Mono-acylation of piperazine and homopiperazine via ionic immobilization

A method for the selective mono-acylation of piperazine and homopiperazine has been developed. In a flow system, initially the diamine is ionically immobilized on a sulfonic acid funtionalized silica gel, acylated with an appropriate reagent and finally liberated with ammonic methanol. Examples with high yield and purity are presented.