The amide protonation of (-)-N-benzoylcytisine in its perchlorate salts

highlights � The new salts of (–)-Nbenzoylcytisine were characterized by spectroscopic methods. � The energy calculations for tautomeric forms of the salts is presented. � The structures were established by crystallographic analysis. � In crystal, the protonation is on oxygen atom at cyclic amide, not at benzoic moiety. � N-benzoylcytisinium salts protonation is at the oxygen atom instead nitrogen atom. graphical