Manufacturing Process
2.33 g 95% sodium amide were added to a boiling solution of 11.35 g 2-
ethyl-10H-phenothiazine (BP: 135°-136°C) in 150 ml dry xylene by stirring at
reflux for 1.5 hours. The solution of 7.72 g of 1-dimethylamino-2-methyl-3-
chloropropane in 90 ml of dry xylene was poured in the above solution at the
same temperature for 45 minutes. The mixture was heated at reflux else 18
hours. On cooling it was stirred with the mixture of 70 ml 1 N
methanesulfonic acid and 40 ml water whereupon a xylene layer was
removed. The water layer was extracted with 200 ml ether and basified with
10 ml NaOH (d=1.33), again extracted with ether and dried over potassium
carbonate. The ether was distilled off, a residue was distilled to give 10-(3-
dimethylamino-2-methylpropyl)-2-ethylphenothiazine; BP: 162°-182°C/0.45
mm.
The prepared base was in 60 ml acetone dissolved and 24.5 ml 1.7 N HCl was
added and a precipitate of ethyl-2-(dimethylamino-3-methyl-2-propyl)-10-
phenothiazine chlorohydrate dropped out. It was filtered off, washed with
acetone and ether and dried. MP: 160°-163°C.
