反应详情

A suspension of 3-carbomethoxypicolinic acid (15.0 g, 0.083 mol) and 4-fluorobenzaldehyde (90.8 g. 0.732 mol) in 250 mL of p-cymene is heated to reflux under a stream of N2 for 16 hours. The mixture is then allowed to cool to room temperature, filtered and the filtrate distilled in vacuo to remove p-cymene. A solution of the crude residue in CH2Cl2 is chromatographed on silica gel (using Et2O-hexane (2:1) as the eluent). Recrystallization from hexane-EtOAc gives pure 7-(4-fluorophenyl)-5-oxo-5,7-dihydrofuro[3,4-b]pyridine. M.P. 116°-117.5° C.

1. temperatureis heated
2. filtrationfiltered
3. distillationthe filtrate distilled in vacuo
4. customto remove p-cymene
5. customA solution of the crude residue in CH2Cl2 is chromatographed on silica gel (
6. customRecrystallization from hexane-EtOAc