Liquid-crystal 4H-3,1-benzoxazln-4-ones

2,6-Disubstituted 4H-3,1-benzoxazin-4-ones that have mesogenic properties were synthesized by the reaction of 5-substituted anthranilic acid with aroyl chlorides in pyridine. The introduction of a 4H-3,1-benzoxazin-4-one fragment increases the absolute value of the anisotropy of the dielectric permeability. The temperatures and heats of the phase transitions are presented.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1335–1337, October, 1981.