Synthesis in the phenothiazine series

Quaternary salts of imidazo4,5,1-k,l]phenothiazine were reduced with potassium borohydride to 1,2-dihydro-2-methylimidazo4,5,1-k,l]phenothiazine, which was converted to 1,2 dihydro-2-methylimidazo4,5,1-k,l]phenothiazine-1-thione and 1-methylamino-10-formylphenothiazine. The latter was hydrolyzed to 1-methylaminophenothiazine, which was also obtained by reduction of methyl phenothiazine-1-carbamate. The PMR and IR spectra of some of the derivatives are discussed.See 1] for communication XXXV.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 372–374, March, 1974.