This research, included prepare of some new aza-beta lactam and 1,2,3, 4-tetrazole derivatives from 2-aminobenzothiazole. The first step includes formation of imidazo[2,1-b]benzothiazoles (1) by the condensation of 2-aminobenzathiazole and ethyl-2- chloro acetoacetate in acetone, then compound (1) reaction with hydrazine hydrate 80% to form hydrazone derivative (2). Schiff bases (3-6) were prepared from condensation of hydrazone(2) with various aromatic aldehyde with little drops of glacial acetic acid. Phenyl isocyanate and sodium azide were used for the cyclocyclization of new Schiff bases to form diazetidine (7-10) and tetrazole (11-14) derivatives. Moreover, Newly prepared derivatives were measured by Fourier-transform infrared and some of them by 1H & 13C-NMR. Furthermore, some new derivatives were evaluated as antibacterial.