A simple metal-free synthesis of 2-substituted pyridine-4,5-dicarboxylates and their N-oxides

Herein a simple, metal-free synthesis of 2-alkyl-, 2-cycloalkyl-, 2-aryl-, and 2-heteroaryl-substituted pyridine 3,4-dicarboxylates and their N-oxides from the corresponding methyl ketones in good to excellent yield, demonstrated with 22 examples in each case, is described. The method complements the current coupling reactions of 2-heterocyclic organometallic reagents. (C) 2012 Elsevier Ltd. All rights reserved.