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Herbicide.

ChEBI: An aromatic ketone that is cyclohexane-1,3-dione substituted by a 2-chloro-4-(methylsulfonyl)benzoyl group at position 2.

Sulcotrione is commercially produced via a multi-step process starting with the Friedel-Crafts acylation of 1,2,4-trichlorobenzene with 2-chloropropionyl chloride using aluminium chloride to form 2-chloro-1-(2,4,5-trichlorophenyl)propan-1-one, which undergoes intramolecular cyclization under basic conditions to yield the benzoyl cyclohexanedione core; subsequent oxidation with air or sulphur in the presence of a base introduces the sulfonyl group, producing the compound.

Absorbed mainly by the leaves but also some root uptake. Bleaching: inhibition of 4-hydroxyphenyl-pyruvate-dioxygenase.

Mode of action studies with sulcotrione first led to the identity of HPPD as a highly effective herbicide target site. Early observations showed that a related compound caused increased levels of tyrosine in the plasma and urine of treated rats (12). Further studies showed that one of the tyrosine catabolism enzymes, 4-hydroxypyruvate dioxygenase, was inhibited by cyclohexanediones (13,14)—this enzyme being required for the formation of quinones, such as plastoquinone in plants (12,15,16). Inhibition results in the perturbation of carotenoid synthesis and inhibition of photosynthetic electron transport (16).

Sulcotrione is readily absorbed through the leaves and via the roots. In the soil, metabolism involves ring opening of the cyclohexanedione, eventually to give the corresponding benzoic acid (17) and, finally, CO2 (8).
In the soil, the half-life of sulcotrione can vary considerably (between 15 days in loamy sand and 72 days in fine loam), depending on a number of factors, especially the soil organic matter content (18,19).

Herbicide