Design, synthesis and structure-activity relationships of novel ALS inhibitors

The paper describes the biophore models of sulfonylurea, imidazolinone, tri azolopyrimidinesulfonamide and 5-pyrimidyltriazolo-3-sulfonamides establish ed by the Apex-3D method. A series of N-phenylsulfonyl-N'-(thiadiazol-2-yl) oxamides and three types of triazolopyrimidinesulfonamide were synthesised and their herbicidal activities determined to assess the validity of the m odel. In general, the model gave useful leads to activity, although the act ual level was not always predicted accurately. In only a few cases did comp ounds predicted as being active prove to be inactive in the bioassay, and c ompounds with little or no activity were clearly indicated, As a result of this work, the compound N,N'-[1-(5,7-dimethyl-1,2,4-triazolo[1,5-a]pyrimidi n-2-ylthio)butane-2,3-di-imino]bis(2-chlorobenzenesulfonamide) was selected as showing good activity against a range of species, and will be used as a lead for further development, (C) 2000 Society of Chemical Industry.