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BromicAcid
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Living in the USA, and possibly elsewhere, Capri Sun "Island Refreshers" are a newly available drink. The bottle is aluminum with a stainless steel bottom along with a cap that
screws on with a nice tight seal. Aside from seal integrity, these are almost identicle to the bottles used to store ether in at
professional institutes. They also work good for storing other solvents 
[Edited on 7/4/2004 by BromicAcid]
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Magpie
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ether storage bottle
Organikum has warned us to place a copper wire in the ether receiver and storage container. Does anyone know if the commercial metal ether containers
have copper or other peroxide preventer built in? Or, how do they deal with this problem?
The single most important condition for a successful synthesis is good mixing - Nicodem
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Organikum
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Commercial ether contains liquid peroxide inhibitors admixed alone for the reason if someone fills other containers with the ether.....
Which depends on the manufacturer and the intended use of the ether. I cannot imagine that any ether is shipped without protection against peroxides.
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Mendeleev
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Those preservatives won't mess up grignard reactions, will they? I have found two great deals on anhydrous ether, and they both have
preservatives. One is from Mallinckrodt Chemicals, 14L anhydrous ether for $110.10 US, which contains no preservative, and one from VWR, 20 L
anhydrous ether for $170.38 US. this contains 2,6-diterbutylcresole. These are usually inert preservatives that don't interfere with the ethers
chemical value as a grignard solvert, no?
Trogdor was a man. A dragon man. Or maybe just a dragon. . .
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Cyrus
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Mendeleev, you love to have lots of a chemical. 
How many tons of chemicals do you have?
[Edited on 9-7-2004 by Cyrus]
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Mendeleev
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No tons. Yet... . I am interested in drying my ether with sodium, as it is much
faster. Usually commercial sodium is packaged in kerosene to prvent reacton with the air or water vapor in the air. So how do you go about preparing
commercial sodium for drying ether, or is the kerosene not a significant contaminant in Griganrds? Also how much sodium should be used per liter of
ether?
[Edited on 14-7-2004 by Mendeleev]
Trogdor was a man. A dragon man. Or maybe just a dragon. . .
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The_Davster
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I remember that sodium wire is used for drying ether. The book I got this info from also gave instructions for a "sodium press" which would
force lumps of Na through a tiny hole thus making wire. The press was suposedly have been able to have been constructed from OTC pipes and fittings.
I think this was a library book that I no longer have unfortunatly.
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S.C. Wack
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A type of press is illustrated on page 164 of the Vogel 3rd ed., for this purpose. Just a reminder, because I know everyone here has downloaded and
read this of course.
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JohnWW
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Another route to the preparation of ethyl ether: electrophilic heavy-metal cations that form halides insoluble in ethanol, e.g. Ag+ (as
ethanol-soluble salts like nitrate, nitrite, perchlorate, fluoride) react with alkyl halides in ethanol to form alkyl ethyl ethers. Hg++ and Pb++
salts may also work.
It produces AgCl as a white precipitate, and, with ethyl chloride as the alkyl halide, diethyl ether, with an acid left in the ethanol solution, in a
"SN1" reaction. (any soluble silver salt will also do - heat is required):
C2H5Cl + Ag+ + C2H5OH -> C2H5-O-C2H5 + AgCl + H+
The first of two steps is:
C2H5-Cl + Ag+ -> C2H5-Cl+-Ag -> C2H5+ + AgCl
and the second step is:
C2H5+ + C2H5-OH -> C2H5-OH2+ + C2H5-O-C2H5 + H+
The Ag+, as a Lewis acid, coordinately with an electron pair on the Cl. This weakens the C-Cl bond, the AgCl covalent bond being stronger.
Reference: Organic Chemistry, T.W.G. Solomons (Wiley - 3rd ed. 1984), page 200, and other comprehensive organic texts.
The reaction is driven by the greater affinity (enthalpy of reaction) of AgCl over the ethyl chloride, Ag+ being an electrophile or Lewis acid; and in
the second step by the electrophilic affinity of the carbonium ion produced in the first step for the unused electrons on the O in
C2H5OH, which is greater than that for the anion of the Ag+ salt ion, although the
possibility of trace amounts of an ethyl ester being formed cannot be discounted.
The acid produced may form an ester with the ethanol, if any H2SO4 is present, which tends to rule out using Ag2SO4.
John W.
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Hermes_Trismegistus
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| Quote: | Originally posted by rogue chemist
I remember that sodium wire is used for drying ether. The book I got this info from also gave instructions for a "sodium press" which would
force lumps of Na through a tiny hole thus making wire. The press was suposedly have been able to have been constructed from OTC pipes and
fittings.. |
You could just invest in a garlic press..
http://www.amazon.com/exec/obidos/tg/detail/-/B00004OCJX/002...
Arguing on the internet is like running in the special olympics; even if you win: you\'re still retarded.
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The_Davster
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Yes but a garlic press has many holes, not just a single one. But I gues one could solder closed the other holes, that would probally work.
Neat idea Hermes.
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Hermes_Trismegistus
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Perhaps not.
The sodium was to be utilized for the drying of ether, it's easier to have a bunch of small wire bits of sodium than to have a single long thread
of sodium that would have to be chopped into peices anyway.
If a person was to run a knife edge back and forth across the front of the press while extruding the sodium, you would have a reasonable facsimile of
sodium sand.
Hermes.
Arguing on the internet is like running in the special olympics; even if you win: you\'re still retarded.
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The_Davster
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Ah, that makes sense. Whenever I have heard the phrase "dry the ____ with sodium wire", I had always thought that one would stirr the
substance with a single strand of sodium wire, untill it stopped reacting. This clears things up a bit.
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mick
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I think the idea of the sodium press is you put the bottle or solvent right under it and the clean sodium falls straight into the solvent + solvent
vapours without any oxidation.
Mick
I have used a sharp knife to take very thin slices that fall straight into the solvent, pre-dried MgSO4 or something.
[Edited on 30-8-2004 by mick]
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Esplosivo
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| Quote: | Originally posted by Mendeleev
Those preservatives won't mess up grignard reactions, will they? I have found two great deals on anhydrous ether, and they both have
preservatives. One is from Mallinckrodt Chemicals, 14L anhydrous ether for $110.10 US, which contains no preservative, and one from VWR, 20 L
anhydrous ether for $170.38 US. this contains 2,6-diterbutylcresole. These are usually inert preservatives that don't interfere with the ethers
chemical value as a grignard solvert, no? |
In my case the diethyl ether available from my supplier contains 2,4-Di-tert-butyl-4-methylphenol (BHT) which is in very small quantities,
approximately 5 - 10 ppm. I seriously doubt that such small quantities could interefere with any reaction. At such a conc the worst which could happen
is a very small decrease in the yield, but nothing to worry about I think
Theory guides, experiment decides.
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Mendeleev
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Vogel calls for a tube to extend from the addition funnel into the sulfuric acid solution, when adding more ethanol in the synthesis of ether. Is
this really necessary? Is it done to prevent splashing inside the flask. I was thinking maybe the ethanol would evaporate before getting a chance to
react when it hits a liquid which is at a temperature 50 degrees higher than its boiling point. If this were the case, the tube extending into the
reaction mixture would help prevent this.
Trogdor was a man. A dragon man. Or maybe just a dragon. . .
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Eclectic
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Grignard Reactions in "Wet" Ether
David H. Smith
Department of Chemistry, Doane College, Crete, NE 68333-2496
A small laboratory ultrasonic bath can be used to initiate the Grignard reaction of alkyl or aryl bromides in regular laboratory-quality, undried,
diethyl ether and in simple undried test tubes. The reaction typically starts within 30 to 45 seconds and is self-sustaining. Yields and products are
the same as obtained with carefully dried ether and equipment. We normally run this reaction at the 1.5-gram scale, but the procedure can be scaled up
to at least 10 g of the bromide.
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Mendeleev
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Weird Results
So I tried to do vintage ether synthesis a la Vogel. I did everything by the book: equal volumes of "rectified spirit", that is denatured
alcohol from the hardware store, was mixed with sulfuric acid that I concentrated myself and confirmed by a density check to be 96-97%. 250 mL of
ethanol was added to the flask followed by 250 mL of the sulfuric acid which was added very slowly to prevent excessive heating.
When the two substances were well mixed well. I configured an apparatus consiting of a 1L flask with a three-hole stopper, bearing a thermomter, a
long glass tube, and a short bent tube. The short bent tube was connected to a 300 mm liebig condenser which was connected to a flask in an ice bath.
The long tube was connected by tubing to an addition funnel with ethanol. Vogel says the tube must extend to within a cm of the bottom of the flask
which I did.
Next he says heat to 140 and maintain between 140 and 145 while adding the ethanol in the funnel at the same rate that liquid distills. This I did,
taking 5 hours to add 500 mL ethanol, the temperature staying at 140 give or take a couple of degrees the whole time. I believe the volume of ethanol
added is twice that which is mixed with the acid.
Here's the weird part. About 180 mL of distillate was obtained but it was apparently not ether. It did not smell too much like ether more like
fruity odor. What is this ethylene? When I proceeded to wash it with water, I only added about 5 mL to a test tube first to check. It would not
separate from the 5% NaOH soluiton  . When shook(without NaOH solution) it
gives bubbles like mad! I held my thumb over the test tube and very lightly shook it. This caused so much pressure to build up, it nearly shot out,
and it was ice cold too.
I have no clue as to what the hell happened. Either I have a solution of ethylene in water or the laws of physics cease to exist on my hotplate .
[Edited on 31-12-2004 by Mendeleev]
Trogdor was a man. A dragon man. Or maybe just a dragon. . .
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S.C. Wack
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And what brand of denatured alcohol did you use? Do you know its actual content?
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Mendeleev
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Crown brand. It comes in a blue can with an orange box on the front labeled "Denatured Alcohol". Two other things about this reaction:
After mixing and heating, as the heat rose the mix darkened turning from having a very light tinge of yellow to a deep amber color. As alcohol
addition continued it turned completely black. Also now that I've had a chance to clean the glassware, I noticed the condenser was streaked with
some sort of white polymer goop .
[Edited on 31-12-2004 by Mendeleev]
Trogdor was a man. A dragon man. Or maybe just a dragon. . .
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HNO3
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I know PE can be decomposed by H2SO4 in the presence of ethyl alcohol. PE can be made by bubbling C2H4 through a NaOH solution. In fact, I think
that's the industrial procedure.
\"In the beginning, God...\" Wait a minute, God doesn\'t exist!!!!!!!!!! \"OK, in the beginning, ummm, hydrogen...\" Wait a minute, what about the
laws of thermodynamics? \"OK, in the beginning, ummm.....UMMMMM, what\'s left to choose from?
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BromicAcid
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It's solvent grade denatured alcohol, the description of the reaction mixture darkening and the streaks in the vessle clench it in my mind as
dissolved organic matter, there is no rigid standard as to purity, the company that made the denatured alcohol probably just collected the excess
alcohol from some other industrial process, no telling what's dissolved in it, try evaporating 10 ml or so slowly and see what you're left
with, if you get a film then I wouldn't use if for this reaction.
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S.C. Wack
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I've yet to find a hardware brand that was more "alcohol" than "denatured". I buy the cheap vodka when it is on sale but even
then it doesn't cost much less than 95% EtOH ($14/750 ml), going by alcohol content. Every hardware brand I've run into is loaded with MeOH
and/or ethyl acetate.
Well, here is the MSDS for your product. No surprise.
http://www.packserv.com/Content-Public/Products-By-Brand/Pag...
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Mendeleev
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Yeah I guess you're right. I actually have a pint of 200 proof, but I was saving it for a special occasion(it's not denatured  ). I guess you guys are right, the alcohol is the only variable. Drat. But why
would the reaction turn black, is that supposed to happen? Can anyone make a good guess as to what's in the distillate? It smells very fruity,
like acetaldehyde or something, I think I've heard that ethylene and several esters smell that way.
EDIT: Just saw S.C. Wack's post, it must be the ethyl acetate that smells fruity, that or a combination of ethyl acetate and ethylene.
EDIT2: Another thing I remembered, at the start of the reactin when the temperature hit 135ish, lots of white fumes were generated. I cautiously
smelled the end of the hose that was connected to the receiving flask, and the white fumes billowing out also smelled very fruity.
EDIT 3: What the hell ! I just read the msds for the crown denatured ethanol!
It's 65-75% METHANOL! No wonder there were so many fumes produced that was probably dimethyl ether, which boils at 0 C if I remember correctly.
And the black color could have been anything with all the IPA and ketones in there.
EDIT 4: On the other hand at least we have found a very large source of OTC methanol, those damn HEET cans only contain 300 mL.
EDIT5: Thanks a lot S.C. Wack, that Crown page helps a lot as I buy many of their products.
[Edited on 31-12-2004 by Mendeleev]
[Edited on 31-12-2004 by Mendeleev]
[Edited on 31-12-2004 by Mendeleev]
[Edited on 31-12-2004 by Mendeleev]
[Edited on 31-12-2004 by Mendeleev]
Trogdor was a man. A dragon man. Or maybe just a dragon. . .
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trilobite
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It could also be the denaturants, which are often ketones such as acetone, MEK or methyl isobutyl ketone, that can undergo various condensation
reactions (aldol with dehydration which releases water btw, michael addition) under acidic conditions giving products that can have a floral smell. I
don't know if this would explain your distillate, but it could explain its smell. Could it be that most of the solution is still ether?
I have some ethanol denatured with MEK (Bp. 79,6' ) and MIBK (strong taste and smell). Some time ago I put some of this alcohol in a flask,
poured in a smallish amount of sodium hydroxide, and refluxed it. The colour change was from yellow to orange, red and eventually quite dark. This
took from 6 to 8 hours, after which I decided there were enough signs of polymerizing the ketones and distilled it. The distillate was clear and not
alkaline at all. It smelled mostly of ethanol, but it's taste told that there were still some denaturants left. I didn't try refluxing the
distillate with NaOH to see if it would change colour. All this left me an impression that I had gotten rid of most of the denaturants.
Of course, there are other denaturants too... maybe you should try distilling the "ether" you got, check it's boiling point etc?
Edit: Oh, that explains something.
[Edited on 31-12-2004 by trilobite]
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