Common name: Isoproturon

Other name: isoproturon (BSI, E-ISO, (m) F-ISO) /IPU; ipuron*

Iupac name: 3-(4-isopropytphenyl)-1,1-dimethylurea; 3-p-cumenyl-1 ,1-dimethylurea

Chemical abstracts name:     N,N-dimethyl-N`-[4-(l-methylethyl)phenyl]urea

Type: Herbicide

CAS RN: [34123-59-6]

M.F.: C₁₂H₁₈N₂O

Mol Wt: 206.3

 

Form (appearance): /Colourless crystals.

Composition: Tech. is >98.5% pure.
M.P.: 158℃; (tech.,153-156℃) V.p. 3.15x10 3mPa(20oc):82 x10 3mPa(25℃)

S.G.: 1.2 (20℃)

Solubility.: In water 65 mg/l (22℃). In methanol 75, dichtoromethane 63, acetone 38, benzene 5, xylol 4, n-hexane c. 0.2 (all in g/l, 20℃).

Stability: Very stable to light, acids, and alkalis. Hydrolytically cleaved by strong alkalis on heating.

Henry: l.46×10^-5 Pa m³ mol^-1

K_owlogP: 2.5 (20℃)

 

Formulation types: SC; WP

Biochemistry: Photosynthetic electron transport inhibitor at the photosystem II receptor site.

Mode of action: Selective systemic herbicide, absorbed by the roots and leaves, with translocation.

Uses: Pre- and post-emergence control of annual grasses (Alopecurus myosuroides, Apera spica-venti, Avena fatua and Poa annua) and many annual broad-leaved weeds in spring and winter wheat (except durum wheat), spring and winter barley, winter rye, and tridcale, at 1.0-1.5 kg a.i./ha.

Phytotoxicity: Non-phytotoxic to cereals, except durum wheats.

 

Oral: Acute oral LD₅₀ for rats 1826-2417, mice 3350 mg/kg.

Skin and eye: Acute percutaneous LD₅₀ for rats >2000 mg/kg. Non-irritating to skin and eyes (rabbits).

Inhalation: LC₅₀ (4 h) for rats >1.95 mg/l air.

Noel: (90 d) for rats 400, dogs 50 mg/kg diet: (2 y) for rats 80 mg/kg diet.

ADI: 0.0062 mg/kg b.w.
Water GV 9 ,μg/l (TDI 3 Hg/kg b.w.).

Toxicity: WHO (a.i.) III

EC hazard: R401 Xn; R22| N; R50, R53

 

Birds: Acute oral LD₅₀ for Japanese quail 3042-7926, pigeons >5000 mg/kg.

Fish: LC₅₀ (96 h) for golden orfe 129, bluegill sunfish >100, guppies 90, rainbow trout 37, carp 193, catfish 9 mg/l.

Daphnia: LC₅₀ (48 h) 507 mg/l.

Algae: LC₅₀ (72 h) 0.03 mg/l.

Worms: LC₅₀ (14 d) for Eisenia foetida >1000 mg/kg dry artificial soil.
Bees: Not toxic to bees; LD₅₀ (48 h, oral) >50->100 μg/bee.
Other beneficial spp, A dose of up to 1.5 kg/ha (as `Arelon`) was harmless to adult female Aleocham bilineata.

 

Plant: In plants, degradation is mainly via hydroxylation of the isopropyl group to 1,1-dimethyl-3-[4-(2`-hydroxy-2` propyl)phenyl]urea; N-deall< occurs. also>

Animals: In rats, following oral administration, 50% is eliminated within the first 8 h, predominantly in the urine.

Soil/Environment: Undergoes enzymic and microbial demethylation at the nitrogen, and hydrolysis of the phenylurea to 4-isopropylaniline. DT₅₀ in soil 6-28 d; rate of degradation increases 3x between 10℃ and 30℃ (sandy soil) and 10x in an organic soil over the same temperature range.