Target of this work is to design liquid crystalline bent-core molecules which avoid smectic phase formation and may form nematic phases instead. Here bent-core molecules with different lateral groups were synthesized, which could inhibit the formation of smectic phases. Cyano-, 4-cyanophenyl and alkyl chains with different length were used as lateral groups attached at the convex side of the bent-core molecules and alkyl chains were also used as lateral groups attached in the bay position at the concave side. Further modifications of the structure were done by introduction of terminal siloxane groups and replacement of outer benzene rings by thiophene rings. The mesophase behaviour of the synthesized compounds was investigated by means of polarization microscopy, differential scanning calorimetry, electrooptical experiments and X-ray scattering.