Removing Triphenylphosphine Oxide Byproduct or Coproduct from a Reaction Mixture

Triphenylphosphine oxide is a common and annoying coproduct in the Wittig reaction, for example. Many ways have been proposed for the separation of this contaminant but most are not fast, cheap, rugged, or necessarily quantitative. It is known that triphenylphosphine oxide forms large blockish cocrystals with N-acetylglycine with a very strong hydrogen bond between amide and phosphine oxide. It can be imagined that these adducts further associate as dimers through the free carboxyl group producing an even high molecular weight dimeric adduct. Perhaps the addition of excess N-acetyl glycine into a solution of desired product and triphenylphosphine oxide impurity could precipitate the cocystals and perhaps residual N-acetyl glycine. This has not been established. But, if it works filtration would give a purified solution of the desired product with just some residual dissolved N-acetyl glycine and so long as the desired product is not acidic, this residual N-acetylglycine will be cleanly back extract  into aqueous base.