Imidazolinones discovery

Other ALS Inhibitors. A remarkable turn of agrichemical history is found in the independent discovery of the imidazolinone herbicides (also in Ae mid-1970 s) at American Cyanamid, and the subsequent finding that diese very active compounds also act solely through inhibition of ALS (12, Dow has announced that the... 

Introduction. Since their discovery, the imidazolinone herbicides have been the focus of much synthetic activity at American Cyanamid. This is due to their ability to control a broad spectrum of weeds at very low rates (e.g. 0.08-0.5 kg/Eia). The original discovery of the imidazolinone class of herbicides was described in detail by Los (1). His chapter describes the chemisny leading to tiie development of several compounds that are the active ingredients in commercial products. These include AC 222,293 (imazamethabenz) for control of mustard and wild oats in wheat, AC 243,997 (imazapyr), a total vegetation herbicide, and AC 252,214 (imazaquin), a broad spectrum herbicide for use in soybeans. An additional commercial compound AC 263,499 (imazethapyr) also used primarily for weed control in soybeans has been described (2). The satisfactory performance of these products has spurred interest in the discovery of other novel members of the imidazolinone class with good herbicidal properties. 

---