反应详情

温度

40 °C

POCl3 (2.23 mL, 24.3 mmol) was added dropwise to a stirred solution of N-oxide 1 (5.0 g, 20.2 mmol) in dry DCM (100 mL) and the mixture stirred at 40° C. for 16 h. The solution was poured into a slurry of ice/1 M NaOH solution (100 mL) and the mixture stirred for 10 min. The mixture was extracted with DCM (3×50 mL), the combined organic extract dried and the solvent evaporated. The residue was purified by column chromatography, eluting with 20% EtOAc/pet. ether, to give benzoate 2 (4.12 g, 77%) as a white powder: mp (EtOAc) 127-128° C.; 1H NMR (CDCl3) δ 8.06-8.12 (m, 4H, H-2, H-3, H-5, H-6), 4.56 (s, 2H, CH2Cl), 3.94 (s, 3H, OCH3), 2.45 (s, 3H, CH3); MS m/z 266.6 (MH+, 100%). Anal. calcd for C13H12ClNO3: C, 58.77; H, 4.55; N, 5.27. Found: C, 58.82; H, 4.43; N, 5.18%.

1. stirringthe mixture stirred for 10 min
2. extractionThe mixture was extracted with DCM (3×50 mL)
3. extractionthe combined organic extract
4. customdried
5. customthe solvent evaporated
6. customThe residue was purified by column chromatography
7. washeluting with 20% EtOAc/pet. ether