反应详情

To a solution of (4-bromo-2-chloro-5-fluorophenyl)methanol (3.95 g, 16.49 mmol) and 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) (0.5 mL, 3.34 mmol) in methylene chloride (30 mL) was added trichloroacetonitrile (, 2.50 mL, 24.93 mmol) over 5 min at 0° C., stirring was continued for 4 h at 0° C. After concentrated in vacuo, the residue was purified by column chromatography eluting with 5% ethyl acetate in hexanes to give 4-bromo-2-chloro-5-fluorobenzyl 2,2,2-trichloroacetimidate as a colorless solid (5.80 g, 91%): δ 8.49 (s, 1H), 7.59 (d, J=6.3 Hz, 1H), 7.32 (d, J=9.0 Hz, 1H), 5.37 (s, 2H).

1. concentrationAfter concentrated in vacuo
2. customthe residue was purified by column chromatography
3. washeluting with 5% ethyl acetate in hexanes