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Author: Subject: Acetic anhydride preparation
Waffles SS
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[*] posted on 22-11-2018 at 22:03


Quote: Originally posted by clearly_not_atara  

I was expecting that Cu2+ would oxidize SO2.
Fe(OAc)3 may be a somewhat stronger oxidizer, but it is much harder to dry. AgOAc is easy to dry, but expensive and probably insoluble. Pb(OAc)4 is cheaper but toxic. Perhaps Fe2(SO4)3 could be used?


I didnt find any reference for making Ac2O by this method
(i think this is time that you test your idea and publish it)

[Edited on 23-11-2018 by Waffles SS]




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NZniceguy
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[*] posted on 11-7-2019 at 01:52


Has anyone actually tried the Sodium Pyrosulphate and Sodium Acetate method from the Henry Dreyfus patent? I have seen that some people have had success with it on another forum but it looked like it was quickly dismissed in this thread without anyone actually trying it.
It is also supposed to work with Propionate salts to get Prop. Anhydride.
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clearly_not_atara
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[*] posted on 11-7-2019 at 16:36


IIRC tests by SM members showed that the method does work for propionic anhydride but does not work for acetic anhydride.

One possibility is to use pyrosulfate to make benzoic anhydride and then react this with anhydrous metal acetate to get acetic anhydride. Benzoic anhydride is probably a good case for this rxn since it is not enolizable or easily oxidized. Also sodium benzoate can bee had in bulk and IIRC is not hygroscopic.

[Edited on 12-7-2019 by clearly_not_atara]




[Edited on 04-20-1969 by clearly_not_atara]
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Waffles SS
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[*] posted on 11-7-2019 at 23:32


Quote: Originally posted by clearly_not_atara  
IIRC tests by SM members showed that the method does work for propionic anhydride but does not work for acetic anhydride.

One possibility is to use pyrosulfate to make benzoic anhydride and then react this with anhydrous metal acetate to get acetic anhydride. Benzoic anhydride is probably a good case for this rxn since it is not enolizable or easily oxidized. Also sodium benzoate can bee had in bulk and IIRC is not hygroscopic.

[Edited on 12-7-2019 by clearly_not_atara]


I tried reaction of Pyrosulfate with acetate and propionate salt without any success.I will be so happy if someone show this method is not bullshit and Henry Dreyfus is not lier !

Ac2O from Benzoic anhydride is possible and i mentioned this method on page 33




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[*] posted on 4-8-2019 at 23:27


Quote: Originally posted by Waffles SS  
Quote: Originally posted by clearly_not_atara  
IIRC tests by SM members showed that the method does work for propionic anhydride but does not work for acetic anhydride.

One possibility is to use pyrosulfate to make benzoic anhydride and then react this with anhydrous metal acetate to get acetic anhydride. Benzoic anhydride is probably a good case for this rxn since it is not enolizable or easily oxidized. Also sodium benzoate can bee had in bulk and IIRC is not hygroscopic.

[Edited on 12-7-2019 by clearly_not_atara]




I tried reaction of Pyrosulfate with acetate and propionate salt without any success.I will be so happy if someone show this method is not bullshit and Henry Dreyfus is not lier !

Ac2O from Benzoic anhydride is possible and i mentioned this method on page 33


I have seen reports that the Propionic salt and Pyrosulphate has worked for people but I just tried it and it failed. Im unsure if I managed to get Pyrosulphate from Bisulphate though which may have been the problem.

What happened when you tried the propionic salt with pyrosulphate?

Has anyone here had success with the pyrosulphate method?


[Edited on 5-8-2019 by NZniceguy]
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Waffles SS
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[*] posted on 5-8-2019 at 04:24


Quote: Originally posted by NZniceguy  


What happened when you tried the propionic salt with pyrosulphate?



I just got something like propionic acid each time(I even used dry Merck pyrosulfate and propionic salt)

My advise : dont waste your time by this method




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[*] posted on 25-8-2019 at 03:22


Making acetic anhydride is very easy and straightforward if done safely using ketene. The key word here is SAFELY as ketene is on par with hydrogen cyanide. Just follow the setup that doug uses on dougs lab youtube channel or a variation of the setup. Ive had no problem using this method and if done safely it is extremely simple to achieve in a amature home lab with a fume hood. Ive also used the S2Cl2 and sodium acetate method which is also quite easy but a lot more work and messy/smelly because you have to synthesize the S2Cl2. I don't know why so many people ask about making acetic anhydride when its so simple to synthesize. I can also vouch that the pyrosulfate method is bullshit for acetic and for propionic anhydride. I had no luck with either i did however find propionic anhydride extremely simple to synth via ketene and propionic acid.
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