Synthesis and Acaricidal Evaluation of Some 2-Arylidene-[1,3]-Thiazolo[3,2 а]Benzimidazol-3(2H)-ones Derivatives and Their Impact on Cucumber (Cucumis sativus L) Growth Performance

A series of 2-(arylidene)thiazolo[3,2-a]benzimidazol-3(2H)-ones derivatives 7a-13a and 7b-13b were synthesized using an efficient and straightforward method. The reaction of 2-mercaptobenzimidazole or its derivatives 3a-c with ethyl 2-bromoacetate 4 under reflux in ethanol afforded thiazolo[3,2-a]benzimidazol-3(2H)-one 5a-c through intramolecular cyclization. These intermediates were then condensed with various aryl aldehydes 6a-g to yield the corresponding 2-arylidene derivatives. The structures of all compounds were confirmed by spectral analyses. Preliminary Acaricidal activity of these compounds was evaluate by determined Phytosanitary and agronomic parameters. The results showed that compounds 5b and 7b, exhibited promising dual functionality. These treatments not only significantly reduced pest presence, especially mites and mealybugs, but also enhanced key agronomic traits such as fruit size, weight, and yield.