ortho-phenylenediamine (Aldrich);
D-glucose (Aldrich);
Acetic acid (Fisher);

Synthesis of (1R,2S,3R)-1-(quinoxalin-2-yl)butane-1,2,3,4-tetraol: (30.54 g, 282 mmol) ortho-phenylenediamine was placed in a 500 ml round-bottom flask and suspended in 10% acetic acid (140 ml); D-glucose (10.16 g, 282 mmol) was added in five portions over 30 min. and the solution changed to a deep golden colour. The mixture was heated to 80ºC for 2 h and changed colour to a deep red, left to cool to ambient temperature and stored at +4ºC for 12 h. A mass of golden plate like crystals are deposited and the isolated by filtration, the solid was washed with a little cold water (2 x 20 ml) and dried in an vacuum oven (60ºC, 0.02 mm Hg) for 5 h. (25.0 g, 35 %).

1H NMR (300 MHz, DMSO-d6): 9.19 (s, 1H, ArH), 8.05-8.11 (m, 2H, ArH), 5.63 (d, 2H), 5.17 (d, 1H), 4.74 (d, 1H), 4.64 (d, 1H), 4.42 (t, 1H), 3.65-3.72 (m, 3H). 13C NMR (75 MHz, DMSO-d6): 159.4, 145.2, 141.0, 140.8, 129.9, 129.2, 128.8, 128.6, 74.3, 72.5, 71.2, 63.5.

A. E. Harms, Org. Process Res. Dev., 2004, 8, 666-669.