Metal-Free Direct Amidation of Naphthoquinones Using Hydroxamic Acids as an Amide Source: Application in the Synthesis of an HDAC6 Inhibitor.

A novel synthetic approach to amidoquinones by the reaction of naphthoquinones with hydroxamic acids under basic conditions was developed. The reaction is mild and operationally simple, and it affords high yields of amidoquinones. With this new method, a novel, very strong HDAC6 inhibitor, which showed high toxicity to AML cells, was successfully synthesized.