Crystal structure of 1′-(2-methyl­prop­yl)-2,3-di­hydro­spiro­[1-benzo­thio­pyran-4,4′-imidazolidine]-2′,5′-dione

In the title compound, C15H18N2O2S, the 2,3-di­hydro-1-benzo­thio­pyran ring adopts a sofa conformation and the hydantoin ring is twisted with respect to the benzene ring at 78.73 (17)°. In the crystal, pairs of N—H⋯O hydrogen bonds link the mol­ecules into inversion dimers.