3-Nitrobenzaldehyde → 7-(3-Nitrophenyl)-furo[3,4-b]pyridin-5-one

Participants

Reaction Conditions

Reaction Steps

A solution of 2,3-pyridinyldicarboxylic anhydride (20 g, 134 mmoles) in 25 ml of anhydrous methanol was refluxed for 30 minutes. The methanol was removed and the two positional isomers (2-carboxy-3-methoxycarbonylpyridine and 2-methoxycarbonyl-3-carboxypyridine) are isolated and separated. The 2-carboxy-3-methoxycarbonyl pyridine was added to a solution of 3-nitrobenzaldehyde (101.35 g, 670 mmoles) in p-cymene (105 ml, 670 mmoles) and heated at 180° C. for 13.5 hours. The solution was cooled, filtered and the excess 3-nitrobenzaldehyde and p-cymene removed by bulb to bulb distillation using a Kugelrohr apparatus. The residue was triturated with methylene chloride and the solid residue was discarded. The product was isolated from the filtrate yielding 12.7 g of 7-(3-nitrophenyl)-furo[3,4-b]pyridin-5-one (37.2%).

Provenance & Evidence