反应详情

To a solution of 2-(biphenyl-4-yl)-1-phenylethanone (Intermediate 5) (430 mg, 1.57 mmol), 3-ethoxy-4-hydroxy-5-nitrobenzaldehyde (333 mg, 1.57 mmol), and urea (217 mg, 4.71 mmol) in 20 mL of ethanol was added 0.2 mL of concentrated HCl, the mixture was stirred at reflux for 4 days. After the solvent was removed under reduced pressure, the residue was purified by column chromatography on silica gel (PE:EtOAc=3:1-0:1) and thin layer chromatography (PE:EtOAc=1:2) to give Compound 18 (23 mg, yield 2.9%). 1H NMR (CD3OD 400 MHz TMS): δ 7.61 (d, J=2.0 Hz, 1H), 7.49 (d, J=7.2 Hz, 2H), 7.38-7.27 (m, 10H), 7.02 (s, 1H), 6.98 (d, J=8.0 Hz, 2H), 5.23 (s, 1H), 4.02-3.99 (m, 2H), 1.38 (t, J=6.8 Hz, 3H); MS (ESI): m/z 508.2 [M+1]+.

1. temperatureat reflux for 4 days
2. customAfter the solvent was removed under reduced pressure
3. customthe residue was purified by column chromatography on silica gel (PE:EtOAc=3:1-0:1) and thin layer chromatography (PE:EtOAc=1:2)