An efficient synthesis of a class of heterobifunctional photo-reactive crosslinkers, labels, and probes

Aryl esters are selectively reduced with DIBAL-H in the presence of an azide functional group to provide access to 4-azido-2-alkoxybenzaldehydes in five steps with overall yields ranging from 72 to 78%. This methodology improves traditional approaches to this class of compounds, which suffer from poor overall yields (4–11%). Our approach can be used to synthesize a variety of new aryl azide cross-linkers, labels, and probes.