Preparation of certain 2-N-alkylamino-and 2-N,N-dialkylamino-10-methylphenothiazines via phenothiazyne

The treatment of 2-chloro-10-methylphenothiazine, 1 , with lithium alkylamide/alkylamine or lithium dialkylamide/dialkylamine yields the corresponding 2-N-alkylamino-or 2-N,N-dialkylaminophenothiazines in good yields via phenothiazyne. No significant reduction of 1 to 10-methylphenothiazine is observed. Yields of amines obtained by this method are considerably higher than those obtained by reacting 1 with sodamide in refluxing amine solvent. Attempts to introduce the -CH₂CN moiety onto the phenothiazine nucleus by treating 1 with sodamide and acetonitrile in liquid ammonia produced only 2-amino-10-methylphenothiazine.