The title isomers, viz. the N-(3-methylphenyl)-, (I), and N-(2-methylphenyl)-, (II), derivatives, both C(26)H(28)N(2)O(4)S, adopt an E configuration that places the thiophene and trimethoxyphenyl groups on opposite sides of the C=N double bond, providing a suitable orientation for formation of an intramolecular N-H...N hydrogen bond. However, while the molecule in (I) is close to being planar, the N-methylphenyl group in (II) is twisted significantly from the plane of the remainder of the molecule. Both crystal structures are essentially layered and there are no intermolecular N-H...O hydrogen bonds. Compound (I) has a significantly higher calculated density than (II) (1.340 cf 1.305 Mg m(-3)), indicating that the molecular packing in the meta isomer is overall more efficient than that in the ortho isomer.