The isothiocyanates 2, obtained from aza-Wittig reactions of vinyliminophosphoranes 1 with CS2, reacted with hydrazine to give 3-amino-2-thioxo-4-imidazolidinones 4. One-pot reactions of 4, aromatic isocyanates, Ph3 P, C2Cl6, and Et3N 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 Ciner...
