few barrels of TBME using the correct name.
There are so many non-IUPAC conforming names and chemists know what they are. As such, every chemist knows what MTBE stands for, and starting to use
TBME instead is just asking trouble. It's the same as demanding to use hydrogen oxide instead of water.
MTBE does form peroxides, but much slower then diethyl ether. It is generally resistant against hydrogen peroxide, but it is not against hydroxyl
radical.
damnant quod non intelligunt
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leu
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An alternative to halogenated solvents that actually works is used in this procedure from Organic Syntheses, note the authors of the referenced
citations:
Attachment: CV7P0126.pdf (155kB)
This file has been downloaded 1587 times
Chemistry is our Covalent Bond
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stoichiometric_steve
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| Quote: | Originally posted by leu
An alternative to halogenated solvents that actually works is used in this procedure from Organic Syntheses |
that is the first and only useful reply to my initial question.
leu, YOU RULE 
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WizardX
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SYNTHESIS OF EPOXIDES USING DIMETHYLDIOXIRANE: trans-STILBENE OXIDE
http://www.orgsyn.org/orgsyn/prep.asp?prep=cv9p0288
Albert Einstein - \"Great ideas often receive violent opposition from mediocre minds.\"
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