It'd be a bad thing. Seems as though piperazine is extremely difficult to mono-substitute. Looks as though I need resort to trivalent cerium in strict anhydrous conditions using acid halides to get me a selective result, looks like 99% is possible of a monoacylpiperazine is possible.
And if thats doable, then its a simple matter of alkylation with cinnamyl chloride then 15 hour reflux in concentrated to decarobxylate and rxn with the desired acyl halide or acid anhydride, I prefer the halides myself, the acyl halides react FAST and unlike using an acid anhydride you don't get a corresponding quantity of the acid as well as the acyl ester, amide, etc. that you wish to make, whereas you need to heat the anhydride reactions, so thermo-sensitive substrates, your better off using the acid halide instead. Actually I fucking hate carboxylic anhydride rxns. They reek something awful, they are slower and require extensive workup. Plus genertion of an equimolar amount of the acid also, To whit I've had the vomit-like stench of butyric anhydride following me like a damn bloodhound for three days, IF I'd had enough money to buy instead butyryl chloride or better, bromide or iodide then it would be quick, and clean.
Semicolon, where are you? We miss you!