Teflubenzuron

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.

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.

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.

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.

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.

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.

uSE: Insecticide.

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.

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).

Teflubenzuron is more readily hydrolysed at alkaline pH than in acid media. The DT₅₀ at 50 °C was 5 days at pH 7 and 4 hours at pH 9 (PM).

Acute oral LD₅₀ for rats: >5,000 mg/kg