Bored with bastardly low yields of my current project, and avoid trying it again, since the medication that comes in bulk form, piperazine hydrogen phosphate has been discontinued in this country. And avoidance of 1,4-bis-acyl products requires that a mono-salt be used and I have only a couple of grams left. I could, I guess try recovery of a mixture of piperazine and mixed acyl anhydride and alkyl chloride then acid-base to recover the desired amine.
But that needs at least 15 hours watching boiling caustic soda 30%, Which I doubt very much is kind to glassware.
Semicolon, where are you? We miss you!