Synthesis of Some New 2‐Oxo‐ N ‐[(10 H ‐phenothiazin‐10‐yl)alkyl] Derivatives of Azetidine‐1‐carboxamides

The synthesis of a new series of 4‐aryl‐3‐chloro‐2‐oxo‐ N ‐[3‐(10 H ‐phenothiazin‐10‐yl)propyl]azetidine‐1‐carboxamides, 4a – 4m , is described. Phenothiazine on reaction with Cl(CH 2 ) 3 Br at room temperature gave 10‐(3‐chloropropyl)‐10 H ‐phenothiazine ( 1 ), and the latter reacted with urea to yield 1‐[3‐(10 H ‐phenothiazin‐10‐yl)propyl]urea ( 2 ). Further reaction of 2 with several substituted aromatic aldehydes led to N ‐(arylmethylidene)‐ N′ ‐[3‐(phenothiazin‐10‐yl)propyl]ureas 3a – 3m , which, on treatment with ClCH 2 COCl in the presence of Et 3 N, furnished the desired racemic trans ‐2‐oxoazetidin‐1‐carboxamide derivatives 4a – 4m . The structures of all new compounds were confirmed by IR, and 1 H‐ and 13 C‐NMR spectroscopy, FAB mass spectrometry, and chemical methods.