Chemical Properties
Colorless crystalline solid. Odorless.
Chemical Properties
Pale Yellow Solid
Uses
A commonly used herbicide/pesticide.
Uses
Preemergence herbicide used for controlling certain annual grasses (e.g., bluegrass, barnyardgrass, crabgrass, goosegrass, sprangletop) and broad-leaved weeds (e.g., cudweed, dayflower, filaree, groundsel, jimsonweed, morningglory, mustards, pigweed, redmaids, smartweed, sowthistle, velvetleaf) in turf, lawns, orchards and ornamentals.
Definition
ChEBI: Oxadiazon is an aromatic ether.
General Description
Crystalline solid. Used as an herbicide.
Air & Water Reactions
Dust may form an explosive mixture in air.
Reactivity Profile
Oxadiazon is a diazo 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.
Trade name
CARPETMAKER®; CHIP SHOT®[C];
GOLD KIST®; PAR EX®; PRO GROW®; REGAL
O-O®; REGALSTAR®; RONSTAR®; RP-17623®;
TURFIC®; VERTAGREEN®; WILBRO
Mechanism of action
Selective with contact action. Inhibits protoporphyrinogen oxidase, leading to irreversible cell membrane damage.
Safety Profile
Moderately toxic by ingestion, inhalation, and skin contact. When heated to decomposition it emits toxic vapors of NOx and Clí.
Synthesis
To a 20 mL autoclave was added a stirrer, 0.2 mmol of pivaloyl chloride-2,4-dichloro-5-isopropoxyphenylhydrazone, 0.5 mmol of cesium fluoride, 0.24 mmol of 18-crown-6 and 2 mL of toluene. Carbon dioxide was passed until the pressure reached 2.0 MPa, and the reaction was stirred at 25°C for 24 hours. After the reaction was completed, the heating and stirring were stopped, and the unreacted carbon dioxide was slowly released after the system was cooled to room temperature. The reaction solution was transferred to a partition funnel, 15 mL of water was added and extracted three times with 15 mL of ethyl acetate. The organic phases were combined and washed sequentially with water and saturated saline. The organic phase was dried over anhydrous sodium sulfate and concentrated under reduced pressure to remove the solvent to obtain the crude product. The crude product was purified by column chromatography with the eluent of petroleum ether and ethyl acetate (30:1, v/v) to afford the target product 5-(tert-butyl)-3-(2,4-dichloro-5-isopropoxyphenyl)-1,3,4-oxadiazol-2(3H)-one in 88% yield.
Potential Exposure
An oxadiazolinone/oxidiazole preemergence
and early postemergence herbicide used to control
annual grasses, sedges, and broadleaf weeds. Originally
registered for use on turf and ornamentals; has wide use on
golf courses.
Environmental Fate
Soil. The reported half-life in soil is approximately 3–6 months (Hartley and Kidd,
1987). Oxadiazon degraded slowly in both moist and flooded soils. After 25 weeks, only
0.1–3.5% degraded to carbon dioxide and 0.5–1.1% as volatile products. Metabolites
identified included oxadiazonphenol, oxadiazon acid and methoxyoxadiazon (Ambrosi et
al., 1977).
Plant. Reported half-lives of oxadiazon in rice and orchard fruit are 1–2 and 3–6
months, respectively (Hartley and Kidd, 1987).
Shipping
UN3077 Environmentally hazardous substances,
solid, n.o.s., Hazard class: 9; Labels: 9-Miscellaneous hazardous
material, Technical Name Required.
Incompatibilities
Dust may form explosive mixture in
air. Diazo 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.
This chemical is sensitive to prolonged exposure to heat.
This chemical is incompatible with strong oxidizing
agents.
Toxics Screening Level
This inhalation potency results in an IRSL of 0.05 μg/m3 with annual averaging.
Waste Disposal
It is the responsibility of
chemical waste generators to determine the toxicity and
physical properties and of a discarded chemical and to
properly identify its classification and certification as a hazardous
waste, and to determine the disposal method. United
States Environmental Protection Agency guidelines for the
classification determination are listed in 40 CFR Parts
261.3. Additionally, waste generators must consult and follow
all regional, national, state, and local hazardous waste
laws to ensure complete and accurate classification and disposal
methods. Follow recommendations for the disposal of
pesticides and pesticide containers. Containers must be disposed
of properly by following package label directions or
by contacting your local or federal environmental control
agency, or by contacting your regional EPA office.
Do not discharge into drains or sewers. Dispose of waste material as hazardous waste using a
licensed disposal contractor to an approved landfill. Consult with environmental regulatory agencies for guidance on acceptable disposal practices. If allowed, incineration with effluent gas scrubbing is recommended. Containers must be
disposed of properly by following package label directions or
by contacting your local or federal environment
References
[1] Journal of Organic Chemistry, 2017, vol. 82, # 14, p. 7637 - 7642
[2] Patent: CN106866573, 2017, A. Location in patent: Paragraph 0073; 0074; 0075; 0076; 0077; 0078
![N-[2,4-Dichloro-5-(1-methylethoxy)phenyl]-2,2-dimethylpropanehydrazonoyl chloride](/CAS/20210305/GIF/51166-88-2.gif)
