Products
BENTAZONE
Herbicide:benzothiadiazinone
NOMENCLATURE
bentazone
Common name bentazone (BSI, E-ISO, (f) F-ISO, JMAF);
bentazon (ANSI, Canada, WSSA); bendioxide (Republic of South Africa)
IUPAC name 3-isopropyl-1H-2,1,3-benzothiadiazin-4(3H)-one
2,2-dioxide
Chemical Abstracts name 3-(1-methylethyl)-1H-2,1,3-benzothiadiazin-4(3H)-one
2,2-dioxide
CAS RN [25057-89-0] EEC no. 246-585-8
PHYSICAL CHEMISTRY
bentazone
Composition ³96% pure. Mol. wt. 240.3 M.f. C10H12N2O3S Form Colourless
crystals. M.p. 139.4-141 °C V.p. 0.17
mPa (20 °C) KOW logP = 0.77 (pH 5),
-0.46 (pH 7), -0.55 (pH 9) Henry 7.167 ´ 10-5 Pa
m3 mol-1 (calc.) S.g./density 1.41 (20 °C) Solubility In
water 570 mg/l (pH 7, 20 ºC). In acetone 1387, methanol 1061, ethyl acetate
582, dichloromethane 206, n-heptane 0.5 ´ 10-3 (all in g/l, 20 ºC). Stability Very
resistant to hydrolysis in both acidic and alkaline media. Decomposed by sunlight. pKa 3.3
(24 ºC)
bentazone-sodium
Solubility In water 2.3 ´ 106 ppm (US EPA
1988).
Biochemistry Photosynthetic electron transport
inhibitor at the photosystem II receptor site. Mode of action Selective
contact herbicide, absorbed mainly by the foliage, with very little translocation,
but also absorbed by the roots, with translocation acropetally in the xylem.
Uses A contact herbicide controlling Anthemis, Chamomilla and Matricaria spp., Chrysanthemum
segetum, Galium aparine, Lapsana communis and Stellaria
media in winter and spring cereals, at 1.0-2.2 kg a.i./ha. Other
crops include peanuts, maize, peas, Phaseolus beans, rice
(Cyperus difformis, C. esculentus, C. serotinus, Monochoria
vaginalis, Sagittaria pygmaea, S. sagittifolia, Alisma and Commelina spp., Scirpus
maritimus and S. mucronatus) and soya beans (Abutilon
theophrasti, Capsella bursa-pastoris, Cyperus esculentus, Datura
stramonium, Helianthus spp., Polygonum spp., Portulaca spp., Sida
spinosa, Ambrosia spp., Sinapis arvensis and Xanthium spp.). Formulation
types SL.