The ten aromatic aldazines: 4-nitrobenzal-, 3-nitrobenzal-, 2-nitrobenzal-, 4-dimethylaminobenzal-, 4-methoxybenzal-, 3-methoxybenzal-, 4-fluorobenzal-, 4-chlorobenzal-, 4-bromobenzaldazine and 7 -carboxymethox y-6-hydroxy- 3-sulfoquinolin- 5-carbaldazine, were synthesized by condensing two equivalents of an appropriate aldehyde with one equivalent of hydrazine hydrate. The structure of the received aldazines was determined by IR, 1H-NMR and ESI MS spectra.