plante1999 - 28-3-2013 at 04:12
Is it possible to make an acyl chloride from an acetate ester?
I'm interested in making poly(methacryloyl chloride).
At first I had taugth to pyrolise acrylic glass to get methyl methacrylate, and then hydrolise it in a basic solution to get methacrylic acid,
polymerise methacrylic acid and then finnaly Turn it to the desired acyl chloride using PCl5.
Which way should I use, and does both process work, thanks in advance.
Oh, and the use for this polymeric acyl chloride is to attach chelating group to it, to recover certain elements from spend solution.
Nicodem - 28-3-2013 at 08:40
Direct methyl carboxylates cleavage to the corresponding acyl chlorides is possible (see DOI: 10.1021/jo00909a005), but it is not trivial and besides
you are talking about a polymeric ester which means that the conversion can never reach that obtained by starting from the polymeric acid. You are
also limited by the choice of solvents and how are you going to follow the reaction conversion anyway?
It is much more reasonable to start from sodium polyacrylate which is OTC (the hydrogel used in most diapers today). Sodium salts can be used directly
with SOCl2 or POCl3 to obtain the corresponding acyl chlorides, but a polymer is something else and is certainly not certain that it can behave as
expected. A reflux in a large excess of SOCl2 to assure good conversion, removal of its excess, dissolution with dichloromethane, filtering off the
insolubles and solvent removal might (or might not) give you the polyacrylic chloride. Yet I suggest you to rather check the literature first.