Synthesis of 5‐aryl and 5‐amidocamptothecins

Abstract

Abstract A variety of 5‐aryl‐(20 S )‐camptothecin derivatives were synthesized by the reaction of 5‐hydroxy‐(20 S )‐camptothecin with aromatic hydrocarbons under Friedel‐Craft reaction conditions in moderate to good yield as diastereomeric pairs. The methodology was then extended for the synthesis of 5‐amido‐(20 S )‐camptothecin derivatives by reacting 5‐hydroxy‐(20 S )‐camptothecin with alkyl and aryl nitriles under Ritter type reaction conditions. The reaction is presumed to proceed through an iminium ion intermediate under Friedel Craft and Ritter type reaction condition, which is further trapped by nucleophile present in the reaction medium. J. Heterocyclic Chem., 00 , 00 (2011).