Abstract

Benjamin E. Ezema*¹, Chidimma G. Ezema², Jude I. Ayogu¹, David I. Ugwu¹, Efeturi A. Onoabedje¹

DOI : http://dx.doi.org/10.13005/ojc/310145

Isomeric derivatives of angular aza benzophenothiazine and complex aza benzothiazinophenothiazine rings were successfully synthesized. Reactions of 2-amino-3,5-dibromopyrazine with 6,7-dibromoquinoline-5,8-dione in anhydrous sodium carbonate gave isomeric angular aza benzophenothiazine compounds 6,9-dibromo-1,8,11-triazabenzo[a]phenothiazine-5-one and 6,9-dibromo-4,8,11-triazabenzo[a]phenothiazine-5-one. Further reactions of these compounds, in the first case, respectively with 2-amino-6-methoxypyridin-3-thiol gave the two isomeric aza complex compounds identified as 13-bromo-8-methoxy-1,9,12,15-tetraazabenzo[a][1,4]benzothiazino[3,2-c]phenothiazine and 13-bromo-8-methoxy-4,9,12,15-tetraazabenzo[a][1,4]benzothiazino[3,2-c]phenothiazine. Secondly, reactions of the same angular benzophenothiazine compounds with 4-aminopyrimidin-5-thiol gave two more complex compounds 13-bromo-1,6,8,12,15-pentaazabenzo[a][1,4]benzothiazino[3,2-c]phenothiazine and 13-bromo-4,6,8,12,15-tetraazabenzo[a][1,4]benzothiazino[3,2-c]phenothiazine.  The compounds have very intense colours.

anhydrous sodium carbonate; 2-amino-3,5-dibromopyrazine; 2-amino-6-methoxypyridin-5-thiol; 4-aminopyrimidin-5-thiol; 6,7-dibromoquinoline-5;8-dione; condensation reaction

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