3-methoxy-4-methyl-5-oxo-N-[2-(trifluoromethoxy)phenyl]sulfonyl-1,2,4- triazole-1-carboxamide

Flucarbazone is normally used as the sodium salt. It is a post-emergence herbicide. It is highly soluble in water, semi-volatile but poses a high risk of leaching to groundwater. Flucarbazone is non-persistent in soils but may be very persistent in aquatic systems. Whilst it has a low mammalian toxicity it may bioaccumulate. It is an eye irritant but no other serious human health issues have been identified. It is moderately toxic to birds, most aquatic organisms and earthworms but considered to be non-toxic to honeybees.

Flucarbazone is used as a herbicide for agricultural purposes. An antiparasitic agent.

ChEBI: Flucarbazone is an N-sulfonylurea that is 3-methoxy-4-methyl-5-oxo-4,5-dihydro-1,2,4-triazole-1-carboxamide in which the carboxamide nitrogen has undergone formal condensation with the sulfonic acid group of 2-(trifluoromethoxy)benzenesulfonic acid. An acetolactate synthase inhibitor, it is used (generally as the corresponding sodium salt, flucarbazone-sodium) to control grass weeds in cereal crops. It has a role as an agrochemical, an EC 2.2.1.6 (acetolactate synthase) inhibitor and a herbicide. It is a N-sulfonylurea, a member of triazoles, an aromatic ether and an organofluorine compound. It is a conjugate acid of a flucarbazone(1-).

Flucarbazone follows the broader industrial pattern used for many sulfonylurea-type herbicides: assemble the heterocyclic sulfonamide fragment first, then link it to the appropriate heteroaromatic partner. Manufacturers begin by preparing the triazolinone-based sulfonamide unit, typically formed from a chlorosulfonyl intermediate and a substituted triazolinone under conditions that prevent over-sulfonylation or ring degradation. In parallel, the fluorinated heteroaromatic fragment, central to flucarbazone’s biological activity, is produced using controlled halogenation and nucleophilic substitution chemistry to introduce the trifluoromethyl and chloro substituents without damaging the ring. These two advanced intermediates are then coupled through a selective urea-forming step that joins the sulfonamide and heteroaromatic components into the full flucarbazone scaffold.

Inhibits plant amino acid synthesis - acetohydroxyacid synthase AHAS., Absorbed through roots and foliage and translocated. Exhibits some residual activity.

Herbicide