Conversions of hydrazones to diazo compounds by n-butyllithium and azidotris(diethylamino)phosphonium bromide

Lithium hydrazonides, prepared by reactions of hydrazones with n-BuLi/hexane in THF at −78°C, are converted by azidotris(diethylamino)phosphonium bromide in THF at ∼0°C efficiently, rapidly, and safely to their corresponding diazo compounds along with tris(diethylamino)phosphorimine, nitrogen, and lithium bromide.