Definition
ChEBI: An N-sulfonylurea that is N-[o-(2-chloroethoxy)phenyl]sulfonylurea in which one of the hydrogens attached to the non-sulfonylated nitrogen has been replaced by a 4-methoxy-6-methyl-1,3,5-triazin-2-yl group
A herbicide used to control broad-leaved weeds in cereals, its use within the EU has been banned after September 2017 on the grounds of potential groundwater contamination and risks to aquatic life.
Production Methods
Triasulfuron is commercially produced through a multi-step synthesis involving sulfonylurea chemistry, starting with substituted triazines and sulfonamide intermediates. In industrial production, it is, typically, synthesised by reacting a triazine derivative, typically 2-amino-4-methoxy-6-methyl-1,3,5-triazine, with a sulfonyl isocyanate or sulfonamide intermediate. This reaction forms the characteristic sulfonylurea bridge, which is essential for the herbicidal activity. The process involves precise control of temperature, pH, and solvent conditions to ensure high yield and purity.
Agricultural Uses
Herbicide: Used for the control of annual ryegrass, paradoxa
grass and a wide range of broadleaf weeds in wheat and the
post-emergence control of wild radishes in wheat, oats and
barley. Registered for use in EU countries
. Registered
for use in the U.S
Trade name
AMBER®; CGA 131036®; LOGRAN®;
RAVE®
Mechanism of action
Selective, absorbed by leaves and roots and translocated. Inhibits plant amino acid synthesis - acetohydroxyacid synthase AHAS
Metabolic pathway
Triasulfuron undergoes hydrolytic degradation,
especially under acidic conditions, giving rise to
cleavage of the sulfonylurea linkage, producing the
major products 2-(2-chloroethoxy)benzenesulfonamide
and 4-methyl-6-methoxy-2-amino-1,3,5-triazine and the
minor product acetyltriuret. In plants, hydroxylation
occurs at the 5-position of the phenyl ring to yield 5-
hydroxytriasulfuron as a primary metabolite which is a
major metabolite from the plant microsomal system.
By mammals, orally administered triasulfuron is mainly
excreted in the urine, and O-dealkylation of 2-
chloroethoxy and 6-methoxy groups, and hydroxylation
at the 5-position of the phenyl ring and at the 4-methyl
group of the triazine ring are observed. By UV
irradiation, 2-chloroethoxybenzene is interestingly
identified with (4-methoxyl-6-methyl-1,3,5-triazine)urea,
and, in sunlight, with these two products, 2-amino-4-
methoxyl-6-methyltriazine and 2-(2-
chloroethoxy)benzenesulfonamide are identified.
