Herbicide
HRAC  A WSSA  1; aryloxyphenoxypropionate



NOMENCLATURE
quizalofop-P
Common name quizalofop-P (BSI, draft E-ISO)
IUPAC name (R)-2-[4-(6-chloroquinoxalin-2-yloxy)phenoxy]propionic acid 
Chemical Abstracts name (R)-2-[4-[(6-chloro-2-quinoxalinyl)oxy]phenoxy]propanoic acid 
CAS RN [94051-08-8] 

quizalofop-P-ethyl
Common name quizalofop-P-ethyl (BSI, draft E-ISO)
IUPAC name ethyl (R)-2-[4-(6-chloroquinoxalin-2-yloxy)phenoxy]propionate 
CAS RN [100646-51-3]  Development codes D(+) NC-302 (Nissan); DPX-79376 (Du Pont) 

quizalofop-P-tefuryl
Common name quizalofop-P-tefuryl
IUPAC name (-tetrahydrofurfuryl-(R)-2-[4-(6-chloroquinoxalin-2-yloxy)phenoxy]propionate 
Chemical Abstracts name (RS)-2-tetrahydrofuranylmethyl (R)-2-[4-(6-chloro-2-quinoxalinyloxy)phenoxy]propanoate 
CAS RN [119738-06-6]  Development codes UBI C4874 (Uniroyal)

PHYSICAL CHEMISTRY
quizalofop-P
Mol. wt. 344.8  M.f. C₁₇H₁₃ClN₂O₄

quizalofop-P-ethyl
Mol. wt. 372.8  M.f. C₁₉H₁₇ClN₂O₄  Form White, crystalline, odourless solid.  M.p. 76.1-77.1 ºC  B.p. 220 ºC/26.6 Pa  V.p. 1.1 × 10^-4 mPa (20 ºC)  K_OW logP = 4.66 (23 ºC)  S.g./density 1.36 g/cm³  Solubility In water 0.61 mg/l (20 ºC). In acetone, ethyl acetate and xylene >250, 1,2-dichloroethane >1000 (all in g/l, 22-23 °C); in methanol 34.87, n-heptane 7.168 (both in g/l, 20 °C).  Stability Stable in neutral and acidic media, but unstable in alkaline media; DT₅₀ <1 d (pH 9). Stable at high temperatures and in organic solvents.  Specific rotation [a]_D²⁰ +35.9(20 ºC) 

quizalofop-P-tefuryl
Mol. wt. 428.9  M.f. C₂₂H₂₁ClN₂O₅  Form Thick yellow liquid, which can crystallise upon standing at room temperature.  M.p. 59-68 ºC; (tech. is a liquid)  V.p. 7.9 ×10^-3 mPa (25 ºC, gas saturation method)  K_OW logP = 4.32 (25 ºC)  Henry 8.47 × 10^-4 Pa m³ mol^-1 (calc.)  S.g./density 1283 kg/m³ (21.5 ºC)  Solubility In water 4 mg/l (25 ºC). In toluene 652, hexane 12, methanol 64 (all in g/l).  Stability Stable for ≥14 d at 55 ºC; stable in package for ≥1 y at 25 ºC. Stable ≥7 d in sunlight. In water, DT₅₀ (22 ºC) 82 d, 8.1 d (pH 5), 431 min (pH 9).  Specific rotation [a]_D 31.9 tech. 28-32 pKa 1.25 (25 ºC)  F.p. >110 ºC (Pensky-Martens)

COMMERCIALISATION
History Herbicidal activity of quizalofop-ethyl (ethyl ester of the racemate) reported by G. Sakata et al. (Proc. 10th Int. Congr. Plant Prot., 1983, 1, 315). The herbicidal enantiomers (quizalofop-P-ethyl) introduced by Nissan Chemical Industries, Ltd and quizalofop-P-tefuryl ((tetrahydrofurfuryl ester) (A. R. Bell & A. S. Peddie, Proc. 1989 Br. Crop Prot. Conf. - Weeds, 1, 65) by Uniroyal Chemical Co., Inc. (now part of CK Witco Corp.).

APPLICATIONS
quizalofop-P-ethyl
Biochemistry Acetyl CoA carboxylase inhibitor; inhibition of fatty acid biosynthesis.  Mode of action Systemic herbicide, absorbed from the leaf surface, with translocation throughout the plant, moving in both the xylem and phloem, and accumulating in the meristematic tissue.  Uses Selective post-emergence control of annual and perennial grass weeds in potatoes, soya beans, sugar beet, peanuts, oilseed rape, sunflowers, vegetables, cotton, and flax.  Phytotoxicity Most non-graminaceous crops are tolerant.  Formulation types EC; SC.  Compatibility Can be used in combination with post-emergence broad-leaved herbicides.  Selected tradenames: 'CoPilot' (Nissan); 'Pilot D' (Nissan); 'Pilot Super' (Nissan); 'Targa D+' (Nissan); 'Targa Super' (Nissan); 'Assure II' (USA) (Du Pont); 'Herban LPU' (IPESA); 'Mostar' (IPESA); 'Omega' (Argentina) (Du Pont); 'Sheriff' (Du Pont); 'Targa Prestige' (Aventis)

quizalofop-P-tefuryl
Mode of action Systemic herbicide, absorbed from the leaf surface, with translocation throughout the plant, moving in both the xylem and phloem, and accumulating in the meristematic tissue.  Uses Control of annual grasses such as Avena fatua and Alopecurus myosuroides, and perennial grasses such as Sorghum halepense and Elymus repens, in potatoes, flax, oilseed rape, peas, sugar beet, cotton, and soya beans.  Formulation types EC.  Compatibility Certain post-emergence broad-leaved herbicides are incompatible with quizalofop-P-tefuryl.  Selected tradenames: 'Pantera' (Uniroyal); 'Sector-T' (IPESA)

ANALYSIS
quizalofop-P-ethyl
Product by hplc. Residues by glc. Details from Nissan. 

quizalofop-P-tefuryl
Details available from Uniroyal.

MAMMALIAN TOXICOLOGY
quizalofop-P-ethyl
Oral Acute oral LD₅₀ for male rats 1210, female rats 1182, male mice 1753, female mice 1805 mg/kg.  NOEL (90 d) for rats 7.7 mg/kg daily.  Toxicity class EPA (formulation) II (5EC) 

quizalofop-P-tefuryl
Oral Acute oral LD₅₀ for rats 1012 mg/kg.  Skin and eye Acute percutaneous LD₅₀ for rabbits >2000 mg/kg. Mild eye irritation; non-irritating to skin (rabbits). Non-sensitising to skin (guinea pigs).  Inhalation LC₅₀ (4 h) for rats >4.8 mg/l (12% EC).  NOEL In chronic oncogenic feeding studies, NOEL for rats 1.25, dogs 19 mg/kg b.w. daily.  ADI 0.01 mg/kg.  Toxicity class WHO (a.i.) II; EPA (formulation) III 

ECOTOXICOLOGY
quizalofop-P-ethyl
Birds Acute oral LD₅₀ for mallard ducks and bobwhite quail >2000 mg/kg.  Fish LC₅₀ (96 h) for rainbow trout >0.5 mg/l.  Daphnia LC₅₀ (48 h) 0.29 mg/l.  Algae Assumed similar to racemate.  Bees Assumed similar to racemate.  Worms LC₅₀ >1000 mg/kg. 

quizalofop-P-tefuryl
Birds Acute oral LD₅₀ for bobwhite quail and mallard ducks >2150 mg/kg. LC₅₀ (8 d) for bobwhite quail and mallard ducks >5000 ppm.  Fish LC₅₀ (96 h) for trout 0.51, sunfish 0.23 mg/l.  Daphnia LC₅₀ (48 h) >1.5 mg/l.  Algae LC₅₀ (5 d) for Selenastrum >1.9 mg/l.  Bees LD₅₀ >100 mg/bee.

ENVIRONMENTAL FATE
quizalofop-P-ethyl
Animals The degradation pattern is the same as that for quizalofop-ethyl.  Plants The degradation pattern is the same as that for quizalofop-ethyl.  Soil/Environment In soil, degrades rapidly to quizalofop-P; DT₅₀ ≤1 d.  

quizalofop-P-tefuryl
Animals Main metabolite is quizalofop acid.  Plants Main metabolite is quizalofop acid.  Soil/Environment Aerobic DT₅₀ 4.7 h (sandy loam). Adsorption K_d 8.69, K_oc 477 (both in sandy loam).