Design, synthesis and fungicidal activity of pyrazole-thiazole carboxamide derivatives.

Twenty-one novel pyrazole-thiazole carboxamide derivatives were rationally designed and synthesized. Bioassay results indicated that 6d (EC50 = 5.11 μg/mL) and 6j (EC50 = 8.14 μg/mL) exhibited better in vitro activities than fluxapyroxad (EC50 = 11.93 μg/mL) and thifluzamide (EC50 = 22.12 μg/mL) against Rhizoctonia cerealis. Particularly, compound 6j showed promising in vivo protective activity against Rhizoctonia solani and Puccinia sorghi Schw. with 80% and 90% inhibition at 10 μg/mL, respectively. Our studies found that pyrazole-thiazole is a promising fungicide lead deserving for further derivation.