Acetic Anhydride

Guest · Mon Feb 14, 2005 10:46 am

A novel way to Acetic anhyhdride,
Is to use Bromine, sulphur and sodium Acetate,The halogen can be replace with chlorine,

http://12.162.180.114/dcd/chemistry/anhydrides.html

But it can also be done with Red P, and Sodium acetate, and chlorine,
I just found the patent for The red P method.

GB 128,282

http://12.162.180.114:90/synthetika/pdfs/aceticanhydride128282.pdf

Also by action of Sodium Trioxide on acetate,

http://l2.espacenet.com/espacenet/viewer?PN=GB130660&CY=ie&LG=en&DB=EPD

Really interesting one here,
By action streaming acetic acid, over an earth Phosphate
http://l2.espacenet.com/espacenet/bnsviewer?CY=ie&LG=en&DB=EPD&PN=GB230063&ID=GB++++230063A++I+

For the production of acetic anhydride from anhydrous sodium acetate, sulphur chloride or sulphuryl chloride, and chlorine
http://l2.espacenet.com/espacenet/bnsviewer?CY=ie&LG=en&DB=EPD&PN=GB333991&ID=GB++++333991A++I+

A method for producing AA from Boiling Boric Anhydride, whose manufacture is simply heating Boric acid,Hmmm.....
http://l2.espacenet.com/espacenet/bnsviewer?CY=ie&LG=en&DB=EPD&PN=GB369710&ID=GB++++369710A++I+

More to come

Guest · Mon Feb 14, 2005 8:01 pm

Guest · Mon Feb 14, 2005 8:20 pm

This is the best patent ever found by me regarding the production of ketene by pyrolysis of acetone, which produces acetic anhydride when reacted with acetic acid:

http://l2.espacenet.com/espacenet/viewer?PN=GB425973&CY=ch&LG=de&DB=EPD

This patent contains explicite descriptions of the apparatus (a coppertube of 700mm length and about 3mm inner diameter), temperatures and nice examples for the necessary calculations of flowrate to ration chamber volume.

There are lots of other patents, but this is a VERY good one to start with. The calculations can also be used when instead the small diameter coppertube a wider tube filled with broken porcelain pieces is used, something what is preferred by many experimentors.

I myself prefer the thin tube though, it is considerably easier to heat this thin tube to the needed 700°C to 800°C than a thick tube. The thin tube can just be coiled up - thats nice. Also the thin tube prevents any risk of explosion - its a flameback protector in itself when the guidelines of the patent are observed. Preheat - hot - cooldown zones etc.

/ORG

frogfot · Wed Feb 16, 2005 2:59 am

Whow, the acetate/sulfur/chlorine method seems to be quite easy to perform (comparing to say aquiring of PCl3). They're using acetic anhydride as initial solvent, but I see no disadvantages in using other solvents.. How about using some widely available petroleum distillate? It's inert in theese conditions and easy to remove.

If more polar solvents are needed, why not take glacial acetic acid?

Or did I miss something obvious..

Guest · Wed Feb 16, 2005 5:32 am

Yes, that is what the aa is for, a solvent
I don't see why it wouldn't work with a stable solvent,
although with the bromine, that's you pseudo solvent

syn

Lief · Sat Feb 26, 2005 5:58 am

Check out these patents.

US 2061615 manufacture of aliphatic acids, anhydrides, and ketones

US 2073685 acetic anhydride from metal acetates

US 2073686 acetic anhydride from metal acetates

US 1693331 acetone + CO2 -> acetic anhydride

US 1961542 acetone + acetic acid -> acetic anhydride

US 1153402 acetate + nitric anhydride -> acetic anhydride

US 0683464 Cl2 and SO2

US 1018733 S and Cl2

US 1195205 S and Cl2

US 1195227 NaHSO3, etc. and acetate

US 1283115 -> FR478951 pyrosulfate and acetate

US 1926087 metaphosphate and CH3COOH

US 1430304 pyrosulfate and acetate

Guest · Thu Mar 03, 2005 6:12 pm

That is a great collection Lief,

I will go through those ref's, and post relevant viewable patents,

There are a good amount of novel a simple alternatives in the synthesis of AA,

This is a sysnthesis that is of great importance, and some well written clear pathways, will be a invaluable tool, for the chemist.

Once we can provide several simple pathways, we will have this precursor, in the bag so to speak,

Thanks Lief,
syn

Guest · Fri May 20, 2005 3:54 pm

Lief,

Thos patents are nothing short of brilliant,

I read all of them with much interest,

AA from acetone and acetic acid heated through porcelin at 700C was certainly impressive,
What got me interested was the action of an alkali base aetate combined with a acid corresponding salt to yield the anhydride,

This couldn't mean Sodium acetate & Nacl produces the anhydride,
If not what about Cu acetate, and Cu sulfate
Is thast what they are getting at,

The example was from MnAcetate, and since I only have Mn Oxide, I don;t think fro what I can find that when mixed with acetic acid it will go to the Mn acetate, at which Oxidative stae?

These are such a good read that I recommend any member having problems to read these,

Syn