Diaminocatechol A Useful Building Block in Synthesis of Multimetallic Complexes

4 -DIAMINOCATECHOL A USEFUL BUILDING BLOCK IN SYNTHESIS OF MULTIMETALLIC COMPLEXES 

Submitted by DELL T. ROSA, ROBERT A. REYNOLDS III, STEVEN M. MALINAK, and DIMITRI COUCOUVANIS Checked by MD. MESER ALI and FREDERICK M. MacDONNELL  

5-Diaminocatechol was first synthesized in 1947, but the product was extremely sensitive to air and decomposed readily, making isolation and further work 

Catechol-functionalized salphen molecules can be readily synthesized from the reaction of 2 equiv of the desired salicylaldehyde derivative with 1 equiv of the 4,5-diaminocatechol after the latter is neutralized with 1 equiv of base, either CHsO or pyridine. Pyridine is particularly useful in the procedure since it will deprotonate the quaternized amine but not the catechol. Representative procedures for the syntheses of three different salphen-catechol ligands are provided in the submitted syntheses. 

In addition to providing the synthesis of 4,5-diaminocatechol hydrobromide and three salphen-catechol ligands, we also have included representative syntheses of two metaUated complexes to show the general utility of these new 

---