Synthesis of Carboxy ATTO 647N Using Redox Cycling for Xanthone Access
journal contributionposted on 11.12.2019, 16:50 by James L. Bachman, Cyprian I. Pavlich, Alexander J. Boley, Edward M. Marcotte, Eric V. Anslyn
A synthesis of the carbopyronine dye Carboxy ATTO 647N from simple materials is reported. This route proceeds in 11 forward steps from 3-bromoaniline with the key xanthone intermediate formed using a new oxidation methodology. The step utilizes an oxidation cycle with base, water, iodine, and more than doubles the yield of the standard permanganate oxidation methodology, accessing gram-scale quantities of this late-stage product. From this, Carboxy ATTO 647N was prepared in only four additional steps. This facile route to a complex fluorophore is expected to enable further studies in fluorescence imaging.