Penoxsulam

Synthesis ofTriazolo[1,5-c]pyriniidme Sulfonamides Leading to the Discovery of Penoxsulam, a New Rice Herbicide... 

Triazolopyrimidine, Triazolo[l, 5-a]pyrimidine, Triazolo[l, 5-c]pyrimidine. Sulfonamide, Penoxsulam... 

Metabolism studies conducted on 6 showed that 0-dealkylation of one heterocycle methoxy group was occurring in rice (Fig. 2.4.3) [47]. A comparison of metabolic degradation rates and activity on indica rice, japonica rice and bamyardgrass for 6 indicates that degradation rates explain the major differences observed in activity (Table 2.4.6). Other factors, such as site of uptake and transport, which are modulated by plant structure and metabolism, may contribute to additional rice selectivity observed for penoxsulam. 

Penoxsulam has a toxicological profile similar to other triazolopyrimidine sulfonamides. There was no indication of acute or chronic toxicity issues to mammalian and non-target organisms such as fish, fresh water invertebrates, honey bees, earthworm and beneficial arthropods. 

---