Synthesis, identification and study of mesomorphic properties of compounds containing two C2H2N2O rings

The novel compounds of 1,3,4-C2H2N2O were manufactured from the response of acid hydrazides with carboxylic acids using POCl₃ under reflex. These compounds were obtained from many sequence reactions as in Scheme 1. Converted anasic acid to acorresponding ester and acid hydrazid. The acid hydrazide used as starting materials for synthesis new carboxylic acid [IV] via condensation the acid hydrazide with 4-aminobenzoic acid in POCl₃ to yield compound [III]. Then, the later compound coupling with benzoic acid in suitable conditions to formation compound [IV]. Also this new carboxylic acid [IV]converted to a corresponding ester and acid hydrazide. Finally, the synthesized acid hydrazides [VI] reacted with different type of carboxylic acid in POCl₃ to get new derivatives of 1, 3, 4-C2H2N2O in two synthetic routs. The novel compounds were identified by using FTIR, NMR and Mass spectroscopy. The behaviour of these derivatives was examined under OPM and DSC. Compounds [IV], [VIII]₁ and [XI]_aexhibited nematic mesophase, while the other compounds [V], [VI], [VIII]3, 4, 5, 8, 9 and [XI]_{b, c} did not show any mesomorphic properties.