反应详情

温度

0 °C

To an ice cold solution of diisopropylamine (56 mL, 0.396 mol) in THF 85 (mL) was added n-butyl lithium in hexane solution (240 mL, 1.6 M, 0.393 mol) over 20 min. The mixture was stirred at 0° C. for 30 min, cooled to a bath temperature of −65° C. and ethyl cyclopentane carboxylate (37.4 g, 0.263 mol) in THF (50 mL) was added over 20 min. After 1 hr, a solution of 1,2-dibromoethane (47 mL, 0.545 mol) in THF (50 mL) was added, the mixture was held at −65° C. for 3 hr and allowed to warm to room temperature overnight. The reaction was quenched by addition of saturated ammonium chloride solution (200 mL), the layers were separated and the aqueous layer was extracted with ethyl acetate (100 mL). The combined extracts were washed with 1:1 brine:water (250 mL) and were dried (Na2SO4). The solution was filtered and concentrated, diluted with toluene (100 mL) and concentrated. The dilution and concentration was repeated twice to give ethyl 1-(2-bromoethyl)cyclopentane carboxylate (52.5 g).

1. additionwas added over 20 min
2. waitAfter 1 hr
3. waitthe mixture was held at −65° C. for 3 hr
4. temperatureto warm to room temperature overnight
5. customThe reaction was quenched by addition of saturated ammonium chloride solution (200 mL)
6. customthe layers were separated
7. extractionthe aqueous layer was extracted with ethyl acetate (100 mL)
8. washThe combined extracts were washed with 1:1 brine
9. dry with materialwater (250 mL) and were dried (Na2SO4)
10. filtrationThe solution was filtered
11. concentrationconcentrated
12. additiondiluted with toluene (100 mL)
13. concentrationconcentrated
14. concentrationThe dilution and concentration