The 2-Aminobenzothiazol (A) was prepared by reacting Sulfamethoxazole with potassium thiocyanate in the presence of bromine as a catalyst. The Schiff’s base derivatives (H1-H3) were also prepared by reacting 2-Amino benzothiazol (A) with benzaldehyde derivatives in the presence of glacial acetic acid as a catalyst and ethanol as a solvent. Preparation of thiazines were derived from Schiff’s base derivatives (H1-H3) with the appropriate solvent. The effectiveness of some compounds against four types of bacteria (E. coli, S. aureus, S. pyogenes, K. pneumonia) was tested and the results showed that these prepared compounds have good to moderate activity against the bacteria used in the experiment at different concentrations (0.1, 1, and 10 mg/mL) compared to the standard antibiotic (Fluconazole) at a concentration of 5 mg/ml.