反应详情

NBS (N-Bromosuccinimide, 2.36 g, 13.24 mmol, 1.0 equiv.) was added to a stirred solution of 2-(trichloroacetyl)-1-methylpyrrole (2) (3 g, 13.24 mmol, 1.0 equiv.) in anhydrous THF (35 mL) at −10° C. The reaction mixture was kept at −10° C. for 2 hours and then left to reach room temperature (ca. 4 hours). Excess THF was evaporated in vacuum and the solid was re-dissolved in a mixture of EtOAc/n-hexane (1:9). The resulting mixture was filtered through a plug of silica, and the filtrate was evaporated in vacuo. The resulting solid was recrystallised from n-hexane to give 3 (3.55 g, 88%). IR (FTIR, vmax/cm−1): 3148, 2956, 1669 (C═O), 1458, 1215, 1189, 1062, 923, 842, 823, 748, 678; 1H-NMR (CDCl3, 400 MHz) δ 7.46 (1H, d, J=2.0 Hz), 6.95 (1H, d, J=1.6 Hz) 3.95 (3H, s); 13C NMR (CDCl3, 100 MHz): δ 172.4, 132.8, 124.6, 132.2, 96.1, 38.7; EIMS m/z (+EI) calc. for C7H5BrCl3NO (M)+ 305.38, LCMS analysis found 306.86 (M+H)+

1. waitleft
2. customto reach room temperature
3. custom(ca. 4 hours)
4. customExcess THF was evaporated in vacuum
5. dissolutionthe solid was re-dissolved in a mixture of EtOAc/n-hexane (1:9)
6. filtrationThe resulting mixture was filtered through a plug of silica
7. customthe filtrate was evaporated in vacuo
8. customThe resulting solid was recrystallised from n-hexane