P-Toluenesulfonyl hydrazide

p-Toluenesulfonyl hydrazide is the organic compound with the formula CH₃C₆H₄SO₂NHNH₂. It is a white solid that is soluble in many organic solvents but not water or alkanes. It is a reagent in organic synthesis.

Synthesis

Toluenesulfonyl hydrazide is prepared by the reaction of toluenesulfonyl chloride with hydrazine:

Reactions

Tosylhydrazides can be installed by nucleophilic attack and later removed by base. It thus provides a way to convert C-Cl to C-H.
With ketones and aldehydes, it condenses to give the hydrazones:
Upon heating in solution, it degrades, releasing diimide, a useful reducing agent. Triisopropylbenzenesulfonylhydrazide is far more useful for this reaction.

Use

The compound is an important reagent in organic synthesis, serving as a source of reactive diimide and its subsequent chemical reactions. It condenses with ketones and aldehydes to form hydrazones, which can be further transformed into reactive intermediates such as diazo compounds or carbenes. N-heterocycles can be synthesized through 1,3-dipolar cycloaddition reactions. Ketone hydrazones are defunctionalized using mild reagents in a modified Wolff-Kishner reaction. A notable commercial application of this compound is as a foaming reagent for polymers.