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sonogashira
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Ah, thanks very much  Could I also bother you to ask what 2-stdg
or 4.5-stdg means, as in the sentence:
"Nach kurzem Einleiten trat eine Trübung auf, dann kam es zur Abscheidung eines tief dunkelrot gefärbten Öles, das nach 2-stdg."
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garage chemist
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The sentence is incomplete. 2-stdg. is an abbreviation for 2-stündig, meaning 2 hours long. Post the complete sentence, or better, the complete
procedure so that there are no dangerous misunderstandings.
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sonogashira
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Thanks again! Very kind of you It's not a procedure I'm thinking of doing so I
won't bother you with the whole text. I know the sentence was incomplete but I just wanted to put the abbreviation into some sort of context for you.
Thanks again, I can make much more sense of it now. 
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solo
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| Quote: | Originally posted by solo
In a rearrangement of a well known aldehyde poured into a very cold H2SO4 (-16C) rearrangement of the aldehyde occurs and a ketone is produced
.......along with a large amount of water with a distinctive rooten egg smell......my question is what can i treat this water with to salt out the
sulfur and rid of the smell as it makes for a very uncomfortable reaction waste product that I don't want to pour down the drain.....solo
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...........in this same reaction there is a yield of a ketone and unreacted aldehyde...but both distillation point is too close hence oxidation is
recommened........i used Potassium permanganate in water....but since water and the ketone don't mix i just got a mess.....the ketone doesn't seem to
solvate in either methanol or ethanol ....any suggestion as to what trans phase solvent to use to be able to oxidise the aldehyde to propionic acid,
and remove my ketone .......solo
It's better to die on your feet, than live on your knees....Emiliano Zapata.
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Klute
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Solo, you might want to try acetone as a solvent, it will surely dissolve your ketone, and if 5-10% water is added, sufficent permanganate will
dissolve.
By rotten eggs smell, do you mean H2S is present? In that case NaOCl is a effective treatment to neutralize it, forming some sulfur and sulfides
presumably.
Regarding the drying glassware with solvents: I routinely use acetone to dry glassware for any type of reaction where an aqueous is not going to be
present, or for drying erlen/beakers etc in which I am going to transfert organic solutions and dry them for example.
Of course this doesn't suffice for water-sensitive reactions, but is a very quick and efficient way of getting surface-dry glassware... using a hair
drier speeds things up.
the used acetone can be kept and recycled by simple distn to relatively dry (not anhydrous) acetone, or used to wash out organics from glassware for
example.
\"You can battle with a demon, you can embrace a demon; what the hell can you do with a fucking spiritual computer?\"
-Alice Parr
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franklyn
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For those who know
maybe you can clue me in
What's the meaning of a CAS number when the same compound can have many
different ones referring only to it's state of hydration.
Cupric dinitrate ( anhydrous ) . . . . . . . .Cu(NO3)2 . . . . . . . . . . . .CAS 10402-29-6
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .CAS 3251-23-8
Cupric dinitrate Basic ( double salt ) . Cu(NO3)2•3Cu(OH)2 . . CAS 12158-75-7
Cupric dinitrate hydrate . . . . . . . . . . . . .Cu(NO3)2•H2O . . . . . . . CAS 13778-31-9
Cupric dinitrate hemipentahydrate . . . Cu(NO3)2•2.5 H2O. . . . CAS 19004-19-4
dicopper tetranitrate pentahydrate . . . [Cu(NO3)2]2•5 H2O. . . . ( same thing of course)
Cupric dinitrate trihydrate . . . . . . . . . . .Cu(NO3)2•3H2O . . . . . . . CAS 10031-43-3
Copper trihydroxy dinitrate ( also known as )
Systematic and trivial naming adds further confusion. The term Cupric can instead be
called Copper II or just Copper nitrate as well as dinitrate.
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not_important
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Well, the basic nitrate is a rather different compound so I don't see why you included it.
Anhydrous compounds can have quite different properties than their hydrated forms, Cu(NO3)2 is an example as is AlCl3 vs AlCl3.6H2O - which would you
want to deal with a spill of?
CAS numbers are supposed to serve as a unique identifier of a compound or substance, and the various hydration states are different compounds. If you
buying a nickel compound for its nickel content and you were quoted a price per kg, whould you want to know the hydration state? How about mixing
benzene, acetyl chloride, and aluminium chloride, might not hydration state be important - and all the opaque container is labeled with is "aluminium
chloride".
CAS numbers also get around the various naming conventions, you use whatever naming is standard for where you are, find the CAS number, and everyone
will know exactly which substance you are referring to. Is copper chloride CuCl, CuCl2, or CuCl2.2H2O? How about vanadium fluoride - give me the
formula for which one I mean.
Naming has a lot of historical baggage involved, especially in industry where trivial names and abbreviations are not that infrequently used - some of
which have been used for a century and a half or more.
Not even formula are a perfect solution, for several reasons. The symbols for some elements vary in different countries; ask the European members how
they'd write the chemical name and formula for cobalt iodide, if they weren't writing for an international audience.
So CAS reduces confusion, a given compound has but one CAS number and a CAS number refers to a single compound, not one of several possible compounds.
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kclo4
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How could one turn a Ketone into an alcohol?
For example Benzophenone to Diphenylmethanol, also known as benzhydrol?
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solo
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Formula: NaBH4
Content 99.5~~99%
Mol. Vt: 37.85
Chemical properties:
Physical state: White crystalline powder particle
Melting point: 400C(slowly decomposes above 400C, completely decompose at higher temperature)
Specific gravity: 1.07-1.08
Solubility in water: Reactive(insoluble in ether and hydrocarbons)
Description and usage.
Sodium borohydride is a milder reducing agent, can be used in aqueous solution. It converts selectively aldehydes and ketones the corresponding
alcohols in the manufacture of pharmaceuticals and other fine chemicals. It will not react with esters, amides, or carboxylic acids, the more powerful
reducing agent lithium aluminum hydride(LAH) is used to reduce these compounds. LAH is the more powerful reducing agent than sodium borohydride due to
the weaker Al-H bond compared to the B-H bond. The reactivity of sodium borohydride can be modified by addition of iodine or methanol in BH3-THF to
reduce esters into the corresponding alcohols like the reaction of benzyl benzoate to benzyl alcohol. Sodium borohydride is used as a hydrogen source
for fuel cell systems and a foaming agent for rubbers. Sodium cyanoborohydride converts certain alcohol groups to methylene groups. Sodium
Cyanoborohydride is used as a selective amination reductant. It converts aldehydes (chemoselective), ketones (stereoselective) to the corresponding
alcohols in the manufacture of pharmaceuticals and other fine chemicals. It is used in the reductive alkylation of amines, novel metals and oximes.
Some examples of reducing agents are: PHYSICAL STATE white crystalline powder particle
It's better to die on your feet, than live on your knees....Emiliano Zapata.
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kclo4
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Sorry, One that isn't so pricey. I really should have specified.
Isn't there some easy reduction similar to a clemmensen reduction that can turn a ketone/aldehyde into an alcohol?
Thanks for your response 
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panziandi
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Aluminium isopropoxide in isopropanol is an excellent way of reducing ketones to alcohols.
In fact this method is used for Benzhydrol on page 885 of Vogel 3rd edition
[Edited on 21-9-2008 by panziandi]
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S.C. Wack
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If you bought or found in the library a later edition, say the fifth, you would find a different method for benzhydrol involving zinc. Someone should
scan that edition sometime.
EDIT: It's also in OS CV1, page 90.
[Edited on 21-9-2008 by S.C. Wack]
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Klute
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Clemmensen? You prefer working with marge amounts of HgCl2 than NaBH4?
Atmospheric hydrogeantion over Cu/SiO2, very easily prepared from Cu(NO3)2.xH2O, 30% NH3 and silica gel, is a very cheap alternative. Aromatic ketones
are desoxygenated to the alkanes with higher catalyst loadings.
\"You can battle with a demon, you can embrace a demon; what the hell can you do with a fucking spiritual computer?\"
-Alice Parr
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sonogashira
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I attach the procedure using zinc reduction from Vogel's 5th... Kindly provided by S.C. Wack
Attachment: Benzophenone to Benzohydrol with Zn.pdf (73kB)
This file has been downloaded 942 times
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kclo4
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Klute, What happens if you don't use any mercury compounds? Wouldn't it still work, but just not as well? I'd like to know why it would matter.
I never clemmensen would work or that i've done it, I just said was wondering if there was something similiar to it. However, I do have a decent
amount of Mercury, while I don't have any NaBH4 
Thank you for the PDF file, and the other options guys
I'll look into all of them.
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solo
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| Quote: | Originally posted by Klute
Solo, you might want to try acetone as a solvent, it will surely dissolve your ketone, and if 5-10% water is added, sufficent permanganate will
dissolve.
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....acetone does not dissolve the ketone and the micellaneous sticky stuff....tried DMC and although it dissolves the ketone, the water and the
current oxidising agent , Potassium Permangenate , will not mix, hence I need some help finding another oxidant that will be soluble in
DMC......although not sure what to use.......perhaps I will need some phase transfer material.........solo
It's better to die on your feet, than live on your knees....Emiliano Zapata.
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Klute
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I think a clemmensen without Hg will only give the alcohol in some case. i remeber seeing something like that when looking into the Zn reduction of
unsaturated ketone to the ketones...
Solo, maybe try AcOEt and TCCA? TCCA is very soluble in AcOEt... Or use DCM and TCCA with a PTC (I always use TBAB), this worked well enough for
oxidation of various alcohols into aldheydes with TEMPO. You could try KMnO4 with TBAB or similar in DCM..
Sounds like a tricky ketone, not soluble in acetone!
\"You can battle with a demon, you can embrace a demon; what the hell can you do with a fucking spiritual computer?\"
-Alice Parr
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Nicodem
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| Quote: | Originally posted by solo
....acetone does not dissolve the ketone and the micellaneous sticky stuff....tried DMC and although it dissolves the ketone, the water and the
current oxidising agent , Potassium Permangenate , will not mix, hence I need some help finding another oxidant that will be soluble in
DMC......although not sure what to use.......perhaps I will need some phase transfer material.........solo |
Then the obvious conclusion is that what you have is not the ketone you think it is. I have a very hard time imagining a ketone containing only H2SO4
resistant functional groups and not being soluble in acetone. What you have is most probably some polymeric goo. Was it vacuum distilled? What kind of
analysis have you performed?
KMnO4 is soluble in acetone and this is the solvent commonly used for KMnO4 in organic oxidations. If your KMnO4 does not dissolve in acetone than it
is not KMnO4 or perhaps your acetone is not acetone.
Edit: Sorry, I misunderstood the post which only mentions the insolubility of the crude ketone in acetone and not KMnO4.
[Edited on 22/9/2008 by Nicodem]
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panziandi
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KMnO4 often contains some MnO2 as a contaminant even in lab grade samples also you can buy KMnO4 as powdered or as larger crystalized material. The
later dissolves very slowly even in water, takes a lot of stirring to get a complete solution. Perhaps if your KMnO4 is in crystals you could grind it
to a powder?
I too am very surprised that your ketone/aldehyde mixture does not dissolve in acetone 
Many aldehydes do polymerize in highly acidic conditions, how long did you let the reaction go for? I would imagine what is happening is the aldehyde
and ketone ARE dissolving in the acetone but what is left is the high molecular weight crap.
Perhaps remove as much acetone as possible after the goo has settled and evaporate this off to see if anything has dissolved in the acetone (very
likely it has)... If so then isolate all of the acetone extration and treat with KMnO4 powder...
Just had a shocking brainwave (doesn't explain your KMnO4 not dissolving but may explain organics not dissolving...) perhaps your acetone is not dry
or has been diluted with quite a few % of water? Perhaps distil before use and/or try drying with CaCl2 / Na2SO4 / K2CO3 and another distillation
[Edited on 22-9-2008 by panziandi]
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vulture
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| Quote: |
Does anyone have any relevant data on the polymer PPP, or poly(p-phenylene), things like glass transition temperature, % crystallinity, solvent
resistances etc. My old crc handbook is too outdated (1972) and the infinet gave me nothing except derivatives of said polymer.
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Try the handbook of conducting polymers, it's on gigapedia.
Does anybody know a solvent for triphenylphosphine, excluding the following: hexane, pentane, THF, diethylether, toluene?
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DJF90
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How about benzene?
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kclo4
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Can Propionaldehyde be produced by dehydrogenating N-Propyl alcohol over Copper catalyst much like how formaldehyde or acetaldehyde is produced?
I have read that Zinc oxides and other weird oxides can be used, but that's about all i could find.
If not, How would I produce it on the lab scale?
Dang, I thought my reagents for organic synthesis book would help me out more then it does 
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not_important
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| Quote: | Originally posted by kclo4
Can Propionaldehyde be produced by dehydrogenating N-Propyl alcohol over Copper catalyst much like how formaldehyde or acetaldehyde is produced?
...
Dang, I thought my reagents for organic synthesis book would help me out more then it does |
Yes, although you get some condensation products too. If not adding air/O2, which is tricky to control, the conversion is incomplete; you'll want to
fractionate the product and recycle the n-propanol.
Pre-WW2 books are the best bet for this sort of method, pre-Depression a even better bet.
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Klute
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I would go for TEMPO-catalyzed oxidation, with NaOCl or TCCA as a secondary oxidant..... Good yields on butanol to the aldehdye have been reported!
4-oxo-TEMPO is easy to prepare, and you need very little.
\"You can battle with a demon, you can embrace a demon; what the hell can you do with a fucking spiritual computer?\"
-Alice Parr
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Ephoton
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I would like to know if it is possible to swap alkyl chains on alkoxides and how it is done if
it is possible.
eg.
sodium ethoxide + ?????????? ----> sodium methoxide.
I also have second question that I would truly love answered.
what is the best way to extract pure vanillan from the brown
vanilla extract in suppermarkets.
bisulfite sucks
we are dealing with ethanol and vanilla bean extract.
maby sometimes some glycerol at worst.
[Edited on 24-9-2008 by Ephoton]
e3500 console login: root
bash-2.05#
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