Products

 

BISPYRIBAC-SODIUM

 

Herbicide
HRAC  B WSSA  2; pyrimidinyloxybenzoic



NOMENCLATURE
Common name bispyribac-sodium (BSI, pa ISO)
IUPAC name sodium 2,6-bis(4,6-dimethoxypyrimidin-2-yloxy)benzoate 
Chemical Abstracts name sodium 2,6-bis[(4,6-dimethoxy-2-pyrimidinyl)oxy]benzoate 
CAS RN [125401-75-4] for acid; [125401-92-5] for sodium salt  Development codes KIH-2023; KUH-911 (both Kumiai); V-10029

PHYSICAL CHEMISTRY
Composition Tech. is >93%.  Mol. wt. 452.4  M.f. C19H17N4NaO8; C19H18N4O8 for the acid  Form White powder.  M.p. 223-224 °C  V.p. 5.05 ×10-6 mPa (25 ºC)  KOW logP = -1.03 (23 °C)  Henry 3.12 × 10-11 Pa m3 mol-1 (calc.)  S.g./density Bulk density 0.0737 (20 °C, CIPAC MT 3)  Solubility In water 73.3 g/l (25 ºC). In methanol 26.3, acetone 0.043 g/l (25 °C).  Stability Stable in water; DT50 >1 y (pH 7 & 9), 448 h (pH 4). Stable to light. Not decomposed after 14 d at 55 °C.  pKa 3.05

APPLICATIONS
Biochemistry Branched chain amino acid synthesis (ALS or AHAS) inhibitor.  Mode of action Selective, systemic post-emergence herbicide, absorbed by foliage and roots.  Uses Control of grasses, sedges and broad-leaved weeds, especially Echinochloa spp., in direct-seeded rice, at rates of 15-45 g/ha. Also used to stunt growth of weeds in non-crop situations.  Formulation types SC; water-soluble liquid.