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Author: Subject: Acetic anhydride preparation
Waffles SS
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[*] posted on 28-2-2018 at 11:08


Thanks byko3y.that is great information
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clearly_not_atara
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[*] posted on 29-6-2018 at 13:26


Quote: Originally posted by clearly_not_atara  
Nitriles react with HCl but the reaction does not stop at an imidoyl chloride:

https://www.researchgate.net/publication/244701085_Studies_o...


This study, which describes the formation of a compound I suspect chlorinates acids, is attached. However, the 2:3 adduct, which contains the crucial alpha,alpha-dichloro moiety, appears to be unstable. It may form transiently during the acetonitrile method, but it may not be feasible to isolate it.

Attachment: phpkMmtNR (1.1MB)
This file has been downloaded 39 times





[Edited on 04-20-1969 by clearly_not_atara]
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[*] posted on 11-8-2018 at 01:48


why not do a baeyer-villiger on diacetyl to get AA ? -https://books.google.co.in/books?id=AcpPyv0HWRsC&lpg=PP1...
diacetyl is available as butter flavour :D
anyways,if you want AA only for acetylation ,you can do it using acetic acid/TCT instead :)
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Waffles SS
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[*] posted on 11-8-2018 at 07:38


Quote: Originally posted by CuReUS  
why not do a baeyer-villiger on diacetyl to get AA ? -https://books.google.co.in/books?id=AcpPyv0HWRsC&lpg=PP1...
diacetyl is available as butter flavour :D
anyways,if you want AA only for acetylation ,you can do it using acetic acid/TCT instead :)



Quote:


2.png - 8kB

5,4 g Diacetyl (63 Millimole) wurden in 500 cm3 Ather gegossen, die 14,1 g Perphtalsaure(77,5 Millimole) gelost enthielten. Nach wenigen Stunden war die einem Mol. entsprechende Menge Perphtalsaure verbraucht. Unter Ruhren haben wir hierauf wahrend
einer Stunde trockenes NH3-Gas eingeleitet, hierauf die Flussigkeit von dem entstandenen Niederschlag abdekantiert und sie auf 20 cm3 eingeengt. Uber Nacht krystallisierte daraus Acetamid aus, das nach Umkrystallisieren aus Benzol bei 81 schmolz und mit Acetamid keine Schmelzpunktsdepression zeigte. Ausbeute 0,87 g, d. h. 24% der Theorie.

Zur Oxydation von α‐Diketonen und einigen Derivaten von solchen mit Phtalpersäurev
Karrer; Hohl - Helvetica Chimica Acta, 1949, vol. 32, p. 1933




[Edited on 11-8-2018 by Waffles SS]




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[*] posted on 11-8-2018 at 13:21


sincerely I dont read the 36 page of this thread.


In the patent of 1933 number 42573 preparate acetic anhydride with sodium pirosulfate ( from SO4HNa calcinated ) and ammonium acetate.

[Edited on 11-8-2018 by GrayGhost-]
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[*] posted on 11-8-2018 at 21:02


Quote: Originally posted by GrayGhost-  
sincerely I dont read the 36 page of this thread.


In the patent of 1933 number 42573 preparate acetic anhydride with sodium pirosulfate ( from SO4HNa calcinated ) and ammonium acetate.

[Edited on 11-8-2018 by GrayGhost-]


Maybe you have to read or search some pages of this topic.this method and similar method tested many times without any success.




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[*] posted on 12-8-2018 at 01:20


Quote: Originally posted by Waffles SS  
5,4 g Diacetyl (63 Millimole) wurden in 500 cm3 Ather gegossen, die 14,1 g Perphtalsaure...

Oxone would be a better,cheaper and more OTC choice than perpthalic acid -https://www.organic-chemistry.org/abstracts/lit4/052.shtm
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[*] posted on 12-8-2018 at 05:04


Quote: Originally posted by CuReUS  

Oxone would be a better,cheaper and more OTC choice than perpthalic acid

Of course ;)

[Edited on 12-8-2018 by Waffles SS]




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[*] posted on 12-8-2018 at 06:39


It appears that in the BV oxidation of diacetyl, the AA needs to be trapped in situ, because it reacts with nucleophiles which are present. But maybe the trapping reagent could be something which gives an activated acetyl, such as imidazole or N-hydroxysuccinimide.



[Edited on 04-20-1969 by clearly_not_atara]
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[*] posted on 12-8-2018 at 08:03


Quote: Originally posted by Waffles SS  
Quote: Originally posted by GrayGhost-  
sincerely I dont read the 36 page of this thread.


In the patent of 1933 number 42573 preparate acetic anhydride with sodium pirosulfate ( from SO4HNa calcinated ) and ammonium acetate.

[Edited on 11-8-2018 by GrayGhost-]


Maybe you have to read or search some pages of this topic.this method and similar method tested many times without any success.



I dont tempt make , but i sure what this reaction should be in strictly anhydrous conditions like Grignard and Friedel-Craft.

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[*] posted on 12-8-2018 at 21:02


Quote: Originally posted by GrayGhost-  


I dont tempt make , but i sure what this reaction should be in strictly anhydrous conditions like Grignard and Friedel-Craft.



Please read more pages !




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[*] posted on 13-8-2018 at 03:05


Quote: Originally posted by clearly_not_atara  
It appears that in the BV oxidation of diacetyl, the AA needs to be trapped in situ, because it reacts with nucleophiles which are present.
I don't see any potential nucleophiles in the oxone paper I linked above
Quote:
But maybe the trapping reagent could be something which gives an activated acetyl, such as imidazole or N-hydroxysuccinimide.
won't imidazole or NHS themselves get oxidised under BV conditions ?

Isn't there any other way of isolating the AA,either by using a biphasic medium or nucleophile scavengers ?
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