Triazolopyrimidine Sulfonanilide Herbicides and Related Compounds

The synthesis, chemistry and structure-activity relationships in the triazolopyrimidine sulfonanilide class of acetolactate synthase inhibiting herbicides is reviewed. Sulfonanilides based on the l,2,4-triazolo[l,5-a]pyrimidine, l,2,4-triazolo[l,5-c]pyrimidine, imidazolo[l,2-a]pyrimidine, pyrazolo[l,5-a]pyrimidine, l,2,4-triazolo[l,5-a]-l,3,5-triazine, pyrazolo[l,5-a]-l,3,5-triazine and thiazolo[3,2-b]-l,2,4-triazole ring systems are included in this review. Aryl sulfonamide derivatives of 2-amino-l,2,4-triazolo[l,5-a]pyrimidine, 2-amino-l,2,4-triazolo[l,5-a]-l,3,5-triazine and 2-amino-l,2,4-pyrazolo- [l,5-a]pyrimidine are also covered.