Hydrazides & Schiff's bases are important organic compounds , It is present in most common pharmaceutical compounds and they are used as ligands in the preparation of some complexes in inorganic chemistry due to the presence of pair electrons on the nitrogen atom and the double bond between carbon and nitrogen which give highly effective, The reaction of aldehyde with the acid hydrazide will known as hydrazone. Hydrazone (2) was also prepared in this work from the reaction of the ester of decanoic acid, Where the C=N bond was converted to a tetracyclic ring by reacting with α-chloroacetylchloride to give azetidine (3), Hydrazone (2) was reacted with thioacetic acid to give thiazolidine (4). Also, the imine bond can be cyclized to the oxazepine seven ring heterocyclic by its reaction with phthalic acid or malic anhydride (6, 7), finally the hydrazone was cyclized using sodium azide to give a substituted tetrazole ring (5). The imidazole ring where prepared from the reaction of hydrazone with ethyl acetoacetate (8) in the presence of glacial acetic acid. The imidazole ring contains acidic alpha hydrogen that can be converted to a substituted chalcone on the ring (9). The physical and spectroscopic properties were used to determine the identity of the prepared compounds as infrared spectroscopy and nuclear magnetic resonance spectroscopy. An evaluation of the antibacterial activity of two types of gram-positive and gram-negative bacteria was conducted, and it gave good results.