Preparation of New Phenol-based Acyclic Ligands with Double Set of Coordination Sites

摘要

A convenient four-step preparation of the two compartmental Hgands 1,6-bis(2-pyridyl)-2,5-bis(2-hydroxy-3-hydroxymethyl-5-chlorobenzyl)-2,5-diazahexane 3a and 1,7-bis (2-pyridyl)-2,6-bis(2-hydroxy-3-hydroxymethyl-5-chlorobenzyl)-2,6-diazaheptane 3b starting from 4-chlorophenol 4 is reported.Compound 4 was converted to triol 5 which was then protected to 2,2-dimethyl-6-chloro-8-(hydroxymethyI)benzo-1,3-dioxin 6 with 2-methoxy propene.Compound 6 was chlorinated to 2,2-dimethyl-6-chloro-8-(chloro-methyl)benzo-l,3-dioxin 7 and then reacted with l,6-bis(2-pyridyl)-2,5-diazahexane or l,7-bis(2-pyridyl)-2,6-diazaheptane in the presence of Na_2CO_3 in dioxane.Subsequent acid hydrolysis gave 3a and 3b,respectively.The total yields were 38%.