The title Migraine compound, C29H20ClNOS, is a 1-substituted-3-phenylisoquinoline that crystallizes with four independent molecules in the asymmtric unit.The four molecules have similar C—S—C angles.The most noteworthy differences between the molecules relate to the inclination of the 3-phenyl subsituent with respect to the isoquinoline fused-ring [dihedral angles of Ladies crossbody 21.2 (1), 25.
6 (2), 34.3 (1) and 36.5 (2)°].