反应详情

To a stirred solution of crude ethyl 2-(2,4-dibromobutanamido)acetate (2.847 g, 8.60 mmol) in benzene (8.6 mL) at 5° C. was added portionwise a 60% mineral oil dispersion (344 mg) of sodium hydride (206 mg, 8.60 mmol) over 20 minutes. The reaction was stirred an additional 10 minutes before being poured onto ice water and diluted with ethyl acetate. The layers were separated. The organic phase was brine-washed, dried over sodium sulfate, filtered, concentrated down, and dried. The mixture of starting dibromide and product was purified by eluting through a silica gel column with a 0 to 100% ethyl acetate/heptane gradient to afford the title racemic compound (523 mg, 24% yield) as a clear oil. MS (ESI) [m/e, (M+H)+]=251.5. 1H NMR (400 MHz, chloroform-d) δ ppm 4.46 (dd, J=7.07, 3.03 Hz, 1H), 3.96-4.28 (m, 4H), 3.63-3.72 (m, 1H), 3.43-3.53 (m, 1H), 2.63-2.76 (m, 1H), 2.34-2.43 (m, 1H), 1.26-1.34 (m, 3H).

1. additionbefore being poured onto ice water
2. customThe layers were separated
3. washwashed
4. dry with materialdried over sodium sulfate
5. filtrationfiltered
6. concentrationconcentrated down
7. customdried
8. additionThe mixture of starting dibromide and product
9. customwas purified
10. washby eluting through a silica gel column with a 0 to 100% ethyl acetate/heptane gradient