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Author Topic: Acetic Anhydride by a strange route  (Read 1015 times)

lugh

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Re: Acetic Anhydride by a strange route
« Reply #20 on: November 10, 2011, 01:22:12 AM »
One patent of many that describe the process is attached  8)
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Enkidu

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Re: Acetic Anhydride by a strange route
« Reply #21 on: November 10, 2011, 10:01:28 AM »
I'd appreciate a translation..

antibody2

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Re: Acetic Anhydride by a strange route
« Reply #22 on: November 10, 2011, 06:36:45 PM »
here is the ref for the pyrosulfate rxn

fresh1

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Re: Acetic Anhydride by a strange route
« Reply #23 on: November 27, 2011, 12:50:34 AM »
what about tthis . . .

Tennessee Eastman acetic anhydride process

Acetic anhydride is produced by carbonylation of methyl acetate in a process that was inspired by the Monsanto acetic acid synthesis.[3]

    CH3CO2CH3 + CO ? (CH3CO)2O

In this process lithium iodide converts methyl acetate to lithium acetate and methyl iodide, which in turn affords through carbonylation acetyl iodide. Acetyl iodide reacts with acetate salts or acetic acid to give the product. Rhodium iodides and lithium salts are employed as catalysts. Because acetic anhydride is not stable in water, the conversion is conducted under anhydrous conditions in contrast to the Monsanto acetic acid synthesis

Lithium Iodide is found in some batteries, Methyl Acetate is very OTC and inert atmospheres are not too hard, it seems viable, no huge pressures or temps....... :-\



 
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Wizard X

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Re: Acetic Anhydride by a strange route
« Reply #24 on: November 27, 2011, 01:06:23 AM »
Fresh1: If you can get glacial acetic acid, your able to make Acetic anhydride?

http://scifun.chem.wisc.edu/chemweek/pdf/aceticacid.pdf
http://en.wikipedia.org/wiki/Acetic_anhydride#Production
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Dr. Tox

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Re: Acetic Anhydride by a strange route
« Reply #25 on: November 27, 2011, 02:52:08 AM »
Speaking of strange routes to AA: A few years ago a friend in Bulgaria was waiting at a bus stop, found a box sitting there, opened it and lo! 5 liters or so of AA from the local chem supply.  :D

No joke.
Alimentary, dear Watson; I had a gut feeling.

smellslikeindole

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Re: Acetic Anhydride by a strange route
« Reply #26 on: November 27, 2011, 02:56:02 AM »
Fresh1, making Ac2O by an industryal way isn't an easy thing.

Some data from this reaction:
With  methyl iodide; Rhodium trichloride; triphenylphosphine
T=190°C; P=37503 Torr;

another:
With  hydrogen; chitosan; methyl iodide; Rhodium trichloride in  acetic acid
T=190°C; P=37503 Torr

and another one:
With  hydrogen; lithium iodide; methyl iodide; rhodium in  acetic acid
T=190°C; P=19860.5 Torr - Patent: US7553991

This is not a kind of a reaction what could be made in a home lab, and if You hope that Ac2O will come out from OTC MeAc and lithium ion batteries  you are really wrong...

Learn chemistry from chemistry books and not from wikipedia.

Ac2O could be easily prepared from silver-acetate (made eaasily from sodium-acetate and silver salts), the silver acetate should be dried out in vacuum and heated to 300-400 Celsius in CO2 (or argon) atmosphere. Ac2O will distill out and Ag2O will be remained in the heating tube.
Yield: +90%.

Other info: Gmelin Handbook:  Ag: Vol.B5, page 125 - 126.

Dr.Tox,
I also know a kitty who got 1 liter of it for free(:

Dr. Tox

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Re: Acetic Anhydride by a strange route
« Reply #27 on: November 27, 2011, 03:02:23 AM »
HAHA! ^5
Alimentary, dear Watson; I had a gut feeling.

fresh1

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Re: Acetic Anhydride by a strange route
« Reply #28 on: November 27, 2011, 03:47:18 AM »
I was floating around looking at variations on the theme, this actually came from researching catalysts, not wiki/AA, so to Assume this

Quote
Learn chemistry from chemistry books and not from wikipedia.

Is a bit "quick off the mark"

AA is a pet topic :o

wizard thanx for the links, GAA is easy to acquire, its dehydrating the stuff thats never come easy! I once investigated SOCl dehydration BUT talk about "fuckin smelly :o" so I have wandered around looking for other ways...I'm surprised I hadnt seen this before, I guess its coz I dont look at "industrial processes" usually, rarely are they viable(ketene lamps etc-high pressures/temps) I'm far too ghetto and dont wish to end up "smelling like indole" ;D ( or SO2 or a salad, for that matter ::))

TCE+NaAc hmmm? cant say I've seen this,-- 1,1,1 or 1,1,2, TCE ? sounds too easy!
 
Actually I really like jons tek, although I go through "phases" of wanting anhydrous acids ;)
« Last Edit: November 27, 2011, 08:59:40 AM by fresh1 »
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uchiacon

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Re: Acetic Anhydride by a strange route
« Reply #29 on: February 02, 2012, 11:59:56 PM »
That Na acetate and Na pyrosulfate method sounds really interesting. How were the yields jon?

The main problem would be finding a source of pyrosulfate... might be a bit difficult. Could try the sulfuric acid manufacturers? Or if anyone has any suggestions...

Assyl Fartrate

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Re: Acetic Anhydride by a strange route
« Reply #30 on: February 03, 2012, 12:47:22 AM »
Pyrosulfate is easily made by heating the hell out of sodium hydrogen sulfate (sold as pH down for pools).
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Assyl Fartrate

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Re: Acetic Anhydride by a strange route
« Reply #31 on: February 03, 2012, 04:17:46 PM »
It failed for you?
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fresh1

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Re: Acetic Anhydride by a strange route
« Reply #32 on: February 03, 2012, 07:06:58 PM »
blow me down if a random person out of the blue didnt give me an old unopened bottle of 1,1,2, TCE last week  :o

Old Kodak movie film cleaner

and now I cant find the reference I had

anybody?
« Last Edit: February 03, 2012, 07:11:05 PM by fresh1 »
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Assyl Fartrate

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Re: Acetic Anhydride by a strange route
« Reply #33 on: February 03, 2012, 08:18:58 PM »
Maybe your temperatures are too high and you're decomposing the pyrosulfate. Jon reports no problems with this method.

fresh1 - are you referring to refluxing TCE with sulfuric acid to form chloroacetyl chloride?
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jon

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Re: Acetic Anhydride by a strange route
« Reply #34 on: February 03, 2012, 11:12:07 PM »
i had problem with sodium acetate because it caked and stopped reacting in that case you can wet it with acetic acid and heat it to 100C
then distill of the acetic acid and then the acedtic anhydride.
i use an oven to heat the sodium sulfate set to broil i did'nt get too much so3 evolution if you do it's way too hot.

Assyl Fartrate

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Re: Acetic Anhydride by a strange route
« Reply #35 on: February 04, 2012, 06:15:37 AM »
Quote
i had problem with sodium acetate because it caked and stopped reacting in that case you can wet it with acetic acid and heat it to 100C
then distill of the acetic acid and then the acedtic anhydride.

hxxp://www.orgsyn.org/orgsyn/orgsyn/prepContent.asp?prep=cv1p0091

Maybe it's possible to use phosphoric acid as well to kickstart the reaction?
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jon

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Re: Acetic Anhydride by a strange route
« Reply #36 on: February 04, 2012, 03:02:13 PM »
it's not that the reaction itself is hindered.
the whole mass agglomerates.
to remedy this all you need to do is wet it with acetic acid.
if i use another salt like calcium propionate the agglomeration is'nt a big problem and i don't need to wet it with any acid, saving me the hassle of fractionating it.
if your making acetic anhydride to in turn make phenyl propanoic anhydride by the mixed anhydride method you will have better luck using propionic anhydride to make your mixed anhydride.
because propionic anhydride boils higher and the difference between boiling points is broader so you have more room for error.
say for example you take phenyl propionic acid.
add propionic anhydride and boil until the acid distills off to make you phenyl propionic anhydride.
the endpoint of the reaction is determined when no acid distills off any longer, easy peasy.

Balkan Bonehead

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Re: Acetic Anhydride by a strange route
« Reply #37 on: July 12, 2012, 02:27:34 AM »
Quote from: reckless on April 25, 2012, 05:50:23 AM
Aa
CH3CONH2+CH3COOH+HCl->(CH3CO)2O+NH4Cl
2CH3CONH2+2CH3COOH+H2SO4->2(CH3CO)2O+(NH4)2SO4
Acetyl chloride
CH3CN+CH3COOH+2HCl->CH3COCL+CH3CONH2*HCL
CH3COOH+C6H5COCl->CH3COCl+C6H5COOH

Now would be a good time to provide refs.

atara

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Re: Acetic Anhydride by a strange route
« Reply #38 on: July 13, 2012, 06:23:46 AM »
The aluminium diacetate route is the most interesting -- sodium aluminate is very very easy and not prone to decomposition or caustic the way pyrosulfate is. The aluminum compound also shouldn't be hygoroscopic.

NaAlO2 + 3AcOH --> AcONa + Al(AcO)2OH + H2O

I'm having trouble believing aluminium acetate is insoluble in water and not prone to hydrolysis, though that would mean a very easy work-up.

Balkan Bonehead

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Re: Acetic Anhydride by a strange route
« Reply #39 on: July 13, 2012, 11:02:22 AM »
How is the acetamide method supposed to work, just add acetamide to GAA, add conc. sulfuric, and then distill out the acetic anhydride?
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