A Mechanistic Study of Metal Template Syntheses of Dibenzo-tetraaza(14)annulene Macrocyclic Complexes
Cutler, A.R. and David Dolphin
J. Coord. Chem.
I (R = H, Me) were prepared by 2 different template syntheses: 1) 1,5-benzodiazepinium salts react either with Ni(OAc)2 to give I directly in approx. 20% yields or with o-C6H4(NH2)2 in presence of Ni(II) ions via hydrolytic ring opening to give the intermediates II (R = H, Me) which then react with 1,1,3,3-tetramethoxypropane (III) to give I; 2) refluxing aqueous solutions of o-C6H4(NH2)2 and III in presence of Ni(II) ions gives analytically pure I in >85% yields via intermediate formation of II. II (R = H) was isolated and its reaction with acetylacetone in ethanolic NaOH gave IV.