1053. Bentazon

Nomenclature

CAS number: 25057-89-0
3-(1-Methylethyl)-1H-2,1,3-benzothiadiazin-4(3H)-one 2,2-dioxide; 3-isopropyl-1H-2,1,3-benzothiadiazin-4(3H)-one 2,2-dioxide; bentazone; bendioxide; Basagran (BASF).
C10H12N2O3S; mol wt 240.28.
C 49.99%, H 5.03%, N 11.66%, O 19.98%, S 13.34%.

Description and references

Selective post-emergence herbicide. Prepn: A. Zeidler et al., ZA 6705164; eidem, US 3708277 (1968, 1973 both to BASF). Weed control: C. E. G. Mulder, G. B. Wortmann, Proc. 3rd Natl. Weeds Conf. S. Afr. 1980, 159. HPLC determn in sugar maize and surface water: E. A. Hogendoorn, C. E. Goewie, J. Chromatogr. 475, 432 (1989); in soil: F. S. Rasero et al., Sci. Total Environ. 123/124, 57 (1992). Stability in ground, surface, soil waters: C. Mouvet et al., Chemosphere 35, 1083 (1997). Toxicity data: G. Ugazio et al., Res. Commun. Chem. Pathol. Pharmacol. 74, 349 (1991). Review of synthesis: G. Hamprecht et al., Kem. - Kemi 1, 590-592 (1974); of environmental behavior: R. Huber, S. Otto, Rev. Environ. Contam. Toxicol. 137, 111-134 (1994).

Chemical structure

Properties

White crystalline powder, mp 137-139°. Soly (w/w) at 20°: water 0.05%; acetone 150.7%; benzene 3.3%; chloroform 18%; ethanol 86.1%. pKa (24°): 3.3. Vapor pressure at 20°: 1.7 × 10-6 hPa. Log P (octanol/water) at 22°: 0.456 (pH 7). LD50 in male, female rats (mg/kg): 383.2, 433.6 orally (Ugazio).

Use

Herbicide.