Substituted 1‐Azaphenothiazines and Their 10‐(2′‐Morpholinylethyl) Derivatives: Synthesis, Characterization and Anticancer Evaluation

Abstract A series of substituted 1 ‐azaphenothiazine was synthesized by Smiles rearrangement and was further used to synthesize 10 ‐( 2 ′‐morpholinylethyl) derivatives. All compounds were characterized by various specroscopic techniques. One derivative from each series was also characterized by single crystal X‐ray diffraction (SCXRD) method. Compounds of both series were screened for their anticancer activity toward colon (CaCO2, SW48), lung (A549), pancreatic (SW1990) and human breast (MDA‐MB‐231, MCF‐7) cancer cell lines. 10 ‐( 2 ′‐Morpholinylethyl)‐ 1 ‐azaphenothiazine derivatives were found to be more potent than that of 1 ‐azaphenothiazine derivatives toward anticancer activities. Among all compounds, one of the morpholinylethyl derivative which is substituted with chlorine at 3‐ position of pyridine ring, exhibits better selectivity toward both colon cancer (SW48) and breast cancer cells (MCF7).