[limpet chicken]

I will be attempting a reaction soon, whic needs a small amount of acetic anhydride, at the moment, I have glacial acetic acid, I realise a ketene lamp wouldn't be too tricky to set up, but its a bit of a pain to run, and ketene is an arse to work with, so, its either GAA/ketene to produce AA, or, I was thinking, first react GAA with NaOH, dehydrate the NaOAc, then treat some H2SO4 with enough SO3, produced by thermal decomposition of ferrous sulfate to give oleum, which should give AA fairly cleanly when reacted with NaOAc.

Which way would you choose? for practicality's sake, personally, I am tempted to go with the H2SO4*SO3 route.

[mike]

Phase managed organic synthesis 3. Symmetrical anhydrides from carboxylic acids via polymer assisted reaction.
Wilmer K. Fife, * and Zhi-dong Zhang

Tetrahedron Letters
Volume 27, Issue 41 , 1986, Pages 4937-4940


Why not buy some?

[limpet chicken]

Thanks, I don't have access to those journals though, as to why not buy some, two reasons, the main one being I don't want police at my door, asking WTF I am doing, or for that matter, police at my door for any other reason, its a very suspicious chemical, I actually HAVE a source for it, but I am no way in hell going to order any, for that exact reason.

The second reason, is I only need quite a small quantity, and I would no doubt end up having to buy masses more than I needed, and get left with a very suspicious sitting duck, quacking at my ass

I just checked out the abstract of that journal reference, and that sort of thing, is the exact sort of thing I wished to avoid, I could probably do this any number of ways, but I am aiming for simplicity, synthing a batch of thionyl chloride just adds more steps, and more money needed (home synthesis of thionyl chloride isn't the most pleasant of tasks either)

[mike]

Sorry, I misunderstood what you wanted.

Good luck with the synthesis.

Can you dehydrate acetic acid to make acetic anhydride?

What about reacting the acid chloride with sodium acetate (or is this what you are effectively doing already?)?

[limpet chicken]

It seems many routes to AA require phosphorus chlorides, or acetyl chloride, heh if I had acetyl chloride, I wouldn't NEED to synthesise AA in the first place, as for many reactions they are interchangeable, I am fairly sure it can't be simply dehydrated, looking at things, SO3 and H2SO4 have both been tried, as as P2O5, unsuccessfully, and if those won't dehydrate something, I will be damned if anything will

I think I am going to go with a ketene lamp, should save a lot of hassle.

[mike]

hmmm, well it is in effect being dehydrated at some point, hence the name "anhydride", I guess it just depends how you do it

This website looked interesting, maybe give you some more ideas (?)

http://nexant.ecnext.com/coms2/gi_0255-3045/Acetic-Anhydride-Cellulose-Acetate.html