Synthesis of 5-arylpyrimidine-2-carboxylic acids and the liquid-crystal characteristics of their aryl esters

5-Arylpyrimidine-2-carboxylic acids were synthesized by the hydrolysis of 5-aryl-2-cyanopyrimidines and the oxidation of 5-aryl-2-styrylpyrimidines under the conditions of phase-transfer catalysis. The aryl esters of the acids were obtained, and their liquid-crystal characteristics were studied. The p-substituted aryl esters of 5-phenylpyrimidine-2-carboxylic acid do not exhibit mesomorphism, but the introduction of a butyloxy group at the p position of the phenyl residue leads to the appearance of nematic characteristics. Aryl 5-phenylpyrimidinylcarbonyloxy-benzoates are nematic liquid crystals with a thermally stable meso phase and an existence range of 50–80 °C.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 380–388 March, 1986.The authors express their gratitude to M. F. Grebenkin and V. T. Lazareva for useful discussion of the results.