The synthesis of 4-(2′-methylbutyl)phenyl4′n-heptylbiphenyl-4-carboxylate-d18(7BEF5-d18) is presented. The compound is intended to be used as a means of studying the collective modes of liquid crystals by the coherent inelastic neutron scattering technique. The 4′-n-heptylbiphenyl-4-carboxylic acid-d12, a liquid crystalline intermediate was prepared as well; its acid chloride was coupled with 4-(2′-methylbutyl)phenol-d6to obtain the final product. The intermediates and final products were investigated by spectroscopic methods.