Synthesis of some new 2,6-bis pyridines incorporating with tetra-substituted pyrazole heterocycles

Abstract

Several new tetra-substituted pyrazoles attached to pyridine nucleus at positions 2 and 6 were synthesized from the reactions of 2,6-bis(ethoxycarbonyl-acetyl)pyridine (2) with different series of hydrazonoyl chlorides including; C-acetyl-N-aryl-hydrazonoyl chlorides (3a-c) and (Cethoxycarbonyl)-N-aryl-hydrazonoyl chlorides (12a-c). The structures of the synthesized products were established on the basis of their elemental analysis and spectral data in addition to, the chemical behavior of the reaction products with hydrazine hydrate to afford the corresponding pyrazolo [4,3-d]pyridazine derivative.