One-Pot Synthesis and Fungicidal Activities of Derivatives of Imidazo [2,1-b]-1,3,4-thiadiazol-5(6H)-one

The isothiocyanates 2, obtained from aza-Wittig reactions of vinyliminophosphoranes 1 with CS ₂ , reacted with hydrazine to give 3-amino-2-thioxo-4-imidazolidinones 4. One-pot reactions of 4, aromatic isocyanates, Ph ₃ P, C ₂ Cl ₆ , and Et ₃ N generated imidazo[2,1-b]-1,3,4-thiadiazol-5(6H)-ones 7. Compound 7 exhibited good fungicidal activities, especially against Sclerotinia sclerotiorum de Bary and Botrytis Cinerea Pers.

Keywords:

• Imidazo[2,1-b]-1,3,4-thiadiazol-5(6H)-one
• aza-Wittig reaction
• fungicidal activities
• synthesis

Acknowledgments

We gratefully acknowledge financial support of this work by the Natural Science Foundation of Hubei Education Commission of China (Project No. D200560003) and the National Natural Science Foundation of China (Project No. 20102001).

Notes

*Isolated yields of 7 based on imidazolidinones 4.