Abstract

New ten macrocycles 5_{a-cand e-k} and one cryptand 5_d were synthesized by the reaction of diamine compounds 4_a-k with N,N'-bis(2-chloroacetamido)-2,6-diaminopyridine (BCDP) 3 in the presence of K₂CO₃ and KI in good to high yields. Also the template effects of cations such as Na⁺, K⁺, K⁺/KI and Cs⁺ on the reaction yields for macrocycles (4_{a-c and I, k)} were investigated. In this study it is found that size matching and template effect of K⁺ with KI as catalyst are most suitable for macrocyclization process. The structures of macrocycles and cryptand were confirmed by IR, ¹H NMR, ¹³C NMR and Mass spectroscopies. Additionally, computational ¹H and ¹³C NMR parameters of cryptand 5_d were obtained using density functional theory (DFT) at B3LYP/6-31G* level. The calculated chemical shifts were found to be in agreement with experimental data.

Keywords: Aza macrocycle, cryptand, 2, 6-Diaminopyridine, template effect, computational NMR.