The general procedure for the synthesis of 4,5-dihydro-4-oxofuro[3,2]pyridine from (E)-3-(furan-2-yl)acryloyl azide was as follows: (E)-3-(furan-2-yl)acryloyl azide (150 g, 920 mmol) was added to toluene (800 mL) preheated to 100 °C and the reaction mixture was stirred for 30 min. Upon completion of the reaction, the solvent was removed by distillation under reduced pressure. The residue was dissolved in o-dichlorobenzene (800 mL) and iodine (1 g) was added as a catalyst. The reaction mixture was stirred at 180 °C for 2 h, followed by evaporation under reduced pressure to remove the solvent. The residue was dissolved in methanol, the precipitate was collected by filtration and the filtrate was concentrated under reduced pressure. Finally, the residue was washed with diisopropyl ether to afford the target product 4,5-dihydro-4-oxofuro[3,2]pyridine (100 g, 80% yield). The product was characterized by 1H-NMR (DMSO-d6): δ 6.85 (1H, dd, J = 7.1, 1.0 Hz), 6.92 (1H, dd, J = 1.9, 1.0 Hz), 7.29 (1H, d, J = 7.1 Hz), 7.86 (1H, d, J = 1.9 Hz), 11.42 (1H, brs).
![4,5-DIHYDRO-4-OXOFURO[3,2-C]PYRIDINE](/CAS/GIF/26956-43-4.gif)