Synthesis and mesomorphic properties of aryl 5-alkyl-(and alkoxy) pyrimidine-2-carboxylates

Some aryl 5-alkyl(and alkoxy)pyrimidine-2-carboxylates (I) and 5-alkylpyrimidinoyloxybenzoates (II) have been obtained. It has been found the former do not display mesomorphism, but the latter are nematic liquid crystals with a range over which the mesophase exists of 50–90C. The transition to the liquid crystal state in these compounds takes place at approximately the same temperatures as in their benzene analogues, but the thermal stability of the mesophase is somewhat less. Cyano-derivatives of pyrimidine effectively increase the value of the dielectric anisotropy of the matrix mixture, but they have a marked effect on its clarification temperature.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, 1228–1235, September,1986.