Diamine preparation for synthesis of a water soluble Ni(II) salen complex

Article abstract of DOI:10.1016/S0960-894X(99)00020-7

A reliable and efficient synthesis of a Ni(II) salen complex useful in probing nucleic acid structure is described and illustrates a general approach for constructing cis diamines suitable for assembly into N₂O₂ Schiff base complexes. Two equivalents of an aryllithium reacted with 1,4- dimethylpiperazine-2,3-dione to form the symmetric α-dione. This material was then converted to its dioxime and reduced by TiCl₄/NaBH₄ to yield the meso-diamine. Condensation of the diamine and salicyladehyde, coordination of nickel and final methylation generated the desired water soluble and redox active complex.