Chemical properties
Pure Teflubenzuron is white crystal. m.p.223～225℃ (The original compound 222.5℃)，saturated vapor pressure0.8×10-9Pa(20℃), relative density 1.68(20℃). Its solubility at 20～23℃ are 66g/L in dimethyl sulfoxide, 20g/L in cyclohexanone, 10g/L in acetone, 1.4g/L in ethanol, 850mg/L in methylbenzene， 50mg/L in hexane, 0.02mg/L in water. Stable at room temperature. Its hydrolysis half-life period are 5d（pH=7）and 4h (pH=9） at 50℃ and 2～6 weeks in soil.
Uses
Teflubenzuron’s a fluorobenzoylurea insect growth regulator and a chitinase inhibitor. It achieves the insecticidal purpose through the inhibition of normal molting and development of larvae. It has a particularly high activity on lepidoptera pests, also achieves a good effect when it comes to the larvae of whitefly families, diptera, hymenoptera, coleoptera pests, but it’s invalid for many parasitic insects, predatory insects and spiders. It is mainly used on vegetables, fruit trees, cotton and teabush. E.g. 2000~4000 times diluent of EC can be applied by spraying to larvae of cabbage caterpillar and plutella xylostella in the egg incubation period to 1 to 2 instar.1500～3000 times diluent of EC can be applied by spraying to larvae of plutella xylostella, asparagus caterpillar, prodenia litura in the egg incubation period to 1 to 2 instar, which are resistant to organic phosphorus and pyrethroids. 1500～2000 times diluent of EC can be applied by spraying to cotton bollworm and pink worm in the egg incubation period of the second and third generations, and the elimination rate is about 85% after 10 days.
Production Method
Method 1
The addition reaction of 2,6-Difluorobenzamide and 2,4-difluoro-3,5-dichlorophenyl isocyanate
Method 2
preparation of 2,4-Difluoro-3,5-dichlorophenylamine
2,3,4,5-tetrachloronitrobenzene and Potassium fluoride react in DMF solvent at 140℃ for 15h to obtain 2,4-Difluoro-3,5-dichloronitrobenzene，which is then reduced to 2,4-Difluoro-3,5-dichlorophenylamine
Preparation of Teflubenzuron
As for the preparation of 2,6-difluorobenzoyl isocyanate, see details in the preparation of Teflubenzuron.
2,6-difluorobenzoyl isocyanate and 2,4-Difluoro-3,5-dichlorophenylamine react at room temperature for 15h to obtain Teflubenzuron
As for the nitrification, chlorination, reduction, fluorization and condensation of 1,2,4-Trichlorobenzene to prepare Teflubenzuron, see details in bibliography.
Hazards & Safety Information
Category: Pesticide
Toxicity Grade: low toxicity
Acute Toxicity: LD50: 5000 mg/ kg(Rats oral)
Flammability: Flammable with toxic gases of nitrogen oxides, fluorides and chlorides
Storage: in dry ventilated storeroom at low temperature, away from food materials
Extinguishant: dry powder extinguisher, foam extinguisher, sand.
Uses
Teflubenzuron is used for the control of Lepidoptera, Coleoptera,
Diptera, Aleyrodidae, Hymenoptera, Psyllidae and Hemiptera larvae on
vines, pome fruit, citrus, vegetables, soyabeans, tobacco and cotton. It also
controls fly and mosquito larvae and immature stages of locusts.
Uses
Teflubenzuron is an benzoylphenylurea chitin synthesis inhibitor used to control a wide range of insect pests and mites in fruit, vegetable, cereal and seed crops.
Definition
ChEBI: Teflubenzuron is a N-acylurea that is N-carbamoyl-2,6-difluorobenzamide substituted by a 3,5-dichloro-2,4-difluorophenyl group at the terminal nitrogen atom. It has a role as a xenobiotic, an environmental contaminant and an insecticide. It is a dichlorobenzene, a N-acylurea and a difluorobenzene. It is functionally related to a N-benzoylurea.
Metabolic pathway
There is limited published information on the metabolism of teflubenzuron
but an IPCS review is in preparation. Metabolic processes reported
are cleavage of the urea bond and hydroxylation of both phenyl rings,
including replacement of a fluorine in the 3,5-dichloro-2,4-difluorophenyl
ring (see Scheme 1).
Degradation
Teflubenzuron is more readily hydrolysed at alkaline pH than in acid
media. The DT
50 at 50 °C was 5 days at pH 7 and 4 hours at pH 9 (PM).
Toxicity evaluation
Acute oral LD
50 for rats: >5,000 mg/kg
