反应详情

2-trichloroacetyl pyrrole 6 (5.00 g, 23.3 mmol) was dissolved in anhydrous chloroform (20 mL). The solution was cooled to −10° C. before the drop-wise addition of bromine (1.20 mL, 23.3 mmol) to the flask. Once addition was complete the reaction was allowed to warm to room temperature on its own accord while stirring for an additional 30 minutes. The reaction was poured into water (40 mL) and extracted with chloroform (3×20 mL). The combined organic layers were washed with sat. NaHCO3 (2×30 mL), brine (1×20 mL), dried over anhydrous sodium sulfate, filtered, and evaporated to dryness. Purification of the residue by column chromatography (Hexanes/Diethyl Ether 95:5) yielded the title compound 7 (6.37 g, 93%) as an off-white solid: 1H NMR (300 MHz, DMSO-d6) δ 12.86 (s, 1H), 7.54 (s, 1H), 7.32 (s, 1H); 13C NMR (100 MHz, DMSO-d6) δ 171,67, 129.06, 122.01, 121.54, 97.60, 94.56; HRMS (FAB) calcd for C6H3BrCl3NO (M+) 288.8464, found 288.8479.

1. additionOnce addition
2. extractionextracted with chloroform (3×20 mL)
3. washThe combined organic layers were washed with sat. NaHCO3 (2×30 mL), brine (1×20 mL)
4. dry with materialdried over anhydrous sodium sulfate
5. filtrationfiltered
6. customevaporated to dryness
7. customPurification of the residue by column chromatography (Hexanes/Diethyl Ether 95:5)