Post-emergence herbicide for use in grains and sugarcane; inhibits the enzyme, acetohydroxyacid synthase. Prepn: H. Kehne et al., EP 342569; eidem, US 5104443 (1989, 1992 both to Hoechst). Comprehensive description: E. Hacker et al., Brighton Crop Prot. Conf. - Weeds 1995, 73. Mode of selective action: H. K"ocher, G. Dickerhof, ibid. 249. Field study in summer rice: M. K. Bhowmick, R. K. Ghosh, Adv. Plant Sci. 15, 499 (2002).