P-Toluenesulfonyl hydrazide
# P-Toluenesulfonyl hydrazide

p-Toluenesulfonyl hydrazide is the organic compound with the formula $CH_3C_6H_4SO_2NHNH_2.$ It is a white solid that is soluble in many organic solvents but not water or alkanes. It is a reagent in organic synthesis.

## Reactions

With ketones and aldehydes, it condenses to give the hydrazones:

    $CH_3C_6H_4SO_2NHNH_2$ + $R_2C=O$ → $CH_3C_6H_4SO_2NHN=CR_2$ + $H_2O$

Upon heating in solution, it degrades, releasing diimide $(N_2H_2),$ a useful reducing agent. Triisopropylbenzenesulfonylhydrazide is far more useful for this reaction.

## Synthesis

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

    $CH_3C_6H_4SO_2Cl$ + 2 $NH_2NH_2$ → $CH_3C_6H_4SO_2NHNH_2$ + + $[NH_2NH_3]Cl$

## Reactions

    Preparation of 4-chloroquinazoline and its tosylhydrazide.

Tosylhydrazides can be installed by nucleophilic attack and later removed by base. It thus provides a way to covert C-Cl to C-H.

