Tethered Blatter Radical for Molecular Grafting: Synthesis of 6-Hydroxyhexyloxy, Hydroxymethyl, and Bis(hydroxymethyl) Derivatives and Their Functionalization

Synthetic access to 7-CF3-1,4-dihydrobenzo[e][1,2,4]triazin-4-yl radicals containing 4-(6-hydroxyhexyloxy)phenyl, 4-hydroxymethylphenyl or 3,5-bis(hydroxymethyl)phenyl groups at the C(3) position and their conversion to tosylates and phosphates are described. The tosylates were used to obtain disulfides and an azide with good yields. The Blatter radical containing the azido group underwent a copper(I)-catalyzed azide-alkyne cycloaddition with phenylacetylene under mild conditions, giving the [1,2,3]triazole product in 84% yield. This indicates the suitability of the azido derivative for grafting Blatter radical onto other molecular objects via the CuAAC click reaction. The presented derivatives are promising for accessing surfaces and macromolecules spin-labeled with the Blatter radical.

Automated summary

This paper presents a synthetic method for accessing spin-labeled compounds by synthesizing 7-CF3-1,4-dihydrobenzo[e][1,2,4]triazin-4-yl radicals containing different substituents and converting them into tosylates and phosphates. The obtained tosylates were used to obtain disulfides and azides. The Blatter radical containing an azido group showed good reactivity in a copper(I)-catalyzed azide-alkyne cycloaddition reaction, indicating its potential for grafting onto other molecular objects via the CuAAC click reaction.