Microwave-assisted, one-pot syntheses and fungicidal activity of polyfluorinated 2-benzylthiobenzothiazoles

Polyfluorinated 2-benzylthiobenzothiazoles 3a–l are prepared via a microwave-assisted, one-pot procedure. The advantages, such as good to excellent yields, shorter reaction time (14–21 min), readily available starting material, and simple purification procedure, distinguish the present protocol from other existing methods used for the synthesis of 2-benzylthiobenzothiazoles. Bioassay indicated that most of the compounds showed significant fungicidal activity against Rhizoctonia solani, Botrytis cinereapers, and Dothiorella gregaria at a dosage of 50 μg/mL. Interestingly, compared to the control of commercial fungicide, triadimefon, compound 3c exhibited much higher activities against R. solani, B. cinereapers, and D. gregaria, which showed that the polyfluorinated 2-benzylthiobenzothiazoles can be used as lead compound for developing novel fungicides.

Reagents and conditions: (i) potassium O-ethyl dithiocarbonate, DMF, MW, 120 °C; (ii) benzyl bromide, MW, 90 °C.Figure optionsDownload as PowerPoint slide