Chlorotoluron

Chloroturon is a commonly used urea herbicide. It is moderately soluble in water, volatile with a high potential for leaching to groundwater. It is moderately persistent in soil but tends not to be persistent in water due to rapid aqueous photolysis. Chloroturon has a low mammalian toxicity but may bioaccumulate. Whilst it is non-toxic to honeybees it is moderately toxic to birds, earthworms and most aquatic organisms.

Pure product is white needle crystal. m.p. 147～148°C, vapor pressure 4.79×10-6Pa (20°C), solubility in 100mL acetone, benzene, dichloromethane is 5g, 2.4g and 4.3g respectively, solubility in water is 10mg/L. Stable at room temperature, decomposed by acid and alkali at high temperature. Half-life in soil is about 30d.

Herbicide.

ChEBI: A member of the class of ureas that is N-methyl urea substituted by a 3-chloro-4-methylphenyl group at position 3 and a methyl group at position 1. A herbicide that is non-toxic to honeybees but is moderately toxic to mammals, birds, ea thworms and most aquatic organisms.

Chlorotoluron is commercially produced through a five-step chemical synthesis starting from toluene. The process involves nitration to form nitrotoluene, followed by chlorination, hydrogenation to convert the nitro group to an amine, phosgenation to form an isocyanate, and finally reaction with dimethylamine to yield the herbicide.

Selective, non-systemic absorbed by roots and foliage. Acts by the inhibition of photosynthetic electron transport.

Chlortoluron is rapidly metabolized in winter wheat. Hydroxylation of the methyl group on the phenyl ring has been demonstrated as a detoxification mechanism for chlortoluron resistance in winter wheat, whereas in the susceptible weed blackgrass (Alopecurus myosuroides Huds.), the main metabolite is the mono N-demethylated metabolite (107). In a tolerant weed, Persian speedwell (Veronica persica Poir.), chlortoluron is rapidly transformed to the nonphytotoxic di-N-demethylated metabolite (107).

Herbicide