Synthesis, characterization, and biological activities of novel ( Z )‐3‐(( E )‐1‐(alkyloxyimino)ethyl)‐5‐arylidene‐4‐hydroxypyrroline‐2‐one derivatives

Twenty‐four novel tetramic acid derivatives ( Z )‐3‐(( E )‐1‐(alkyloxyimino)ethyl)‐5‐arylidene‐4‐hydroxypyrroline‐2‐ones 6a , 6b , 6c , 6d , 6e , 6f , 6g , 6h , 6i , 6j , 6k , 6l , 6m , 6n , 6o , 6p , 6q , 6r , 6s , 6t , 6u , 6v , 6w , 6x were synthesized by the reaction of ( Z )‐3‐acetyl‐5‐arylidene‐4‐hydroxypyrroline‐2‐ones 4 with O ‐alkyl hydroxylamines 5 under reflux conditions in good yields (77.2–92.4%). Their structures were confirmed by IR, 1 H‐NMR, MS, and elemental analysis. The preliminary bioassays showed that most of the title compounds exhibited noticeable fungicidal activities against Colletotrichum orbiculare and a certain degree of fungicidal activities against Fusarium gramineaum and Rhizoctonia cerealis at a concentration of 100 μg/mL. J. Heterocyclic Chem., (2010).