Description
Bispyribac-sodium is a post-emergence herbicide used in aquatic situations, turf and sports grounds amongst other situations. It is highly soluble in water, non-volatile and is not expected to be persistent in soil systrs but may be, depending on conditions in water. Based on its physico-chemical properties bispyribac-sodium is not expected to leach to groundwater. Its toxicity to biodiversity is generally low to moderate. It has a low mammalian oral toxicity and may be a skin sensitizer.
Uses
Bispyribac is used as a herbicide for the prevention and control of weeds.
Definition
ChEBI:Bispyribac-sodium is the organic sodium salt of bispyribac. It is used as a broad spectrum post-emergent herbicide for the control of grasses, sedges and broadleaf weeds in rice crops. It has a role as a herbicide, an agrochemical and an environmental contaminant. It contains a bispyribac(1-).
Production Methods
Bispyribac-sodium is synthesised through a condensation reaction between 2,6-dihydroxybenzoic acid and 2-(alkylsulfonyl)-4,6-dialkoxypyrimidine in the presence of at least one base and one solvent. This process may use catalysts such as sodium alkyl sulfinates and potassium carbonate to facilitate the reaction. The solvent system typically includes organic solvents like toluene, chlorobenzene, or dimethylformamide, chosen for their ability to support high reaction yields and clean processing. After condensation, the product is purified, followed by cooling, filtration, and drying.
Mechanism of action
Selective, systemic action absorbed by foliage and roots.Inhibits plant amino acid synthesis - acetohydroxyacid synthase AHAS.
Metabolic pathway
More than 90% of the radioactivity is excreted in rat
urine 96 h after the rats are orally administered 14C-
bispyribac sodium. Most of the radioactivity detected in
the urine, feces, liver, and plasma consists of
unchanged bispyribac sodium. The metabolites
identified are derived from hydroxylation on the
pyrimidine ring, O-demethylation, cleavage of the ether
linkage between pyrimidine and phenyl rings yielding
5-hydroxylated and mono-O-desmethylbispyribac
acids, and salicylic acid and 2-pyrimidinole derivatives.
