Synthetic study on the unique dimeric arylpiperazine: access to the minor contaminant of aripiprazole

The dimeric derivative of Aripiprazole was synthesized via the two notable synthetic technologies as a key step: (1) efficient aldehyde bis-arylation by Bi(OTf)3 and (2) facile Wynberg amination at room temperature. The synthesis has established the structural identity with the minor contaminant sometimes present in Aripiprazole.