1-Acetyl-4-(phenylsulfanyl)imidazolidin-2-one

The five-membered ring in the title imidazolidinone derivative, C11H12N2O2S, adopts an envelope conformation with the S-bound C atom being the flap atom. Overall, the molecule has a U-shaped conformation as both rings are folded towards each other [dihedral angle = 31.66 (6)°]. An eight-membered amide {⋯HNCO}2 synthon leads to hydrogen-bonded dimeric aggregates in the crystal: these are additionally linked by C—H⋯π interactions.