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.

p-Toluenesulfonyl hydrazide

Names
IUPAC name 4-methylbenzenesulfonohydrazide
Other names tosyl hydrazide
Identifiers
CAS Number	1576‐35‐8 Y
3D model (JSmol)	Interactive image
ChEMBL	ChEMBL221182
ChemSpider	14566
ECHA InfoCard	100.014.917
EC Number	216-407-3
PubChem CID	15303
UNII	LR93R5002M Y
CompTox Dashboard (EPA)	DTXSID8051756
InChI InChI=1S/C7H10N2O2S/c1-6-2-4-7(5-3-6)12(10,11)9-8/h2-5,9H,8H2,1H3 Key: ICGLPKIVTVWCFT-UHFFFAOYSA-N
SMILES CC1=CC=C(C=C1)S(=O)(=O)NN
Properties
Appearance	white solid
Melting point	108–110 °C (226–230 °F; 381–383 K)
Hazards
GHS labelling:
Pictograms
Signal word	Danger
Hazard statements	H242, H301, H302, H315, H317, H319, H341, H373, H410
Precautionary statements	P201, P202, P210, P220, P234, P260, P261, P264, P270, P272, P273, P280, P281, P301+P310, P301+P312, P302+P352, P305+P351+P338, P308+P313, P314, P321, P330, P332+P313, P333+P313, P337+P313, P362, P363, P370+P378, P391, P403+P235, P405, P411, P420, P501
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Synthesis

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

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 convert C-Cl to C-H.

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

CH₃C₆H₄SO₂NHNH₂ + R₂C=O → CH₃C₆H₄SO₂NHN=CR₂ + H₂O

Upon heating in solution, it degrades, releasing diimide (N₂H₂), 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 diimine 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.