A new series of 𝑁-[3-(10𝐻-phenothiazin-1-yl)propyl]-4-(substituted phenyl)-3-chloro-2-oxo-1-azetidinecarboxamide 4(a-m) have been synthesized from phenothiazine in four steps. Phenothiazine on reaction with Cl(CH₂)₃Br at room temperature gave 1-(3-chlorophenyl)-10𝐻-phenothiazine, 1. The compound 1 yielded the condensation product with urea at room temperature, 𝑁-[3-(10𝐻-phenothiazin-1-yl)propyl]urea 2. The compound 2 on further reaction with several substituted aromatic aldehydes produced 𝑁-[3-(10𝐻-phenothiazin-1-yl)propyl]-$N'$-[(substituted phenyl)methylidene]-urea 3(a-m). The compounds 3(a-m) on treatment with ClCH₂COCl in the presence of Et₃N furnished final products 4(a-m). The structures of all the newly synthesized compounds were confirmed by IR, ¹H NMR, ¹³C NMR and FAB-Mass spectra and chemical methods. All the final synthesized compounds were evaluated for their antibacterial, antifungal and antitubercular activities which displayed acceptable activities.