Copper(I) mediated facile synthesis of potent tubulin polymerization inhibitor, 9-amino-α-noscapine from natural α-noscapine

Abstract Facile synthesis of natural α-noscapine analogue, 9-amino-α-noscapine, a potent inhibitor of tubulin polymerization for cancer therapy, is achieved via copper(I) iodide mediated in situ aromatic azidation and reduction of 9-bromo-α-noscapine (obtained by bromination of natural α-noscapine) with NaN 3 in DMSO at 130  ° C in the presence of l -proline as an amino acid promoter. The protocol developed here avoided isolation of 9-azido-α-noscapine and did not cleave the sensitive C–C bond between two heterocyclic phthalide and isoquinoline units.