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Synthesis and characterization of new p-substituted aromatic hydrazones

M.Jankulovska, K.Colanceska-Ragenovik, V.Dimova, I.Spirevska, P.Makreski

A three series of p-substituted aromatic hydrazones have been synthesized by condensation of benzhydrazide/p-substituted benzhydrazides (CH3,  OCH3, Cl and OH) with benzaldehyde/p-substituted benzaldehydes ( OCH3 and NO2). Initially, p-substituted esterswere prepared frombenzoic acid, p-substituted benzoic acid and methanol. In the second step, p-substituted hydrazides were prepared from the previously synthesized esters and hydrazine hydrate. Finally, p-substituted aromatic hydrazones were obtained from hydrazides and benzaldehyde or p-substituted benzaldehyde. The identity of the synthesized hydrazones was confirmed by the following techniques: 1H NMR, 13C NMR, IR and UV spectroscopy and element analysis (CNH). The proposed method of synthesis resulted in excellent yield and purity of the prepared hydrazones. Using three conventional LFER models based on mono and the dual substituent parameters, quantitative assessment of the substituent effects on the substituent chemical shifts (SCS) was made. In order to obtain the correlation models for investigated series the IR (C=O, C=N and NHC=O), 1HNH, 1H=CH, 13C=CH- and 13CC=O peaks were used.