Regio-Selective C−H Halogenation of 8-Amido-Quinolines under Transition Metal Free Conditions

Abstract

A transition metal free highly regioselective remote C−H halogenation has been developed. Oxidative halogenation (Cl, Br, I) of C5-H of 8-amido quinolone with inexpensive potassium persulfate as an oxidant and cheap halogenating agents like N-halosuccinimide (NXS) or tetrabutylammonium halides (TBAX) were employed. Two reaction conditions were developed and in both routes have advantages such as C5-selectivity, high to excellent yields (up to 98 %) and broad substrate scope. The reaction also carried out in water, open to air condition.