Experimental

R factor = 0.034; wR factor = 0.080; data-to-parameter ratio = 13.9. In the title compound, C16H14ClNO3S, the dihedral angle between the almost-planar benzothiazole ring system [maximum deviation = 0.012 (3) Å] and the aromatic ring of the trimethoxyphenyl group is 15.56 (6). In the crystal, the molecules are arranged into layers parallel to the bc plane, held together only by weak van der Waals forces. Related literature For the biological activites of benzothiazole compounds, see: Chohan et al. (2003); Hutchinson et al. (2002); Chua et al. (1999); Burger & Sawhney (1968); Palmer et al. (1971). For the crystal structures of related benzothiazole derivatives, see: Yousuf et al. (2012a,b)