Phenothiazine derivatives are biologically active and pa vital role in medicinal chemistry. The present report explains a simple and efficient synthesis of title compounds. The compounds are also screened for their biological activity and shown good results. Potassium 1-amino-10,10a-dihydro-4aH-phenothiazine- 3-sulfonate (1) reacts with Benzaldehyde to form Potassium-1-(benzylideneamino)-10,10a-dihydro-4aHphenothiazine- 3-sulfonate (2), which undergoes N-alkylation to give potassium-1-(benzylideneamino)- 10,10a-dihydro-10-((oxiran-2-yl)methyl)-4aH-phenothiazine-3-sulfonate (3). Compound 3 reacts with different amines to give Potassium-1-(benzylideneamino)-10, 10a-dihydro-10-(2-hydroxy-2-(pyrrolidin-1- yl)ethyl)-4aH-phenothiazine-3-sulfonate (4a-e). All the newly synthesized quinoxaline-benzohydrazide derivatives have been characterized by 1H NMR, IR and mass spectroscopic analysis. The synthesized compounds have been screened for antibacterial activity. Most of the compounds show significant antibacterial activity.