| abstract |
Triphenylenes are electrophilically substituted in the alpha-position by dissolving the triphenylene in a mixture of semipolar and polar solvents (eg an ether and a carboxylic acid) and adding an electrophile or precursor thereof (eg HNO3, BR2, R-Z, RCO-Z, or Aryl-CO-Z; where Z is halogen). The alpha-substituted triphenylenes are claimed per se. Thus hexa- beta -substituted hexyloxytriphenylene is alpha -substituted by an electrophile in mixed polar cosolvents according to the reaction scheme:- <IMAGE> Such compounds are or may be used to prepare discotic liquid crystals. |