HEMI-SYNTHESIS AND UV-VISIBLE SPECTROPHOTOMETRIC CHARACTERIZATION OF 2,4-DINITROPHENYLHYDRAZONES DERIVED FROM CITRAL AND CITRONELLAL ESSENTIAL OILS OF TWO AROMATIC PLANTS ACCLIMATIZED IN CONGO-BRAZZAVILLE

The orange-yellow and colorless essential oils with respective yields of 1.54% 3.59% were extracted from the dry leaves Cymbopogoncitratus (DC.) Stapf Eucalyptus citriodora Hook. collected south Brazzaville. Analysis by gas chromatography (GC) coupled mass spectrometry (GC/MS) allowed identification fifteen (15) eight (8) constituents representing (96.25%) (98.46%) total respectively. oil consists mainly geranial (51.99%) neral (32.94%), two geometric isomers constituting citral which occupies a rate 84.93%. While citronellal high level (80.72%) citronellol (10.48%) are major compounds citriodora. Geranial (citral a) 2,4-dinitrophenylhydrazones hemi-synthesized simple, easy method, respectively conversion (yields) 20%. 37%, in short time (three to five minutes). UV-visible spectrophotometry showed maximum absorption wavelengths 390 nm 370 spectrophotometric method employed for determination these hydrazones is convenient, fast simple. could be useful pharmaceutical industry, perfumery, cosmetic biomedicine.