Hydrazobenzene

Structural formula
General
Surname	Hydrazobenzene
other names	N , N ′ -diphenylhydrazine 1,2'-diphenylhydrazine N , N ′ -bianiline Hydrazobenzene
Molecular formula	C 12 H 12 N 2
Brief description	colorless solid with a camphor-like odor
External identifiers / databases
CAS number 122-66-7 EC number 204-563-5 ECHA InfoCard 100.004.149 PubChem 31222 ChemSpider 28962 Wikidata Q424993
properties
Molar mass	184.24 g mol −1
Physical state	firmly
density	1.158 g cm −3
Melting point	123-126 ° C
Vapor pressure	1.16 hPa (20 ° C)
solubility	practically insoluble in water Easily soluble in ethanol and diethyl ether
safety instructions
GHS hazard labeling from  Regulation (EC) No. 1272/2008 (CLP) , expanded if necessary danger H and P phrases H: 302-350-410 P: 201-273-308 + 313-501
As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Hydrazobenzene is a chemical compound from the group of organic hydrazine derivatives .

Extraction and presentation

Hydrazobenzene can be obtained by reacting nitrobenzene with sodium hydroxide and tin (II) chloride or with sodium amalgam and then reacting the resulting azobenzene with zinc .

A direct route by reducing two nitrobenzene with zinc and sodium hydroxide to hydrazobenzene is also possible.

Another way is the synthesis of azoxybenzene by condensation of nitrosobenzene with phenylhydroxylamine and subsequent reduction to hydrazobenzene.

properties

Hydrazobenzene is a colorless, flammable solid with a camphor-like odor. It decomposes when heated, whereby aniline and azobenzene (partly also carbon monoxide, carbon dioxide and nitrous gases) can develop. The heat of decomposition determined by DSC is −81 kJ · mol ⁻¹ or −442 kJ · kg ⁻¹ . On contact with air, hydrazobenzene is superficially oxidized to azobenzene, which causes the crystals to turn red. Upon contact with strong acids, it is converted to benzidine ( benzidine rearrangement ).

use

Hydrazobenzene is an intermediate in the manufacture of pharmaceuticals (such as phenylbutazone or sulfinpyrazone ).

safety instructions

Hydrazobenzene is classified as a category 2 carcinogen .

Individual evidence

1. ↑ ^{a b c d e f} Entry on hydrazobenzene in the GESTIS substance database of the IFA , accessed on January 9, 2019(JavaScript required) .
2. ↑ ^{a b c d} Toxicological assessment of hydrazobenzene (PDF) at the professional association for raw materials and chemical industry (BG RCI), accessed on August 22, 2012.
3. ↑ Entry on hydrazobenzene in the Classification and Labeling Inventory of the European Chemicals Agency (ECHA), accessed on February 1, 2016. Manufacturers or distributors can expand the harmonized classification and labeling .
4. ↑ Organikum . 23rd edition. Wiley-VCH, ISBN 978-3-527-33968-6 , pp. 633-634 .
5. ^ Latscha and Klein: Basic knowledge of chemistry, Springer Verlag 1994.
6. ↑ Grewer, T .; Klais, O .: Exothermic decomposition - investigations of the characteristic material properties , VDI-Verlag, series "Humanisierung des Arbeitsleben", Volume 84, Düsseldorf 1988, ISBN 3-18-400855-X , p. 9.
7. ↑ Entry on hydrazobenzene. In: Römpp Online . Georg Thieme Verlag, accessed on May 1, 2014.
8. ^ National Institute of Environmental Health Sciences , 14th Report on Carcinogens (RoC): Hydrazobenzene , accessed January 28, 2019.