Description
Butachlor is a herbicide used for pre-emergence control of annual grasses and some broadleaved weeds. It has a moderate aqueous solubility and a low volatility. Depending on local conditions it may be moderately persistent in some soils. It is not expected to leach to groundwater. It is moderately toxic to most fauna and flora, the main exception being honeybees for which butachlor has a low toxicity. It has a moderate oral mammalian toxicity if ingested and is both a skin and eye irritant.
Chemical Properties
Yellow Oil
Uses
Butachlor is a pre-emergent chloroacetanalide herbicide. Butachlor is commonly used for weed control in rice as well as cotton, maize, wheat and other crops.
Uses
Pre-emergence selective anilide herbicide used
to control grass and broad-leaved weeds in seeded
and transplanted rice paddies.
Definition
ChEBI: Butachlor is an aromatic amide that is 2-choro-N-(2,6-diethylphenyl)acetamide in which the amide nitrogen has been replaced by a butoxymethyl group. It has a role as a herbicide, an environmental contaminant and a xenobiotic. It is an aromatic amide, an organochlorine compound and a tertiary carboxamide. It is functionally related to a N-phenylacetamide.
Production Methods
The commercial production of butachlor typically involves the condensation of 2-chloro-N-(2,6-diethylphenyl)acetamide with butyl isocyanate. The process begins by synthesising the acetamide intermediate through the reaction of 2,6-diethylaniline with chloroacetyl chloride under controlled conditions. This intermediate is then reacted with butyl isocyanate in the presence of a solvent such as ethanol or dioxane, often with a catalyst to enhance yield. The reaction produces butachlor and hydrogen chloride as a byproduct. After completion, the mixture is neutralized, purified through distillation or crystallization, and dried to obtain high-purity butachlor.
Agricultural Uses
Herbicide: Used for pre-emergence control of annual grasses,
sedges and broadleaf weeds in rice crops. Used primarily
in Asia, South America, Europe and Africa. Not registered
for use in the U.S. Not approved for use in EU countries.
Trade name
BUTANEX®; BUTANOX®; CP 53619®;
HILTACHLOR®; LAMBAST®; MACHETE®;
MACHETTE®; PILLARSET®; RASAYANCHLOR®;
WEEDOUT®; VENDAVAL®
Metabolic pathway
In vitro incubation of butachlor with rat liver fractions
forms a considerable amount of glutathione conjugate,
while the conjugating activity is not efficient for the
kidney S9 fraction. Further biotransformation of the
glutathione conjugate to mercapturate is not observed
in the liver S9 fraction. Butachlor is initially conjugated
with glutathione in the liver and is apparently
transported to the kidneys where it is transformed to
mercapturic acid.
