反応 #7257

反応方程式

NH4Cl

2-fluoropyridine

lithium diisopropylamide

DMF

→

title compound

収率 15.0%

2-fluoro-pyridine-3-carbaldehyde

収率 15.0%

溶媒

EtOAc

THF

THF

反応条件

後処理

1. 1
   workup.STIRRINGstirring
2. 2
   workup.WAITwas continued at −78° C. for 2.5 h
3. 3
   温度to warm to room temperature
4. 4
   洗浄the organic phase was washed with saturated NaHCO3(aq) (20 mL) and brine (10 mL)
5. 5
   乾燥dried (MgSO4)
6. 6
   濃縮concentrated in vacuo
7. 7
   その他Purification of the crude material by chromatography on silica gel (10% EtOAc/hexanes)

実験手順

A solution of 2-fluoropyridine (306 mg, 3.15 mmol) in THF (1 mL) was added to a solution of lithium diisopropylamide in THF (0.20 M, 17 mL, 3.4 mmol) at −78° C. The solution was stirred at −78° C. for 4 h, then DMF (0.73 mL, 9.4 mmol) was added dropwise and stirring was continued at −78° C. for 2.5 h. Saturated NH4Cl(aq) (2 mL) was added, and the mixture was allowed to warm to room temperature. The mixture was diluted with EtOAc (20 mL), and the organic phase was washed with saturated NaHCO3(aq) (20 mL) and brine (10 mL), then dried (MgSO4) and concentrated in vacuo. Purification of the crude material by chromatography on silica gel (10% EtOAc/hexanes) gave the title compound as a yellow liquid (58 mg, 15%). 1H NMR (CDCl3) □ 7.39 (m, 1H), 8.32 (m, 1H), 8.48 (m, 1H), 10.33 (s, 1H).

出典