Synthesis of 5-[3,6-di(pyridin-2-yl)pyridazine-4-yl]-2′-deoxyuridine-5′-O-triphosphate-a potential probe for fluorescence detection and imaging DNA

Efficient synthesis of 5-[3,6-di(pyridin-2-yl)pyridazine-4-yl]-2′-deoxyuridine-5′-O-triphosphate, a potential substrate for fluorescence detection and imaging of DNA is reported. Inverse electron demand Diels-Alder (invDA) reaction between the electron-rich 5-vinyl-2′-deoxyuridine-5′-O-triphosphate and electron-deficient tetrazine dienophile 3,6-di(pyridin-2-yl)-1,2,4,5-tetrazine resulted in the formation of 5-[3,6-di(pyridin-2-yl)pyridazine-4-yl]-2′-deoxyuridine-5′-O-triphosphate in 80% yield. This class of molecules will find applications in polymerase chain reactions for fluorescence detection and imaging applications of cellular DNA.