bifenazate (74)
Acaricide
NOMENCLATURE
Common name bifenazate (ANSI, BSI proposed)
IUPAC name isopropyl 3-(4-methoxybiphenyl-3-yl)carbazate
Chemical Abstracts name 1-methylethyl 2-(4-methoxy[1,1'-biphenyl]-3-yl)hydrazinecarboxylate
CAS RN [149877-41-8] Development codes D2341; NC-1111 (Nissan)
PHYSICAL CHEMISTRY
Composition Tech. is >90% m/m. Mol. wt. 300.4 M.f. C17H20N2O3 Form White, odourless crystals; (tech. is a beige solid). M.p. 120-124 癈 V.p. <1 ?10-2 mPa (25 癈) KOW logP = 3.4 (25 癈, pH 7) Henry 1 ?10-3 Pa m3 mol-1 S.g./density 1.31 Solubility In water 3.76 mg/l (20 癈). Stability Stable for >1 y at 20 癈 and 50% r.h. DT50 (hydrolysis) 20 h (25 癈, pH 7); DT50 (photolysis) 17 h (25 癈, pH 5). F.p. 110 癈
COMMERCIALISATION
History Reported by M. A. Dekeyser et al. (Proc. Br. Crop Prot. Conf. - Pests Dis., 1996, 2, 487). Discovered by Uniroyal Chemical Co., Inc. (now part of CK Witco Corp.). Developed jointly by Uniroyal and Nissan Chemical. Patents US 5367093; US 5438123 Manufacturers Uniroyal
APPLICATIONS
Mode of action Non-systemic acaricide with predominantly contact action and long residual action. Uses Under development by Uniroyal Chemical Co. for control of phytophagous mites (both eggs and motile stages) on crops including citrus, tree fruits, vines, hops, nuts, vegetables, ornamentals, cotton and maize. Proposed use rates are 0.25-0.75 kg/ha. Formulation types SC; WG; WP.
OTHER TRADENAMES
'Acramite' (Uniroyal); 'Floramite' (Uniroyal); 'Mitekohne' (Uniroyal, Nissan)
ANALYSIS
Product analysis by rp hplc.
MAMMALIAN TOXICOLOGY
Oral Acute oral LD50 for rats >5000 mg/kg. Skin and eye Acute percutaneous LD50 for rats >2000 mg/kg. Not a skin sensitiser. Inhalation LC50 for rats >4.4 mg/l. Other Negative in Ames test, not teratogenic or mutagenic.
ECOTOXICOLOGY
Birds Acute oral LD50 for bobwhite quail 1142 mg/kg. Dietary LC50 (5 d) for bobwhite quail 2298, mallard ducks 726 mg/kg diet. Fish LC50 (96 h) for bluegill sunfish 0.58, rainbow trout 0.76 mg/l. Daphnia EC50 (48 h) 0.50 mg/l. Bees LD50 (48 h, contact) 8.5 mg/bee. Other beneficial spp. Harmless to predacious mites such as the phytoseiids Amblyseius fallacis, Galendromus occidentalis and Zetzellia mali.
ENVIRONMENTAL FATE
Animals In animals, the product is considered of poor bioavailability, and most of the dose is excreted in the faeces. The small proportion that is absorbed undergoes oxidation to the corresponding azo compound, and hydroxylation; hydroxylated metabolites appear in the urine as sulfate or glucuronide conjugates. Plants Considered to be non-systemic; most residues stay on the surface and peel of the crops, where it is mostly not metabolised. Traces that penetrated the peel were metabolised as for animals. Soil/Environment DT50 in aerobic soil c. 7 h; DT50 (anaerobic) c. 80 d. Neither bifenazate nor its metabolites leached in a variety of soil types. DT50 in natural water 45 min. |
