In the title compound, C13H19NO2, the dioxane ring adopts a chair conformation and its mean plane makes a dihedral angle of 45.36 (8)° with the phenyl ring. In the crystal, molecules are linked by pairs of N - H⋯O hydrogen bonds, forming inversion dimers with R 2 2(12) ring motifs. These dimers are consolidated by pairs of C - H⋯O hydrogen bonds with R 2 2(8) ring motifs.