Synthesis of benzoazacrown ethers by transformation of benzocrown macrocycle and preparation of related complexing agents

Abstract

The results of studies aimed at producing and developing a new methodology of synthesis of functional derivatives of benzoazacrown ethers by stepwise transformation of the benzocrown macrocycle are generalized. The comprehensive study of the spatial structure and complexation properties of the starting benzocrown ethers, target benzoazacrown ethers, and their nearest structural analogs shows that the N-alkylbenzoazacrown derivatives exhibit a much higher ability to bind metal and ammonium cations compared to the corresponding N-phenylazacrown ethers. They are comparable with benzocrown ethers in complexation properties and exceed them in some cases. A new approach to the synthesis of dinitrodibenzodiazacrown ethers is proposed based on the one-step transformation of the macrocycle of the dinitrodibenzo18-crown-6 cis-isomer under the action of aliphatic diamines. The synthesis of styryl dyes containing the N-methylbenzoazacrown fragment is described. The detailed studies by electron spectroscopy, NMR spectroscopy, and X-ray diffraction analysis revealed a high potential of these dyes as optical molecular sensors for alkaline and alkaline-earth metal cations.