In the title compound, C16H16ClNO2S2, the piperidine ring is in a chair conformation. In the coumarin ring system, the dihedral angle between the benzene and pyran rings is 3.5 (1)°. In the crystal, a weak C—H...O hydrogen bond links molecules into chains along [001]. In addition, π–π stacking interactions are present involving the benzene and pyran rings, with a centroid-to-centroid distance of 3.712 (2) Å. The crystal studied is a nonmerohedral twin with refined components 0.221 (1) and 0.779 (1)

In the title compound, C16H17NO3S2, the 2H-chromene ring is close to being planar [maximum deviation = 0.034 (2) Å] and the pyrrolidine ring is twisted about the C—C bond opposite the N atom. The dihedral angle between the ring-system planes is 75.24 (16)° and an intra­molecular C—H⋯S inter­action occurs. In the crystal, mol­ecules are linked by C—H⋯O hydrogen bonds and the packing also exhibits π–π inter­actions, with a distance of 3.6106 (13) Å between the centroids of the benzene rings of neighbouring mol­ecules.

In the title compound, C19H17NO3S2, the morpholine ring is in a chair conformation. In the coumarin ring system, the dihedral angle between the benzene and pyran rings is 3.9 (1)°. In the crystal, weak C—H⋯O inter­actions link the mol­ecules into corrugated layers parallel to (102). The crystal packing also exhibits π–π inter­actions, with distances of 3.644 (1) and 3.677 (1) Å between the centroids of the benzene rings of neighbouring mol­ecules.

In the title compound, C17H15NO2S2, the 3H-benzo[f]chromene ring system is distinctly twisted; the dihedral angle between the pyran ring and its opposite benzene ring is 9.11 (8)°. The N,N-dimethyl­carbamodithio­ate residue lies almost perpendicular to the pyran ring [dihedral angle = 85.15 (7)°]. In the crystal, weak C—H⋯O hydrogen bonds link the mol­ecules into C(10) chains propagating in [001].

In the title compound, C20H19N O2S2,the 3Hbenzo-chromene ring system is nearly planar, with a maximum deviation of 0.036 (2) Å, and the piperidine ring adopts a chair conformation: the bond-angle sum for its N atom is 358.7°. The dihedral angle between the 3H-benzo[f]chromene ring and the piperidine ring is 89.07 (8)°. In the crystal, C—H⋯O hydrogen bonds lead to [010] C(6) chains and weak aromatic π–π inter­actions between the fused pyran ring and fused benzene ring of benzochromene [centroid–centroid distance = 3.652 (1) Å] are also observed.