3-[(4-Oxo-4H-thio-chromen-3-yl)meth-yl]-4H-thio-chromen-4-one.

The title mol-ecule, C19H12S2O2, lies on a twofold rotation axis. The thio-chromonone unit is essentially planar, with a maximum deviation of 0.0491 (14) Å. The dihedral angle between the thio-chromenone ring systems is 64.48 (4)°. In the crystal, there are weak π-π stacking inter-actions, with a centroid-centroid distance of 3.7147 (9) Å.

Bromination of deactivated aromatics: a simple and efficient method.

Highly deactivated aromatic compounds were smoothly monobrominated by treatment with N-bromosuccinimide (NBS) in concentrated H2SO4 medium affording the corresponding bromo derivatives in good yields. Mild reaction conditions and simple workup provides a practical and commercially viable route for the synthesis of bromo compounds of deactivated aromatics.