cyclanilide
Plant growth regulator
NOMENCLATURE
Common name cyclanilide (pa ISO)
IUPAC name 1-(2,4-dichloroanilinocarbonyl)cyclopropanecarboxylic acid
Chemical Abstracts name 1-[[(2,4-dichlorophenyl)amino]carbonyl]cyclopropanecarboxylic acid
CAS RN [113136-77-9] Development codes RPA-090946 (Rhône-Poulenc)
PHYSICAL CHEMISTRY
Mol. wt. 274.1 M.f. C11H9Cl2NO3 Form White powdery solid. M.p. 195.5 °C V.p. <0.01 mPa (25 °C); 8 ´ 10-3 mPa (50 °C) KOW logP = 3.25 (21 °C) Henry £7.41 ´ 10-5 Pa m3 mol-1 (calc.) S.g./density 1.47 (20 °C) Solubility In water 0.0037 (pH 5.2), 0.0048 (pH 7), 0.0048 (pH 9) (all in g/100 ml, 20 °C). In acetone 5.29, acetonitrile 0.50, dichloromethane 0.17, ethyl acetate 3.18, hexane <0.0001, methanol 5.91, n-octanol 6.72, isopropanol 6.82 (all in g/100 ml, 20 °C). Stability Relatively stable to photolysis. Stable to hydrolysis. pKa 3.5 (22 °C)
COMMERCIALISATION
History Reported by Fritz, Proc. 21st Ann. Mtg. PGRSA 1994, p. 154. First marketed in Argentina in 1995. Patents US 4736056 Manufacturers Bayer CropScience
APPLICATIONS
Biochemistry Inhibits polar auxin transport. Uses Plant growth regulator for cotton. Applied in mixture with ethephon at end of season, it promotes boll opening, defoliation and inhibition of terminal foliar regrowth. Formulation types SC. Selected products: mixtures: 'Finish' (+ ethephon) (Bayer CropScience)
ANALYSIS
Product analysis by hplc. Residue analysis by glc. Details available from Bayer CropScience.
MAMMALIAN TOXICOLOGY
Oral Acute oral LD50 for female rats 208, male rats 315 mg/kg. Skin and eye Acute percutaneous LD50 for rabbits >2000 mg/kg. Slight skin irritant. Inhalation LC50 (4 h) for rats >5.15 mg/l. NOEL (2 y) for rats 7.5 mg/kg b.w. Other Negative in Salmonella Reverse Mutation and CHO/HGPRT tests. Toxicity class EPA (formulation) I ('Finish')
ECOTOXICOLOGY
Birds Acute oral LD50 for bobwhite quail 216, mallard ducks >215 mg/kg b.w. Dietary LC50 (8 d) for bobwhite quail 2849, mallard ducks 1240 ppm diet. Fish LC50 (96 h) for bluegill sunfish >16, rainbow trout >11, sheepshead minnow 49 mg/l. Daphnia EC50 (48 h) >13 mg/l. Algae Moderately toxic. Other aquatic spp. EC50 (96 h) for Eastern oyster 19 mg/l; LC50 (96 h) for mysid shrimp 5 mg/l; EC50 (14 d) for Lemna gibba >0.22 mg/l; EC50 (120 h) for Anabaena flos-aquae 0.08 mg/l. Bees LD50 (contact) for bees >100 mg/bee. Worms Moderately toxic.
ENVIRONMENTAL FATE
Animals Rapidly excreted, primarily as unchanged cyclanilide. Plants Little degradation occurs in plants; cyclanilide is the major residue. Soil/Environment Low to moderate persistence, DT50 c. 15-49 d under aerobic conditions. Degrades primarily by microbial activity. Medium to low mobility (average Koc 346). Consequently little potential for leaching.
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