AN IMPROVED PROCESS FOR THE PREPARATION OF QUINOXALINE-2(1H) ONES FROM 3,4-DIHYDROQUINOXALINE-2(1H) ONES

摘要

An improved process for the preparation of qunoxaline-2(1H) ones, represented by Formula (A) of figure 1 of the accompanying drawing, wherein R3, R5, R6, R7 and R8 stand for hydrogen or as described in the specification from 3, 4- dihydroquinoaxaline-2(1H) ones represented by Formula B of figure 2 of the accompanying drawing where R3, R5, R6, R7 and R8 having the same meaning as hereinbefore described, which process comprising oxidation of aqueous alkaline solution of 3, 4-dihydroquinoxaline-2(1H) ones at temperature of 45 to 80 degree Celsius characterized in that said oxidation is carried out in the presence of redox catalyst hereinbefore described, and recovering the quinoxaline-2(1H) ones from the reaction mixture by the known manner.