Mechanism-based inactivation of thymidylate synthase by 5-(3-fluoropropyn-1-yl)-2′-deoxyuridine 5′-phosphate

5-Fluoropropynyl-2′-deoxyuridine 5′-phosphate (Scheme 1, Figure 3 and ) was designed as a mechanism-based inactivator of thymidylate synthase (TS). The inhibitor was synthesized from 5-iodo-2′-deoxyuridine and propargyl alcohol by palladium-catalyzed coupling, followed by fluorination and selective phosphorylation. Incubation of TS with Scheme 1, Figure 3 and , in the presence or absence of the CH2H4folate cofactor, caused rapid, irreversible inactivation of the enzyme.