Methyl trans-(±)-1-oxo-2-phenethyl-3-(thio-phen-2-yl)-1,2,3,4-tetra-hydro-isoquinoline-4-carboxyl-ate.

In the title compound, C(23)H(21)NO(3)S, the piperidine ring of the tetra-hydro-isoquinolinone unit adopts a screw-boat conformation. The thio-phene ring is disordered in a 0.700 (3):0.300 (3) ratio by an approximate 180° rotation of the ring around the C-C bond linking the ring to the tetra-hydro-isoquinolinone unit. The benzene ring of the tetra-hydro-isoquinolinone unit makes dihedral angles of 83.1 (2) and 62.38 (11)° with the major occupancy thio-phene ring and the phenyl ring, respectively. The dihedral angle between the phenyl ring and the thio-phene ring is 71.0 (2)°. In the crystal structure, mol-ecules are linked together by inter-molecular C-H⋯O and C-H⋯π inter-actions.