Convenient synthesis of mesitylene‐bridged hexaazamacrobicyclic compounds

Two mesitylene‐bridged hexaazamacrobicyclic ligands 1 and 2 were prepared by a three‐step process from available 2,4,6‐tris(bromomethyl)mesitylene ( 9 ) and N, N' ‐di‐ p ‐tosylethylenediamine and N, N' ‐di‐ p ‐tosyl‐1,3‐diaminopropane. First, mono‐BOC‐protected ditosylamines 5 and 6 were prepared by treating the two diamines with BOC‐O‐BOC. These mono‐BOC‐protected diamines were treated with the tris(bromomethyl)‐mesitylene followed by deprotection to give 2,4,6‐tris(2,5‐ditosyl‐2,5‐diazapentyl)mesitylene ( 3 ) and its 2,6‐diazahexyl analog 4 . These latter intermediates were treated with tris(bromomethyl)mesitylene to give the mesitylene‐bridged hexaazamacrobicycles. This three‐step synthesis replaces the reported nine‐step process.