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Ephoton
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well back a few pages ago I posted a patent in french that went down like a lead weight.
eventualy it was agreed that it would give 60+% yeild from easy to get or make reagents like acetaldehyde.
but "Mr Sauron" said that at 21 degree boiling point it was not possible to do a 40C reaction with out an
autoclave.
then I found me this 
http://en.wikipedia.org/wiki/Schlenk_flask
check out that schlenk bomb flask truly nice.
can be had on ebay and in reasonable sizes too.
so "Mr Sauron" what say you now we could have been going the easy way ages ago but no ephoton
is not so politicaly correct.
anyway back to lurking in the depths Ill get this ring to the fires one day even if I have to chew sams ear off
on the way. 
[Edited on 17-2-2010 by Ephoton]
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Waffles SS
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| Quote: |
"...(1) Acetic anhydride. To 50 g. acetic anhydride in a round-bottomed flask of 1500 cc. capacity, placed in cold water, 440 g. of powdered sodium
acetate (dried by fusion at 320 C) and at the same time a solution of 22. g of sulfur in 320 g. bromine is added while stirring. The operation takes
about 30 minutes.
"The mixture is then stirred for a further 5 minutes, after which period the initially dark brownish-red colour has changed into pale yellow, and the
anhydride is distilled off from a water bath under reduced pressure. The crude anhydrie (310 g) is redistilled under normal pressure, and the fraction
boiling between 134-138 C is collected. Yield, 295 g. of 98% purity = 87.5%. The so purified anhydride contains neither bromine nor sulphur compounds
and leaves no residue on evaporation..."
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NaOAc+S2Br2=AcO-S-S-AcO+NaBr
AcO-S-S-AcO+Heat=Ac2O+S+SO2
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Mix quickly and thoroughly 205-215 g of pulverized fine NaOAc and 10g dry sulfur powder, the mixture is quickly transferred to a wide-mouth 1 liter
RBF and wetted w/25 ml acetic anhydride. Into the flask through the rubber cork extend 1) a wide tube for chlorine in-flow 2) an overhead stirrer,
which is sealed with the aid of a piece of rubber tubing greased with vaseline and 3) an out-leading tube for excess Cl2 release. The flask is
immersed in an ice-bath. Chlorine is initially passed in very carefully, with frequent stirring or shaking, over the passage of time the rxn gets
hotter and more and more liquid, so the stirrer may bee after some time rotated with a motor. Chlorine stream should bee regulated so that almost all
of it is absorbed. When the reaction mixture stops heating and Cl2 is no longer taken up, the rxn contents are distilled in vacuo at oil bath temp
~150-180�C, then redistilled at ordinary pressure, collecting the fraction boiling between 132 and 142�C. Yield ~90%.
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NaOAc+S2Cl2=AcO-S-S-AcO+NaCl
AcO-S-S-AcO+Heat=Ac2O+S+SO2
In this reaction Br2 and Cl2 after produce S2X2 make AcO-S-S-AcO and finally anhydrid ,may I2 make same?
[Edited on 19-2-2010 by Waffles SS]
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User
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| Quote: |
Mix quickly and thoroughly 205-215 g of pulverized fine NaOAc and 10g dry sulfur powder, the mixture is quickly transferred to a wide-mouth 1 liter
RBF and wetted w/25 ml acetic anhydride. Into the flask through the rubber cork extend 1) a wide tube for chlorine in-flow 2) an overhead stirrer,
which is sealed with the aid of a piece of rubber tubing greased with vaseline and 3) an out-leading tube for excess Cl2 release. The flask is
immersed in an ice-bath. Chlorine is initially passed in very carefully, with frequent stirring or shaking, over the passage of time the rxn gets
hotter and more and more liquid, so the stirrer may bee after some time rotated with a motor. Chlorine stream should bee regulated so that almost all
of it is absorbed. When the reaction mixture stops heating and Cl2 is no longer taken up, the rxn contents are distilled in vacuo at oil bath temp
~150-180�C, then redistilled at ordinary pressure, collecting the fraction boiling between 132 and 142�C. Yield ~90%.
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This is really interesting.
It is as OTC as could be.
I even thought of this method before ever seeing it.
Could the AA in the reaction be replaced for GAA ?
I can imagine that the only reason for the AA is to create a liquid medium as absorption would be very poor when doing this dry.
Also is the first distillation in vacuo for purity reasons?
[Edited on 19-2-2010 by User]
What a fine day for chemistry this is.
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Waffles SS
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Quote: Originally posted by User  |
This is really interesting.
It is as OTC as could be.
I even thought of this method before ever seeing it.
Could the AA in the reaction be replaced for GAA ?
I can imagine that the only reason for the AA is to create a liquid medium as absorption would be very poor when doing this dry.
Also is the first distillation in vacuo for purity reasons?
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| Quote: |
To 66.5g fused AcONa (made from AcOH + NaOH) was added a soln. of 3.3g S in 48.4g Br2 over 5mins, under manual stirring. Brown colour disappears
rapidly on stirring to give slightly off-white mixture. Stirring continued for another 15mins. Mixture has v. strange consistancy; becomes almost
liquid while stirring but as soon as one stops stirring it becomes solid again. Thus formed sludge was scooped up and dumped in a distillation flask
(spilling much in the process - do this rxn in the same flask you're gonna distil from), and distilled.
Yield of Ac2O = 29.2g as a clear pungent liquid.
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No Ac2O needed.
http://www.erowid.org/archive/rhodium/chemistry/anhydrides.h...
also:
http://www.sciencemadness.org/talk/viewthread.php?tid=9096
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franklyn
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Refering back to here _
http://www.sciencemadness.org/talk/viewthread.php?tid=9&...
http://www.hsia.org/white_papers/111tri%20wp.html
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User
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Can someone tell me how AA smells?
If the compound that I made actually is what it should be it smells like acetic acid with a garlic like undertone, maybe my nose is just retarded 
Anyone?
Lol i know that there are more scientific methods!
[Edited on 4-3-2010 by User]
What a fine day for chemistry this is.
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hissingnoise
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I'd imagine it'd smell just like glacial acetic acid as any vapour from the anhydride would be quickly hydrolysed in air.
Putting your nose close to it, it might have added pungency!
It's guesswork, unfortunately. . .
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entropy51
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Ac2O smells somewhat different than AcOH, but I can't really describe it; I try to avoid breathing the stuff. Above thread these tests were cited to
identify Ac2O:
| Quote: Originally posted by IPN | This is what Practical Methods of Organic Chemistry (Gattermann) says about detecting acetic anhydride:
| Quote: |
5 c.c. of water are treated with 0,5 c.c. of acetic anhydride. The latter sinks to the bottom and does not dissolve even on long shaking. If the
mixture be warmed, solution takes place. |
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2 c.c. of alcohol are added to 1 c.c. of acetic anhydride in a test-tube, and heated gently for several minutes. It is then treated with water and
carefully made slightly alkaline. The acetic ester can be recognised by its characteristic pleasant odour. |
| Quote: |
Add 1 c.c. of aniline to 1 c.c. of acetic anhydride, heat to incipient ebullition, and then, after cooling, add twice the volume of water. The
crystals of acetanilide separate out easily if the walls of the vessel be rubbed with a glass rod. |
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As noted, it is not nearly as easily soluble in H2O as is AcOH.
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Waffles SS
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| Quote: Originally posted by Plasmapyrobattics | Na2O (Sodium monoxide) might be a problem to procure.
What about Calcium oxide ?
2 mol 1,1,1-Trichloroethane reacted with 3 mol CaO :
3 CaO + 2 CH3C.Cl3 --> (CH3CO)2O + 3 CaCl2
168 g CaO (3 mol) with 267 g / 202 ml (2 mol) Trichloroethane.
Any thoughts ? |
I did this reaction
That was unsuccessful.no anhydrid acetic made
I mixed 168 g CaO and 202 ml TCE.and reflux for 1 hour in normal pressure and then distil.no anhydrid come.
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entropy51
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| Quote: Originally posted by Waffles SS | I did this reaction
That was unsuccessful.no anhydrid acetic made
I mixed 168 g CaO and 202 ml TCE.and reflux for 1 hour in normal pressure and then distil.no anhydrid come. |
Proving one more time that just because you can balance an equation doesn't mean it will work.
| Quote: Originally posted by franklyn |
Accordingly it seems much more sensible to just heat together stoichiometric
amounts of 1,1,1-Trichloroethane and caustic soda , Na2O.
1,1,1-Trichloroethane is known to be incompatible with caustic soda.
2 CH3CCl3 + 3 Na2O -> (CH3CO)2O + 6 NaCl
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The conditions cited in the patent are very different than those you tried (150 C vs reflux at 75 C) for
starters.
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Waffles SS
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| Quote: Originally posted by entropy51 |
The conditions cited in the patent are very different than those you tried (150 C vs reflux at 75 C) for starters.
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In patent water react with TCE and make anhydrid acetic and HCl in autoclave.
Sure autoclave must made from special stainless steel because HCl in 150c will dissolve it.
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halogenstruck
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the easiest method is to use NaHSO4 and heating[maybe in microwave] and preparing Na2S2O7 and then heating with Dry Sodium Acetate[dried in microwave
beforehand] in acetic acid or anhydride solvent.us patent no. 1430304
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Formatik
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That patent was mentioned in the very beginning of this thread. It's also attached below.
Attachment: US1430304.pdf (194kB)
This file has been downloaded 1574 times
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Waffles SS
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I tried it several time but was unsuccessful(1430304 )
I used Merck Sodium Pyrosulfate but no anhydrid come just H2S and AcOH.
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JohnWW
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For some reason. it seems that it has recently become IMPOSSIBLE to download ANY attached PDF files here beyond 64 Kb! At that point, the downloads
all cut out.
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Satan
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| Quote: Originally posted by Waffles SS | I tried it several time but was unsuccessful(1430304 )
I used Merck Sodium Pyrosulfate but no anhydrid come just H2S and AcOH. |
Patent also sugest using diluent, but I think you didnt use any, am I correct? Good method might be to grind both reagents with acetic anhydride and
then distil.
@JohnWW downloads works for me. It might be your computer.
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Waffles SS
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Also I used diluent(AcOH and Ac2O) but no anhydrid produced(i did this method several time and in diffrent condition)
[Edited on 4-4-2010 by Waffles SS]
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Ephoton
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the best discription I can give for the smell of AA is burnt polystyrene.
very acrid and cutting but a lot thinner and etherial than GAA smells.
[Edited on 17-4-2010 by Ephoton]
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crossf!re
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...ive tried the reaction with S2Cl2 and NaOAc. On the temperature between 60C°-70C° the reaction was vigorous - than i take out the AA with Vacuum
( first without heating, at the end of the reaction i take an it in a oilbath). First ive mixed The Sodiumacetate with S2Cl2 in a beaker because it
was a siroupy mass, which was not easy to stir and to get it into a round flask.
but the Result was a liquid that boils between 139C° and 140C°.
the yield was round about 80%
and it has the typical smell of AA...but with a little smell of acetic acid..
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Fleaker
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I would far rather make a tube furnace and do acetone pyrolysis and deal with ketene than bother with the sulfur halides.
This has been a very impressive thread so far.
I'm surprised more people haven't attempted the pyrolysis method?
Neither flask nor beaker.
"Kid, you don't even know just what you don't know. "
--The Dark Lord Sauron
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Sedit
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I want to big time and am 99% sure I can do it but my mind thinks back to people who thought they could do something but the corner said it didn't go
to well.
Knowledge is useless to useless people...
"I see a lot of patterns in our behavior as a nation that parallel a lot of other historical processes. The fall of Rome, the fall of Germany — the
fall of the ruling country, the people who think they can do whatever they want without anybody else's consent. I've seen this story
before."~Maynard James Keenan
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hypnos
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I read that one can make AA by bubbing CO through sodium acetate...has anyone seen this synth anywhere? Does it 'make sense'...looks very easy...
CH3CO2CH3 + CO → (CH3CO)2O
[Edited on 24-5-2010 by hypnos]
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bbartlog
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Your equation shows methyl acetate, not sodium acetate. Looks totally implausible to me but if you can actually remember where you read it I'd love to
take a look.
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hypnos
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ahem yeah oops methyl acetate it is.....i saw it mentioned in Wiki in the 'Acetic Anhydride' entry
Acetic anhydride is produced by carbonylation of methyl acetate:[1]
CH3CO2CH3 + CO → (CH3CO)2O
This process involves the conversion of methyl acetate to methyl iodide and an acetate salt. Carbonylation of the methyl iodide in turn affords acetyl
iodide, which reacts with acetate salts or acetic acid to give the product. Rhodium and lithium iodides are employed as catalysts. Because acetic
anhydride is not stable in water, the conversion is conducted under anhydrous conditions. In contrast, the Monsanto acetic acid process, which also
involves a rhodium catalyzed carbonylation of methyl iodide, is at least partially aqueous.
does sound too good to be easy
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not_important
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It isn't too good to be true, just a little challenging for amateurs - 140 C and 5 bar CO for a complexed Pd catalyst http://www.rsc.org/delivery/_ArticleLinking/DisplayArticleFo... 25 to 100 bar and a bit hotter for Rh/LiI, up to 200 bar or more and often
hotter for Ni based systems.
Getting even 5 bar pressure of carbon monoxide will be a little tricky, you'll need to watch out for nickle-containing alloys as the can produce
nickle carbonyl which is just a little tiny bit toxic. MeI is kinda fun too, especially if you've more than a few years of life expectancy before you
start messing with it as a hot gas under pressure.
And you need some good fractionation gear, too.
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