Acetochlor 14%+bensulfuron-methyl 4% WP

acetochlor (7)
Herbicide
HRAC K3 WSSA 15; chloroacetamide
NOMENCLATURE
Common name acetochlor (BSI, E-ISO, ANSI, WSSA); ac閠ochlore ((m) F-ISO)
IUPAC name 2-chloro-N-ethoxymethyl-6'-ethylaceto-o-toluidide
Chemical Abstracts name 2-chloro-N-(ethoxymethyl)-N-(2-ethyl-6-methylphenyl)acetamide
CAS RN [34256-82-1] EEC no. 251-899-3 Development codes MON 097 (Monsanto)

PHYSICAL CHEMISTRY
Composition Tech. is 92% pure. Mol. wt. 269.8 M.f. C14H20ClNO2 Form Clear viscous liquid; (tech. is a wine red to yellow or amber oil). M.p. 10.6 癈 B.p. 172 篊/5 mmHg V.p. 400?30 mPa (20 癈) KOW logP = 4.14 Henry 3.83 ?10-1 Pa m3 mol-1 (calc.) S.g./density 1.1221 (20 癈) Solubility In water 223 mg/l (25 篊). Soluble in diethyl ether, acetone, benzene, chloroform, ethanol, ethyl acetate, and toluene. Stability Stable for over 2 years at 20 篊 (EC formulation). F.p. 160 癈 (Tag closed cup)

COMMERCIALISATION
History Herbicide discovered and introduced by Monsanto Co. Manufacturers 蒑V; Monsanto; Nitrok閙ia; Sanachem; Sinon

APPLICATIONS
Biochemistry Inhibits cell division by blocking protein synthesis. Maize tolerance of chloroacetamides is due mainly to conjugation with glutathione; P450 metabolism may also be a factor. Mode of action Selective herbicide, absorbed mainly by the shoots and secondarily by the roots of germinating plants. Uses Used pre-emergence or pre-plant to control annual grasses, certain annual broad-leaved weeds and yellow nutsedge in maize (at 3 kg/ha), peanuts, soya beans, cotton, potatoes and sugar cane. Formulation types CS; EC. Selected tradenames: 'Harness' (Monsanto); 'Acenit' (Nitrok閙ia); mixtures: 'Sacemid A' (+ TI-35) (North Hungarian); 'Surpass' (+ dichlormid) (Dow AgroSciences); 'Trophy' (+ dichlormid) (Dow AgroSciences)

OTHER TRADENAMES
'Degree' (with safener) (Monsanto); 'Guardian' (Monsanto); 'Acetocas' (CAS); 'Curagrass' (Sanachem); 'Relay' (Sanachem); 'Sprint' (Sanachem); 'Vault' (Sanachem); 'Wenner' (Dow AgroSciences) mixtures: 'Degree Xtra' (+ atrazine) (with safener) (Monsanto); 'Field Master' (+ atrazine+ glyphosate) (glyphosate as isopropylammonium salt) (Monsanto); 'Harness Extra' (+ atrazine) (Monsanto); 'Double Play' (+ EPTC) (Dow AgroSciences); 'Erunit' (+ atrazine) (Nitrok閙ia); 'Fultime' (+ atrazine+ dichlormid) (Dow AgroSciences); 'Topnotch' (+ dichlormid) (Dow AgroSciences); 'Troph閑' (+ dichlormid) (Dow AgroSciences); 'Twin Pack' (+ flurochloridone) (Dow AgroSciences) Discontinued names mixtures: 'Racer' * (+ flurochloridone) (Zeneca)

ANALYSIS
Product by gc. Residues by hplc. Details from Monsanto.

MAMMALIAN TOXICOLOGY
Oral Acute oral LD50 for rats 2148 mg/kg. Skin and eye Acute percutaneous LD50 for rabbits 4166 mg/kg. Contact sensitisation reactions observed in guinea pigs. Practically non-irritating to eyes and skin (rabbits). Inhalation LC50 (4 h) for rats >3.0 mg/l air. NOEL (2 y) for rats 10 mg/kg b.w. daily; (1 y) for dogs 12 mg/kg b.w. daily. ADI 0.01 mg/kg b.w. Toxicity class WHO (a.i.) III EC hazard Xn; R20| Xi; R37/38| R43| N; R50, R53

ECOTOXICOLOGY
Birds Acute oral LD50 for bobwhite quail 1260 mg/kg. LC50 (5 d) for quail and mallard ducks >5620 mg/kg. Fish LC50 (96 h) for rainbow trout 0.36, bluegill sunfish 1.5 mg/l. Daphnia LC50 (48 h) 9 mg/l. Bees LD50 (24 h) (contact) >200 mg/bee; (oral) >100 mg/bee. Worms LC50 (14 d) 211 mg/kg.

ENVIRONMENTAL FATE
Animals The primary routes of metabolism are glutathione conjugation and metabolism by cytochrome P450. Plants In maize and soya beans, rapidly absorbed and metabolised in the germinating plant. In maize, the first metabolite is glutathione, and in soya beans homoglutathione (E. J. Breaux, J. Agric. Food Chem., 1986, 34, 884). Soil/Environment Adsorbed by soil, with little leaching. Microbial degradation accounts for most loss from soil; DT50 8-18 d.

Bensulfuron-methyl (66)
Herbicide
HRAC B WSSA 2; sulfonylurea


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NOMENCLATURE
bensulfuron-methyl
Common name bensulfuron-methyl
Chemical Abstracts name methyl 2-[[[[[(4,6-dimethoxypyrimidin-2-yl)-amino]carbonyl]amino]sulfonyl]methyl]benzoate
CAS RN [83055-99-6] EEC no. 401-340-6 Development codes DPX-F5384 (Du Pont)

bensulfuron
Common name bensulfuron (BSI, ANSI, WSSA, draft E-ISO, (m) draft F-ISO)
IUPAC name a-(4,6-dimethoxypyrimidin-2-ylcarbamoylsulfamoyl)-o-toluic acid
Chemical Abstracts name 2-[[[[[(4,6-dimethoxy-2-pyrimidinyl)amino]carbonyl]amino]sulfonyl]methyl]benzoic acid
CAS RN [99283-01-9]

PHYSICAL CHEMISTRY
bensulfuron-methyl
Composition Tech. is 96.5%. Mol. wt. 410.4 M.f. C16H18N4O7S Form White to pale yellow, odourless solid. M.p. 185-188 篊 V.p. 2.8 ?10-9 mPa (25 篊) KOW logP = 2.45 (pH 1.5), 0.62 (pH 7) (both at 30 篊) Henry 1.4 ?10-11 Pa m3 mol-1 S.g./density 1.41 Solubility In water 2.9 (pH 5), 12 (pH 6), 120 (pH 7), 1200 (pH 8) (all in mg/l, 25 篊). In acetone 1.38, acetonitrile 5.38, dichloromethane 11.7, ethyl acetate 1.66, hexane >0.01, xylene 0.280 (all in g/l, 20 篊). Stability Aqueous solutions are most stable under slightly alkaline conditions (pH 8), and slowly degrade under acidic conditions; DT50 11 d (pH 5), 143 d (pH 7) (25 篊). pKa 5.2

bensulfuron
Mol. wt. 396.4 M.f. C15H16N4O7S

COMMERCIALISATION
History Herbicidal activity of bensulfuron-methyl reported by T. Yayama et al. (Proc. 9th Asian Pacific Weed Sci. Soc. Congr., 1983, p. 554). Introduced by E. I. du Pont de Nemours and Co. Patents US 4420325 Manufacturers Du Pont

APPLICATIONS
bensulfuron-methyl
Biochemistry Branched chain amino acid synthesis (ALS or AHAS) inhibitor. Acts by inhibiting biosynthesis of the essential amino acids valine and isoleucine, hence stopping cell division and plant growth. Selectivity is due to rapid metabolism in the crop. Metabolic basis of selectivity reviewed (M. K. Koeppe & H. M. Brown, Agro-Food-Industry, 6, 9-14 (1995)). Mode of action Selective systemic herbicide, absorbed by the foliage and roots, with rapid translocation to the meristematic tissues. Uses Selective pre- and post-emergence control of annual and perennial weeds and sedges (e.g. Butomus umbellatus, Scirpus maritimus, Scirpus mucronatus, Alisma plantago-aquatica, Sparganium erectum, Cyperus spp., Typha spp., etc.) in continuously flooded rice, at 30-100 g/ha. Formulation types GR; WG; WP. Selected tradenames: 'Londax' (Du Pont); mixtures: 'Fujigrass' (+ esprocarb) (Du Pont, Syngenta); 'Kusastop' (+ indanofan) (Mitsubishi Chemical); 'Wolf-Ace' (+ mefenacet+ thiobencarb) (Kumiai); 'Zark' (+ mefenacet) (Du Pont, Kumiai, Nihon Bayer, Sankyo)

OTHER TRADENAMES
bensulfuron-methyl
'Rozal' (Du Pont); 'Escuri' (Crystal); 'Papika A I Kilo' (Nihon Nohyaku, Hokko) mixtures: 'Bazooka A' (+ azimsulfuron+ cyhalofop-butyl) (Nihon Nohyaku, Hokko, Tokuyama, Du Pont); 'Bazooka' (+ cyhalofop-butyl+ thenylchlor) (Nihon Nohyaku, Hokko, Tokuyama, Du Pont); 'Papika A' (+ azimsulfuron+ cyhalofop-butyl+ thenylchlor) (Tokuyama, Nihon Nohyaku, Hokko, Du Pont); 'Papika' (+ cyhalofop-butyl+ thenylchlor) (Tokuyama, Nihon Nohyaku, Hokko, Du Pont); 'Sindax' (+ metsulfuron-methyl) (Du Pont); 'Weedless A36' (+ azimsulfuron+ cafenstrole+ daimuron) (Sankyo, Du Pont, Eikou Kasei, SDS Biotech KK); 'Cao Neng' (+ quinclorac) (Anhui); 'Dancing A' (+ azimsulfuron+ indanofan) (Mitsubishi Chemical); 'Dancing L' (+ indanofan) (Mitsubishi Chemical); 'Dancing-Power A' (+ azimsulfuron+ clomeprop+ indanofan) (Mitsubishi Chemical); 'Dancing-Power L' (+ clomeprop+ indanofan) (Mitsubishi Chemical); 'Dinaman' (+ clomeprop+ indanofan) (Mitsubishi Chemical); 'Inegreen D' (+ cyhalofop-butyl+ daimuron+ mefenacet) (Nihon Bayer); 'Inegreen' (+ cyhalofop-butyl+ mefenacet) (Nihon Bayer); 'Joystar' (+ cafenstrole+ cyhalofop-butyl+ daimuron) (Kumiai); 'Karshot' (+ pyributicarb) (Sankyo); 'Kusamets FL' (+ thenylchlor) (Nihon Nohyaku, Tokuyama, Hokko); 'Kusastop A' (+ azimsulfuron+ indanofan) (Mitsubishi Chemical); 'Kusatory Ace Jumbo' (+ cafenstrole+ daimuron) (Sankyo); 'Kusatory E Jumbo' (+ pyributicarb) (Sankyo); 'Londanil' (+ propanil) (Crystal); 'Masakari A Jumbo' (+ azimsulfuron+ clomeprop+ indanofan) (Mitsubishi Chemical); 'Masakari L Jumbo' (+ clomeprop+ indanofan) (Mitsubishi Chemical); 'Non-Poong' (+ benfuresate) (Aventis); 'Push' (+ dimepiperate) (Hokko); 'Rakudar' (+ cafenstrole+ daimuron) (Sankyo); 'Ranger' (+ benfuresate+ dimepiperate) (Aventis, Hokko); 'Tabijin A' (+ azimsulfuron+ cyhalofop-butyl+ pretilachlor+ pyriminobac-methyl) (Kumiai); 'Weedless' (+ cafenstrole+ daimuron) (Sankyo); 'Zark D' (+ daimuron+ mefenacet) (Sankyo) Discontinued names: 'Mariner' * (Du Pont) mixtures: 'Kusatory Jumbo' * (+ daimuron+ pyributicarb) (Sankyo)

ANALYSIS
Product and residue analysis by hplc. Methods for sulfonylurea residues in crops, soil and water reviewed (A. C. Barefoot et al., Proc. Br. Crop Prot. Conf. - Weeds, 1995, 2, 707). Details from Du Pont.

MAMMALIAN TOXICOLOGY
bensulfuron-methyl
Oral Acute oral LD50 for rats >5000, mice >10 985 mg/kg. Skin and eye Acute percutaneous LD50 for rabbits >2000 mg/kg. Non-irritant to skin and eyes. Inhalation LC50 (4 h) for rats >7.5 mg/l air. NOEL (2 y) for rats 750 mg/kg diet. Reproduction (2-generation) NOEL in rats 7500 mg/kg diet; teratogenicity NOEL in rats 500, rabbits 300 mg/kg. Not a mutagen. ADI 0.2 mg/kg. Toxicity class WHO (a.i.) III (Table 5); EPA (formulation) IV EC hazard R43| N; R51, R53

ECOTOXICOLOGY
bensulfuron-methyl
Birds Acute oral LD50 for mallard ducks >2510 mg/kg. Dietary LC50 (8 d) for bobwhite quail, mallard ducks >5620 mg/l. Fish LC50 (96 h) for rainbow trout and bluegill sunfish >150 mg/l; LC50 (48 h) for carp >1000 ppm. Daphnia LC50 (48 h) >100 mg/l. Bees LD50 >12.5 mg/bee.

ENVIRONMENTAL FATE
bensulfuron-methyl
Animals Almost completely biotransformed and rapidly excreted in urine and faeces of rats and goats. Plants After uptake by rice, converted to a non-herbicidal metabolite. Soil/Environment DT50 4-20 w on Flanagan and Keyport silt loam soils. In rice fields, DT50 in water averages 4-6 d.