Key words: Titanium(IV), Hydrazone, Schiff Base, Molecular Structure, Cyclic Voltammetry

Abstract

Tetrahydro-1H-benzo[b]azonin-2,7-dione (2a) has been used as a precursor in the synthesis of dibenzo[ b,f ][1,5]diazacyclododecene and dibenzo[b,g][1,6]diazacyclododecene ring systems 4 and 5, respectively, via periodate oxidation of the appropriate indolo-benzo[b]azonines 3 and 7. The synthesis of hexahydro-benzo[b][1,4]diazecin-2,7-dione (10) has been achieved by the Schmidt reaction of 2a. The periodate oxidation of 9,9´-methylenebis(2,3,4,9-tetrahydro-1H-carbazole) (11) afforded 1,1´- methylenebis(3,4,5,6-tetrahydro-1H-benzo[b]azonin-2,7-dione) (12). Its 6,6´-methylenebis isomer 13 was obtained by treating 2a with formaldehyde. Oxidation of 16 gave the unsymmetrical bi(benzo [b]azonine) 17. The Mannich reaction of 2a led to a mixture of its 6-methylene derivative 19 and the spirocyclic system 20. The reactions of 2a with aldimines and aromatic aldehydes were also investigated.