Abstract:The synthesis of non-linear diaza and tetraaza dichlorophenothiazine derivatives is reported in this article. This was achieved through the thiocyanation of 2,6-diamino-4-chloropyrimidine using potassium thiocyanate, bromine and glacial acetic acid at -5°C to give 2,6-diamino-3-thiocynatopyrimidine, which was hydrolyzed using 20% sodium hydroxide to furnish 2, 6-diamino-4-chloropyrimidin-3-thiol. Base catalyzed condensation reaction of 2, 6-diamino-4-chloropyrimidin-3-thiol and 2, 3-dichloro-1, 4-naphthoquinone gave the first derivative, 10-amino-6, 8-dichloro-9, 11-diazabenzo [a] phenthiazin-5-one, a reddish crystalline product. Similarly, another condensation reaction of 2, 6-diamino-4-chloropyrimidin-3-thiol with the first derivative, 10-amino-6, 8-dichloro-9, 11-diazabenzo[a]phenthiazin-5-one using the same reaction conditions, furnished the second derivative known as 7, 14-diamino-9,12-dichloro-6, 8, 13, 15-tetraazabenzo [a] [1,4] benzothiazino-[3,2-c] phenothiazine, a deep reddish crystalline compound. The synthesized compounds were characterized on the basis of UVVisible, IR, 1 HNMR and 13 CNMR spectra data.