Phenylhydrazine

chembox
| Verifiedfields = changed
| Watchedfields = changed
| verifiedrevid = 464201153
| Name = Phenylhydrazine
| Reference =
| ImageFile = phenylhydrazine. png
| ImageSize = 100px
| ImageName = Phenylhydrazine
| ImageFileL1 = Phenylhydrazine from xtal 3D bs 17. png
| ImageNameL1 = Ball and stick model of phenylhydrazine
| ImageFileR1 = Phenylhydrazine from xtal 3D sf. png
| ImageNameR1 = Space filling model of phenylhydrazine
| PIN = Phenylhydrazine
| OtherNames = Hydrazinobenzene
|Section1=
|Section2=Chembox Properties
| Formula = |C6H5NHNH2
| C=6|H=8|N=2
| Density = 1.0978 g/cm3
| MeltingPtC = 19.5
| MeltingPt notes = (24 °C for hemihydrate)
| BoilingPtC = 243.5
| BoilingPt notes = (decomposition)
| Appearance = Colorless to pale yellow liquid or solid
| LD50 = 188 mg/kg (rat, oral), 175 mg/kg (mouse, oral), 80 mg/kg (rabbit, oral), 80 mg/kg (guinea pig, oral), 200 250 mg/kg (dog, oral)
| REL = Ca C 0.14 ppm (0.6 mg/m3) [2 hr] [skin]

Phenylhydrazine forms monoclinic prisms that melt to an oil around room temperature which may turn yellow to dark red upon exposure to air.

Phenylhydrazine was the first hydrazine derivative characterized, reported by Hermann Emil Fischer in 1875. He prepared it by reduction of a phenyl diazonium salt using sulfite salts. Fischer used phenylhydrazine to characterize sugars via formation of hydrazones known as osazones with the sugar aldehyde. He also demonstrated in this first paper many of the key properties recognized for hydrazines.

Phenylhydrazine is used to prepare indoles by the Fischer indole synthesis, which are intermediates in the synthesis of various dyes and pharmaceuticals. Phenylhydrazine is used to form phenylhydrazones of natural mixtures of simple sugars in order to render the differing sugars easily separable from each other. This molecule is also used to induce acute hemolytic anemia in animal models.

Exposure to phenylhydrazine may cause contact dermatitis, hemolytic anemia, and liver damage.