Facile Synthesis of 2‐Alkylthio‐5,5‐dimethyl‐4H‐imidazol‐4‐ones

Abstract The isothiocyanate 3, obtained from aza‐Wittig reaction of iminophosphorane 2 with CS2, reacts with phenylhydrazine to give thiosemicarbazide 4. Reactions of 4 with alkyl halides in the presence of K2CO3 directly provided 2‐alkylthio‐4H‐imidazol‐4‐ones 6 in good yields.