New Fused Hyterocyclic Compounds: Synthesis of Some 1,4-di[1,2,4- Triazoles[3,4-b]5-phnyl/aryl-1,3,4-thiadiazole] Benzene

Abstract

Inthis paper the synthesis of some substituted di – 1,2,4-triazoles and it isconversion to multi nuclear heterocyclic compounds ; described Terphthalic acidwas esterified to its ethyl ester(1)by its reaction with absolute ethanol ,concentrated sulfuric acid , the ethyl ester (1) was treated with hydrazinehydrate is ethanol to give the acid hydrazide (2). the hydrazide (2) thentreated with ammonium thiocyanate to give thiosemicarbazide (3) , reaction ofthiosemicarbazide (3) with hydrazinehydrate gave 1,4-bis(3-thiol-4-amino-1,2,4-triazole-5-yl) benzene (4). Compound (4) treatment withthree type substituted benzaldehyde gave 1,4-di hydrazones phenyl (5,6 and 7).Cyclization hydrazones compounds (5,6,7) with phosphorous oxychloride in xyleneto gave bicyclic system 1,4-bis[1,2,4-triazole[3,4-b]-5-substituted –1,3,4-thiadiazole] benzene (8,9 and 10). On the other hand some physical parameters of compounds ( 4 -10 )under investigation such as the Mullikan charge at the active atoms, HOMO andLUMO energy levels , hardness (η) , electronic chemical potential (µ) and global electrophilicty index (W) were theoretically calculated using ( Gaussian program ). Theantibacterial activity some of the synthesis compounds was studied. Thestructures of the synthesized compounds were confirmed by physical and spectralmethods.