反应详情

温度

0 °C

To a 150 mL flask was added dichloromethane (70 mL), methyl 1-(2-chloro-2-oxoethyl)cyclopentanecarboxylate] (3.50 g, 16.8 mmol) [prepared as described by Bajaj, et al., J. Indian Chem. Soc. 52:1076-78, 1975] and bromobenzene (2.77 g, 17.6 mmol), and the reaction mixture cooled to 0° C. before aluminum trichloride (4.77 g, 35.7 mmol) was slowly added. The mixture was stirred for 1 h at 0° C., then for 12 h at rt. The reaction mixture was slowly poured into 50 mL chilled (0° C.) 1 N aqueous hydrochloric acid solution. Water (50 mL) was added, followed by ethyl acetate (100 mL), and the mixture stirred for 30 minutes. The layers were separated and the aqueous layer extracted with additional ethyl acetate (100 mL). The combined organic layer was washed with saturated aqueous sodium chloride (100 mL), dried over anhydrous sodium sulfate, and concentrated under reduced pressure to yield a brown oil which was purified by flash chromatography (10:1/hexane:ethyl acetate) to afford methyl 1-[2-(4-bromophenyl)-2-oxoethyl]cyclopentane carboxylate as a yellow, crystalline solid (1.62 g, 30%). LC-MS ret. time 3.45 min, m/z 324.8 (MH+); 1H NMR (300 MHz, CDCl3) δ 1.50-1.83 (overlapping signals, 6H), 2.22-2.33 (m, 2H), 3.37 (s, 2H), 3.66 (s, 3H), 7.59 (d, 2H), 7.80 (d, 2H).

1. additionwas slowly added
2. waitfor 12 h at rt
3. additionThe reaction mixture was slowly poured into 50 mL
4. stirringthe mixture stirred for 30 minutes
5. customThe layers were separated
6. extractionthe aqueous layer extracted with additional ethyl acetate (100 mL)
7. washThe combined organic layer was washed with saturated aqueous sodium chloride (100 mL)
8. dry with materialdried over anhydrous sodium sulfate
9. concentrationconcentrated under reduced pressure
10. customto yield a brown oil which
11. customwas purified by flash chromatography (10:1/hexane:ethyl acetate)