A NEW SYNTHETIC ROUTE TO 6,7-DICHLORO-5,8-QUINOXALINEDIONE AND SYNTHESIS OF ITS DERIVATIVES

6,7-Dichloro-5,8-quinoxalinedione (2), an analogue of Dichlone(R), was prepared from 4-aminophenol (3) in 27% overall yield in 8 steps via c hloroxidation of the sulfuric acid salt of 8-amino-5-quinoxalinol (9) as a key step. And two derivatives, 6-chloro-5-hydroxypyrazino[2,3-a]p henazine (10) and pyrido[1,2-a]imidazo[4,5-g]quinoxaline-6,11-dione (1 1), were prepared by reaction of 2 with 1,2-phenylenediamine and 2-ami nopyridine in 79% and 46% yields, respectively.