recycling unreacted ketones after reductive amination?

[krillin]

My friend was wondering if this is even worth it? Has anyone gone through the trouble of extracting the unreacted mdp2p or p2p oil and distilling it to use in the next reductive amination? If so, What are approximate yield gains?

 

[WillD]

In the reductive amination, we are more often dealing with semi-products. In other cases, fractional distillation or purify through bisulfite adduct.