A new, one-pot, regioselective preparation of 2,5,6,7-tetrahydroimidazo[1,2- a ]imidazol-3-ones by a sequential aza-Wittig/nucleophilic addition/cyclization reaction was developed. The aza-Wittig reactions of ethyl (2 Z)-3-aryl-2-[(triphenylphosphoranylidene)amino] acrylates with aryl isocyanates produced carbodiimide intermediates that were then treated sequentially with 2-aminoethanol and tosyl chloride/triethylamine to give the corresponding (2 Z)-2-[(substituted)benzylidene]-2,5,6,7-tetrahydro-3 H -imidazo[1,2-a]imidazol-3-ones in good overall yields ...
