New Facile Synthesis of Imidazo[2,1-b]-1,3,4-thiadiazol-5(6H)-ones via aza-Wittig Reaction

Abstract

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. Reactions of 4 with triphenyphosphine, hexachloroethane and Et₃N produced iminophosphoranes 5. A tandem aza-Wittig reaction of iminophosphoranes 5 with isocyanates generated imidazo[2,1-b]-1,3,4-thiadiazol-5(6H)-ones 7 in moderate yield.

Key words

imidazo[2,1-b]-1,3,4-thiadiazol-5(6H)-one - iminophosphorane - carbodiimide - aza-Wittig reaction - synthesis

References

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