Potassium Permanganate → 2-(2,3-Dioxo-1,2,3,4-tetrahydroquinoxalin-1-yl)acetic acid

Participants

Reaction Steps

The procedure of Borthakur, N. et at., Ind. J. Chem. 20B:822 (1981) was adapted. To a stirred solution of 1-carboxymethyl-1,2,3,4-tetrahydroquinoxaline-3-one (15.400 g, 0.075 mol) and sodium hydroxide (5.20 g, 0.13 mol) in water (250 mL), was added gradually, a solution of KMnO4 (20.800 g 0.132 mol) in aq. NaOH (4% w/v, 120 mL) and the dark purple colored solution was refluxed for 4 h, cooled and filtered. The clear filtrate was acidified (pH~2) with concentrated HCl. Filtration under vacuum (water aspirator) afforded 9.200 g (56%, pure by 1H NMR) of 1-carboxymethyl-1,4-dihydro-2,3-quinoxalinedione as a cream colored powder, m.p.>300° C. (decomposes) (lit. m.p.>300° C., Borthakur et al., supra). It was sufficiently pure for use in the next reaction; 1H NMR: δ4.84 (s, 2H), 7.13-7.27 (m, 4H), 12.16 (s, 1H); IR (KBr, cm-1): 3431, 1743, 1687, 1481, 1406, 1393, 1250.

Provenance & Evidence