Synthesis of Proton-Ionizable p-Nitrophenol-Containing Tetraazacrown and Diazadithiacrown Ethers from an Aromatic Building Block Prepared via the Einhorn Reaction

• Published in: Journal of organic chemistry 1998-07, Vol.63 (14), p.4786-4791
• Main Authors: Hu, Kejiang, Bradshaw, Jerald S, Pastushok, Victor N, Krakowiak, Krzysztof E, Dalley, N. Kent, Zhang, Xian Xin, Izatt, Reed M
• Format: Article
• Language: English
• ISSN: 0022-3263; 1520-6904
• DOI: 10.1021/jo980414z

A series of p-nitroanisole-containing tetraazacrown (14−18), diazacryptand (22), and diazadithiacrown (23−25) macrocycles has been prepared by treating the appropriate secondary diamine, diazacrown, or dimercaptan with 2,6-bis[(2-chloroacetamido)methyl]-4-nitroanisole (BB). Five of these p-nitroanisole-containing macrocycles were reported earlier. Four new bis(p-nitroanisole)-containing macrocycles resulting from a 2 + 2 macrocyclization of diamine or dimercaptan with BB were also isolated. Six of the p-nitroanisole-containing macrocycles (16, 17, 22−25) were converted to the p-nitrophenol-containing macrocycles (27−32) on treatment with LiI in refluxing pyridine. Thermodynamic quantities (log K, ΔH, and TΔS) for the interactions of four new compounds (24, 27, 31, and 32) with Na+, K+, Ba2+, Ag+, and Pb2+ were evaluated by calorimetric titration at 25.0 °C in either 70% or absolute methanol solution. The compounds show strong interactions with Ag+ and Pb2+ but very weak interactions with Na+, K+, and Ba2+. Ligand 31 exhibited high selectivity for Ag+ over Pb2+. X-ray crystal structures were obtained for diazadithia macrocycle 23 and the Ag+−31 complex.