The combination of disc-shaped triphenylene with cholesteryl moiety in one molecule would result in interesting physical properties. In this paper, cholesterol-based triphenylene derivatives C₁₈H₆(OC₅H₁₁)₅(OC₅H₁₀COOCh) (2), 2,7-C₁₈H₆(OC₅H₁₁)₄(OC₅H₁₀COOCh)₂ (4), C₁₈H₆(OR)₃(OC_nH_{2nCOO- Ch)3 (6a～6f) and C18H6(OC5H10COOCh)6 (8) (R＝C5H11, C7H15, C9H19, C11H23, n＝1, 5, 10, Ch＝cholesteryl) were synthesized, and their thermotropic liquid crystalline properties were investigated by polarizing optical microscopy and differential scanning calorimetry. The results show that, compounds 4 and 6a～6e have glass states and chiral discotic nematic phases (ND*), while 8 has smectic B phase and glass state. Their glass transition temperatures (Tg) and clearing points (Tc) decreased with lengthening spacer n and alkyl chain, and decreasing cholesteryl moieties.}

Key words: triphenylene, cholesteryl, discotic liquid crystal, chiral discotic nematic phase, smectic B phase