反应详情

Diethyl malonate (0.87 mL, 5.7 mmol) was added dropwise to a suspension of NaH (55% in mineral oil, 0.27 g, 6.2 mmol) in DMF (6 mL) at 0° C. The ice-bath was removed and the mixture was stirred under N2 at r.t. for 20 min. 5-Bromo-2,3-dichloropyridine (1.0 g, 4.4 mmol) was added, and the mixture was stirred at 120° C. overnight. The mixture was allowed to cool and was then partitioned between water containing NaCl and EtOAc. The organic phase was dried (MgSO4) and evaporated to give a crude product which was purified by flash chromatography (25 g SiO2, heptane/EtOAc gradient) affording the title compound (0.8 g, 2 mmol, 52% yield) containing a residue of unreacted malonic ester. MS (ES+) m/z 350 [M+H]+. A part of this material was used as such in the subsequent step.

1. customThe ice-bath was removed
2. stirringthe mixture was stirred at 120° C. overnight
3. temperatureto cool
4. customwas then partitioned between water
5. additioncontaining NaCl and EtOAc
6. dry with materialThe organic phase was dried (MgSO4)
7. customevaporated
8. customto give a crude product which
9. customwas purified by flash chromatography (25 g SiO2, heptane/EtOAc gradient)