SYNTHESIS OF ESTER DERIVATIVES OF 7-TRIAZACYCLONONANE-1,4,7-TRIS(METHYLENEPHOSPHONIC ACID) AND AZACYCLONONANE-1,4,7-TRIS(METHYLENEETHYLPHOSPHINIC ACID)

Two methods have been developed for the synthesis of new 1,4,7-triazac yclononanetris(methylenephosphonic acid)(3-6,8-11)and -tris(methylenee thylphosphinic acid) (7, 12) ester derivatives. The first procedure in cludes the synthesis of 2 in anhydrous THF which can then be used as a useful synthetic intermediate for several new derivatives of 1,4,7-tr iazacyclononane (1). In the second procedure, compound 1 and dialkyl p hosphite or ethyl ethylphosphinate are reacted with paraformaldehyde i n refluxing benzene yielding the corresponding eaters in good to excel lent yield. New macrocyclic complexing agents 8-12 have been prepared by either basic (8-11) or acidic (12) hydrolysis of the corresponding ester derivatives, or directly from the starting macrocycle 12. Side r eactions decreasing the yield and purity of the products are also disc ussed.