metolachlor

97%tech, 87.3%ec,

Herbicide

HRAC  K3 WSSA  15; chloroacetamide

NOMENCLATURE

Common name metolachlor (BSI, E-ISO, ANSI, WSSA); métolachlore ((m) F-ISO)

IUPAC name 2-chloro-6'-ethyl-N-(2-methoxy-1-methylethyl)aceto-o-toluidide 

Chemical Abstracts name 2-chloro-N-(2-ethyl-6-methylphenyl)-N-(2-methoxy-1-methylethyl)acetamide 

CAS RN [51218-45-2]  EEC no. 257-060-8  Development codes CGA 24 705 (Ciba-Geigy) 

PHYSICAL CHEMISTRY

Composition Racemic mixture of (1S)- and (1R)- isomers.  Mol. wt. 283.8  M.f. C15H22ClNO2  Form Colourless to light tan liquid.  M.p. -62.1 °C  B.p. 100 ºC/0.001 mmHg  V.p. 4.2 mPa (25 ºC) (OECD 104)  KOW logP = 2.9 (25 ºC)  Henry 2.4 ´ 10-3 Pa m3 mol-1 (calc.)  S.g./density 1.12 (20 ºC)  Solubility In water 488 mg/l (25 ºC) (OECD 105). Miscible with benzene, toluene, ethanol, acetone, xylene, hexane, dimethylformamide, ethylene dichloride, cyclohexanone, methanol, octanol, and dichloromethane. Insoluble in ethylene glycol, propylene glycol, and petroleum ether.  Stability Stable up to c. 275 ºC. Hydrolysed by strong alkalis and strong mineral acids. On hydrolysis in buffer (20 ºC), DT50 (calc.) >200 d (2£pH £10).  F.p. 190 °C (1013 mbar) 

APPLICATIONS

Biochemistry Cell division inhibitor. Maize tolerance of chloroacetamides is attributed to rapid detoxification by glutathione transferases.  Mode of action Selective herbicide, absorbed predominantly by the hypocotyls and shoots. Inhibits germination.  Uses Control of annual grasses and some broad-leaved weeds in maize, sorghum, cotton, sugar beet, fodder beet, sugar cane, potatoes, peanuts, soya beans, safflowers, sunflowers, various vegetables, fruit and nut trees, and woody ornamentals. Applied pre-emergence, pre-plant incorporated or early post-emergence at, 1.0-2.5 kg a.i./ha. Often used in combination with broad-leaved herbicides, to extend the spectrum of activity.  Phytotoxicity Well tolerated by most broad-leaved crops, maize, sorghum (safened with fluxofenim or oxabetrinil).  Formulation types EC; FW; GR; SC.