1,4-Diazaphenothiazine, the parent compound of this heterocyclic ring has now been prepared from 2,3-dichloropyrazine and 2-aminothiophenol. Replacement of 2,3-dichloropyrazine with 2,3-dichloroquinoxaline and 2,3,6-trichloroquinoxaline led to the corresponding 1,4-diazabenzo[b]phenothiazine in good yields. Structural assignments were made by spectroscopic studies and by certain chemical transformations.
Journal of Heterocyclic Chemistry 03/1981; 18(2):405 – 407. DOI:10.1002/jhet.5570180235