Abstract
By the photolysis of riboflavin in alkaline medium, lumiflavin was formed which is decomposed further to 3,4-dihydro-3-keto-4,6,7-trimethyl-2-quinoxaline carboxylic acid (lumiflavin-keto acid) by alkali. Lumiflavin-keto acid is further converted methyloxoviolet after 94 hours at room temperature in the presence of hydrogen peroxide in alkaline solution. Methyloxoviolet was proved to be identical with 4,6,7-trimethyl-2,3-dioxotetrahydroquinoxaline synthesized from 1,2-dimethyl-4-amino-5-methylaminobenzene.
