Green and efficient enantioseparation of amlodipine using a novel pairwise crystallization-circulating extraction coupling method aimed at in situ reuse of mother liquor

•A new pairwise crystallization-circulating extraction coupling method was designed.•PC-CE is a green enantioseparation method for the in situ reuse of mother liquor.•Ternary phase diagram analysis and experiments proved the feasibility of PC-CE.•After reuse of mother liquor for 15 times, the ee of crystal was remained at >98%.•The overall yields can be considered close to 100% except for the operating loss.