Oxalic Acid → 1,4,7,8,9,10-Hexahydropyrido[3,4-f]quinoxaline-2,3-dione

Participants

Reaction Conditions

Reaction Steps

A solution of Example 29 (01.27 g, 0.96 mmol) in 25 mL 3 N HCl, was treated with oxalic acid (0.15 g, 1.2 mmol) and heated at reflux for 4 h. The mixture was cooled in an ice bath and the precipitate collected by filtration and washed with 3 N HCl, water and then diethyl ether consecutively. After air drying, the solid was suspended in 10 mL water and heated at approximately 90° C., basifyed with ammonium hydroxide solution to pH 8, and filtered hot. The solid was washed first with water, then with diethyl ether and then dried in a vacuum oven to give an off-white solid (0.17 g, 81% yield) mp=294-297° C. MS (CI) M+1, 218; IR 1691, 1659 cm-1.

Provenance & Evidence