The chemicals used in this study, such as phenothiazine, allyl bromide, 2-pyridyl acetonitrile, and phosphorus oxychloride, were purchased from Sigma-Aldrich in Bangalore. Solvents, including dimethylformamide, chloroform, acetonitrile, acetone, tetrahydrofuran, hexane, and ethyl acetate, were purchased from Avra and used without further purification.