An Improved Synthesis of the Free Base and Diglycolate Salt of CEP-33779; A Janus Kinase 2 Inhibitor

CEP-33779 is a triazole that has been reported to show highly selective inhibition of Janus kinase 2 (JAK2). An efficient process to form CEP-33779 will be presented that uses multiple palladium couplings to provide the drug substance in a convergent manner. The existing medicinal chemistry route was modified to avoid chromatographic purification, improve safety, and utilize palladium ligands which are available in quantities amenable to scale-up. Challenges faced during the development of the new process included optimization of conditions for Buchwald–Hartwig and Suzuki couplings, control of homocoupled impurities and removal of residual palladium. In addition, a screen of conditions to form a diglycolate salt of the parent compound are also presented.