Ethanol → 9-Bromo-5-formyl-6,7-dihydro-1H, 5H-pyrido[1,2,3-de]quinoxaline-2,3-dione

Participants

Reaction Steps

A mixture of 9-bromo-5-hydroxymethyl-6,7-dihydro-1H, 5H-pyrido[1,2,3-de]quinoxaline-2,3-dione (520 mg, 1.67 mmol) and Dess-Martin periodinane (945 mg, 2.27 mmol) in THF (140 mL) was stirred for 5 h at room temperature. The excess reagent was decomposed by addition of ethanol and the resulting mixture was concentrated. The residual solids were triturated with dichloromethane and the insoluble materials were removed by filtration. The filtrate was concentrated and the residue was purified by silica gel column chromatography with 0.2% acetic acid/ethyl acetate to give 330 mg of the title compound (64%): 1H NMR (270 MHz, DMSO-d6) δ12.30 (bs, 1H), 9.57 (s, 1H), 7.21 (d, 1H, J=2 Hz), 7.19 (d, 1H, J=2 Hz), 5.31~5.37 (m, 1H), 2.85 (dm, 1H, J=15.8 Hz), 2.45~2.68 (m, 2H), 1.92~2.10 (m, 1H).

Provenance & Evidence