Regioselective Reaction of Heterocyclic NOxides, an Acyl Chloride and Cyclic Thioethers [component]

Treatment of electron deficient pyridine N-oxides with 4-nitrobenzoyl chloride and a cyclic thioether in the presence of triethylamine leads to the corresponding 2-functionalized product in up to 74% isolated yield. The transformation can also be accomplished with alternative nitrogen containing heterocycles including quinolines, pyrimidines, and pyrazines. To expand the scope of the transformation diisopropyl ether can be used as the reaction medium to allow for the use of solid thioether
more » ... rates. Nitrogen containing heterocycles including pyridines, quinolines, pyrazines, and pyrimidines are embedded in many molecules of agrochemical and pharmaceutical significance. 1 Methods for either the generation or selective functionalization of these heterocycles are therefore of great interest. 2-4 2-Substituted derivatives represent an important subset of this family which show a broad spectrum of biological activities as exemplified by nexium, pirfenidone, boscalid, and lunesta ( Figure 1 ) which contain carbon, oxygen, chlorine, and nitrogen substitution at the 2-position respectively.
doi:10.1021/acs.joc.7b02457.s001 fatcat:mxxiphr5t5alddjsf3toeajxja