反応 #67636

反応方程式

toluene water

Compound 1020

2,5-dibromo-3-methoxypyridine

potassium phosphate

→

5-bromo-2-cyclopropyl-3-methoxypyridine

収率 70.0%

溶媒

EtOAc

NaCl

反応条件

後処理

1. 1
   その他The reaction mixture was flushed with nitrogen gas for 10 minutes
2. 2
   workup.ADDITIONPd(PPh3)4 (1.4 g, (1.21 mmol) was added
3. 3
   温度The reaction mixture was refluxed for 18 hours
4. 4
   その他resulting in a mixture of products by HPLC analysis
5. 5
   温度The reaction was cooled
6. 6
   その他The organics were separated
7. 7
   乾燥dried (MgSO4)
8. 8
   濃縮concentrated under reduced pressure
9. 9
   その他to provide a solid, which
10. 10
    その他was purified by medium pressure silica gel chromatography (0-8% EtOAc/hexanes gradient)

実験手順

As shown in step 6-v of Scheme 6, Compound 1020 (3.6 g, 13.5 mmol), potassium cyclopropyl-trifluoro-boron (2.5 g, 16.9 mmol), and potassium phosphate (8.6 g, 40.5 mmol) were taken up in about 80 mL of a toluene/water mixture. The reaction mixture was flushed with nitrogen gas for 10 minutes and Pd(PPh3)4 (1.4 g, (1.21 mmol) was added. The reaction mixture was refluxed for 18 hours, resulting in a mixture of products by HPLC analysis. The reaction was cooled, diluted with EtOAc and saturated NaCl. The organics were separated, dried (MgSO4), and concentrated under reduced pressure to provide a solid, which was purified by medium pressure silica gel chromatography (0-8% EtOAc/hexanes gradient) to give 5-bromo-2-cyclopropyl-3-methoxypyridine (Compound 1022, 0.54 g, 70% pure): ESMS (M+H) 227.9/229.9. This compound was used as is in subsequent reactions.

出典