Nitrogen–Sulfur Ligand Systems via Reduction of Schiff's Base – Zinc Complexes Derived from Benzothiazolines

The coordinated imine groups of the Schiff's base – zinc complexes derived from various 2-substituted benzothiazolines are easily reduced with sodium borohydride to the corresponding amines. Removal of the metal ion from these reduced complexes yields the free ligands, providing a simple route to novel aminomercaptan chelating agents. Compounds of bi-, tri-, and tetradentate types were prepared in this manner.Evidence is given for a disproportionation of 2,2′-dimethyl-2,2′-bibenzothiazolinyl into 2-methylbenzothiazoline and 2-methylbenzothiazole in chloroform solution.