Glacial acetic acid would appear to be the solvent of choice for this endevour, given the conditions of the reaction. Does anyone have any info or best guesses about the quantity of gaa needed to dissolve a quantity of paa? Yes, swim knows he can try it and see, but it would be nice to have a general idea before beginning.
Simply make a small-scale test using 1g of PAA to see how much GAA is needed to dissolve it at RT. That way you will know the solubility beforehand.
80g fused NaOAc will be added to 300g Ac2O and brought to about 120-130c (at first aming for just below reflux temp of solution with AcOH so that CO2 evolution may be observed and drip rate can be set, followed by increasing temp to reflux.) Then, 80g PAA will be added dropwise in a solution of AcOH
This corresponds to a 1:3.75 ratio between PAA:Ac2O - which is suboptimal for good yields. According to the procedures in https://www.thevespiary.org/rhodium/Rhodium/chemistry/phenylacetone.html#phenylacetic (https://www.thevespiary.org/rhodium/Rhodium/chemistry/phenylacetone.html#phenylacetic)
you should aim for a ratio of 1:6 instead or your yields will be lower (unreacted Ac2O will be recycled anyway). You won't need a 1:1 ratio between NaOAc:PAA either, a 1:2 ratio is enough.
You should also shake the crude reaction mixture extract with 5-10% sodium hydroxide rather than sodium hydrogen carbonate, as you need to fully hydrolyze any phenyl-2-propanone enol acetates to phenyl-2-propanone before distilling (Enol acetates = Compounds 23/24 in Fig. 9 in this document (https://www.thevespiary.org/rhodium/Rhodium/chemistry/p2p.phenylacetic.html)
(https://www.thevespiary.org/rhodium/Rhodium/chemistry/p2p.phenylacetic.html))
In the following post, terbium quotes his reaction parameters for this synth as follows:
1l Ac2O
280g PAA added in 4 portions
275g anhydrous KAcO
reflux 12 hours
Post 478232 (https://www.thevespiary.org/talk/index.php?topic=7754.msg47823200#msg47823200)
(terbium: "Phenylacetic acid / Acetic anhydride", Stimulants)
This corresponds to an even smaller ratio of Ac2O to PAA than swim's outlined procedure.
Swim assumed that terbium added the paa in portions so as to assure that an excess of Ac2O was always present. This was swim's intent as well, only at a much more finite scale (Ac2O always present in extreme excess due to dropwise addition).
comments terbium?