反应详情

To a suspension of sodium hydride (5.08 g, 127 mmol) in N,N-dimethylformamide (75 mL) was added diethyl malonate (19.26 mL, 127 mmol) at 0° C. The solution was then stirred at ambient temperature for 30 minutes and a solution of 5-bromo-2-chloro-3-nitropyridine (30 g, 127 mmol) in N,N-dimethylformamide (75 mL) was added dropwise. The dark brown mixture was then stirred at 100° C. for 2 hours before being cooled to ambient temperature and quenched with a saturated solution of ammonium chloride (500 mL) at 0° C. The mixture was extracted with ethyl acetate (3×500 mL) and the combined organics were dried over magnesium sulfate and filtered. The solvent was removed in vacuo to give a dark brown oil which was purified by flash column chromatography (10% ethyl acetate/hexane) to afford diethyl 2-(5-bromo-3-nitropyridin-2-yl)malonate as a brown solid (31.8 g, 69%). 1HNMR (400 MHz, CDCl3, δ): 8.86 (s, 1H), 8.61 (s, 1H), 5.44 (s, 1H), 4.29 (q, 4H), 1.27 (t, 6H).

1. stirringThe dark brown mixture was then stirred at 100° C. for 2 hours
2. temperaturebefore being cooled to ambient temperature
3. customquenched with a saturated solution of ammonium chloride (500 mL) at 0° C
4. extractionThe mixture was extracted with ethyl acetate (3×500 mL)
5. dry with materialthe combined organics were dried over magnesium sulfate
6. filtrationfiltered
7. customThe solvent was removed in vacuo
8. customto give a dark brown oil which
9. customwas purified by flash column chromatography (10% ethyl acetate/hexane)