Synthesis of nitrogen mustards on cobalt(III).

Bis(bidentate) and bis(tridentate) Co(III) complexes of -(2-hydroxyethyl)ethane-1,2-diamine (heen), 2-[(2-aminoethyl)amino]ethan-1-olate (heen-H), or -(2-chloroethyl)ethane-1,2-diamine (ceen) ligands have been synthesised, and a range of reaction conditions established for their syntheses by different routes. They can all be ultimately derived from (OC-6-12')-[Co(heen)(NO)]NO and provide access to the amine chloride nitrogen mustard complex, (OC-6-12')-[Co(ceen)(Cl)]Cl. Although complex isomeric mixtures were obtained from the reaction of (OC-6-12')-[Co(heen)(NO)]NO under different reaction conditions, ultimately, the amine chlorido configuration around the Co(III) metal centre of the (OC-6-12')-[Co(ceen)(Cl)]Cl complex was favoured.