Description
Azoxybenzene is an obsolete insecticide used to control aphids and other sucking insects. It has a low aqueous solubility and is highly volatile. Little else is known about its environmental fate and behaviour. Ecotoxicology data is scant but it is moderately toxic to fish. Azoxybenzene is moderately toxic to mammals including humans if ingested. It may be a liver and kidney toxicant and is a recognised irritant.
Chemical Properties
ORANGE-YELLOW TO ORANGE CRYSTALS
Uses
Fenazox is used in the synthetic preparation of amides via reductive amidation of esters, which is used in the synthesis of bio-active molecules and natural products.
Uses
Intermediate in organic synthesis.
Definition
ChEBI: Azoxybenzene is an azoxy compound.
Production Methods
Azoxybenzene is commercially produced through the partial reduction of nitrobenzene under alkaline conditions, typically using sodium hydroxide and a reducing agent such as glucose or sodium acetate. In one common method, nitrobenzene is heated with sodium hydroxide and glucose at 55–75 DegC, leading to the formation of azoxybenzene via intermediate steps involving phenylhydroxylamine and nitrosobenzene. The product is then isolated by steam distillation, followed by acidification and crystallisation.
General Description
Bright yellow crystals or yellowish-brown solid.
Air & Water Reactions
Dust may form an explosive mixture in air. Insoluble in water.
Reactivity Profile
AZOXYBENZENE is an azo compound. Azo, diazo, azido compounds can detonate. This applies in particular to organic azides that have been sensitized by the addition of metal salts or strong acids. Toxic gases are formed by mixing materials of this class with acids, aldehydes, amides, carbamates, cyanides, inorganic fluorides, halogenated organics, isocyanates, ketones, metals, nitrides, peroxides, phenols, epoxides, acyl halides, and strong oxidizing or reducing agents. Flammable gases are formed by mixing materials in this group with alkali metals. Explosive combination can occur with strong oxidizing agents, metal salts, peroxides, and sulfides.
Fire Hazard
Flash point data for AZOXYBENZENE are not available; however, AZOXYBENZENE is probably combustible.
Mechanism of action
Non-systemic, contact action.
Safety Profile
Poison by
subcutaneous route. Moderately toxic by
ingestion, skin contact, and other routes. A
skin and eye irritant. Mutation data reported.
Combustible. When heated to
decomposition it emits toxic fumes of NOx.
Purification Methods
Crystallise azobenzene from EtOH or MeOH, and dry it for 4hours at 25o/10-3mm. Sublime it before use. [Bigelow & Palm Org Synth Coll Vol II 57 1943, Beilstein 16 II 326.]
Pesticide Type
Insecticide; Acaricide
