Chelation-Controlled Regioselectivity in the Synthesis of Substituted Pyrazolylpyridine Ligands. 2. Tridentates

Article abstract of DOI:10.1021/jo00086a029

A new, more reliable synthesis of tetraketone 4 was found.With t-BuNHNH2, PhNHNH2, and 4-hydrazinobenzoic acid, it condensed to give mostly in,in-disubstituted derivatives (7ii-9ii) of the parent, C-linked 2,6-bis(pyrazol-3-yl)pyridine 5, along with some