(Chemical Equation Presented) Ketene N,S-acetals reacted with β-ketoesters in the presence of Zn(NO3)2 · 6H2O as catalyst, in ethanol solvent, giving 6-alkylsulfanylpyridines 4 in good yields without complicated purification procedures. Oxidization of compounds 4 with aqueous hydrogen peroxide in the presence of catalytic sodium wolframate led to the formation of 6-alkylsulfonylpyridine derivatives 5, which could be further derivatized in the 6-position by nucleophilic reactions with phenols or amines to give multisubstituted pyridine compoun...
