N‐Chlorosuccinimide Mediated Regioselective Sulfenylation and Halogenation of 4H‐Pyrido[1,2‐a]pyrimidin‐4‐ones at Room Temperature

Abstract A simple and efficient strategy for N‐chlorosuccinimide mediated regioselective C−H sulfenylation and halogenation of 4 H ‐pyrido[1,2‐ a ]pyrimidin‐4‐ones has been established at room temperature using aryl thiols and phenyliodine(III) diacetate (PIDA) respectively. This methodology tolerated a broad variety of functional groups to obtain structurally diverse sulfenyl and halogenated 4 H ‐pyrido[1,2‐a]pyrimidin‐4‐one derivatives under mild conditions. It delivered a range of products which can serve as the key precursors for the synthesis of complex products relevant to pharmaceutical applications.