Originator
Levoprome ,Lederle,US,1966
Manufacturing Process
95% sodamide (2.33 g) is added to a boiling solution of 3- methoxyphenthiazine (12 g) in anhydrous xylene (150 cc) and the mixture is heated with agitation under reflux for 1? hours. A solution of 1- dimethylamino-2-methyl-3-chloropropane (8.2 g) in anhydrous xylene (90 cc) is then run in over a period of 45 minutes while the reaction temperature is maintained and heating under reflux is continued for 18 hours.
After cooling, the reaction mixture is agitated with a mixture of water (40 cc) and a normal solution of methanesulfonic acid (70 cc), the xylene layer is removed and the acid liquors are washed with ether (200 cc). The aqueous phase is then made alkaline with sodium hydroxide (d = 1.33; 10 cc) and the liberated base is extracted with ether. The ethereal solution is dried over anhydrous potassium carbonate and concentrated at normal pressure. On distillation of the residue under reduced pressure 3-(3-methoxy-10- phenthiazinyl)-2-methyl-1-dimethylaminopropane (11.3 g) is obtained, MP 103°C, BP 182° to 191°C/0.15 mm Hg. The hydrochloride prepared in isopropanol melts at about 90°C.
