反応 #44295

反応方程式

2-(2-bromoethoxy)tetrahydro-2H pyran

4-iodopyrazole

Cs2CO3

DMF

→

4-iodo-1-[2-(tetrahydro-pyran-2-yloxy)-ethyl]-1H-pyrazole

収率 87.1%

溶媒

water

EtOAc

反応条件

後処理

1. 1
   workup.STIRRINGthe reaction was stirred at 70° C. for 16 hours
2. 2
   温度After cooling down
3. 3
   その他The organic layer was collected
4. 4
   抽出the aqueous layer was extracted with EtOAc (3×100 mL)
5. 5
   洗浄The combined organic layers were washed with water (3×100 mL)
6. 6
   乾燥dried over Na2SO4
7. 7
   濃縮concentrated
8. 8
   その他to afford dark brown oil
9. 9
   その他The crude product was purified on a silica gel column
10. 10
    洗浄eluting with ethyl acetate and hexanes

実験手順

In a round bottom flask was added 4-iodopyrazole (10.22 g, 52.70 mmol), Cs2CO3 (20.6 g, 63.2 mmol), and anhydrous DMF (100 mL). The suspension was stirred at 23° C. for 5 min. 2-(2-bromoethoxy)tetrahydro-2H pyran (9.95 mL, 63.2 mmol) was added and the reaction was stirred at 70° C. for 16 hours. After cooling down, EtOAc (100 mL) and water (100 mL) was added to the reaction. The organic layer was collected, and the aqueous layer was extracted with EtOAc (3×100 mL). The combined organic layers were washed with water (3×100 mL), dried over Na2SO4, and concentrated to afford dark brown oil. The crude product was purified on a silica gel column eluting with ethyl acetate and hexanes to provide 4-iodo-1-[2-(tetrahydro-pyran-2-yloxy)-ethyl]-1H-pyrazole as yellow oil (14.78 g, 87% yield). 1H NMR (300 MHz, DMSO-d6) δ 7.89 (s, 1H) 7.52 (s, 1H) 4.47-4.56 (m, 1H) 4.25-4.35 (m, 2H) 3.81-3.96 (m, 1H) 3.66-3.75 (m, 1H) 3.45-3.57 (m, J=2.83 Hz, 1H) 3.32-3.40 (m, 1H) 1.34-1.71 (m, 6H).

出典