Thiacloprid

NOMENCLATURE
Common name thiaclopride ((m) F-ISO); thiacloprid (BSI, E-ISO)

IUPAC name (Z)-3-(6-chloro-3-pyridylmethyl)-1,3-thiazolidin-2-ylidenecyanamide
Chemical Abstracts name (Z)-[3-[(6-chloro-3-pyridinyl)methyl]-2-thiazolidinylidene]cyanamide

CAS RN [111988–49–9] 

PHYSICAL CHEMISTRY
Composition Tech. is ≥97.5% Mol. wt. 252.7 M.f. C₁₀H₉ClN₄S Form Yellowish crystalline powder. M.p. 136 °C (EU Rev. Rep., EPA Fact Sheet) B.p. Decomp. >270 °C V.p. 3 × 10^-7 mPa (20 °C) K_ow logP = 0.74 (unbuffered water), 0.73 (pH 4), 0.73 (pH 7), 0.74 (pH 9) Henry 4.1 × 10^-10 Pa m³ mol^-1 (calc.) S.g./density 1.46 (EU Rev. Rep., EPA Fact Sheet) Solubility In water 185 mg/l (20 °C). In n-hexane <0.1, xylene 0.30, dichloromethane 160, n-octanol 1.4, n-propanol 3.0, acetone 64, ethyl acetate 9.4, polyethylene glycol 42, acetonitrile 52, DMSO 150 (all in g/l, 20 °C). Stability Stable to hydrolysis at pH 5 to 9 (25 °C) (EU Rev. Rep.).

APPLICATIONS
Biochemistry Acts as an agonist of the nicotinic acetylcholine receptor in the central nervous system, thus disturbing synaptic signal transmissions. Mode of action Acute contact and stomach poison, with systemic properties. Uses For use by foliar application against sucking and biting insects, at 48–216 g/ha, in pome fruit, stone fruit, small berries, cotton, vegetables, sugar beet, potatoes, rice and ornamentals. Pests controlled include aphids, whiteflies, beetles (e.g. Leptinotarsa decemlineata, Anthonomus pomorum, Lissorhoptrus oryzophilus) and Lepidoptera such as leaf miners and Cydia pomonella. Formulation types GR; OD; SC; SE; WG.

ENVIRONMENTAL FATE
Animals Thiacloprid was quickly and completely absorbed from the gastrointestinal tract, followed by a fast and uniform distribution to the organs and tissues of the rat. The major portion of the administered dose was quickly eliminated with the urine and faeces. There was no indication of an accumulative behaviour in rats. Besides the parent compound, 26 metabolites were identified in urine and faeces; metabolism proceeds by oxidation of the thiazolidine ring, hydroxylation of the thiazolidine ring and of the cyanamide moiety, opening of the thiazolidine ring and oxidative cleavage of the methylene bridge. In goats, the compound was also quickly excreted, mainly with the urine. Only a very small amount was secreted with the milk. Similarly in poultry, only a minute amount was found in the eggs. Plants Metabolism in tomatoes, apples, cotton and wheat, after spray application, and in rice, after nursery box treatment, is similar in all crops. The parent compound is always the major component at harvest. Hydrolysis, oxidation and conjugation of the parent compound were the main degradation steps. Soil/Environment Soil DT₅₀ (6 soils) 7–21 d; soil mobility (6 soils) low to medium. Mean K_oc 615 (6 soils).

MAMMALIAN TOXICOLOGY
Oral Acute oral LD₅₀ for male rats 621–836, female rats 396–444 mg/kg. Skin and eye Acute dermal LD₅₀ for male and female rats >2000 mg/kg. Non-irritating to skin and eyes (rabbits). Not a skin sensitiser (guinea pigs). Inhalation (4 h, nose only) for male rats >2535, female rats c. 1223 mg/m³ air (aerosol). NOEL NOAEL (2 y) for rats (chronic toxicity, carcinogenicity) 25 ppm (1.23 mg/kg b.w. daily). ADI (JMPR) 0.01 mg/kg b.w. [2006]; (EC) 0.01 mg/kg b.w. [2004]; (EPA) aRfD 0.01, cRfD 0.004 mg/kg b.w. [2003]. Other No primary carcinogenic potential; no primary developmental toxicity in rats and rabbits; no evidence of a genotoxic or mutagenic potential. Toxicity class WHO (a.i.) II.

ECOTOXICOLOGY
Birds Acute oral LD₅₀ for Japanese quail 49, bobwhite quail 2716 mg/kg. LC₅₀ (8 d) for bobwhite quail 5459, Japanese quail 2500 ppm. Fish LC₅₀ (96 h) for rainbow trout 30.5, bluegill sunfish 25.2 mg/l. Daphnia EC₅₀ (48 h, 20 °C) ≥85.1 mg/l. Algae E_rC₅₀ (72 h, 20 °C) for Scenedesmus subspicatus 97 mg/l; EC₅₀ for Pseudokirchneriella subcapitata >100 mg/l. Bees LD₅₀ (oral) 17.32 μg/bee; (contact) 38.83 μg/bee. Worms LC₅₀ (14 d, 20 °C) for Eisenia foetida 105 mg/kg.